research article polyethylene glycol mediated kinetic

Hindawi Publishing CorporationJournal of ChemistryVolume 2013 Article ID 703271 10 pageshttpdxdoiorg1011552013703271

Research ArticlePolyethylene Glycol Mediated Kinetic Study ofNitro Decarboxylation of 120572120573-Unsaturated Acids byBlaursquos Fe(III) Phen Complex

K Ramesh1 S Shylaja1 K C Rajanna2 P Giridhar Reddy1 and P K Saiprakash2

1 Department of Chemistry CBIT Gandipet Hyderabad 500 075 India2Department of Chemistry Osmania University Hyderabad 500 007 India

Correspondence should be addressed to K C Rajanna kcrajannaouyahoocom

Received 17 May 2013 Accepted 11 August 2013

Academic Editor Charles A Mebi

Copyright copy 2013 K Ramesh et al This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

Polyethylene glycol (PEG) mediated kinetic study of nitro decarboxylation of 120572120573-unsaturated acids (USA) has been taken up byBlaursquos [Fe(III) nitrate-Phen] yellow complex in acetonitrile medium Kinetics of the reactions indicated Michaelis-Menton type ofmechanism and rate law Reaction rates are significantly influenced by the structural variation and concentration of PEG Catalysisof PEG was explained on the lines of nonionic micelles such as TX-100 because of their structural resemblance and also due to aslight negative charge developed on polyoxyethylene and cationic form(s) of Fe(III) chelates in the intermediate stages

1 Introduction

The concept of atom efficiency has proven to be a populartool in the evaluation of the ldquogreennessrdquo of a chemical process[1] which revealed a comparison between various sectorsof chemical manufacturing In pharmaceutical and finechemicals manufacturing the high value of the product hasbeen particularly a significant feature in the establishment ofmany highly (atom) inefficient processes Thus the creationand use of green chemical conditions are more importantin pharmaceutical and fine chemicals manufacturing In thedirection of achieving green chemical processes catalysis notonly helps in replacing reagents or enabling more efficientprocesses but the demonstration of their value in reducingthe environmental hazardness impact and the costs of theprocesses The cost reduction of the processes will alsocatalyze the greening of chemistry [2 3] In view of the abovestriking features there has been an upsurging interest in thesearch of eco-friendly catalysts which satisfy the conditionsof green chemistry or at least improve the greenery ofreaction conditionsThemost significant alternatives include(a) the use of eco-friendly materials as catalysts (b) envi-ronmentally benign solvents such as water and polyethylene

glycols (PEGs) [4ndash6] (c) the use of nonconventional energysources such as sonication (by using ultrasonic waves) andmicrowave (MW) irradiation [7] A special attention has alsobeen focused on conducting the reactions under solvent freeconditions by grinding the reactants in a mortar with a pestleor by microwave irradiation to achieve greenery conditions[8] For the past few decades our group has also been activelyengaged in exploiting the use of the above cited tools to assistvarious organic transformations such as Vilsmeier-HaackHunsdiecker [9ndash11] and nitration reactions [12ndash14]

It is customary to measure the efficiency of a catalyst bythe number of reusable cycles Similarly the value of a newsolvent medium basically depends on its environmentalimpact the ease with which it could be recycled and solventproperties namely low vapor pressure nonflammability andhigh polarity for solubilization In performing the majorityof organic transformations solvents also play an importantrole in mixing the ingredients to make the system homoge-neous and allow molecular interactions to be more efficientPolyethylene glycol (PEG) is a neutral hydrophilic polyetherand is less expensive The use of PEG avoids the use of acidor base catalysts and moreover PEG can be recovered andreused Thus it offers a convenient inexpensive nonionic

2 Journal of Chemistry

HH OOn

(I) Structure of polyethylene glycol (PEG)

Scheme 1

nontoxic and recyclable reaction medium for the replace-ment of volatile organic solvents This protocol also offers arapid and clean alternative and reduces reaction times seeScheme 1

On the other hand it is unreasonable to note that over theyears transition metal ions or their complexes with differentenvironments have been used as catalysts probably becausethey are economically cheap and available in any laboratorydesk Ferric salts or the complexes of Fe(III) have also beenin the forefront as efficient catalysts under homogeneous aswell as heterogeneous conditions Earlier reports show thatFe(III) oxidation reactions are sluggish in acidic media anddo not proceed in highly concentrated solutions Howeverthe addition of even trace amounts of Phenanthroline (Phen)to the reaction medium increases the formal potential ofFe(II)Fe(III) couple rendering the reaction thermodynami-cally feasible by forming yellow colored Fe(III) chelates [15ndash18] Phenanthroline functions as a typical bidentate chelatemolecule which interacts withmetal ion through the nitrogenatoms with the formation of five-membered rings Furtherit is interesting to note that the above mentioned yellowcomplexes of Fe(III) are isolated as crystalline solids andwell-characterized by Blau [15] These complexes are reported tobe substitution labile and entirely different from ferroin (bluecomplexes of Fe(III) with Phen) which could not be obtainedby direct mixing but only by the oxidation of ferroin andwerealso found to be substitution inert

Borodin [19] was the first to report the classical Huns-diecker-Borodin reaction (HBR) in the year 1861 Huns-diecker et al [20 21] later on developed this reaction in 1942It is one of the most versatile reactions in organic synthesisfor the conversion of 120572120573-unsaturated aromatic carboxylicacids to 120573-bromostyrenes The reaction also depicted thatsilver carboxylates when treated with molecular bromine atreflux temperatures underwent facile bromo decarboxylationto afford the corresponding alkyl bromides Over a periodof years this reaction underwent several modifications asevidenced from quite a few number of publications [22ndash28] In view of these striking features the author has takenup nitration of 120572120573-unsaturated acids in this chapter usingBlaursquos yellow complexes of Fe(III) (ferric nitrate and Phen) inPEGmedia by avoiding mineral acids completely In order tothrow light on the most effective PEG we have used an arrayof PEGs in this study

2 Experimental

All the 120572120573-unsaturated acids used in the present study areAnalaR grade and obtained from BDH Merck AldrichFluka or Loba chemicals The rest of the chemicals are pro-cured from BDH-Merck India Polyethylene glycols (PEGs)

were used as such which were procured from the suppliersHPLC grade Acetonitrile was used throughout the study

21 General Procedure for Solvent Mediated Synthesis of 120573-Nitro Styrene In this procedure reactions are conductedusingDCE andMeCN as solvents Cinnamic acid (0001mol)dissolved in DCEMeCN and 0001 moles of Blaursquos complex(mixture of equimolar mixture of Fe(III) nitrate and 110-Phenanthroline (Phen) ligand) were suspended in a threenecked round bottomed flask The flask is equipped witha mechanical stirrer and reflux condenser The reactionmixture is stirred for some time until the evolution of CO

2

completely ceases The mixture is cooled in an ice bathand the precipitate is removed by filtration The residue iswashed with CCl

4and the filtrates are combinedThe solvent

is removed by distillation using a modified Claisen distil-lation apparatus with a 6 cm condenser After completionof the reaction as indicated by TLC the reaction mixtureis quenched with 2 sodium carbonate solution and theorganic layer was separated dried over Na

2SO4 evaporated

under vacuum and purified with column chromatographyusing ethylacetate hexane (3 7) as eluent to get pure prod-uct Table 1 shows the reaction times and under kineticconditions also the product of the reaction was found to be120573-nitro styrene as characterized by spectroscopic methods(Table 2) But the reactions are too sluggishwith long reactiontimes even at elevated temperatures and the yields are too lowunder these conditions

22 Kinetic Measurements Progress of the reaction was fol-lowed by recording the absorbance values of the productof oxidation [Fe(II)-(Phen) complex] produced as a func-tion of time at 510 nm (molar absorptivity minus120576 = 111 times

104 dm3molminus1 cmminus1) on a Beckman-DU model spectropho-tometer (equipped with thermostatic cell compartments)Control experiments revealed that the products of oxidationthat is Fe(II) chelates are quite stable under the experimentalconditions

3 Results and Discussion

31 Salient Kinetic Features (1) Under pseudo first orderconditions namely (i) [Phen]≫ [Fe(III)] [USA]≫ [Fe(III)]in the case of Blaursquos yellow complexes the plots of ln(119886(119886minus119909))or [ln(119860

infinminus 1198600)(119860infin

minus 119860119905)] versus time were found to be

linear with negative gradients in all the systems studied Firstorder rate constant (1198961015840) could be obtained either by point-wise calculation using first order rate expression or from theslopes of linear plots cited (1198961015840) Both the values agreed witheach otherThis observation indicates first order with respectto [Fe(III) Phen] in all the systems Similar observations werenoticed when the reactions were studied in all PEG media(Figures 1 and 2)

(2) This reaction is also conducted under secondorder conditions with equal concentrations of [Phen] ≫

[Fe(III)]o = [S]o Kinetic plots of [1(119886 minus 119909)] or [1(119860infin

minus

119860119905)] versus time have been found linear with a positive

gradient and definite intercept on ordinate vertical axisindicating overall second order kinetics (Figures 3 and 4)

