Bis-(tetraethylammonium)[tetraazidocuprate(II)] and catena-di-mu-1,1-azido-[di-mu-1,1-azido-bis-(2,4-dimethylpyridine)dicopper(II)]

Two new copper(II) azido complexes, namely bis-(tetraethylammonium)[tetraaz idocuprate(II)] (1) and catena-di-mu -1,1-azido-[di-mu -1,1-azido-bis-(2,4- dimethylpyridine)dicopper(II)] (2), have been prepared and characterized by spectroscopic and crystallographic methods. Complex (1) consists of isolat ed NEt4+ cations and [Cu(N-3)(4)](2-) anions. The site symmetry around the copper atom in the anion is 4/m. Complex (2) features a 1 D chain structure , five coordinated square pyramidal copper(II) atoms with both azides funct ioning as mu -1,1-bridges. The i.r. spectra reveal that both complexes cont ain asymmetric azido ligands. The solid and solution electronic spectra of (1) and (2) show very strong absorption bands in the visible region associa ted with N-3(-) --> Cu-II charge-transfer transitions. The e.p.r. spectra o f powder samples and solutions at room temperature were recorded and discus sed.