Synthesis and crystal structure of a new copper(II) complex based on 5-ethyl-3-(pyridin-2-yl)-1,2,4-triazole

Abstract

The title compound, bis[μ-3-ethyl-5-(pyridin-2-yl)-1H-1,2,4-triazol-1-ido]bis[acetato(dimethylformamide)copper(II)], [Cu2(C9H9N4)2(C2H3O2)2(C3H7NO)2] or [Cu2(L Et)2(OAc)2(dmf)2], is a triazolate complex, which contains two 3-(2-pyridyl)-5-ethyl-triazolates (L Et)− in bidentate-bridged coordination modes. Both copper atoms are involved in the formation of a planar six-membered metallocycle Cu–[N—N]2–Cu. The inversion center of the complex is located at the mid-point of the Cu...Cu vector. Each CuII atom has a distorted trigonal–bipyramidal environment formed by the three nitrogen atoms of the deprotonated bridging 3-(2-pyridyl)-5-ethyl-triazolate unit, oxygen atoms of the OAc− group and dmf molecule. In the crystal, C—H...O hydrogen bonds link the molecules into chains running along the c-axis direction.

Solvent- and functional-group-assisted tautomerism of 3-alkyl substituted 5-(2-pyridyl)-1,2,4-triazoles in DMSO–water

“…This suggests that 9b-A is equally capable of acting as a chelating ligand through the N1,N7 and N4,N7 donor sites. Transition metal complexes with both rotameric forms of the pyridine ring of 9b-A-I/II 51,52 and 9b-A-III/IV 53,54 are well known.…”