Journal of Chemistry 3

Table 1 Effect of different PEGs on Fe (III)-Phen triggered nitro Hunsdiecker reactions with unsaturated carboxylic acids

Entry Substrates Without PEG PEG-200 PEG-300 PEG-400 PEG-600 PEG-6000RT (hr) Yield () RT (hr) Yield () RT (hr) Yield () RT (hr) Yield () RT (hr) Yield () RT (hr) Yield ()

1 CA 26 55 250 78 175 86 175 82 175 80 30 752 4-ClCA 28 60 30 75 200 85 250 80 275 80 375 783 4-OMeCA 24 70 175 80 150 94 150 84 175 82 275 804 4-MeCA 24 60 20 80 150 90 175 84 20 80 275 785 4-NO2CA 28 55 30 70 200 82 275 78 30 75 40 656 4-OHCA 24 65 20 78 150 90 175 86 175 82 275 807 AA 26 63 20 76 150 92 175 88 20 86 275 828 CRA 28 65 30 75 200 85 275 80 30 78 40 709 3-PhCRA 26 70 275 76 150 90 150 85 20 78 275 7210 2-ClCA 28 60 30 80 200 86 200 82 275 80 40 7811 2-MeCA 25 55 20 78 150 88 150 82 175 80 275 75

Table 2 NMR and mass spectral data for selected reaction products

Entry Substrates Product Spectral data119898119911

1H NMR

1 CA 120573-Nitro styrene 149 120575 64 (d 1H 120573-CH) 120575 73ndash765 (m 5H Ar-H)12057578(d 1H 120572-CH)

2 4-ClCA 4-Chloro 120573-nitro styrene 184 120575 66 (d 1H 120573-CH) 120575 72 (d 2H Ar-H)120575 76 (d 2H Ar-H) 120575 83 (d 1H 120572-CH)

3 4-OmeCA 4-Methoxy 120573-nitro styrene 179120575 38 (s 3H OCH3) 120575 64 (d 1H 120573-CH)120575 732ndash77 (m 4H Ar-H)120575 79 (d 1H 120572-CH)

4 4-MeCA 4-Methyl 120573-nitro styrene 163 120575 30 (s 3H CH3) 120575 66 (d 1H 120573-CH)120575 74ndash77 (m 4H Ar-H) 120575 79 (d 1H 120572-CH)

5 4-NO2CA 4-Nitro 120573-nitro styrene 194 120575 66 (d 1H 120573-CH) 120575 74 (d 2H Ar-H)120575 78 (d 2H Ar-H) 12057582 (s 1H 120572-CH)

6 4-OHCA 4-Hydroxy 120573-nitro styrene 165120575 65 (d 1H 120573-CH) 120575 73 (d 2H Ar-H)120575 78 (d 2H Ar-H) 120575 81 (d 1H 120572-CH)120575 105 (s 1H Ar-OH)

7 AA 1-Nitro ethene 73120575 592 (d 1H 120573-CH)120575 66 (d 1H trans 120573-CH)120575 725 (q 1H 120572-CH)

8 CRA 1-Nitro propene 87 120575 212 (d 3H CH3) 120575 70 (d 1H 120572-CH)120575 715 (m 1H 120573-CH)

9 3-PhCRA 3-Phenyl 1-nitro propene 163 120575 33 (d 2H CH2) 120575 723ndash733 (m 5H Ar-H)120575 82 (d 1H 120572-C-H)

10 2-ClCA 2-Chloro 120573-nitro styrene 183 120575 66 (d 1H 120573-CH) 120575 73ndash77 (m 4H Ar-H)120575 82 (d 1H 120572-C-H)


Since the order with respect to [Fe(III)] is one under pseudoconditions this observation suggests that order in [S] is alsoone Thus from the foregoing process of kinetic results weconclude that [Fe(III) Phen] mediated Hunsdiecker-Borodinreaction follows an overall second order kinetics

(3) Even though the plots of 11198961015840 versus 1[Phen] aswell as 11198961015840 versus 1[Phen]2 were found linear with positiveslope and intercept on 11198961015840-axis the plots between (11198961015840) and

1[Phen] indicated better correlation coefficients (1198772 gt 0990)than those obtained from 1119896

1015840 versus 1[Phen]2 plots Theseobservations probably suggest the formation of a precursor(formation of 1 1 Fe(III)-Phen complex) between Fe(III) andPhen Similar observations were recorded in all PEG mediaand the representative data are presented in Figure 5

(4) All the reactions have been studied in different PEGmedia and significant rate enhancements were observed


0

05

1

15

2

25

0 100 200 300 400 500Time (min)

ln(aa minus x)

ln(aa

minusx

)

Plot of ln(aa minus x) versus time

Time (min)0 0

30 020008160 035164690 0498176

120 0650991180 0942153210 1082824240 1215146270 1377665300 1543754360 1863758420 2201541

y = 0005x + 0025 R2 = 0999

Figure 1 Pseudo first order kinetic plot of cinnamic acid (ln(119860infinminus 119860119905) versus time) at 313 K [CA] = 625 times 10minus3mol dmminus3 [Phen] = 375 times

10minus3mol dmminus3 [Fe(III)] = 125 times 10minus3mol dmminus3 [PEG-200] = 937 times 10minus1mol dmminus3

005

115

225

335

4

0 100 200 300 400 500Time (min)

ln(aa

minusx

)

R2 = 09999

Pseudo first order kinetic plot of acrylic acid(ln(aa minus x) versus time) at 313K

Time (min) 0 0

30 031281260 055326990 0841066

120 104277150 1289373180 1499445210 1765713240 2014609270 2342053300 2598728360 3078301420 3563809

ln(aa minus x)

y = 0008x + 0032

Figure 2 Pseudo first order kinetic plot of acrylic acid (ln(119860infinminus 119860119905) versus time) at 313 K [AA] = 625 times 10minus3mol dmminus3 [Phen] = 375 times


32 Reactive Species Although reactive Fe(III) species arecomplicated Whiteker and Davidson [17] were the first togive a clear picture regarding the formation and analysis ofvarious types of Fe(III) species in aqueous sulphuric acidmedium On similar lines various forms of Fe(III) nitratespecies such as Fe(NO

3)3 Fe+(NO

3)2 Fe2+(NO

3) Fe3+(aq)

and Fe(OH)2+ could be formulated Fe3+(aq) forms Fe(OH)2+upon hydrolysis

Fe3+ +H2O119870ℎ

999447999472 Fe(OH)2+ +H+ (1)

119870ℎvalue for this reaction was reported as 20 times 10

minus3 at 27∘CFe3+ readily forms various types of nitrate species in nitricacid according to the following equilibria

Fe(OH)2+ +H2O 999447999472 Fe(OH)

2

++H+ (2)

Fe3+ (aq) +HNO3999447999472 Fe(NO

3)2+

+H+ (3)

Fe(NO3)2+

+HNO3999447999472 Fe(NO

3)2

+

+H+ (4)

Fe(NO3)2

+

+HNO3999447999472 Fe(NO

3)3+H+ (5)

In a reaction occurring in solution phase the reactivespecies partaking in a rate limiting step are consideredmainly

on the basis of results obtained from (i) acidity (pH) (ii) ionicstrength (120583) and (iii) dielectric constant (solvent) variationson the rate of the reaction But in the present investigationthe reactions are conducted in nonaqueous (MeCN) mediacontaining PEG and Lewis bases (L) such as Phenanthroline(L = Phen) Literature reports show that Gaines Jr et al [18]earlier synthesized the solid crystalline complexes by directmixing of the ligand to an aqueous solution of Fe(III) contain-ing sulphate ions From magnetic susceptibility data it hasbeen substantiated that the resultant complexes exhibited thecomposition of [Fe(III)][Phen] = 12 They also mentionedthat a greater stability of these [Fe(III)L

2] complexes is

achieved when direct mixing is done in solution If thiscontention has beenmore probable the reciprocal plot of 11198961015840versus 1[Phen]2 should have indicated a better linearity over11198961015840 versus 1[Phen] plots (Supplementary Tables S12 to S20

depict detailed kinetic data related to these plots The plotsare linear with very good to excellent correlation coefficientssee Tables S12 to S20 in Supplementary Material availableonline at httpdxdoiorg1011552013703271) It is thereforereasonable to consider that Fe(III) nitrate binds with oneunit of Phen to form 1 1 complex (ie [Fe(III)][Phen] = 1rather than 12) Further the reactions are conducted underPEG environment in addition to Phen It is also important


005

115

225

335

0 100 200 300 400 500 600Time (min)

y = 0006x +

R2 = 09999

1(A

infinminusA

t)

1(Ainfin minus At)

Second order kinetic plot for cinnamic acid 1(Ainfin minus At)versus time at 323K

Time (min)

0 0316448

60 0685

120 1029519

180 1391746

240 1788889

300 2129492

360 2460784

420 2791176

480 32104

0323

Figure 3 Second order kinetic plots of cinnamic acid 1119860119905versus time at 323K [CA] = 625 times 10minus3mol dmminus3 [Phen] = 625 times 10minus3mol dmminus3

[Fe(III)] = 125 times 10minus3mol dmminus3 [PEG-200] = 937 times 10minus1mol dmminus3

