x

TABLE 1 - CHARACTERIZATIONDATA FORR2SnX2.2Me2NH ADDUCTS

m.p. Found (%) (calc.) Mol. wt(0C) found

Sn N (calc.)

R = PHENYL210 27'70 6·22 310

(27-42) (6'45) (434)198 18·98 4·37

(19'29) (4'54)R = O-TOLYL

158 25·56 5·85 340(25'75) (6'06) (461)

240 21'52 5·00(21.59) (5.08)

228 18'62 4·10(18'45) (4,34)

R = m-TOLYL162 25·60 6·20 290

(25'75) (6'06) (461)

R = P-TOLYL185 25'80 6·03 305

(25,75) (6'06) (461)191 20·99 5'02

(21'59) (5'08)188 18·25 4·10 408

(18-45) (4'34) (554)

Cl

I

Cl

Br

Cl

Cl

Br

I

vasym(Sn-N) and '1sym(Sn-N) respectively. Theobservations are in good agreement with thosereported earlier by Tanaka et at.5 and the presentauthor's recent studv".

In conformity with the observations of Polleret al.7,8, the v(Sn-aryl) at 288 ± 8 and 242 ± 3 cm!remain unaltered in the spectra of the presentlystudied Lewis acids and their adducts. The peakat 257 ± 8 cm-i ident ified in the spectra of the chloro-complexes, is assigned to Sn-CI stretching vibrationand is in agreement with the observations of Polleret al. The '1Sn- Br and '1Sn- I have been identifiedat 158 ± 3 and 142 ± 3 ern"! respectively. The lower-ing of the absorption On coordination parallels theobservations of Poller et al.7,8.

The analytical, molecular weight and conductancedata indicate hexa-coordinated complexes andsince two Sn-aryl and one Sn-X stretching fre-quencies have been identified, it may reasonablybe concluded that two aryl groups occupy cispositions, while the two halogen atoms are transto each other.

However, it is likely that the other Sn -Clstretching mode may have been masked by thestrong in-plane and out-of-plane ring deformationmodes occurring in the range 225-180 crrr+, There-fore, a distorted octahedral structure in which thetwo halogen atoms occupy cis positions and thetwo aryl groups are trans to each other, isalso possible. A recent Mossbauer study on similarsulphoxide complexes suggests distorted octahedralstructure in which two chlorine atoms and theligand occupy cis positions while the organic groupsare trans to each other but the C-Sn-C angle isnot 1800 (ref. 9).

Thanks are due to Prof. T. N. Srivastava,Chemistry Department, Lucknow University, Luck-

NOTES

now for his keen interest and valuable discussionsand to the Director, CDRI, Lucknow for elementalanalysis. Thanks are also due to the CSIR, NewDelhi for financial assistance.

References1. SHUKLA,P. R, J. prakt. Chem., 303 (1966), 109.2. INGHAM, R K., ROSENBERG,S. D. & GILMAN, H., Chem.

Rev., 59 (1960), 459.3. BUTLER, M. J. & MCKEEN, D. c.. Spectrochim. Acta,

21 (1965), 465.4. GREENWOOD,N. N. & WADE, K., J. chem. Soc., (1960),

1130.5. TANAKA,T., KOMURA,M., KAWASAKI,Y. & OKAWARA,R.,

J. organometal. Chem., 1 (1964),484.6. SRIVASTAVA,T. N., SRIVASTAVA,P. C. & SRIVASTAVA,

KUSUM, J. inorg. nucl. Chem., 37 (1975), 1803.7. POLLER, R C., RUDDICK, J. N. R., THEVARASA,M. &

MCWHINNIE, W. R, J. chem, Soc., A (1969), 2327.8. MAY, J. R, MCWHINNIE, W. R & POLLER, R. C.,

Sbectrochim; Acta, 27A (1971), 969.9. LIENGME, B. V., RANDALL, R S. & SAMS, J. R., Can. J.

Chem., 50 (1972), 3212.

