The cyanate and azide ions as bridging ligands in transition-metal complexes of 3- and 4-cyanopyridines

摘要: Complexes of the type MLx(NCO)2 are described (M = Mn, Fe, Co, Ni, or Zn; L 3- 4-cyanopyridine; x= 2 4). It is shown from spectra and magnetic X-ray measurements that, with exception M Zn, all ML2(NCO)2 complexes contain six-co-ordinate metal ions. I.r. establish that nitrile function cyanopyridine not co-ordinated therefore NCO group bonded to two Evidence presented, mainly i.r. spectra, for a single-atom (nitrogen) bridge, M–N–M in cyanato-complexes (and also some isomorphous azides) rather than three-atom M–NCO–M, which occurs bridged thiocyanato-complexes.The moments MnL2(NCO)2 MnL2(N3)2 anomalously low temperature-dependent. suggested these effects due weak antiferromagnetic exchange between paramagnetic centres non-magnetically dilute structure M–N–M.