use of organic reagents in inorganic analysis
TRANSCRIPT
Victoria College, Coochbehar, India
Use of Organic Reagents in Inorganic Analysis Par t IX*
Analytical Reactions of Maleanilic Acids By
S&CHINDRA ~UMAR DATTA
(Received April 6, 1959)
The analytical properties of maleanilie acids have not been studied by any worker before. I n this paper, 18 n~aleanilie acids have been prepared f rom maleic anhydride and various aromatic amines and their analytical behaviour has been investigated. The amines used for the preparat ion of these acids are: aniline, o-chloroaniline, p-chloroaniline, 2:5-dichloro- aniline, m-nitroaniline, p-nitroaniline, o-toluidine, p- tohidine , o-anisi- dine, p-anisidine, p-phenitidine, p-aminoaeetanilide, 1-naphthylamine, 2-naphthylamine, o-phenylenediamine, m-phenylenediamine, benzidine and tolidine. The preparat ion of most of these acids are not found in the literature. The maleanilie acids are more insoluble in water than the corresponding phtha]anilic acids :, t hey are however soluble in alcohol, acetone, chloroform and benzene. They are unstable to heat and change to anils on heating above their melting points.
~0 c-cS ~ Hc-U;H
II }o + I + II HC--C~0 NI-I-- R HC--C~-NH--R ~0
It was observed that most of these reagents produced precipitates with mercury(I), lead, cerium(IV), thorium and zirconium. But precipi- tations with thorium and zirconium were found to be more or less quanti- tative with most of the reagents. Iron(III) gave unstable coloured pro- ducts with many and gold and platinum solutions were reduced.
Experimental Preparation o/Maleanilic Acids
Maleic anhydride (B. D. H. Reagent grade) was reerystalliscd from dry benzene. One molar quantity of maleic anhydride was dissolved in hot benzene, to this solution was mixed one molar quantity of the aromatic amine also dissolved in benzene, the total volume of the mixture was made up to 50 ml with benzene and then refluxed on water-bath from 20 minutes to 1 hour, when the anilic acid separa- ted in the form of solid. Some anilic acids, e.g., those obtained from aniline, p-phe- nitidine, p-anisidine, formed rapidly in the cold with vigorous reaction; some
* Part VIII : See Z. analyt. Chem. 163, 403 (1958).
Organic Reagents in Inorganic Analysis. IX 419
required only a few minutes' heating, e.g., anilic acids from ortho- and parachloro- anilines and p-toluidine, etc, formed within 15--20 minutes, whereas very few required long heating, e.g., anilic acids from dichloroaniline and nitroanilines separated after heating for about one hour. In general, it was noticed that the maleanilic acids formed at a much quicker rate than the corresponding phthal- anilie acids. The acids were filtered, washed with benzene and then recrystallised from benzene or alcohol. Almost all the acids possessed characteristic colours.
Reagents and Chemicals Molar stock solution of soluble chlorides or nitrates of different metals (A.R.)
were prepared for qualitative tests with the reagents. Buffer solutions of various pH values were prepared by mixing different quantities of M hydrochloric acid and M sodium acetate solutions. 1~ alcoholic (80~ solution of the reagents were prepared.
Properties o/the Reagents M o s t o f t h e ma l ean i l i e ac ids possess c h a r a c t e r i s t i c colours. The acids
a re u n s t a b l e to h e a t a n d d e c o m p o s e to t h e ant is on h e a t i n g a b o v e t he i r
m e l t i n g poin ts . T h e y are p r a c t i c a l l y inso lub le in w a t e r b u t a re soluble in
a lcohol , benzene , a ce tone a n d ch lo ro fo rm. T h e y r e s p o n d to Taf fe l ' s
co lour tes ts . T h e acids p r e p a r e d h a v e been l i s t ed in Tab l e 1, w i t h t h e i r p roper t i e s .
Table 1. Maleanilic Acids Prepared (Sp. denotes sparingly; h. w. hot water; ale ~ alcohol, sol = soluble)
Serial No.
5'Ialeanilic acid from
Colour
3
)iiP.
4
Taffel's colour tests (reagent-cone.
H2SO~--K~Cr2OT)
Cold Warm
5 6
Solubility
7
M-1
3/[-2
M-3
5'I-4
M-5
M-6
M-7
M-8
Aniline
o-Cl-aniline
p-Cl-aniline
2:5-di-C1- aniline
m-Nitrani- line
p-Nitrani- line
o-Toluidine
p-Toluidine
205
120
198
102
196
194
118
201 Idecomp.)
greenish grey
greenish blue
red
green
yellow
reddish brown brown
yellow- green
blue
greenish blue
red- brown
green
green
greenish grey bluish grey
grey
sp. sol in water, sol in ale, ace- tone, benzene etc.
sp. sol in water, sol in alc, ace- tone, benzene, etc.
sp. sol in water sol in ale.
sp. sol in water, sol in ale, aeet.
sp. sol in water, sol in alc, a c e t o n e .
sp. sol in water, sol in ale.
sp. sol in water, sol in rect. spt.
sp. sol in water, sol in ale.
