Synthesis and crystal structure of two stereochemical isomers of the trans-dichloro(1,4,8,11-tetraazacyclotetradecane)chromium(III) cation

Abstract

Two stereoisomers of the cationic trans-[Cr(cyclam)Cl₂]⁺ complex (cyclam = 1,4,8,11-tetraazacyclotetradecane) were prepared and isolated as the nitrate and tetrachlorozincate salts and their structures determined by X-ray diffraction studies of the monoclinic crystals of the nitrate salt, a= 6.480(2), b= 18.862(12), c= 13.628(6)Å, β= 100.28(3)°, and tetragonal crystals for the tetrachlorozincate salt, a= 16.377(4), c= 6.821(2)Å. The two complexes show an octahedral geometry about the metal atoms with the RSSR configuration but with differences in the conformations of the six-membered rings.