Bismuth Bound to Transition Metals: Visible-Light-Induced Olefin Coordination, Reductive Elimination, and Oxidative Addition

Abstract

A series of dibenzobismepinyl (C₁₄H₁₀Bi) substituted transition metal complexes of the type [(C₁₄H₁₀Bi)M(CO)_x(L)] (M=Mn, Co, Fe) was prepared in salt elimination reactions from a halobismepine and sodium metallates. Irradiation of these complexes with visible light has been investigated, aiming at the elimination of one carbonyl ligand and the concomitant coordination of the bismepine's olefin moiety to the transition metal center. The resulting complexes of the type [{κ²C,κ¹Bi-(C₁₄H₁₀)Bi}M(CO)_x-1(L)] (M=Co, Fe) have been isolated and fully characterized. When two dibenzobismepinyl units are positioned in the coordination sphere of an iron carbonyl complex fragment, reductive elimination/oxidative addition events of the dibismuthane (C₁₄H₁₀Bi)₂ have been shown to be relevant. The analytical techniques applied in this work include (heteronuclear) NMR spectroscopy, elemental analysis, single-crystal X-ray diffraction analysis, UV/Vis spectroscopy, IR spectroscopy and (TD)-DFT calculations.

Keywords: Bismuth; Bismuth transition metal complexes; Carbonyl ligands; Dibismuthanes; Olefin ligands.