005

115

225

335

0 100 200 300 400 500 600 700 800Time (min)

Second order kinetic plot for acrylic acid 1At versus timeat 313K

y = 00043x +

R2 = 09996

1(A

infinminusA

t)

Time (min)0 0237634

60 0528235

120 0749351

240 1218143

360 1781301

480 2299863

600 2782222

660 3045455

720 333333

1(Ainfin minus At)

02397

Figure 4 Second order kinetic plots of acrylic acid 1119860119905versus time at 313 K [AA] = 625 times 10minus3mol dmminus3 [Phen] = 625 times 10minus3mol dmminus3


0

005

01

015

02

025

0 02 04 06 08 11[Phen]

(1k

998400 )

(1k998400)

y = 02459x + 00242

R2 = 09995

Plot of 1k998400 versus 1[Phen] for cinnamic acid in PEG-300at 320K

1[Phen]

08 02204 0125

026 008802 0072923

016 00625

Figure 5 Effect of variation of [Phen] on first order 1198961015840 of cinnamic acid in PEG-300 medium at 320K

to consider that structural variation of PEG affected the rateof reaction considerably from PEG-200 to PEG-600 with amaximum activity with PEG-300 This observation probablysupports the idea of PEG bound Fe(III) as reactive species inthe present study

33 Mechanism of Nitrodecarboxylation The foregoing sali-ent kinetics features namely first order in oxidant first orderdependence in USA and linearity of the plots of 11198961015840 versus1[Phen] may probably indicate the formation of a precursorprior to the rate limiting decomposition step According to

Gaines Jr et al [18] when polynuclear heterocyclic basessuch as Phenanthroline are directly added to Fe(III) solutionssubstitution liable yellow complexes of the type [L

2Fe-O-

FeL2]4+ and [Fe(III)L

2]3+ resulted However in solution

state [Fe(III)L2]3+ is more likely to exist Dimeric species of

Fe(III) reactive species could be ruled out because of verylow concentrations of Fe(III) (sim10minus4mol dmminus3) used in thepresent study On the basis of foregoing discussions a mostplausiblemechanism for nitrodecarboxylation of unsaturatedacids could be written as a sequence of reaction steps shownin Scheme 2


(solvent)

slow

Fast

Fast

Fast

Fe(NO3)3 (H2O)3 + ACN Fe(NO3)3 (ACN)2 H2O

Fe(NO3)3 (ACN)2 H2O + Phen Fe(NO3)2 (Phen) (OH)(ACN)2minusHNO3

K1

NO2+ + NO3

minus HNO3H2O

Fe(NO3)(Phen)(OH)(RCH CH-COO)(ACN)2 Fe(NO3)2(Phen)(RCH CH-COO)(ACN)2

NO2+

RCH CH-NO2 + CO2

[Fe(NO3)(OH)(Phen)(ACN)2]+ [Fe(NO3)2(OH)(Phen)(ACN)2]NO3

minus

RCH CH-COOH

k

Scheme 2

For the mechanism given in Scheme 2 the rate law wasderived according to the following sequence of steps Fromthe second step of Scheme 2 we haveRate (]) = 119896 [Fe(NO

3)2L(OH)(ACN)

2][RCH=CHndashCOOH]

(6)Considering the total concentration of ([M]tot) as the alge-braic sum of free metal ion species and metal ion bound-ligand (complex) species

[M]tot = [M] + [ML] (7)From metal ion-ligand binding equilibrium

1198701=

[ML][M] [L]

or [M] =

[ML]1198701 [L] (8)

Substitution of [M] in (7) gives[ML]

(1198701 [L])

+ [ML] = [M]tot

[ML] (1 + 1198701 [L]) = [M]tot1198701 [L]

[L] asymp 119862L

[ML] =[M]tot1198701119862L(1 + 119870

1119862L)

=

1198701 [Fe (III)] [Phen]

(1 + 1198701 [Phen])

Or [Fe+(NO3)2L] = [ML]

=

1198701 [M] 119862L

1 + 1198701 [L]

=

1198701 [Fe (III)] [Phen]

1 + 1198701 [Phen]

(9)

Substituting this in rate limiting step (6) rate law comes outas

] =1198961198701 [Fe (III)] [Phen] [USA](1 + 119870

1 [Phen]) (10)

This equation is in accordance with all the observedkinetic features According to the reciprocal form of (10)plots of 11198961015840 versus 1[Phen] have been realized in the presentstudy showing the validity of the proposedmechanism Fromthe observed straight line plots with positive slope (119898) andintercept (119862) kinetic constants 119870

1and 119896 could be evaluated

where

119898 =

1

1198961198701

119862 =

1

119896

1198701=

119862

119898

119896 =

1

119862

(11)

Formation constants (1198701) and rate constant (119896) data are

presented in Tables 3 and 4 (for details please refer to TablesS1 to S20 in Supplementary Material)

34 Effect of [PEG] on Mechanism of NitrodecarboxylationProgress of the reaction has been studied in the presenceof different PEGs with varied structures Reaction ratesare significantly influenced by the structural variation andconcentration of PEG which can be attributed to the electrondensity on polyoxyethylenemoiety of PEGwith an increase inmethyl groups and found that the reaction is accelerated byall the PEGs with an increasing order PEG-200 lt PEG-300 gtPEG-400gtPEG-600gtPEG-6000This could be attributed tothe negative charge developed on polyoxyethylene moiety of


PEG + Fe(NO3)2(Phen)(OH)(ACN)2

RCH CH-COOH RCH CH-COOH

[OH-CH2-(CH2-O-CH2-)n-CH2-O-Fe(NO3)2Phen(ACN)2][PEG-Fe(NO3)2 (Phen)(ACN)2]Normal reaction

Products

PEG path

Scheme 3

Table 3 Activation parameters involving rate constant (119896)

Substrate PEG119896 Δ119867

Δ119866

Δ119878

dm3 molminus1 sminus1 at310 K kJmol JKmol

Cinnamicacid

200 2318 217 562 minus111300 5925 588 620 minus102400 1975 238 562 minus104600 2857 365 557 minus620

Crotonicacid


Acrylicacid


Methoxycinnamicacid

200 1584 183 566 minus122300 5333 345 666 40400 3018 752 729 75600 2857 365 388 minus74

Nitrocinnamicacid


PEG in the lines of nonionic micelles such as TX and oxidantspecies as mentioned above Mechanism could probably fitinto the Menger and Portnoy [29 30] model which closelyresembles that of an enzymatic catalysis According to thismodel formation of micelle-substrate complex (MS) couldoccur in the preequilibrium step due to the interaction ofsubstrate (S) with micelle (M) The complex thus formedmay possess higher or lower reactivity to gives productsThe catalytic activity of PEG could be explained through theformation of (PEG bound Fe(III)L) by binding model

PEG + [Fe(NO3)2Phen (OH) (ACN)

2]

999445999468 [OHndashCH2ndash(CH

2ndashOndashCH

2ndash)119899

ndashCH2ndashO ndashFe (NO

3)2Phen(ACN)

2]

+H2O

[PEG-Fe(NO3)2Phen (OH) (ACN)

2]

(12)

Table 4Thermodynamic parameters involving formation constant(1198701)

Substrate PEG1198701

Δ119867 Δ119866 Δ119878

dm3 molminus1 at310 K

kJmol JKmol

Cinnamicacid

200 0307 149 30 382300 0067 448 44 130400 0618 228 12 696600 0350 66 27 126

Crotonicacid

200 0176 137 361 430300 0078 126 685 384400 0356 118 1021 347600 0224 128 535 395

Acrylicacid

200 0618 250 12 767300 0172 507 45 149400 0085 202 63 440600 0362 96 200 224

Methoxycinnamicacid

200 0284 217 32 597300 0123 448 43 130400 0281 301 33 867600 0350 66 27 126

Nitrocinnamicacid

200 0350 149 304 383300 0470 235 20 696400 0109 520 57 149600 0119 696 55 206

A generalmechanism is proposed by considering the bulkphase and micellar phase reactions as shown in Scheme 3

Data presented in Table 1 show that the reactions aretoo sluggish with longer reaction times (gt24 hrs) even underreflux conditions while remarkable rate enhancements asso-ciated with shorter reaction times and enhanced productyields are observed in PEG mediated reactions On the basisof these observations mechanism of PEGmediated reactionscould be explained with the participation of unsaturated acidand PEG-bound-Fe(III) nitrate species in the slow step asshown in Scheme 4

35 Effect of Structure on Enthalpy and Entropy ChangesWhen a series of structurally related substrates undergothe same general reaction or when the reaction conditionsfor a single substrate are changed in a systematic way


Slow

Fast

Fast

Fast

Fe(NO3)2(Phen)(OH)(ACN)2

PEG + Fe(NO3)2 (Phen)(OH)(ACN)2minusH2O

[OH-CH2-(CH2-O-CH2-)n-CH2-O-Fe(NO3)2Phen(ACN)2]

[PEG-Fe(NO3)2 (Phen)(ACN)2]

RCH CH-COOH

NO2+ + NO3

minus

NO3minus

HNO3HNO3

[PEG-Fe(Phen)(OH)(RCH CH-COO)(ACN)2] [PEG-Fe(NO3)(Phen)(RCH CH-COO)(ACN)2]

