Synthesis, spectroscopy, and X-ray structure of the polymer catena-[bis(azido-N)-copper(II)-mu-bis(2-benzimidazolyl)butane]

The title compound, catena-[bis(azido-N)-copper(II)-mu(bis(2-benzimidazolyl )butane). [Cu(C18H18N4)(N-3)(2)](n), was obtained from the reaction of the ligand bis(2-benzimidazolyl)butane and Cu(N-3)(2). The x-ray crystal struct ure is reported. The compound crystallizes in the monoclinic space group P2 (1)/c with a = 8.2524(10), b = 12.765(5). c = 9.1125(15) Angstrom, beta = 1 06.423(12)degrees, Z = 2. The Cu(II) ions are square-planar coordinated wit h trans-oriented end-on binding azido ligands. The structure is a polynucle ar chain with the benzimidazole bridging at each end. In addition a N-(liga nd)-H ... N-(azido) H-bridge [N-(ligand)... N-(azido) = 2.994(7) Angstrom] is present, resulting in a pseudo 2-dimensional lattice. The characteristic azido infrared vibrations are found at 2060 and 2077 cm(-1) (nu(as)(N-3)) and 1284 and 1297 cm(-1) (nu(N-3)).