Synthesis, Structure and Bonding in Triorganogermyl-alanes and Triphenylgermyl-aluminates

• Published in: Zeitschrift für Naturforschung. B, A journal of chemical sciences Vol. 64; no. 11; pp. 1387 - 1396
• Main Authors: Habereder, Tassilo, Nöth, Heinrich, Suter, Max
• Format: Journal Article
• Language: English
• Published: BERLIN Verlag der Zeitschrift für Naturforschung 01.12.2009; Walter De Gruyter
• Subjects: Chemistry; Chemistry, Inorganic & Nuclear; Chemistry, Organic; Physical Sciences; Science & Technology; Triorganogermyl-alanes; Triphenylgermyl-aluminates; X-Ray Strucrures; Triphenylgermyl-aluminates; LIALH4; Triorganogermyl-alanes; X-Ray Strucrures; STANNYLMETALLATION; CRYSTAL-STRUCTURES; LITHIUM; DIBORATION; GE
• ISSN: 0932-0776; 1865-7117
• DOI: 10.1515/znb-2009-11-1220

Triphenylgermyl-lithium in diethyl ether/THF did not react with Al Me to form [(Ph Ge)AlMe ]- Li(THF) . Addition of TMEDA to this solution yielded crystalline Ph GeLi(THF)TMEDA. The reaction of Ph GeLi in diethyl ether/hexane solution with H Al-NMe in diethyl ether/THF generated [Ph GeAlH ]Li(THF) while the reaction with Me AlCl led to Ph GeAlMe (OEt ) and the trigermyl-aluminate [(Ph Ge) AlMe]Li. The analogous aluminate [(Ph Ge) AlH]Li(THF) was obtained by reacting LiGePh with AlH Cl(OEt ) in the presence of THF. It was expected that the bulky bis(tetramethylpiperidino)chloroalane would react with Ph GeLi to give the germyl-alane tmp AlGePh which was observed when only diethyl ether was used as a solvent, but in an Et O/toluene mixture only Ph Ge could be isolated. Increasing the steric requirement of the germyllithium compound by using the bulky (tBu Si)Me Ge group instead of the Ph Ge group led to a straightforward reaction generating the first structurally characterized germyl-alane (tBu Si)Me Ge- Al(tmp) with a planar tri-coordinated Al center. The X-ray structure determinations showed that the germyl-aluminates have shorter Ge-Al bonds than the germyl-alane inspite of the lower coordination number