Crystal and molecular structure of dicarbonylchlorobis-[o-phenylene(dimethylarsino)]molybdenum(II) tri-iodide–bischloroform

Abstract

Crystals of the title compound are orthorhombic, space group Pnma, with a= 11·75(1), b= 15·27(1), c= 24·15(2)Å, Z= 4. The structure was solved by the heavy-atom method from 1048 independent reflections, collected by counter methods, and refined by full-matrix least-squares techniques to R 0·080. The symmetry of the cation is very close to C_2v(mm) with one of the mirror planes imposed by the space group. Thus the molybdenum atom has a 1,4,2-capped trigonal prismatic environment with a chlorine atom in the unique capping position [2·575(11)Å], four arsenic atoms in the capped quadrilateral face [2·614(5), 2·617(5)Å], and two carbonyl groups making up the remaining edge [1·92(5), 1·87(5)Å]. The tri-iodide ion lies with the central atom on a crystallographic mirror plane [2·903(2)Å, 176·9(2)°].