STUDIES ON THE COMPLEXES OF SUCCINIMIDE AND DERIVATIVES OF DICHLORO BIS (ETHYLENEDIAMINE) COBALT (III) CHLORIDE

Abstract

The reaction of imides in the ammoniacal, ethanolic and 1 2 pyridin media have been carried out . Ley and Werner reported the hydrolytic nature of the succinimide complex of copper. Cambi3 studied the magnetic properties of complex derivatives of succinimide with iron, nickel and cobalt. These studies were confined to the study of the interaction of these heavy metals with succinimide in non aqueous media. No attempt, however, seems to have been made to study these systems in aqueous medium and determine the nature and composition of these complexes. Investigation in this direction was therefore undertaken employing various physico-chemical methods to establish the composition and to determine the stability of the complexes, The structure of the complexes were determined on the basis of i.r. studies and magnetic measurements. Present report comprises of four aspects of the problem : (i) Composition, stability and structure determinations of the simple metal succinimide complexes, (ii) Composition and stability determination of mixed ligand complexes, (iii) Interaction of cis and trans dichloro bis (ethylenediamine) cobalt (HI) chloride with chromate, dichromate, molybdats and tungstate ions and to establish the nature of chromate and dichromate ions as a monodentate and bidentate. (ii) (iv) Analytical use of succinimide for the spectrophotometric determination of copper (II) and cobalt (II) and of cis dichloro bis (ethylenediamine) cobalt (III) chloride for the amperometric determination of mercuric chloride. The section I and II of parti (A) deal with the simple succinimide complexes of Cu(II), Ni (II), Co (H), Fe (II), Hg (II), Pd (II), Au (in), Ce (IV), Pt. (IV) and Th (IV) in aqueous medium. Composition and stability constants of the complexes have been established by conductometric, amperometric and pH metric methods. The results have been further confirmed from chemical analysis of the isolated products, i. r. studies and magnetic measurements. pK values of succinimide as determined by potentiometric titration of succinimide with KOH were found to be 9.45, 9. 70, 9.55 and 9.30 in KCL KNOg, K2S04 and NaC104 medium of 0.1 Mrespectively. The electrometric titrations provide evidence for the formation of 1:1 (M : succinimide) complex with Fe(II), Ni (II), Hg (II), Au (III) and Pt (IV) and 1:2 (M: succinimide) complex with Cu (II), Co (II), Pd (II), Ce (IV) and Th (IV). The value of logK (concentration constant) was found to be 3.30, 3.10, 6.88, 6.20 and 8.40 for 1:1 (M : succinimide) complexes of Ni (II), Fe (II), Hg (II), Au (ni) and Pt (IV) respectively and 6.44 (logK1 = 3.68, logK2 = 2.76); 6.28 (logiq • 3.17, logK2 = 3.11); 17.4 (logKj - 9.1, logK2 = 8.3); 18.9 (logKj = 10.2, logK2 = 8.7); and 14.6 (logK1 • 7.5, logK2 = 7.1) for 1:2 (M: succinimide) complexes of Cu (II), Co (H), Pd (n), Ce (IV) and Th (IV) respectively. (iii) The n values beyond :^:2. 0 in case of Pd (II), Ce (IV), Th (IV) and ^1.0 in case of Au (in) and Pt (IV) and 0.5 in case of Fe (II) could not be obtained with accuracy due to the onset of hydrolysis. The presence of polynuclear species could be neglected since the formation curves ( n Vs - logA) determined from the ligand metal ratio of 5:1 and 6:1 were found identical. The complexes could be isolated in the solid form and were analysed for the metal, carbon and hydrogen. However, we remained unable to isolate the compounds of Au (ni) and Pt (IV) in the solid form. All the complexes are of non-electrolytic nature in nitroben zene. The complexes of Cu (II), Ni (II), Co (n) and Fe (II) were found to be paramagnetic with 1, 2, 3 and 4 unpaired electrons respectively. The main characteristic features of the i. r. spectra were the same as 4 reported earlier with the difference of the bands associated with coordinated hydroxo group (1030 cm and 600 cm ) and water molecules (82 0 cm and 660 cm ). On the basis of the above observations the following formulae can be assigned to the isolated complexes. 1. _Cu (C4H402N)2(H20)2 | : 2. ^i^H^N) (OH) (HgO) 2 '4 . r 3. Co (C4H402N)2 (H20)2 j : 4. Fe(C4H402N) (OH) (H20)4 ! 5. [Hg (C4H402N) (OH) "1 : 6. Im^H^N) (fL^1 7. Tee (C4H402N)2 (OH)2~ : 8. pTMC^OjjN^ (OH)2l Palladium complex, on treatment with ammonia, or aliphatic amine gave white coloured crystalline complexes. The chemical analysis for the palladium, carbon and hydrogen favoured the formulae of the (iv) type [Pd (C .H ON) (A)~\ where A=ammonia, methyl amine, »— 4422 2J ethyl amine, isopropyl amine or isobutyle amine. All these complexes were diamagnetic and of nonelectrolytic nature in nitrobenzene. The section I of part 1(B) deals with the mixed ligand succinimide complexes of metal amine chelates. Mixtures containing (I) perchloric acid (U) dipyridyl or O-phenanthroline (HI) succinimide (IV) metal and dipyridyl or O-phenanthroline in the ratio of 1:1 (V) metal, dipyridyl or O-phenanthroline and succinimide in the ratio of 1:1:1 were prepared. The ionic strength of the mixture solutions was kept 0.1M sodium perchlorate. All of them also contained equal concentrations of perchlo ric acid. The mixture solutions were then, separately titrated with standard NaOH solution. Stability constants of the mixed ligand complexes were calculated from the curves using the wen known equations . These complexes could be isolated in the solid form by mixing the reactants in the ratio of 1:1:1 and keeping the ionic concentra tion of sodium perchlorate between 1.0M and 2.0M and then adjusting the pH of the reaction mixtures cu 9. 5 with KOH. The magnetic moments indicate the presence of 1, 2 and 3 unpaired electrons in the complexes of Cu (n), Ni (II) and Co (II) respectively. The values of stabHity constants and magnetic moments are given in the following table.