Structure of trans-dichlorobis-[o-phenylene(bisdimethylarsine)]-cobalt(III) perchlorate

Abstract

Trans-dichlorobis-[o-phenylene(bisdimethylarsine)]cobalt(III) perchlorate, crystallises in spacegroup C2 with a= 12·67, b= 10·27, c= 13·42 Å, β= 127° 28′. Z= 2 for which both the complex cation and the perchlorate group are required to have strict two-fold rotational symmetry. Structure analysis, based on 549 reflections comprising a pseudo-three-dimensional data set, shows the crystallographic C₂ axis to coincide with the Cl–Co–Cl direction of the cation. The structural parameters indicate appreciable rotational disordering of the perchlorate group. The final R for a model not involving rotational disorder of the perchlorate is 0·08 and corresponds to mean bond length estimated standard deviations of 0·003 (Co–As), 0·01 (Co–Cl), 0·04 (As–C), and 0·05 Å(C–C). There is a characteristic shortening of the Co–As bond distances due to π-bonding.