Synthesis and Structure of the Dicationic Bisborate Adduct [(tBu3PN)2Ti{μ-MeB(C6F5)3}2]

✍ Scribed by Frédéric Guérin; Douglas W. Stephan

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 93 KB
• Volume: 112
• Category: Article
• ISSN: 0044-8249
• DOI: 10.1002/(sici)1521-3757(20000403)112:7<1354::aid-ange1354>3.0.co;2-6

✦ Synopsis

7 13 C, 19 F, 11 B, and 31 P NMR spectroscopic data confirmed the presence of the B and Ti moieties. The observation of a distinct 31 P chemical shift indicated that this new product 3 was not the 1:1 zwitterionic species 2. Moreover, the presence of a single, temperature-invariant, Ti ± methyl environment suggested the formation of a bis-B(C 6 F 5 ) 3 adduct.

Crystals of 3 ´2 CH 2 Cl 2 were isolated from CH 2 Cl 2 . A crystallographic study confirmed that [(tBu 3 PN) 2 Ti{m-MeB(C 6 F 5 ) 3 } 2 ] (3), an unprecedented di-zwitterionic species, sits on a position with crystallographically imposed twofold symmetry (Figure ). The pseudo-tetrahedral coordination sphere about Ti comprises the nitrogen atoms of the 7.75 (s, 1 H, H 5' ), 7.76 (s, 1 H, H 6' ), 7.80 (s, 2 H, H 5,6 ), 7.99 (s, 1 H, H 4' ), 8.07 (s, 1 H, H 7' ), 8.12 (d, J 8.3 Hz, 2 H, H 3,8 ), 8.31 (d, J 8.3 Hz, 2 H, H 4,7 ), 8.43 (d, J 8.8 Hz, 4 H, H o ); FAB-MS: m/z calcd for C 65 H 55 N 4 O 8 : 1019.