Azido-amine-cobalt(III) complexes Crystal structures of cis-[Co(tren)(N_3)_2]ClO_4 and trans-[Co(3, 2, 3-tet)(N_3)_2]ClO_4

摘要

The structures of the two complexes cis-[Co(tren)(N_3)_2]ClO_4 (I) trans-[Co(3, 2, 3-tet)(N_3)_2]ClO_4 (II) (tren = 2, 2',2"-triaminotriethylamine; 3, 2, 3-tet = 1, 10-diamino-4, 7-diazadecane) have been determined by X-ray crystallography. The compounds consist of isolated complex cations [Co(tren)(N_3)_2]~+ and [Co(3, 2, 3-tet)(N_3)_2]~+ with distorted octahedral geometry and ClO_4~- counter ions. The two single coordinated azido ligands are arranged cis and trans in the cations of I and II, respectively. The Co-N(azido) distances vary from 1.946(3) to 1.964(3) A. The configurational geometry for these complexes were previously reported based on the position of the asymmetric stretching mode of vibration of the coordinated azido ligands, va(N_3) in the 2000-2065 cm~(-1) region. The results of X-ray studies are consistent with the previous assigned geometry based on the IR of va(N_3) and strongly support its use as a valuable tool for elucidating the geometrical isomerism in octahedral diazido metal complexes.