Synthesis and characterization of divalent metal complexes with bipyridylamide ligands

Abstract

Reaction of N-(4-pyridyl)picolinamide (4-ppa), N-(4-pyridyl)nicotinamide (4-pna), N-(4-pyridyl)isonicotinamide (4-pina), and N-(2-pyridyl)isonicotinamide (2-pina) with divalent metal salts led to the formation of six new coordination complexes. The X-ray structure of [Zn(4-ppa)2Cl2] (1) shows a mononuclear structure with interesting intermolecular hydrogen bonding interactions. [Zn(4-pna)(OAc)2]n (2), Cu(4-pna)(OTf)2(DMF)2]n (3), {[Zn(4-pina)(DMF)4](OTf)2}n (4), {[Fe(4-pina)(DMF)4](OTf)2}n (5), and [Cu(2-pina)(OTf)2(DMF)2]n (6) are one-dimensional coordination polymers with conformational differences caused by the coordination donor disposition, which demonstrates the flexibility of the pyridylamide ligands in polymeric structures. Reflectance UV-visible spectra and thermal properties of the coordination polymers are also reported.