Studies on the metalamide bond. II. The crystal structure of the deprotonated copper(II) complex of N,N′-bis-(2′-pyridinecarboxamide)-1,2-benzene

Abstract

Aqua [N,N′bis(2′-pyridinecarboxamido)-1,2-benzene]copper(II), C 18H 14N 4O 3Cu, is triclinic, space group P 1 , with a = 7.443(3), b = 9.560(2), c = 11.197(4), Å, α = 92.63(2), β = 100.02(2), γ = 84.50(2)°, Z = 2. The structure was refined to R = 0.038 for 2813 diffractometer data using least-squares methods. The copper atom is five-coordinate, the ligand acting as a planar N 4 tetradentated in encompassing the base of a distorted square-based pyramid [CuN(amide) 1.933(2) Å, average CuN (pyridine) 2.023(2) Å, N(amide)CuN(amide) 82.8°, N(pyridine)CuN(pyridine) 110.7°] and with the Cu atom raised 0.19 Å above the N 4 plane towards the apical water molecule (CuO 2.286(2) Å). The water molecule hydrogen bonds carbonyl oxygen atoms of adjacent chelate molecules, which are packed in layers parallel to (21 2 . An intra-molecular steric interaction between the two H atoms in the 6-positions of the pyridine rings (H ▪H 1.98 Å) is evident.