Synthesis and Structures of Amino(triphenylgermyl) Boranes and Trihydro(triphenylgermyl) Borates

✍ Scribed by Tassilo Habereder; Heinrich Nöth

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: German
• Weight: 251 KB
• Volume: 627
• Category: Article
• ISSN: 0372-7874
• DOI: 10.1002/1521-3749(200105)627:5<1003::aid-zaac1003>3.0.co;2-e

✦ Synopsis

The B-(triphenylgermyl)borazines 4 a and 4 b, the 1,2-bis(dimethylamino)-1,2-bis(triphenylgermyl)-diborane(4), 5, and the (2,2,6,6-tetramethylpiperidino)(triphenylgermyl)boranes 6 and 7 were prepared by allowing LiGePh 3 to react with the corresponding B-bromoborazines and aminochloroboranes, respectively. BH 3 dissolved in thf readily adds to LiGePh 3 generating Li(H 3 BGePh 3 ), 8 a, in thf solution. Addition of N-bases to the solution of 8 a produced (tmen thf)Li(H 3 BGePh 3 ), 8 b, and dimeric (py) 2 Li(H 3 BGePh 3 ), 8 c. The borazine ring in 4 b is distorted into a boat shape. In 5 the NBGe planes are twisted against each other by 85°.

Comparison with analogous (triphenylstannyl)boranes points to a more pronounced steric effect of the Ph 3 Ge group over the Ph 3 Sn group due to the shorter B±Ge bond. A fairly short B±Ge bond is found for the (triphenylgermyl)trihydroborates. The molecular structure of (Et 2 O) 3 LiGePh 3 shows compressed C±Ge±C bond angles. Its molecular parameters fit well into the series L n LiEPh 3 (E = Si, Sn, Pb).