Structural, solid-state NMR and theoretical studies of the inverse-coordination of lithium chloride using group 13 phosphide hosts.

The reaction of MeAlCl 2 with 'PhPLi 2 ' in THF gives [(MeAl-(PPh) 3 Li 4 ·3THF} 4 (μ 4 -Cl)] - Li + . (1). The Ga III and In III analogues, [{MeE-(PPh) 3 Li 4 ·3 THF} 4 (μ 4 -Cl)] - Li + ·(THF) 3 (E=Ga (2), In (3)), are obtained by the in situ reactions of MeECl 2 with PhPLi 2 in THF. For all of the complexes, the cage anions have an unusual cubic arrangement that is similar to a zeolite, and contain large voids (ca. 17 A). The location of the Li + counterions in 1-3 and their coordination environment appears to subtly reflect variations in packing and lattice energy. Whereas in 1 highly mobile, loosely coordinated Li + counterions are present, 2 and 3 contain less mobile THF-solvated counterions within the cavities. X-ray crystallographic and solid-state NMR studies are reported on 1-3, together with model DFT calculations on the selectivity of halide coordination.