27*
420 SACJcKNDRA KU~a~ D A T T A :
Table 1 (continued)
Serial No.
lV[-9
M-IO
1~I-12
M-13
M-14
M-15
M-16
M-17
M-18
Maleanilic a c id f rom
o-Anisidine
p-Anisidine
p-Phenit i- dine
p-Amino- acetanilide
1-Naphthyl- amine
2-Naphthyl- amine
o-Pheny- lenediamine
m-Pheny- lenediamine
Benzidine
Tolidine
Colour
3
~ . :P . ~
4
Taffel 's eolour tests (reagen~-eonc.
It2SO4--K~Cr~07)
Cold W a r m
5 6
yellowish brown green
yellowish brown green
reddish green brown
green green
red- brown browr
red brown
browr brown
yello~ ish yellow- green green
green bluish green
red- greenish brown I grey
i I
Solubility
7
more sol in water, sol in rect. spt.
sp. sol in water, sol in ale.
decomp, in h.w., sol in acetone, ale.
sol in hot ale. very sp. sol in water.
iusol in water, decomp, in b.w., sol in NI-I~Ae., sol in rect. spt.
sp. sot in water, deeomp, in b.w., highly sol in acetone, ale.
sol in h.w., sol in ale, acetone.
sol in h.w., ale, acetone.
insol in water, alc, acetone; not
a suitable reagent
very sp. sol in water, sol in alcohol.
Procedure/or Qualitative Tests To one ml of a solution of the metal were added two ml of buffer solution and to
i t two ml of the freshly prepared 1 p. c. alcoholic (80~ solution of the reagent were then added. Any change in eolour or formation of any precipitate, either in the cold or in the hot, was noted. The filtered and washed precipitate was decomposed by heat ing with acids and the presence or absence of the part icular metal ion was detected by known methods. To tes t for the completeness of precipitation, an excess of the reagent was used for precipitat ion and the filtrate after washing was tested for the presence of the cation.
T h e r e s u l t s h a v e b e e n p l a c e d i n T a b l e 2. T h e m e t a l s w h i c h d i d n o t
r e s p o n d to s u c h t e s t s h a v e n o t b e e n s h o w n i n t h e T a b l e .
Organic Reagents in Inorganic Analysis. IX 421
Table 2. Reactions of Maleanilic Acids with Metals
Serial No. ofreagent
1
M-1
M-2
M-3
M-4
M-5
~e ta I ions
2
HgI
Pb
FelI FeIII
Th
Zr
Au
CeIV
ItgI Pb Th
Zr
CelV
HgI Pb F e l I I
Th
Zr
CelV
Th
Zr
CeiV F e I I I
Th
Zr
CeIV
Au
P~
3
2.2
2.2
2.6 2.6
3.2
3.7
3.2
3.2
2.2 2.2 3.5
3.5
3.2
2.2 2.2 2.6 3.5
3.5
3.2
3.5
3.5
3.2 2.6
3.5
3.5
3.2 3.2
Colour of ppt or solution
4
white ppt.
white ppt.
turbidity on boiling bluish black coln. on heating white ppt with NH4Ae in hot No ppt in cold, turbidity on boiling turbidity, reduction on boiling turbidity
slight ppt slight ppt white ppt with NH4Ac in hot white ppt with NH4Ac in hot white ppt in hot
turbidity turbidity brown solution in hot white ppt with NH4Ac in hot gelatinous white ppt with NH~Ac turbidity
no ppt in cold or hot, voluminous ppt with NH4Ac no ppt in cold or hot, gelatinous ppt with NH4Ac white ppt with NH4Ac brown soln in hot
white ppt with NH4Ac in hot gelatinous ppt with NH4Ae on boiling turbidity rapid reduction
Nature of the ppt or colour
5
not quantitative, sol in acids not quantitative, sol in acids
almost quantitative
quantitative
not quantitative greenish brown on boiling
not quantitative
not quantitative
not quantitative not quantitative almost quantitative, sol in excess of NH4Ae almost quantitative, sol in excess of NHtAc not quantitative
darkens on boiling sp. sol in NH4Ae in excess sp. sol in NH4Ac in excess sp. sol in NH4Ac i n e x c e s s
quantitative
422 SACICIINDRA ]{UMAB DATTA~:
Table 2 (continued)
Serial No. ofreagent
I
M-6
M-7
M-8
M-9
M-IO
lV[-ll
N-12
Yletalions
2
Th
Zr CeIV
Au
Felll
Th Zr CerV
Au
~FeIII
Th Zr CeiV A I
Fe[I Fe IIt
TI Zr At
Fe [II
Tt
Zr Au
l%III
Th
Zr
FeIII Th Zr Au
]OH
3
3.5
3.5 3.2 3.2
2.6
3.5 3.5 3.2 3.2
2.6
3.5 3.5 3.2 3.2
2.6 2.6
3.5 3.5 3.2
2.6
3.5
3.5 3.2
2.6
3.5
3.5
2.6 3.5 3.5 3.2
Colour of ppt or solution
4
yellowish ppt with NH4Ac turbidity turbidity slow reduction
greenish grey soln in hot white ppt in NH4Ac white ppt in NHtAc turbidity reduction
red colouration on heating white ppt in NH~Ac white ppt in NH~Ac turbidity reduction
turbidity red coln on warming, grey ppt on boiling white ppt in NH~Ac white ppt in NH4Ac reduction in cold
violet coln. in cold, deeper on boiling cream powdery ppt in NH~Ac white ppt in NH~Ac reduction in cold
bright pink on warming, brown on boiling. white granular ppt with alcohol and acetone soln, white granular ppt with alcohol and acetone soln.
