Crystal Structure and Spectroscopic Properties of cis-β-Diazido(1,4,7,11-tetraazaundecane)chromium(III) Bromide

The new complex, cis-β-[Cr(2,2,3-tet)(N3)2]Br (2,2,3-tet = 1,4,7,11-tetraazaundecane), was prepared and its structure was determined by single-crystal X-ray diffraction. The chromium(III) atom is in a distorted octahedral environment coordinated by four nitrogen atoms of 2,2,3-tet and two azido ligands in a cis-β arrangement, with bent Cr–N3 linkages at the coordinating azide nitrogen atoms. The mean Cr–N(2,2,3-tet) and Cr–N(azide) bond lengths are 2.084(5) and 2.021(5) A, respectively. The crystal structure is stabilized by ionic interactions, supported by N–H···N(azide) and N–H···Br hydrogen bonds. The IR and electronic spectroscopic properties are also discussed.