Tetraphenylgermane and Hexaphenyldigermane

Preparation of Oligogermanes via the Hydrogermolysis Reaction

“…These yields are generally higher than those usually obtained via other synthetic methods. For example, Bu t 3 GeGeBu t 3 was isolated in 16% yield via the reduction of Bu t 3 GeCl with lithium naphthalenide, Ph 3 GeGePh 3 was obtained in 69% yield from the reaction of PhMgBr with GeCl 4 , , and the coupling reaction of Bu n 3 GeK and Me 3 GeCl furnished Bu n 3 GeGeMe 3 in approximately 60% yield . Digermanes can be obtained from the corresponding trialkylgermanium hydrides when SmI 2 is used as the reductant in 39−96% yield, including Et 3 GeGePh 3 which was isolated in 96% yield and Me 3 GeGeBu n 3 which was isolated in 59% yield. , This procedure thus can offer some synthetic advantages over our method when certain organic substituents are present.…”

“…The synthesis and properties of oligomeric and polymeric silicon- − and tin-containing − systems have been extensively investigated while those of the related germanium systems remain less developed. However, a variety of oligomeric organogermanes have been prepared, ,,,− and many of these species exhibit properties that are dependent on the number of catenated germanium atoms and/or the identity of the organic side groups. ,,,,, For example, it has been shown that a series of linear permethylated oligogermanes exhibits a decreasing ionization potential as the length of the Ge−Ge chain is increased . In a related series of perethylated oligogermanes, the position of the absorbance maximum (λ max ) undergoes a red shift with increasing chain length, and the λ max in a group of organopolygermanes also undergoes a bathochromic shift as the steric bulk of the organic side groups is increased …”

Singly Bonded Catenated Germanes: Eighty Years of Progress

“…Grignard reactions directed at the preparation of Ph 4 Ge from GeCl 4 can have a number of different outcomes depending on the reaction conditions and stoichiometry employed. ,– Compound 1 was not obtained when GeBr 4 was treated with a large excess of PhMgBr in Et 2 O but was isolated in 69% yield from the reaction of GeCl 4 with 7.8 equiv of PhMgBr in THF that contained a 20 mol % excess of magnesium metal . The isolation of 1 in 59% yield using a 14:4 molar ratio of PhMgBr:GeCl 4 also has been reported …”

“…45,[85][86][87][88] Compound 1 was not obtained when GeBr 4 was treated with a large excess of PhMgBr in Et 2 O 81 but was isolated in 69% yield from the reaction of GeCl 4 with 7.8 equiv of PhMgBr in THF that contained a 20 mol % excess of magnesium metal. 89 The isolation of 1 in 59% yield using a 14:4 molar ratio of PhMgBr:GeCl 4 also has been reported. 90 Under similar conditions again using THF as the solvent, it was found that the trigermane Ph 3 GeGePh 2 GePh 3 (2) and the tetragermane Ph 3 GeGePh 2 GePh 2 GePh 3 (3) also are formed as minor products.…”