Investigation On Tetra-Cationic Heavier Di-Pnictanes

Abstract

A thorough characterization of tetra-cationic dipnictane dimers (Sb = [1]2[OTf]4, Bi = [2]2[OTf]4) have been done, the role of solvent in their homolytic cleavage and differing stability in solution by UV-Visible Spectroscopy and the formation of elusive stibine hydride and bismuth hydride species in solution elucidated by NMR spectroscopy. The reactivity of the dimeric compound [2]2[OTf]4, with diphenyl disulfide (Ph2S2), diphenyl diselenide (Ph2Se2), p-Benzoquinone (C6H4O2) and oxygen (O2) were carried out giving rise to compounds [LBi-SPh][OTf]2 = [3][OTf]2, [LBi-SePh][OTf]2 = [4][OTf]2, [LBi-OC6H4O-BiL][OTf]4 = [5][OTf]4, and [LBi-O-BiL][OTf]4 = [6][OTf]4 respectively. The reaction of [2]2[OTf]4 with dicobalt octacarbonyl (Co2(CO)8), dimanganese decacarbonyl (Mn2(CO)10) and bis-cyclopentadienyldiiron tetracarbonyl ((FeCp(CO)2)2) gave rise to complexes [LBi-Co(CO)3-BiL][OTf]3 = [7][OTf]3, [LBi- Mn(CO)5][OTf]2 = [8][OTf]2, and [LBi-FeCp(CO)2][OTf]2 = [9][OTf]2 respectively featuring a transition metal-pnictogen bond. As the [2]2[OTf]4 bismuth dimer have a longer shelf-live in solution, allowed us the perform small molecule activations. The compound [2]2[OTf]4 activates C-C bond in acetonitrile to give [LBi-CH3][OTf]2 = [10][OTf]2, and O-H bond water to give [LBi-(μ-OH)2-BiL][OTf]4 = [11][OTf]4. All these complexes were characterized by NMR Spectroscopy, UV-Visible Spectroscopy and Single-Crystal X-Ray Diffraction analyses.