Complexes derived from the copper(II)/succinamic acid/ N, N′, N″-chelate tertiary reaction systems: Synthesis, structural and spectroscopic studies

Abstract

The use of succinamic acid (H 2sucm) in Cu II/ N, N′, N″-donor [2,2′:6′,2″-terpyridine (terpy), 2,6-bis(3,5-dimethylpyrazol-1-yl)pyridine (dmbppy)] reaction mixtures yielded compounds [Cu(Hsucm)(terpy)] n (ClO 4) n ( 1), [Cu(Hsucm)(terpy)(MeOH)](ClO 4) ( 2), [Cu 2(Hsucm) 2(terpy) 2](ClO 4) 2 ( 3), [Cu(ClO 4) 2(terpy)(MeOH)] ( 4), [Cu(Hsucm)(dmbppy)] n (NO 3) n ·3 nH 2O ( 5 . 3 nH 2O), and [CuCl 2(dmbppy)]·H 2O ( 6·H 2O). The succinamate(−1) ligand exists in four different coordination modes in the structures of 1– 3 and 5, i.e., the μ 2-κ O:κ O′:κ O″ in 1 and 5 which involves asymmetric chelating coordination of the carboxylato group and ligation of the amide O-atom leading to 1D coordination polymers, the μ 2-κ 2 O:κ O′ in 3 which involves asymmetric chelating and bridging coordination of the carboxylato group, and the asymmetric chelating mode in 2. The primary amide group, either coordinated in 1 and 5, or uncoordinated in 2 and 3, participate in hydrogen bonding interactions, leading to interesting crystal structures. Characteristic IR bands of the complexes are discussed in terms of the known structures and the coordination modes of the Hsucm − ligands. The thermal decomposition of complex 5·3 nH 2O was monitored by TG/DTG and DTA measurements.