Formation and Reactions of Ge=O Double-bonded Species Bearing EMind Groups

The reaction of the bulky EMind-based diarylgermylene, (EMind)2Ge: (1a) (EMind = 1,1,7,7-tetraethyl-3,3,5,5-tetramethyl-s-hydrindacen-4-yl), with pyridine N-oxide (Py+–O−) initially formed the Py-coordinated diarylgermanone, (EMind)2Ge(=O)(Py) (3a), which gradually converted to the 1,3,2,4-dioxadigermetane, (EMind)4Ge2(μ-O)2 (4a), through the dimerization of the germanone, (EMind)2Ge=O (2a). The Ge=O double-bond in 3a reacted not only with H2O to give the germanediol, (EMind)2Ge(OH)2 (5a), but also with Py+–O− to form the germanol, (EMind)2Ge(C5H4NO)(OH) (6a), via activation of the ortho C–H bond.