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

The use of succinamic acid (H2sucm) in CuII/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(ClO4)n (1), [Cu(Hsucm)(terpy)(MeOH)](ClO4) (2), [Cu2(Hsucm)2(terpy)2](ClO4)2 (3), [Cu(ClO4)2(terpy)(MeOH)] (4), [Cu(Hsucm)(dmbppy)]n(NO3)n·3nH2O (5.3nH2O), and [CuCl2(dmbppy)]·H2O (6·H2O). The succinamate(−1) ligand exists in four different coordination modes in the structures of 1–3 and 5, i.e., the μ2-κO:κO′:κO″ 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 μ2-κ2O:κO′ 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 5·3nH2O was monitored by TG/DTG and DTA measurements.

Graphical abstractThe use of succinamic acid (H2sucm) in the CuX2·yH2O (X = ClO4, y = 6; X = NO3, y = 3; X = Cl, y = 0)/N,N′,N″-chelate (terpy, dmbppy) reaction system yielded mononuclear and dinuclear complexes as well as 1D coordination polymers generated via the O-amide ligation of Hsucm−. All compounds present interesting molecular and crystal structures.Figure optionsDownload full-size imageDownload as PowerPoint slide