NO2+

RCH CH-NO2+ CO2

[PEG-Fe(Phen)(OH)(ACN)2]+ [PEG-Fe(NO3)(OH)(Phen)(ACN)2]

minusHNO3

Fe(NO3)3(ACN)2H2O + Phen

Scheme 4

25

255

26

265

27

275

28

3 305 31 315 32 325 33 335

ln(N

hkR

T)

103T

Eyringrsquos plot of cinnamic acid (ln(NhkRT) versus103T)

y = minus69939x + 48771R2 = 09991ln(NhkRT)

33333 25436932258 2625083125 268995

30303 275737

103T

Figure 6 Eyringrsquos plot of cinnamic acid (ln(119873ℎ119896119877119879) versus 103119879) Kinetic study with [PEG-300] = 624 times 10minus1mol dmminus3

a considerable variation in the enthalpies and entropies ofactivation is more likely The entropy of activation (Δ119878)provides important information about the transition stateand molecularity of the rate-determining step in the reactionpath Positive values for Δ119878 suggest that entropy increasesupon achieving the transition state which often indicates adissociativemechanism Negative values forΔ119878 indicate thatentropy decreases upon achieving the transition state whichoften indicates an associative mechanism

Eyring plots for rate constant (119896) variation with tem-perature (Figures 6 and 7) are linear and related activationparameters data are presented in Table 3 (more details ofthese plots are given in Supplementary Tables S21 to S25)A positive change in entropy of activation compiled inTable 3 probably indicates a more disordered transition stateDegrees of freedom are ldquoliberatedrdquo ongoing from the ground

state to the transition state and the reaction is fast Theseresults probably support the release of proton from PEGand nitrate from Fe(III) moieties which readily brings aboutchanges in the transition state and causes simultaneousassociation and dissociation of species causing a greaterdisorderliness in the transition state leading to a chemicalreaction Similar trends are recorded in all the PEGs used inthis study The free energy of activation for all the systemsis negative (ie Δ119866

lt 0) indicating that the reaction isspontaneous

Further Vant Hoff rsquos plots (Figures 8 and 9) of ln 1198701

versus (1119879) are also linear with negative slopes indicatingthe endothermic nature of the equilibrium Related acti-vation parameters are evaluated from these plots and thedata are presented in Table 4 (more details of these plotsare given in Supplementary Tables S26 to S30) Entropy


25826

262264266268

27272274276278

3 305 31 315 32 325 33 335

ln(N

hkR

T)

y = minus56379x + 44734R2 = 09991

Eyringrsquos plot for acrylic acid (ln(NhkRT) versus103T

103T

)

103T

ln(NhkRT)

33333 259475

32258 26525

3125 27144

30303 276387

Figure 7 Eyringrsquos plot of acrylic acid (ln(119873ℎ119896119877119879) versus 103119879) Kinetic study with [Phen] = 375 times 10minus3mol dmminus3 [PEG-300] = 624 times

10minus1mol dmminus3 [Fe(III)] = 125 times 10minus3mol dmminus3

2527293133353739

3 305 31 315 32 325 33 335

y = minus27474x + 1209

R2 = 09986

103T

Vant Hoff rsquos plot for cinnamic acid (ln(K) versus 103T

103T

)

4+

ln(K

)

4 + ln(K)

33333 29387

32258 32104

3125 35188

30303 37608

Figure 8 Vant Hoff rsquos plot of cinnamic acid (ln(119870) versus 103119879) Kinetic study with [PEG-300] = 624 times 10minus1mol dmminus3

005

115

225

335

3 305 31 315 32 325 33 335103T

y = minus6103x + 21721

R2 = 09997

Vant Hoff rsquos plot for acrylic acid (ln(K) versus103T103T

)4 + ln(K)

4+

ln(K

)

33333 1369

32258 204

3125 2665

30303 3214

Figure 9 Vant Hoff rsquos plot of acrylic acid (ln(119870) versus 103119879) Kinetic study with [Phen] = 375 times 10minus3mol dmminus3[PEG-300] = 624 times


values compiled in Table 4 of the present study are highlypositive which indicate greater instability and are proneto decompose or move towards another reactant to giveproducts by interacting with it Very small Δ119866 values supportthis contention which also show the nonspontaneous andunstable equilibrium

4 Conclusions

The observed catalytic activity of PEGs could be explained inthe lines of nonionicmicelles (TX)The slight negative chargedeveloped on polyoxyethylene groups probably interact withcationic form(s) of Fe(III) chelates in the intermediate stagesand enhances the rate of reaction

References

[1] P T Anastasas and J C Warner Green Chemistry Theory andPractice Oxford University Press New York NY USA 1988

[2] R A Sheldon ldquoCatalysis and pollution preventionrdquo Chemistryand Industry vol 1 pp 12ndash15 1997

[3] J H Clark ldquoGreen chemistry challenges and opportunitiesrdquoGreen Chemistry vol 1 no 1 pp 1ndash8 1999

[4] R Kumar P Chaudhary S Nimesh and R Chandra ldquoPolyethy-lene glycol as a non-ionic liquid solvent for Michael additionreaction of amines to conjugated alkenesrdquoGreen Chemistry vol8 no 4 pp 356ndash358 2006

[5] J M Harris Poly(Ethylene Glycol) Chemistry Biotechnologicaland Biomedical Applications Plenum Press New York NYUSA 1992


[6] J M Harris Polyethylene Glycol Chemistry and BiologicalApplication ACS Books Washington DC USA 1997

[7] J Hamelin J P Bazureau F Texier-Boullet and A LoubyMicrowave in Organic Synthesis Wiley-VCH Weinheim Ger-many 2002

[8] G R Desiraju and B S Goud in Reactivity of Solids PresentPast and Future V V Boldyrev Ed p 223 Blackwell SciencsLondon UK 1995

[9] M M Ali T Tasneem K C Rajanna and P K Sai PrakashldquoAn efficient and facile synthesis of 2-chloro-3-formyl quino-lines from acetanilides in micellar media by Vilsmeier-Haackcyclisationrdquo Synlett no 2 pp 251ndash253 2001

[10] MMAli S Sana TasneemKC Rajanna andPK SaiprakashldquoUltrasonically accelerated Vilsmeier-Haack cyclisation andformylation reactionsrdquo Synthetic Communications vol 32 no 9pp 1351ndash1356 2002

[11] KC RajannaMMAli S Sana Tasneem andPK SaiprakashldquoVilsmeier-Haack acetylation in micellar media an efficientone pot synthesis of 2-chloro-3-acetyl quinolinesrdquo Journal ofDispersion Science and Technology vol 25 no 1 pp 17ndash21 2004

[12] S Sana K C Rajanna M M Ali and P K Saiprakash ldquoMildefficient and selective nitration of anilides non-activated andmoderately activated aromatic compounds with ammoniummolybdate and nitric acid as a new nitrating agentrdquo ChemistryLetters no 1 pp 48ndash49 2000

[13] S Sana M M Ali K C Rajanna and P K Saiprakash inProceedings of the Second National Symposium in ChemistryIndian Institute of Chemical Technology Hyderabad IndiaJanuary 2000

[14] TasneemMMAli KC Rajanna S Sana andPK SaiprakashldquoAmmonium nickel sulfate mediated nitration of aromaticcompounds with nitric acidrdquo Synthetic Communications vol 31no 7 pp 1123ndash1127 2001

[15] F Blau ldquoUber neue organische Metallverbindungenrdquo Monat-shefte fur Chemie und verwandte Teile anderer Wissenschaftenvol 19 no 1 pp 647ndash689 1898

[16] G S Laurence and K J Ellis ldquoThe detection of a complexintermediate in the oxidation of ascorbic acid by ferric ionrdquoJournal of the Chemical Society Dalton Transactions no 15 pp1667ndash1670 1972

[17] R A Whiteker and N Davidson ldquoIon-exchange and spec-trophotometric investigation of iron(III) sulfate complex ionsrdquoJournal of the American Chemical Society vol 75 no 13 pp3081ndash3085 1953

[18] A Gaines Jr L P Hammett and G H Walden Jr ldquoThestructure and properties of mononuclear and polynuclearphenanthroline-ferric complexesrdquo Journal of the AmericanChemical Society vol 58 no 9 pp 1668ndash1674 1936

[19] CHunsdiecker andHHunsdiecker ldquoDegradationof the salts ofaliphatic acids by brominerdquo Berichte der Deutschen ChemischenGesellschaft vol 75 pp 291ndash297

[20] C Hunsdiecker and H Hunsdiecker ldquoDegradation of the saltsof aliphatic acids by brominerdquoChemical Abstracts vol 37 article23114 1943

[21] C Hunsdiecker H Hunsdiecker and E Vogt ChemicalAbstracts vol 31 p 2233 1937

[22] S Chowdhury and S Roy ldquoManganese (II) catalysed Huns-diecker reaction a facile entry to 120572-(dibromomethyl) benzen-emethanolrdquo Tetrahedron Letters vol 37 no 15 pp 2623ndash26241996

