Anionic Bismuth Oxido Clusters with Pendant Silver Cations: Synthesis and Structures of {[Bi4(µ3‐O)2(TFA)9Ag(tol)2]2} and {Bi4(µ3‐O)2(TFA)10(AgPPh3)2}n

Abstract

BiPh3 and trifluoroacetic acid (TFAH) react in toluene in the presence of Ag2O to form {[Bi4(µ3‐O)2(TFA)9Ag(tol)2]2} (1; tol = PhMe). Similarly, BiPh3, TFAH, PPh3, and Ag2O react in hexane to form [Bi4(µ3‐O)2(TFA)10(AgPPh3)2]n (2). Both contain {Bi4(µ3‐O)2} units, which have been previously observed with a variety of carboxylate ligands in neutral compounds and anionic compounds. In contrast to other anionic [Bi4(µ3‐O)2(TFA)N](N–8)– with metal‐based countercations, the Ag+ ions in 1 and 2 are directly attached to oxygen atoms of the TFA– ligands bonded to the bismuth core. A crystallographic evolution was observed for 1. Solvent‐rich orthorhombic crystals grew initially on standing. However, by three weeks all crystals had converted to a triclinic unit cell that contained no free solvent. The molecular volume decreased from 3146.11 Å3 (orthorhombic) to 2954.06 Å3 (triclinic). The latter had an intermolecular π–π stacking system between silver‐ and bismuth‐bound toluene molecules, which explains the reorganization to a nonsolvated morphology. Compound 2 crystallizes in the triclinic space group P1 as a coordination polymer through bridging carboxylate ligands. The presence of the PPh3 ligands on Ag+ results in a higher Ag/Bi ratio than in 1. The importance of Ag2O in generating the oxido ligands was confirmed by the isolation of {[Bi2(TFA)6(TFAH)(tol)]2}n (3) from the reaction of BiPh3 with TFAH in toluene in the absence of the metal oxide.