2D polymeric copper(I) complexes.: Synthesis, X-ray structures and spectroscopic studies of [CuX(pyrazine)]n (X = NCS and N3) complexes containing molecular and anionic rod ligands

Two mixed ligand complexes of the type CuLX for X=NCS, 1 and N, 2 and L=pyrazine have been synthesized and characterized by spectroscopic and crystallographic methods. The IR and electronic spectra of both complexes are given and discussed. In the monoclinic crystals of complex 1 each copper atom is coordinated by two nitrogen atoms from two mu(N,N)-pyrazine ligands [Cu-N(av)=2.011 Angstrom] and one nitrogen atom and a sulfur atom from two mu(N,S)-thiocyanato ligands [Cu-N=2.112(7) and Cu-S=2.3037(14) Angstrom] giving rise to a two-dimensional structure with the copper atom in a distorted tetrahedral environment. The structure of complex 2 is very close to 1 and contains mu(1,3)-azido ligands [Cu-N=2.149 Angstrom] as well as mu(N,N)-pyrazine ligands [Cu-N=1.994 Angstrom]. The azido ligands are symmetrical [N-1-N-2=N-2-N-3=1.191 (5) Angstrom] and linear [<N-N-N=179.7 degrees]. (C) 1999 Elsevier Science Ltd. All rights reserved.