[23] S Chowdhury and S Roy ldquoThe first example of a catalyticHunsdiecker reaction synthesis of 120573-halostyrenesrdquo Journal ofOrganic Chemistry vol 62 no 1 pp 199ndash200 1997

[24] D Naskar S Chowdhury and S Roy ldquoIs metal necessary inthe Hunsdiecker-Borodin reactionrdquo Tetrahedron Letters vol39 no 7 pp 699ndash702 1998

[25] D Naskar and S Roy ldquo1-Haloalkynes from propiolic acidsa novel catalytic halodecarboxylation protocolrdquo Journal ofOrganic Chemistry vol 64 no 18 pp 6896ndash6897 1999

[26] D Naskar and S Roy ldquoCatalytic hunsdiecker reaction andone-pot catalytic Hunsdiecker-Heck strategy synthesis of120572120573-unsaturated aromatic halides 120572-(dihalomethyl)benzene-methanols 5-aryl-24-pentadienoic acids dienoates and dien-amidesrdquo Tetrahedron vol 56 no 10 pp 1369ndash1377 2000

[27] D Naskar S K Das L Giribabu B G Maiya and S RoyldquoNovel catalytic Hunsdiecker-Heck (CHH) strategy towardall-E stereocontrolled ferrocene-capped conjugated push-pullpolyenesrdquo Organometallics vol 19 no 8 pp 1464ndash1469 2000

[28] J Prakash Das and S Roy ldquoCatalytic Hunsdiecker reaction of120572120573-unsaturated carboxylic acids how efficient is the catalystrdquoJournal of Organic Chemistry vol 67 no 22 pp 7861ndash78642002

[29] RG Johnson andR K Ingham ldquoThedegradation of carboxylicacid salts by means of halogenmdashthe hunsdiecker reactionrdquoChemical Reviews vol 56 no 2 pp 219ndash269 1956

[30] A G Smith Organic Synthesis Wiley Interscience New YorkNY USA 1993

Submit your manuscripts athttpwwwhindawicom

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Inorganic ChemistryInternational Journal of

Hindawi Publishing Corporation httpwwwhindawicom Volume 2014

International Journal ofPhotoenergy


Carbohydrate Chemistry

International Journal of


Journal of

Chemistry


Advances in

Physical Chemistry

Hindawi Publishing Corporationhttpwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2014

Bioinorganic Chemistry and ApplicationsHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

SpectroscopyInternational Journal of


The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Medicinal ChemistryInternational Journal of


Chromatography Research International


Applied ChemistryJournal of



Theoretical ChemistryJournal of


Journal of

Spectroscopy

Analytical ChemistryInternational Journal of


Journal of


Quantum Chemistry


Organic Chemistry International

ElectrochemistryInternational Journal of



CatalystsJournal of


HH OOn

(I) Structure of polyethylene glycol (PEG)

Scheme 1

nontoxic and recyclable reaction medium for the replace-ment of volatile organic solvents This protocol also offers arapid and clean alternative and reduces reaction times seeScheme 1

On the other hand it is unreasonable to note that over theyears transition metal ions or their complexes with differentenvironments have been used as catalysts probably becausethey are economically cheap and available in any laboratorydesk Ferric salts or the complexes of Fe(III) have also beenin the forefront as efficient catalysts under homogeneous aswell as heterogeneous conditions Earlier reports show thatFe(III) oxidation reactions are sluggish in acidic media anddo not proceed in highly concentrated solutions Howeverthe addition of even trace amounts of Phenanthroline (Phen)to the reaction medium increases the formal potential ofFe(II)Fe(III) couple rendering the reaction thermodynami-cally feasible by forming yellow colored Fe(III) chelates [15ndash18] Phenanthroline functions as a typical bidentate chelatemolecule which interacts withmetal ion through the nitrogenatoms with the formation of five-membered rings Furtherit is interesting to note that the above mentioned yellowcomplexes of Fe(III) are isolated as crystalline solids andwell-characterized by Blau [15] These complexes are reported tobe substitution labile and entirely different from ferroin (bluecomplexes of Fe(III) with Phen) which could not be obtainedby direct mixing but only by the oxidation of ferroin andwerealso found to be substitution inert

Borodin [19] was the first to report the classical Huns-diecker-Borodin reaction (HBR) in the year 1861 Huns-diecker et al [20 21] later on developed this reaction in 1942It is one of the most versatile reactions in organic synthesisfor the conversion of 120572120573-unsaturated aromatic carboxylicacids to 120573-bromostyrenes The reaction also depicted thatsilver carboxylates when treated with molecular bromine atreflux temperatures underwent facile bromo decarboxylationto afford the corresponding alkyl bromides Over a periodof years this reaction underwent several modifications asevidenced from quite a few number of publications [22ndash28] In view of these striking features the author has takenup nitration of 120572120573-unsaturated acids in this chapter usingBlaursquos yellow complexes of Fe(III) (ferric nitrate and Phen) inPEGmedia by avoiding mineral acids completely In order tothrow light on the most effective PEG we have used an arrayof PEGs in this study

2 Experimental

All the 120572120573-unsaturated acids used in the present study areAnalaR grade and obtained from BDH Merck AldrichFluka or Loba chemicals The rest of the chemicals are pro-cured from BDH-Merck India Polyethylene glycols (PEGs)

were used as such which were procured from the suppliersHPLC grade Acetonitrile was used throughout the study

21 General Procedure for Solvent Mediated Synthesis of 120573-Nitro Styrene In this procedure reactions are conductedusingDCE andMeCN as solvents Cinnamic acid (0001mol)dissolved in DCEMeCN and 0001 moles of Blaursquos complex(mixture of equimolar mixture of Fe(III) nitrate and 110-Phenanthroline (Phen) ligand) were suspended in a threenecked round bottomed flask The flask is equipped witha mechanical stirrer and reflux condenser The reactionmixture is stirred for some time until the evolution of CO

2

completely ceases The mixture is cooled in an ice bathand the precipitate is removed by filtration The residue iswashed with CCl

4and the filtrates are combinedThe solvent

is removed by distillation using a modified Claisen distil-lation apparatus with a 6 cm condenser After completionof the reaction as indicated by TLC the reaction mixtureis quenched with 2 sodium carbonate solution and theorganic layer was separated dried over Na

2SO4 evaporated

under vacuum and purified with column chromatographyusing ethylacetate hexane (3 7) as eluent to get pure prod-uct Table 1 shows the reaction times and under kineticconditions also the product of the reaction was found to be120573-nitro styrene as characterized by spectroscopic methods(Table 2) But the reactions are too sluggishwith long reactiontimes even at elevated temperatures and the yields are too lowunder these conditions

22 Kinetic Measurements Progress of the reaction was fol-lowed by recording the absorbance values of the productof oxidation [Fe(II)-(Phen) complex] produced as a func-tion of time at 510 nm (molar absorptivity minus120576 = 111 times

104 dm3molminus1 cmminus1) on a Beckman-DU model spectropho-tometer (equipped with thermostatic cell compartments)Control experiments revealed that the products of oxidationthat is Fe(II) chelates are quite stable under the experimentalconditions

3 Results and Discussion

31 Salient Kinetic Features (1) Under pseudo first orderconditions namely (i) [Phen]≫ [Fe(III)] [USA]≫ [Fe(III)]in the case of Blaursquos yellow complexes the plots of ln(119886(119886minus119909))or [ln(119860

infinminus 1198600)(119860infin

minus 119860119905)] versus time were found to be

linear with negative gradients in all the systems studied Firstorder rate constant (1198961015840) could be obtained either by point-wise calculation using first order rate expression or from theslopes of linear plots cited (1198961015840) Both the values agreed witheach otherThis observation indicates first order with respectto [Fe(III) Phen] in all the systems Similar observations werenoticed when the reactions were studied in all PEG media(Figures 1 and 2)

(2) This reaction is also conducted under secondorder conditions with equal concentrations of [Phen] ≫

[Fe(III)]o = [S]o Kinetic plots of [1(119886 minus 119909)] or [1(119860infin

minus

119860119905)] versus time have been found linear with a positive

gradient and definite intercept on ordinate vertical axisindicating overall second order kinetics (Figures 3 and 4)







1H NMR


















0

05

1

15

2

25

0 100 200 300 400 500Time (min)

ln(aa minus x)

ln(aa

minusx

)


Time (min)0 0

30 020008160 035164690 0498176

120 0650991180 0942153210 1082824240 1215146270 1377665300 1543754360 1863758420 2201541

y = 0005x + 0025 R2 = 0999



005

115

225

335

4

0 100 200 300 400 500Time (min)

ln(aa

minusx

)

R2 = 09999


Time (min) 0 0

30 031281260 055326990 0841066

120 104277150 1289373180 1499445210 1765713240 2014609270 2342053300 2598728360 3078301420 3563809

ln(aa minus x)

y = 0008x + 0032




3)3 Fe+(NO

3)2 Fe2+(NO

3) Fe3+(aq)


Fe3+ +H2O119870ℎ

999447999472 Fe(OH)2+ +H+ (1)



Fe(OH)2+ +H2O 999447999472 Fe(OH)

2

++H+ (2)

Fe3+ (aq) +HNO3999447999472 Fe(NO

3)2+

+H+ (3)

