Lewis Acid Properties of Tris(pentafluorophenyl)borane. Structure and Bonding in L−B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub> Complexes
作者:Heiko Jacobsen、Heinz Berke、Steve Döring、Gerald Kehr、Gerhard Erker、Roland Fröhlich、Oliver Meyer
DOI:10.1021/om981033e
日期:1999.4.1
complexes (C6F5)3B·L, L = CNCH3, NCCH3, PH3, CO. A detailed analysis revealed that the bonding in (C6F5)3B·L complexes is mainly dominated by electrostatic interaction, which in turn is responsible for the observed structural and spectroscopic changes. In the context of this work, the bonding of the neutral B(C6F5)3 Lewis acid is compared to the positively charged organometallic d0-Cp3M+ system (M = Zr, Hf)
通过使路易斯碱与过量的B(C 6 F 5)3在戊烷中反应,实验生成了各种三(五氟苯基)硼烷供体加合物。以此方式,腈络合物(C 6 F 5)3 B·NCR(R = CH 3 1a,p -CH 3 -C 6 H 4 1b,p -NO 2 -C 6 H 4 1c),异腈络合物(C 6 F 5)3 B·CNR(R = C(CH 3)3 在图3a中,C(CH 3)2 CH 2 C(CH 3)3 3b,2,6-(CH 3)2 -C 6 H 3 3c)和膦加合物(C 6 F 5)3 B·P(可以制备C 6 H 5)3(6)。通过IR和NMR光谱以及X射线结构分析(1a,1c,3a,3b和6)。腈以及异腈与中性路易斯酸的配位导致C⋮N键强度的显着提高。从νC C N IR谱带向较高波数的明显偏移可以明显看出这一点,并且通过X射线衍射观察到的C⋮N键长的小幅但实验上显着的减小也支持了这种解释。对模型配合物(C