Synthesis and Structural Study of Organoantimony(III) and Organobismuth(III) Triflates and Cations Containing O,C,O-Pincer Type Ligands^†

The reactions of intramolecularly coordinated organoantimony and organobismuth dihalides L1SbCl2 and L2BiCl2, containing two types of O,C,O-pincer ligands 2,6-(ROCH2)C6H3- (L1, R = Me; L2, R = tBu), with silver salts of the weakly nucleophilic polar groups CF3SO3- (OTf) and CB11H12- (in 1:1 and 1:2 molar ratios) gave the following compounds: L1SbCl(OTf) (1), L2BiCl(OTf) (2), L1Sb(OTf)2 (3), L2Bi(OTf)2 (4), L1SbCl(CB11H12) (5), L2BiCl(CB11H12) (6). All compounds were characterized structurally by X-ray diffraction. In the solid state, compounds 1−3 have OTf groups covalently (although weakly) bound to the central metal atom. In compound 4, one of the OTf groups is bound in a unidentate fashion and the other in a weakly chelating fashion. Compounds 5 and 6 exist as separated ion pairs consisting of a [L1SbCl(THF)]+ or [L2BiCl]+ cation and CB11H12- anion. The donor oxygen atoms are coordinated to the metal atoms through strong intramolecular interactions in all compounds. The solution structures of all compounds were studied by the help of variable-temperature 1H NMR measurements.