Fe(NO3)2+

+HNO3999447999472 Fe(NO

3)2

+

+H+ (4)

Fe(NO3)2

+

+HNO3999447999472 Fe(NO

3)3+H+ (5)



2] complexes is




005

115

225

335

0 100 200 300 400 500 600Time (min)

y = 0006x +

R2 = 09999

1(A

infinminusA

t)

1(Ainfin minus At)


Time (min)

0 0316448

60 0685

120 1029519

180 1391746

240 1788889

300 2129492

360 2460784

420 2791176

480 32104

0323



005

115

225

335

0 100 200 300 400 500 600 700 800Time (min)


y = 00043x +

R2 = 09996

1(A

infinminusA

t)

Time (min)0 0237634

60 0528235

120 0749351

240 1218143

360 1781301

480 2299863

600 2782222

660 3045455

720 333333

1(Ainfin minus At)

02397



0

005

01

015

02

025

0 02 04 06 08 11[Phen]

(1k

998400 )

(1k998400)

y = 02459x + 00242

R2 = 09995


1[Phen]

08 02204 0125

026 008802 0072923

016 00625





2Fe-O-






(solvent)

slow

Fast

Fast

Fast



K1

NO2+ + NO3

minus HNO3H2O


NO2+

RCH CH-NO2 + CO2


minus

RCH CH-COOH

k

Scheme 2


3)2L(OH)(ACN)

2][RCH=CHndashCOOH]



1198701=

[ML][M] [L]

or [M] =

[ML]1198701 [L] (8)


(1198701 [L])

+ [ML] = [M]tot

[ML] (1 + 1198701 [L]) = [M]tot1198701 [L]

[L] asymp 119862L

[ML] =[M]tot1198701119862L(1 + 119870

1119862L)

=

1198701 [Fe (III)] [Phen]

(1 + 1198701 [Phen])


=

1198701 [M] 119862L

1 + 1198701 [L]

=

1198701 [Fe (III)] [Phen]

1 + 1198701 [Phen]

(9)


] =1198961198701 [Fe (III)] [Phen] [USA](1 + 119870

1 [Phen]) (10)



where

119898 =

1

1198961198701

119862 =

1

119896

1198701=

119862

119898

119896 =

1

119862

(11)








Products

PEG path

Scheme 3



Δ119866

Δ119878


Cinnamicacid


Crotonicacid


Acrylicacid


Methoxycinnamicacid

200 1584 183 566 minus122300 5333 345 666 40400 3018 752 729 75600 2857 365 388 minus74

Nitrocinnamicacid




2]


2ndashOndashCH

2ndash)119899


3)2Phen(ACN)

2]

+H2O


2]

(12)



Δ119867 Δ119866 Δ119878


kJmol JKmol

Cinnamicacid

200 0307 149 30 382300 0067 448 44 130400 0618 228 12 696600 0350 66 27 126

Crotonicacid

200 0176 137 361 430300 0078 126 685 384400 0356 118 1021 347600 0224 128 535 395

Acrylicacid

200 0618 250 12 767300 0172 507 45 149400 0085 202 63 440600 0362 96 200 224

Methoxycinnamicacid

200 0284 217 32 597300 0123 448 43 130400 0281 301 33 867600 0350 66 27 126

Nitrocinnamicacid

200 0350 149 304 383300 0470 235 20 696400 0109 520 57 149600 0119 696 55 206





Slow

Fast

Fast

Fast





RCH CH-COOH

NO2+ + NO3

minus

NO3minus

HNO3HNO3


NO2+

RCH CH-NO2+ CO2


minusHNO3


Scheme 4

25

255

26

265

27

275

28

3 305 31 315 32 325 33 335

ln(N

hkR

T)

103T



33333 25436932258 2625083125 268995

30303 275737

103T









25826

262264266268

27272274276278

3 305 31 315 32 325 33 335

ln(N

hkR

T)

y = minus56379x + 44734R2 = 09991


103T

)

103T

ln(NhkRT)

33333 259475

32258 26525

3125 27144

30303 276387



2527293133353739

3 305 31 315 32 325 33 335

y = minus27474x + 1209

R2 = 09986

103T


103T

)

4+

ln(K

)

4 + ln(K)

33333 29387

32258 32104

3125 35188

30303 37608


005

115

225

335

3 305 31 315 32 325 33 335103T

y = minus6103x + 21721

R2 = 09997


)4 + ln(K)

4+

ln(K

)

33333 1369

32258 204

3125 2665

30303 3214




4 Conclusions


References









































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of







1H NMR


















0

05

1

15

2

25

0 100 200 300 400 500Time (min)

ln(aa minus x)

ln(aa

minusx

)


Time (min)0 0

30 020008160 035164690 0498176

120 0650991180 0942153210 1082824240 1215146270 1377665300 1543754360 1863758420 2201541

y = 0005x + 0025 R2 = 0999



005

115

225

335

4

0 100 200 300 400 500Time (min)

ln(aa

minusx

)

R2 = 09999


Time (min) 0 0

30 031281260 055326990 0841066

120 104277150 1289373180 1499445210 1765713240 2014609270 2342053300 2598728360 3078301420 3563809

ln(aa minus x)

y = 0008x + 0032




3)3 Fe+(NO

3)2 Fe2+(NO

3) Fe3+(aq)


Fe3+ +H2O119870ℎ

999447999472 Fe(OH)2+ +H+ (1)



Fe(OH)2+ +H2O 999447999472 Fe(OH)

2

++H+ (2)

Fe3+ (aq) +HNO3999447999472 Fe(NO

3)2+

+H+ (3)

Fe(NO3)2+

+HNO3999447999472 Fe(NO

3)2

+

+H+ (4)

Fe(NO3)2

+

+HNO3999447999472 Fe(NO

3)3+H+ (5)



2] complexes is




005

115

225

335

0 100 200 300 400 500 600Time (min)

y = 0006x +

R2 = 09999

1(A

infinminusA

t)

1(Ainfin minus At)


Time (min)

0 0316448

60 0685

120 1029519

180 1391746

240 1788889

300 2129492

360 2460784

420 2791176

480 32104

0323



005

115

225

335

0 100 200 300 400 500 600 700 800Time (min)


y = 00043x +

R2 = 09996

1(A

infinminusA

t)

Time (min)0 0237634

60 0528235

120 0749351

240 1218143

360 1781301

480 2299863

600 2782222

660 3045455

720 333333

1(Ainfin minus At)

02397



0

005

01

015

02

025

0 02 04 06 08 11[Phen]

(1k

998400 )

(1k998400)

y = 02459x + 00242

R2 = 09995


1[Phen]

08 02204 0125

026 008802 0072923

016 00625





2Fe-O-






(solvent)

slow

Fast

Fast

Fast



K1

NO2+ + NO3

minus HNO3H2O


NO2+

RCH CH-NO2 + CO2


minus

RCH CH-COOH

k

Scheme 2


3)2L(OH)(ACN)

2][RCH=CHndashCOOH]



1198701=

[ML][M] [L]

or [M] =

[ML]1198701 [L] (8)


(1198701 [L])

+ [ML] = [M]tot

[ML] (1 + 1198701 [L]) = [M]tot1198701 [L]

[L] asymp 119862L

[ML] =[M]tot1198701119862L(1 + 119870

1119862L)

=

1198701 [Fe (III)] [Phen]

(1 + 1198701 [Phen])


=

1198701 [M] 119862L

1 + 1198701 [L]

=

1198701 [Fe (III)] [Phen]

1 + 1198701 [Phen]

(9)


] =1198961198701 [Fe (III)] [Phen] [USA](1 + 119870

1 [Phen]) (10)



where

119898 =

1

1198961198701

119862 =

1

119896

1198701=

119862

119898

119896 =

1

119862

(11)








Products

PEG path

Scheme 3



Δ119866

Δ119878


Cinnamicacid


Crotonicacid


Acrylicacid


Methoxycinnamicacid

200 1584 183 566 minus122300 5333 345 666 40400 3018 752 729 75600 2857 365 388 minus74

Nitrocinnamicacid




2]


2ndashOndashCH

2ndash)119899


3)2Phen(ACN)

2]

+H2O


2]

(12)



Δ119867 Δ119866 Δ119878


kJmol JKmol

Cinnamicacid

200 0307 149 30 382300 0067 448 44 130400 0618 228 12 696600 0350 66 27 126

Crotonicacid

200 0176 137 361 430300 0078 126 685 384400 0356 118 1021 347600 0224 128 535 395

Acrylicacid

200 0618 250 12 767300 0172 507 45 149400 0085 202 63 440600 0362 96 200 224

Methoxycinnamicacid

200 0284 217 32 597300 0123 448 43 130400 0281 301 33 867600 0350 66 27 126

Nitrocinnamicacid

200 0350 149 304 383300 0470 235 20 696400 0109 520 57 149600 0119 696 55 206





Slow

Fast

Fast

Fast





RCH CH-COOH

NO2+ + NO3

minus

NO3minus

HNO3HNO3


NO2+

RCH CH-NO2+ CO2


minusHNO3


Scheme 4

25

255

26

265

27

275

28

3 305 31 315 32 325 33 335

ln(N

hkR

T)

