Synthesis and structures of a pentanuclear Al(iii) phosphonate cage, an In(iii) phosphonate polymer, and coordination compounds of the corresponding phosphonate ester with GaI3 and InCl3

Abstract

A cationic, pentanuclear aluminium phosphonate cage, [L₄Al₅Cl₆(THF)₆]Cl, 1, supported by (phthalimidomethyl) phosphonate, (L), has been synthesized and characterized. This polynuclear cage features the phosphonate ligand in an unusual coordination mode, supporting five aluminium atoms in two different environments. In comparison, the aqueous reaction of LH₂ with In(ClO₄)₃ afforded [{(LH)In(H₂O)}(H₂O)₂(ClO₄)]_n, 2, an indium(III) phosphonate coordination polymer, that has been crystallographically characterized. Reactions of the corresponding phosphonate ester, diethyl (phthalimidomethyl) phosphonate, (L′), with GaI₃ and InCl₃ afforded the simple coordination complexes, [L′·GaI₃], 3, and [L′·InCl₃(THF)], 4.