pink on standing no ppt no ppt red on standing, reduction on boiling
Nature of the ppt or eolour
5
not quantitative
colour unstable
quantitative quantitative
colour unstable
quantitative quantitative
quantitative quantitative
unstable
quantitative
quantitative
not stable
not quantitative
not quantitative
fairly stable
unstable
Organic l~eagents in Inorganic Analysis. IX
Table 2 (continued)
423
Serial No. of reagent
1
M-13
M-14
M-15
M-16
!V[et M ions
2
FeIII
Th
Zr
HgI Pb
FeIII
Th
Zr
HgI Pb
HgI Pb Th
Zr
FelII
Pd
Pt
Au
HgI Pb FeIII
Th
Zr
Pt
Au
pit
3
2.6
3.5
3.5
2.2 2.2
2.6
3.5
3.5
2.2 2.2
2.2 2.2 3.5
3.5
2.6
3.2
3.2
3.2
2.2 2.2 2.6
3.5
3.5
3.2
3.2
Colour of pp t or solut ion
4
dirty blue coln on boiling white voluminous ppt in NH4Ac white voluminous ppt in NH~Ae grey ppt white ppt
no change in cold, greyish blue coln on heating white ppt in hot in presence of NH4Ae white ppt in hot in presence of NH4Ac grey ppt white ppt
turbidity on boiling white ppt no ppt, slight turbidity with NIt,At no ppt, turbidity with NH4Ac deep brown colour on boiling pale red eolour o11 boiling pinkish turbidity on heating greenish grey coln
white ppt in cold white ppt in cold deep red brown coin on boiling no ppt in cold or hot, voluminous ppt in NH~Ac no ppt in cold, turbi- dity on boiling, white ppt with NH~Ac pinkish turbidity on boiling immediate reduction in cold
Nature of the ppt or colour
5
quantitative
quantitative
not quantitative not quantitative
quantitative, sol in excess of NH4Ac quantitative, sol in excess of NH~Ac not quantitative not quantitative
not quantitative
unstable, turns turbid
unstable
not quantitative not quantitative unstable
quantitative
quantitative
424 SACmSDgA KUMAR DATTA: Organic Reagents in Inorganic Analysis. IX
Table 2 (continued)
Serial No. ofreagent
1
Metal ions
2
Pl~
8
colour of pp t or solution
4
Nature of the ppt or co]our
5
M-17 HgI HglI Pb FelII Th
Zr
Pt Au
2.2 2.2 2.2 2.6 3.5
3.5
3.2 3.2
yellowish white ppt turbidity in hot yellowish white ppt greenish brown ppt cream ppt, more with h~l-I~A c cream ppt, more with NH4Ae brown turbidity immediate reduction in cold.
not quantitative
not quantitative not quantitative quantitative
quantitative
S u m m a r y
Eighteen anilic acids have been prepared from maleic anhydride and various aromatic amines and their properties and analytical reactions with various metal ions have been studied. The acid prepared from ben- zidine was insoluble in all common solvents and, hence, its application could not be studied. Most of these reagents, except those obtained f rom aniline, o- and p-chloroanilines, nitranilines, p-amino-acetanilide and o-phenylenediamine, produced more or less quant i ta t ive precipitations with both thor ium and zirconium. Their actions towards thor ium and zirconium were very much alike. They also gave precipitations with mercury(l) , lead and cerium(IV), bu t such precipitations were no t complete. Ferrous iron showed greyish turbidi ty with most of the reagents, bu t ferric iron produced colourations varying from brown to violet, such colours were, however, found to be unstable either on standing for a while or on heating. Gold and pla t inum underwent reduct ion in presence of these reagents.
The work has been carried out in the chemical laboratories of Darjeeling Govern- ment College, Darjeeling. The author is grateful to the authorities of the College for the laboratory facilities.
R e f e r e n c e s
1 DATTA, S. K.: Z. analyt. Chem. 148, 259 (1955).
SACltINDRA KUMAR DATTA, Chemical Laboratory, Victoria College, Coochbehar, India