Structure of bistrimethylamine–aluminium trichloride, bistrimethylphosphine–aluminium trichloride, and bistrimethylphosphine–indium trichloride. The single-crystal Raman spectrum of bistrimethylamine–aluminium trichloride

Abstract

A single crystal X-ray study of AlCl₃,2NMe₃ shows the space group to be Pnma with four molecules in the unit cell (a= 9·71, b= 10·05, c= 12·95 Å). The compound is isomorphous with CrCl₃,2NMe₃. Powder X-ray diffraction patterns of AlCl₃,2PMe₃ and InCl₃,2PMe₃ show them to be isomorphous with the corresponding trimethylamine adducts. All these compounds show trigonal-bipyramidal co-ordination of the central atom with axial trimethylamine or trimethylphosphine groups. A single-crystal Raman study of AlCl₃,2NMe₃ strongly suggests that a totally symmetric mode at 168 cm.^–1 is principally an aluminium-ligand stretching vibration.