A Digermylene (LGeI -GeIL) on a N-Heterocyclic Carbene-Fluorenyl Hybrid Ligand (L) and its Oxidation by TEMPO and Ph2E2 (E = S, Se)

Abstract

A hybrid N-heterocyclic carbene (NHC)-fluorenyl ligand (L) supported GeIICl complex ([LGeCl]; 1) is made from GeCl2(dioxane) and [LK]n. 1 is reduced by Jones’ MgI2 dimer [(MesNacnacMg)2] (MesNacnac = [{(Mes)NCMe}2CH]─; Mes = 2,4,6-Me3-C6H2) to give the digermylene [LGeI-GeIL] (2) with a gauche-bent conformation. 2 is oxidized by TEMPO (2,2,6,6-tetramethylpiperidinyloxy) and Ph2E2 (E = S, Se) to give [LGe(TEMPO)] (3) and [LGeEPh] (E = S (4), Se (5)], respectively. An overoxidation of 2 by Ph2Se2 to a mixed valent trinuclear species [{(PhSe)2GeII2(μ-L)2GeIV(SePh)2] (6) is also noted. Besides, the precursor 1 is converted to [LGeMe] (7) and [LGeOSiPh3] (8) by treating with MeMgBr and KOSiPh3, respectively. However, none of them lead to a desired [LGeH] species. Also interestingly, Cl-abstraction from 1 by AgSbF6 fails and they rather form a 2:1 adduct [(LGeCl]2Ag]SbF6 (9).