SPECTRAL AND MAGNETIC STUDIES ON THE MIXED LIGAND COMPLEXES OF SOME ACID - IMIDES AND AMINES

Abstract

The work embodied in the thesis is on the interactions of some transition metal ions with imides, amines, organic acids and some sulphur containing ligands. These mixed ligand complexes containing imide or amine as one of the ligands have been prepared and chracterised applying various physicochemical methods. The techniques used are Mossbauer spectroscopy, IR and visible spectroscopy, magnetometry, conductometry, thermal analysis and chemical analysis. For convenience, the thesis has been divided into the following chapters: General Introduction SECTION-A Chapter-I Mixed ligand complexes of iron(III)-phthalimide with some phenolic compounds. Chapter-II Mixed ligand complexes of metal(II) imides with some sulphur containing ligands. SECTION-B Chapter-Ill Mixed ligand complexes of chromium(III) with nitrilotriacetic acid as primary and some dibasic acids as secondary ligands. Ill SECTION-C Chapter-IV Mixed ligand complexes of some amines with sodium bis(thioglycolato) diaquo-ferrate(III). Chapter-V Interaction of cis-dichlorobis(en)cobalt(III) chloride with some sulphur containing ligands. General introduction highlights the relevance and the importance of the ligands used. A brief account of the work done on related type of systems and complexes is also given. Naturally this includes current literature survey relevant to the work. The 1st chapter of section-A deals with the hyperfine interactions in the mixed ligand complexes of phenolic compounds with iron-phthalimide. Six new mixed ligand complexes of iron-phthalimide with gallic acid, pyridoxine, sulphosalicylic acid / salicyladehyde, anisaldehyde and naphthaldehyde have been prepared and characterised. The room temperature Mossbauer spectra exhibit a broad and assymetric doublet which persists down to 50 K. The I.S. and Q.S. values indicate iron to be in +3 and high spin state. The magnetic moment values ( ~ 5.0 BM at 300 K decreasing to - 3.0 BM at 77 K) do not show any magnetic transition. In chapter Ilnd of section-A are incorporated the results on the studies of the complexes of IV diethyldithiocarbamate, thioglycollate, benzylmercapto acetate and 2-mercapto propionate with M(II)-imides, where M=Cu(II), Ni(II) and Co(II) and imides are succinimide and phthalimide. The electronic spectra of copper(II) complexes gave three band at about 21500, 19000 and 15500 cm"1. The complexes were found to have a square planar structure. Similarly the electronic spectra and the diamagnetic character of the complexes of nickel(II)indicated their square planar structure. The values of ^, *2 and *3 have also been calculated. The electronic spectra and the values of magnetic moments in the range 4.90 to 5.10 BM, indicate high spin octahedral structures of the complexes of cobalt(II). Section-B describes the preparation and characterisation of the complexes formed by the interaction of Ammonium Hydroxoaquonitrilotriacetatochromate(III)with some organic acids. The general formulae of the complexes are K[Cr(NTA)(A-A)], K2[Cr(NTA)(CA)] and [Cr(NTA)(Pyx)] where NTA=deprotonated nitrilotriacetic acid, A-A=gallate, mendilate and benzilate ion, CA=chromotropate ion and pyx=pyridoxine. All these complexes are of an octahedral geometry. Ligand field parameters have also been calculated. Chapter IV of section-C, deals with the studies on the hyperfine interactions in the mixed - ligand complexes of amines with sodium bis (thioglycolato) diaquo ferrate (III). The mixed-ligand complexes of sodium bis (thioglycolato)diaquo ferrate (III) with Y-picoline, triethylenetetra amine, morpholine, o-phenanthroline and 2,2'-bipyridyl were prepared and characterized on the basis of conductance, magnetic, IR and electronic spectral studies. Mossbauer spectra exhibited a broad and an assymetric doublet. The I.S. and Q.S. values indicated iron to be in +3 and high spin state. Chapter V of section-C describe the interaction of dichloro bis (ethylenediamine) cobalt(III) chloride with some sulphur containing ligands. The complexes of the type [Co(en)2(A-A)] CI x H20, where A-A = thioglycollate, dithiodiglycollate, mercaptopropionate, mercaptoacetate, diethyl-dithiocarbamate, thiourea and diphenylthiourea were prepared and characterized on the basis of IR and electronic spectra, conductance and magnetic measurements and DTA and TGA analysis.