2D polymeric copper(I) complexes. Synthesis, X-ray structures and spectroscopic studies of [CuX(pyrazine)]_n (X = NCS and N_3) complexes containing molecular and anionic rod ligands

摘要

Two mixed ligand complexes of the type CuLX for X = NCS, 1 and N_3 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 A] 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) A] 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 A] as #mu#(N,N)-pyrazine ligands [Cu-N = 1.994 A]. The azido ligands are symmetrical [N_1-N_2=N_2-N_3 = 1.191 (5) A] and linear [