103T



33333 25436932258 2625083125 268995

30303 275737

103T









25826

262264266268

27272274276278

3 305 31 315 32 325 33 335

ln(N

hkR

T)

y = minus56379x + 44734R2 = 09991


103T

)

103T

ln(NhkRT)

33333 259475

32258 26525

3125 27144

30303 276387



2527293133353739

3 305 31 315 32 325 33 335

y = minus27474x + 1209

R2 = 09986

103T


103T

)

4+

ln(K

)

4 + ln(K)

33333 29387

32258 32104

3125 35188

30303 37608


005

115

225

335

3 305 31 315 32 325 33 335103T

y = minus6103x + 21721

R2 = 09997


)4 + ln(K)

4+

ln(K

)

33333 1369

32258 204

3125 2665

30303 3214




4 Conclusions


References









































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


0

05

1

15

2

25

0 100 200 300 400 500Time (min)

ln(aa minus x)

ln(aa

minusx

)


Time (min)0 0

30 020008160 035164690 0498176

120 0650991180 0942153210 1082824240 1215146270 1377665300 1543754360 1863758420 2201541

y = 0005x + 0025 R2 = 0999



005

115

225

335

4

0 100 200 300 400 500Time (min)

ln(aa

minusx

)

R2 = 09999


Time (min) 0 0

30 031281260 055326990 0841066

120 104277150 1289373180 1499445210 1765713240 2014609270 2342053300 2598728360 3078301420 3563809

ln(aa minus x)

y = 0008x + 0032




3)3 Fe+(NO

3)2 Fe2+(NO

3) Fe3+(aq)


Fe3+ +H2O119870ℎ

999447999472 Fe(OH)2+ +H+ (1)



Fe(OH)2+ +H2O 999447999472 Fe(OH)

2

++H+ (2)

Fe3+ (aq) +HNO3999447999472 Fe(NO

3)2+

+H+ (3)

Fe(NO3)2+

+HNO3999447999472 Fe(NO

3)2

+

+H+ (4)

Fe(NO3)2

+

+HNO3999447999472 Fe(NO

3)3+H+ (5)



2] complexes is




005

115

225

335

0 100 200 300 400 500 600Time (min)

y = 0006x +

R2 = 09999

1(A

infinminusA

t)

1(Ainfin minus At)


Time (min)

0 0316448

60 0685

120 1029519

180 1391746

240 1788889

300 2129492

360 2460784

420 2791176

480 32104

0323



005

115

225

335

0 100 200 300 400 500 600 700 800Time (min)


y = 00043x +

R2 = 09996

1(A

infinminusA

t)

Time (min)0 0237634

60 0528235

120 0749351

240 1218143

360 1781301

480 2299863

600 2782222

660 3045455

720 333333

1(Ainfin minus At)

02397



0

005

01

015

02

025

0 02 04 06 08 11[Phen]

(1k

998400 )

(1k998400)

y = 02459x + 00242

R2 = 09995


1[Phen]

08 02204 0125

026 008802 0072923

016 00625





2Fe-O-






(solvent)

slow

Fast

Fast

Fast



K1

NO2+ + NO3

minus HNO3H2O


NO2+

RCH CH-NO2 + CO2


minus

RCH CH-COOH

k

Scheme 2


3)2L(OH)(ACN)

2][RCH=CHndashCOOH]



1198701=

[ML][M] [L]

or [M] =

[ML]1198701 [L] (8)


(1198701 [L])

+ [ML] = [M]tot

[ML] (1 + 1198701 [L]) = [M]tot1198701 [L]

[L] asymp 119862L

[ML] =[M]tot1198701119862L(1 + 119870

1119862L)

=

1198701 [Fe (III)] [Phen]

(1 + 1198701 [Phen])


=

1198701 [M] 119862L

1 + 1198701 [L]

=

1198701 [Fe (III)] [Phen]

1 + 1198701 [Phen]

(9)


] =1198961198701 [Fe (III)] [Phen] [USA](1 + 119870

1 [Phen]) (10)



where

119898 =

1

1198961198701

119862 =

1

119896

1198701=

119862

119898

119896 =

1

119862

(11)








Products

PEG path

Scheme 3



Δ119866

Δ119878


Cinnamicacid


Crotonicacid


Acrylicacid


Methoxycinnamicacid

200 1584 183 566 minus122300 5333 345 666 40400 3018 752 729 75600 2857 365 388 minus74

Nitrocinnamicacid




2]


2ndashOndashCH

2ndash)119899


3)2Phen(ACN)

2]

+H2O


2]

(12)



Δ119867 Δ119866 Δ119878


kJmol JKmol

Cinnamicacid

200 0307 149 30 382300 0067 448 44 130400 0618 228 12 696600 0350 66 27 126

Crotonicacid

200 0176 137 361 430300 0078 126 685 384400 0356 118 1021 347600 0224 128 535 395

Acrylicacid

200 0618 250 12 767300 0172 507 45 149400 0085 202 63 440600 0362 96 200 224

Methoxycinnamicacid

200 0284 217 32 597300 0123 448 43 130400 0281 301 33 867600 0350 66 27 126

Nitrocinnamicacid

200 0350 149 304 383300 0470 235 20 696400 0109 520 57 149600 0119 696 55 206





Slow

Fast

Fast

Fast





RCH CH-COOH

NO2+ + NO3

minus

NO3minus

HNO3HNO3


NO2+

RCH CH-NO2+ CO2


minusHNO3


Scheme 4

25

255

26

265

27

275

28

3 305 31 315 32 325 33 335

ln(N

hkR

T)

103T



33333 25436932258 2625083125 268995

30303 275737

103T









25826

262264266268

27272274276278

3 305 31 315 32 325 33 335

ln(N

hkR

T)

y = minus56379x + 44734R2 = 09991


103T

)

103T

ln(NhkRT)

33333 259475

32258 26525

3125 27144

30303 276387



2527293133353739

3 305 31 315 32 325 33 335

y = minus27474x + 1209

R2 = 09986

103T


103T

)

4+

ln(K

)

4 + ln(K)

33333 29387

32258 32104

3125 35188

30303 37608


005

115

225

335

3 305 31 315 32 325 33 335103T

y = minus6103x + 21721

R2 = 09997


)4 + ln(K)

4+

ln(K

)

33333 1369

32258 204

3125 2665

30303 3214




4 Conclusions


References









































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


005

115

225

335

0 100 200 300 400 500 600Time (min)

y = 0006x +

R2 = 09999

1(A

infinminusA

t)

1(Ainfin minus At)


Time (min)

0 0316448

60 0685

120 1029519

180 1391746

240 1788889

300 2129492

360 2460784

420 2791176

480 32104

0323



005

115

225

335

0 100 200 300 400 500 600 700 800Time (min)


y = 00043x +

R2 = 09996

1(A

infinminusA

t)

Time (min)0 0237634

60 0528235

120 0749351

240 1218143

360 1781301

480 2299863

600 2782222

660 3045455

720 333333

1(Ainfin minus At)

02397



0

005

01

015

02

025

0 02 04 06 08 11[Phen]

(1k

998400 )

(1k998400)

y = 02459x + 00242

R2 = 09995


1[Phen]

08 02204 0125

026 008802 0072923

016 00625





2Fe-O-






(solvent)

slow

Fast

Fast

Fast



K1

NO2+ + NO3

minus HNO3H2O


NO2+

RCH CH-NO2 + CO2


minus

RCH CH-COOH

k

Scheme 2


3)2L(OH)(ACN)

2][RCH=CHndashCOOH]



1198701=

[ML][M] [L]

or [M] =

[ML]1198701 [L] (8)


(1198701 [L])

+ [ML] = [M]tot

[ML] (1 + 1198701 [L]) = [M]tot1198701 [L]

[L] asymp 119862L

[ML] =[M]tot1198701119862L(1 + 119870

1119862L)

=

1198701 [Fe (III)] [Phen]

(1 + 1198701 [Phen])


=

1198701 [M] 119862L

1 + 1198701 [L]

=

1198701 [Fe (III)] [Phen]

1 + 1198701 [Phen]

(9)


] =1198961198701 [Fe (III)] [Phen] [USA](1 + 119870

1 [Phen]) (10)



where

119898 =

1

1198961198701

119862 =

1

119896

1198701=

119862

119898

119896 =

1

119862

(11)








Products

PEG path

Scheme 3



Δ119866

Δ119878


Cinnamicacid


Crotonicacid


Acrylicacid


Methoxycinnamicacid

200 1584 183 566 minus122300 5333 345 666 40400 3018 752 729 75600 2857 365 388 minus74

Nitrocinnamicacid




2]


2ndashOndashCH

2ndash)119899


3)2Phen(ACN)

2]

+H2O


2]

(12)



Δ119867 Δ119866 Δ119878


kJmol JKmol

Cinnamicacid

200 0307 149 30 382300 0067 448 44 130400 0618 228 12 696600 0350 66 27 126

Crotonicacid

200 0176 137 361 430300 0078 126 685 384400 0356 118 1021 347600 0224 128 535 395

