Crystal structure and properties of the [Cu(C 11H 10N 4)Br 2] compound. Stereochemistry of [Cu(planar tridentate ligand)(unidentate ligand) 2] complexes

Abstract

The crystal structure of the dibromo(pyridine-2-aldehyde 2′-pyridylhydrazone) copper(II) is reported. The compound crystallizes in space group P2 1/ n, with a = 12.86(2), b = 11.944(5), c = 8.770(7) Å, β = 97.17(6)°, U = 1336(3) Å 3, Z = 4, D m = 2.06(1), D x= 2.10 g cm −3, μ(Mo- K α) = 78.92 mm −1, F(000) = 812, T = 293 K. Final R is 0.047 ( R w = 0.049) for 854 observed reflections. The structure consists of discrete molecules in which the copper(II) ion is pentacoordinate with a distorted square pyramidal geometry. The spectroscopic data are in good agreement with the structural results. The stereochemistry of several pentacoordinate complexes of type [Cu(planar tridentate ligand) (unidentate ligand) 2] is examined and the distortions of the coordination polyhedra are calculated.