Sb(IlI) Complexes of Schiff Bases Derivedfrom Salicylaldehyde & n-Propyl- & n-Butyl-

amines & Aniline

O. P. SINGH & J. P. TANDONDepartments of Chemistry, RB.S. College, Agra and

University of Rajasthan, Jaipur 302004

Received 23 July 1975; accepted 16 January 1976

Reactions of Sb(OPrl)3 with the rnononegatfve biden-tate Schiff bases (SBH), having the general formulaHO-C6H,CH=NR (where R=C3H~ C4H; and C6HS) indifferent stoichiometric ratios have yielded Sb(OPrl)2(SB), Sb(OPrl) (SBh and Sb(SB). types of products.In these 1 : 1, 1 : 2 and 1 : 3 complexes, the central anti-mony atom appears to be tetra-, penta- and hexa-coordinated respectively. The infrared spectra of theresulting derivatives have been recorded and tentativeassignments made.

IN .recent years, reactio~s of Sb(III) et~oxideWIth oxygenl-3 and nitrogen+ donor ligands

ha ve been investigated. However, reactions ofSb(III) isopropoxide with the Schiff bases do notseem to have been studied so far. In general,these reactions in different stoichiometric ratiossuch as 1: 1, 1: 2 and 1: 3 give the products Sb(OPriMSB), Sb(OPri)(SB)2 and Sb(SB)3 with thegeneration of 1, 2 and 3 moles of isopropanolrespectively. The products (Table 1) were isolatedin the form of yellow derivatives and found to besoluble in benzene.

The molecular weights determined ebullioscopi-cally in boiling benzene, indicate that all these com-plexes are monomeric and probably contain thecentral metal atom in tetra-, penta-,and hexa-coordinated environment in 1: 1, 1: 2 and 1: 3products respectively.

A comparison of the characteristics IR absorptionbands of the Schiff bases with those of their corres-ponding derivatives reveals the following: Thedisappearance of broad medium bands of the ligandsin the region 3400-3050 cnr" in the spectra of thecomplexes indicate chelation of the ligand through

709

INDIAN J. CHEM., VOL. 14A, SEPTEMBER 1976

Pd(II) Chelate of 2,4-DihydroxyvalerophenoneOximeTABLE 1 - SYNTHESIS AND CHARACTERISTICSOF Sb(III)-SCHIFF BASE COMPLEXES

Molar Reflux Mol. formularatio period

hr

Found (%) (calc.)

Sb N

SCHIFF BASEFROMn-PROPYLAMINE1: 1 4t Sb(OPri}.(C1OH1.NO)* 30·62 3·64

(30·35) (3-49)1:2 7 Sb(OPri) (CloHuNO)~ 23·96 5·45

(24-12) (5'54)1:3 9t Sb(CIOH12NO)~ 19·74 6·64

(20'03) (6,91)

SCHIFF BASE FROM n-BUTYL AMINE1: 1 3 Sb(OPri)2 (CllH14NO)* 25·36 3·28

(26,05) (3'36)1: 2 7 Sb(OPri)(CllHuNO)~ 21·98 5·14

(22'85) (5'25)1: 3 8t Sb(CllH14NO)i 18·53 6·49

(18,74) (6,46)

SCHIFF BASE FROMANILINE1:1 3 Sb (OPri). (C13HIONO)t 27·54 3·16

(27'93) (3'21)1:2 4 Sb(OPri}(C13HIONO)~ 20·64 4·62

(21'23) (4-88)1:3 8 Sb(C13H'ONO)i 16,62 5·76

(17,14) (5,91)

*Compounds obtained as yellow liquids.+Compounds obtained as yellow semisolids.tCompounds obtained as yellow solids.

o as well as N atoms. A strong band in the region1640-1620 em+ in the Schiff bases due to >C=N-group remains almost unaltered in the resultingderivatives8,9-ll. In the IR spectra of the com-plexes, the appearance of a nEW strong band at600 ± 10 cm-1 may be attributed to vSb-O.

