Preparation and Properties of Macrocyclic Ligand and Its Complexes Derived from Trimethoprim and Diethyl Phthalate

Macrocyclic complexes of Mn, Co, Ni and Cu using a macrocyclic ligand derived by the condensation of Trimethoprim and diethyl phthalate have been prepared and characterized by electronic, IR and NMR spectral studies as well as magnetic moment and conductivity. On the basis of spectral studies, an octahedral geometry has been proposed for all the complexes. INTRODUCTION: The chemistry of macrocyclic ligands has been known for several decades . Generally, macrocyclic polyamides are prepared by reaction of polyamine with either the diester salt of dicarboxylic acid or the dicarboxylicacid dichloride . Three novel complexes of Cu(II), Co(II) and Zn(II) using macrocyclic ligand derived by the condensation of diethyl phthalate and benzidine have been designed, synthesized and characterised . The Schiff base condensation of 2, 6 –diamino pyridine with 1, 3 diphenyl 1, 3 dipropanedione in the presence Ni(II), Co(II) and Cu(II)chloride in boiling methanol gives the complexes of the 16-membered macrocycle . New family of 15-membered tetraamide macrocyclic complexes have been synthesized by template condensation reaction of o-aminobenzoicacid with aliphatic or aromatic diamines and diethyl malonate . Macrocyclic ligands are defined as cyclic molecules generally consisting of organic frames, either aliphatic or aromatic units into which the donor atoms are interspersed 8 the macrocyclic ligands have been synthesized by the condensation reaction of diethyl phthalate with o-phenylene diamine . The present work deals synthesis and physiochemical studies of a new series of macrocyclic complexes bearing tetra amide groups derived from trimethoprim with diethyl phthalate in the presence of transition metal ions as template. MATERIALS AND METHODS: All the chemical reagents used in the preparation of macrocyclic Ligands and their metal complexes were of reagent grade (Merck). The solvents used for the synthesis of macrocyclic ligands and metal complexes were distilled before use. All other chemicals were of AR grade and used without further purification. Proton NMR spectra were recorded on a EM 300-30 MHz NMR spectrometer in DMSO. IR spectra of the samples were recorded on a shimadzce FTIR-8400s spectro-photometer in 4000400 cm range in a KBr pellet. The electronic spectra (ethanol) were recorded on the Lamda 35 Correspondence to Author: P. Victor Arockiadoss Research scholar, Postgraduate and Research Department of Chemistry, St.Joseph’s college (Autonomous), Tiruchirappalli-620002, Tamil Nadu, India