From Chlorogermylenes to Stable Hydroxy- and Siloxy-Germylene−Tungsten Complexes

Abstract

Reaction of the chlorogermylene ArGeCl [Ar = 2,6-bis((diethylamino)methyl)phenyl] with lithium amides afforded the aminogermylenes ArGeNR2 1 (1a, R = SiMe3; 1b, R = iPr); 1a was structurally analyzed by X-ray diffraction. A protic reagent such as 2,4,6-trimethylphenol (Ar‘OH) reacts with 1b, leading to the mesityloxygermylene ArGeOAr‘ 2. Subsequent hydrolysis of tungsten complexes 1·W(CO)5 gave ArGeOH·W(CO)5, 3. From 1a, ArGeOSiMe3·W(CO)5 (4) also was obtained. Compounds 3 and 4 are the first stable hydroxy- and siloxygermylene complexes. X-ray analysis of 3 shows an increased coordination of the side-chain nitrogen atoms to the germanium resulting from the complexation Ge→W. This complexation can also explain the significant acidity of the hydroxy group in 3, in the same range as triphenylgermanol Ph3GeOH.