The antimony isopropoxide was prepar~d. bythe sodium chloride methods and was distilled(105°/14 mm) before use: Schiff bases'' and thei.rderivatives+ were synthesized as usual. The expcn-mental details of all the reactions are summarizedin Table 1. Antimony was estimated as antimonouspyrogallate", while nitrogen by Kj,~ldahl.'s methodsIsopropanol was estimated by oxiuimetric methodusing IN KzCrzO, in 12'5% H2S04,References

1. MEHROTRA,R. C. & BHATNAGAR,D. D., J. Indian chem,Soc., 42 (1965), 327.

2. KUMAR, K., MISRA, S. N. & KAPOOR, R. N., Indian J.Chem., 7 (1969), 1249.

3. KUMAR, K. & KAPOOR, R. N., Egypt. J. Chem., 15(1972), 613.

4. MEHROTRA, R. C., RAI, A. K. & BOHRA, RAKESH, J.Indian chem, Soc., 51 (1974), 304.

5. DUBROVINA,O. D., Chern. Abstr., 51 (1957), 6453i.6. MEHROTRA, R. C. & DAYAL, J., Indian J. Chem., 10

(1972), 435. . ., . .7. VOGEL, A. 1., A text book of quamtitatiue inorgamc analysts

(Longmans, Green, London), 1961, 502.8. BRADLEY, D. C., HALIM, F. M. A. & WARDLAW, W.,

J. chem, Soc., (1950), 3450.9. SHARMA,B. D. & BAILER (Jr). J. C., J. Am. chem, Soc.,

77 (1955), 5476.10. BIRADAR,N. S. & KULIARNI, V. H., J. inorg, nucl. Chem.,

33 (1971), 3781.11. PRASAD, R. N. & TANDON, J. P., Z. Naturf., 28b

(1973), 153.

710

JAI SINGH & S. P. GUPTAChemistry Department, D.N. College, Meerut 250002

Received 20 June 1975; accepted 12 March 1976

2,4-Dihydroxyvaleropbenone oxime forms water in-soluble complex with Pd(II) which is extractable intochloroform to give a yellow solution having 1max at400 nm. It has been found to be a good and selectivereagent for gravlmetrtc estimation of palladium andfor its separation from other ions. The structure ofthe 1:2 (metal: ligand) chelate bas been confirmed byelemental analysts, pH-metric titration, spectrophoto-metric, IR and UV spectral studies. The stabilityconstant of tbe chelate is 6·4 x 10'. Beer's law is obeyedin the concentration range 35-75 ppm of Pd(II). Limitsof interference due to the presence of foreign ions in thespectrophotometric and gravimetric determinations.have been determined.

IN continuation of our studiesv+ on the chelatesof 2,4-dihydroxyvalerophenone oxime (DHVOX),

this note deals with the gravimentric ar d spectro-photometric determination oi Pd(II) with DHVOX.The composition and structure of the Pd(II) chelatehave also been determined on the basis of analytical,pH-metric titration, IR and UV spectral data.

All the measurements were carried out afterequilibrating the solutions at 30° ± 0·2° for 30 min.DHVOX Was prepared as reported earlier". Solutionof Pd(II) Was prepared by dissolving palladiumchloride (BDH, AR) in 0'05N HCl. All the otherchemicals used were of BDH, AR. grade and wereused as such.

The method of Vcsburg and Coopers showed thatPd(II) forms only one complex which has Amax at400 om. The complex can be extracted in chloro-form, carbon tetrachloride or ethyl acetate. How-ever, chloroform is found to be a better solvent forextraction. The subsequent studies were carriedout in this medium. In all the experiments 8 mlof chloroform Was used for extraction. Preliminarystudies showed that the absorption is maximumbetween pH 2·0 and 5'0. Subsequent studies werecarried at PH 3'0. Four-fold excess of the ligandWas necessary for maximum colour intensity. Beer'slaw is followed over the concentration range 35-75ppm of Pd(II). From the slope ratio curve themolar extinction coefficient was found to be 7,68 X102 and sensitivity = 0,139 t.t.g Pd/cm2•

Composition oj the complex - The compositionof the complex was found to be 1: 2 by mole-ratiomethod", slope-ratio method' and Job's methodof continuous variation, extended to a two phasesystem by Irving and Pierces.

The stability constant of the complex was cal-culated by the molar ratio method, using the rela-tion:

K =(1-oc)/4C2oc3 and o: =(E",-Es)/E",where Em, Es, IX. and C have their usual meanings.The stability constant was found to be 6,4 X 10'at 400 nm and standard energy of formation (-6.F =RT In K) was found to 10·38 kcaljrnole at 30°C.