Spectral and structural characterization of trans-dibromobis(2-benzoylpyridine)copper(II) and trans-diazidobis(2-benzoylpyridine)copper(II) [CuX 2(2-benzoylpyridine) 2] (X = Br or N 3)

Abstract

Complexes of copper(II) bromide and copper(II) azide with 2-benzoylpyridine (2-Bzpy), namely trans-dibromobis(2-benzoylpyridine)copper(II) ( 1) and trans-diazido-bis(2-benzylpyridine)copper(II) ( 2), have been prepared and characterized by spectroscopic methods and X-ray crystallography. The copper atom in centrosymmetric [CuBr 2(2=-Bzpy) 2] ( 1) is six-coordinated by two nitrogen atoms [CuN = 1.970(4) Å] and two oxygen atoms [CuO = 2.407(4) Å] belonging to the two 2-Bzpy molecules and two trans-bromide atoms at CuBr distances of 2.468(1) Å. In the structure of complex 2, [Cu(N 3) 2(2-Bzpy) 2], the copper atom which is also located at an inversion centre is six-coordinated by pairs of trans-N,O-bidentate chelating 2-Bzpy molecules [CuN = 2.005(3) Å, CuO = 2.467(3) Å] and the terminal azido ligands at CuN distances of 1.989(4) Å. The azido ligands are almost linear [NNN = 176.6(4)°] and asymmetric [N αN β = 1.201(5) and N βN γ = 1.158(5) Å]. The IR and electronic spectral data for both complexes are presented and discussed.