Bis(dimethyloxonium) pentachloridoantimonate(III)

Abstract

Key indicators: single-crystal X-ray study; T = 223 K; mean (b-Cl) = 0.001 Å; R factor = 0.029; wR factor = 0.066; data-to-parameter ratio = 21.8.

Prototypical Phosphine Complexes of Antimony(III)

“…The molecular structure of the [Cl 4 (PMe 3 )Sb] 1− anion is derived from [Cl 5 Sb] 2– by replacing the apical chloride ion with a PMe 3 ligand (Figure ). The Sb–Cl bonds [2.555(2)–2.634(2) Å, average 2.593 Å] are on average shorter than the basal Sb–Cl bonds in [Cl 5 Sb] 2– [2.4775(12)–2.8847(12) Å, average 2.646 Å] and those in [Cl 4 Sb] 1– [2.4317(7)–2.6395(11) Å, average 2.536 Å] . The magnesium center is not engaged by the phosphine due to encapsulation of the hard [Mg] 2+ atom with hard CH 3 CN ligands (solvent), leaving the soft [Cl 4 Sb] 1– anion as the sole coordination site for the soft phosphine donor.…”