Acrylicacid

200 0618 250 12 767300 0172 507 45 149400 0085 202 63 440600 0362 96 200 224

Methoxycinnamicacid

200 0284 217 32 597300 0123 448 43 130400 0281 301 33 867600 0350 66 27 126

Nitrocinnamicacid

200 0350 149 304 383300 0470 235 20 696400 0109 520 57 149600 0119 696 55 206





Slow

Fast

Fast

Fast





RCH CH-COOH

NO2+ + NO3

minus

NO3minus

HNO3HNO3


NO2+

RCH CH-NO2+ CO2


minusHNO3


Scheme 4

25

255

26

265

27

275

28

3 305 31 315 32 325 33 335

ln(N

hkR

T)

103T



33333 25436932258 2625083125 268995

30303 275737

103T









25826

262264266268

27272274276278

3 305 31 315 32 325 33 335

ln(N

hkR

T)

y = minus56379x + 44734R2 = 09991


103T

)

103T

ln(NhkRT)

33333 259475

32258 26525

3125 27144

30303 276387



2527293133353739

3 305 31 315 32 325 33 335

y = minus27474x + 1209

R2 = 09986

103T


103T

)

4+

ln(K

)

4 + ln(K)

33333 29387

32258 32104

3125 35188

30303 37608


005

115

225

335

3 305 31 315 32 325 33 335103T

y = minus6103x + 21721

R2 = 09997


)4 + ln(K)

4+

ln(K

)

33333 1369

32258 204

3125 2665

30303 3214




4 Conclusions


References









































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


(solvent)

slow

Fast

Fast

Fast



K1

NO2+ + NO3

minus HNO3H2O


NO2+

RCH CH-NO2 + CO2


minus

RCH CH-COOH

k

Scheme 2


3)2L(OH)(ACN)

2][RCH=CHndashCOOH]



1198701=

[ML][M] [L]

or [M] =

[ML]1198701 [L] (8)


(1198701 [L])

+ [ML] = [M]tot

[ML] (1 + 1198701 [L]) = [M]tot1198701 [L]

[L] asymp 119862L

[ML] =[M]tot1198701119862L(1 + 119870

1119862L)

=

1198701 [Fe (III)] [Phen]

(1 + 1198701 [Phen])


=

1198701 [M] 119862L

1 + 1198701 [L]

=

1198701 [Fe (III)] [Phen]

1 + 1198701 [Phen]

(9)


] =1198961198701 [Fe (III)] [Phen] [USA](1 + 119870

1 [Phen]) (10)



where

119898 =

1

1198961198701

119862 =

1

119896

1198701=

119862

119898

119896 =

1

119862

(11)








Products

PEG path

Scheme 3



Δ119866

Δ119878


Cinnamicacid


Crotonicacid


Acrylicacid


Methoxycinnamicacid

200 1584 183 566 minus122300 5333 345 666 40400 3018 752 729 75600 2857 365 388 minus74

Nitrocinnamicacid




2]


2ndashOndashCH

2ndash)119899


3)2Phen(ACN)

2]

+H2O


2]

(12)



Δ119867 Δ119866 Δ119878


kJmol JKmol

Cinnamicacid

200 0307 149 30 382300 0067 448 44 130400 0618 228 12 696600 0350 66 27 126

Crotonicacid

200 0176 137 361 430300 0078 126 685 384400 0356 118 1021 347600 0224 128 535 395

Acrylicacid

200 0618 250 12 767300 0172 507 45 149400 0085 202 63 440600 0362 96 200 224

Methoxycinnamicacid

200 0284 217 32 597300 0123 448 43 130400 0281 301 33 867600 0350 66 27 126

Nitrocinnamicacid

200 0350 149 304 383300 0470 235 20 696400 0109 520 57 149600 0119 696 55 206





Slow

Fast

Fast

Fast





RCH CH-COOH

NO2+ + NO3

minus

NO3minus

HNO3HNO3


NO2+

RCH CH-NO2+ CO2


minusHNO3


Scheme 4

25

255

26

265

27

275

28

3 305 31 315 32 325 33 335

ln(N

hkR

T)

103T



33333 25436932258 2625083125 268995

30303 275737

103T









25826

262264266268

27272274276278

3 305 31 315 32 325 33 335

ln(N

hkR

T)

y = minus56379x + 44734R2 = 09991


103T

)

103T

ln(NhkRT)

33333 259475

32258 26525

3125 27144

30303 276387



2527293133353739

3 305 31 315 32 325 33 335

y = minus27474x + 1209

R2 = 09986

103T


103T

)

4+

ln(K

)

4 + ln(K)

33333 29387

32258 32104

3125 35188

30303 37608


005

115

225

335

3 305 31 315 32 325 33 335103T

y = minus6103x + 21721

R2 = 09997


)4 + ln(K)

4+

ln(K

)

33333 1369

32258 204

3125 2665

30303 3214




4 Conclusions


References









































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of





Products

PEG path

Scheme 3



Δ119866

Δ119878


Cinnamicacid


Crotonicacid


Acrylicacid


Methoxycinnamicacid

200 1584 183 566 minus122300 5333 345 666 40400 3018 752 729 75600 2857 365 388 minus74

Nitrocinnamicacid




2]


2ndashOndashCH

2ndash)119899


3)2Phen(ACN)

2]

+H2O


2]

(12)



Δ119867 Δ119866 Δ119878


kJmol JKmol

Cinnamicacid

200 0307 149 30 382300 0067 448 44 130400 0618 228 12 696600 0350 66 27 126

Crotonicacid

200 0176 137 361 430300 0078 126 685 384400 0356 118 1021 347600 0224 128 535 395

Acrylicacid

200 0618 250 12 767300 0172 507 45 149400 0085 202 63 440600 0362 96 200 224

Methoxycinnamicacid

200 0284 217 32 597300 0123 448 43 130400 0281 301 33 867600 0350 66 27 126

Nitrocinnamicacid

200 0350 149 304 383300 0470 235 20 696400 0109 520 57 149600 0119 696 55 206





Slow

Fast

Fast

Fast





RCH CH-COOH

NO2+ + NO3

minus

NO3minus

HNO3HNO3


NO2+

RCH CH-NO2+ CO2


minusHNO3


Scheme 4

25

255

26

265

27

275

28

3 305 31 315 32 325 33 335

ln(N

hkR

T)

103T



33333 25436932258 2625083125 268995

30303 275737

103T









25826

262264266268

27272274276278

3 305 31 315 32 325 33 335

ln(N

hkR

T)

y = minus56379x + 44734R2 = 09991


103T

)

103T

ln(NhkRT)

33333 259475

32258 26525

3125 27144

30303 276387



2527293133353739

3 305 31 315 32 325 33 335

y = minus27474x + 1209

R2 = 09986

103T


103T

)

4+

ln(K

)

4 + ln(K)

33333 29387

32258 32104

3125 35188

30303 37608


005

115

225

335

3 305 31 315 32 325 33 335103T

y = minus6103x + 21721

R2 = 09997


)4 + ln(K)

4+

ln(K

)

33333 1369

32258 204

3125 2665

30303 3214




4 Conclusions


References









































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


Slow

Fast

Fast

Fast





RCH CH-COOH

NO2+ + NO3

minus

NO3minus

HNO3HNO3


NO2+

RCH CH-NO2+ CO2


minusHNO3


Scheme 4

25

255

26

265

27

275

28

3 305 31 315 32 325 33 335

ln(N

hkR

T)

103T



33333 25436932258 2625083125 268995

30303 275737

103T









25826

262264266268

27272274276278

3 305 31 315 32 325 33 335

ln(N

hkR

T)

y = minus56379x + 44734R2 = 09991


103T

)

103T

ln(NhkRT)

33333 259475

32258 26525

3125 27144

30303 276387



2527293133353739

3 305 31 315 32 325 33 335

y = minus27474x + 1209

R2 = 09986

103T


103T

)

4+

ln(K

)

4 + ln(K)

33333 29387

32258 32104

3125 35188

30303 37608


005

115

225

335

3 305 31 315 32 325 33 335103T

y = minus6103x + 21721

R2 = 09997


)4 + ln(K)

4+

ln(K

)

33333 1369

32258 204

3125 2665

30303 3214




4 Conclusions


References









































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of


25826

262264266268

27272274276278

3 305 31 315 32 325 33 335

ln(N

hkR

T)

y = minus56379x + 44734R2 = 09991


103T

)

103T

ln(NhkRT)

33333 259475

32258 26525

3125 27144

30303 276387



2527293133353739

3 305 31 315 32 325 33 335

y = minus27474x + 1209

R2 = 09986

103T


103T

)

4+

ln(K

)

4 + ln(K)

33333 29387

32258 32104

3125 35188

30303 37608


005

115

225

335

3 305 31 315 32 325 33 335103T

y = minus6103x + 21721

R2 = 09997


)4 + ln(K)

4+

ln(K

)

33333 1369

32258 204

3125 2665

30303 3214




4 Conclusions


References









































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of




































Journal of

Chemistry


Advances in

Physical Chemistry



Journal of

Volume 2014














Journal of

Spectroscopy



Journal of


Quantum Chemistry






CatalystsJournal of

research article polyethylene glycol mediated kinetic

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