Synthesis and Physico-Chemical Studies of Polyamide Macrocyclic Metal Complexes
No Thumbnail Available
Date
1999-06
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa Universty
Abstract
The synthesis of bis(macrocyclic) complexes bearing tetraamide groups has been achieved by
template condensation reaction between propylenediatnine, formaldehyde, benzidine, and succinic
acid in the molar ratio of 4:4:1:2, respectively. The appearance of four characteristic amide bands and
two single sharp bands corresponding to u(N -H) of secondary of secondary amine and coordinated
amide groups at their appropriate positions and the absence of bands assignable to primary' amine and
hydroxyl group in the IR spectra strongly suggest the formation of the proposed macrocylic
framework. The assigned band positions in the electronic spectra of Co(II), Ni(II) and Cu(II) confirm
their octahedral geometry'. However, the low molar conductivity' values indicate their lion-electrolytic
nature. The results of elemental analyses agree well with the proposed stoichiometry' of the bis(macrocyclic) complexes A new series of polyamide macrocyclic complexes have also been prepared by' condensation reaction
of hydrazine hydrate and succinic acid with metal ion in 4:4:1 molar ratio, respectively'. The
diagnostic amide bands appearing at their appropriate positions and two single bands corresponding
to u(N-H) of coordinated amide and uncoordinated amide gr oup and non -existence of uncondensed
bands corresponding to primary' amino and hy'droxyl groups provide enough evidence for the
formation of the proposed macrocyclic structure. Two major peaks, a broad signal in the region 8.0-
8.8 ppm and a broad signal in the region 2.3-3.2 ppm in the H NMR spectrum of the zinc(II) complex
corresponding to amide group protons (CO-NH, 8 H) and methylene protons of dicarboxylic moiety
(CO- (CI Qj-CO, 16H) further conoborates the proposed macrocyclic framework . The band positions
hi the electronic spectra of Co(II) and Cu(II) and conductivity' data supported their final geometry'. The
stoichiometry' has been confirmed on the basis of elemental analysis .
Description
Keywords
macrocyclic metal complexes