화학공학소재연구정보센터
Inorganic Chemistry, Vol.58, No.1, 243-249, 2019
Stabilizing Borinium Cations [X-B-X](+) through Conjugation and Hyperconjugation Effects
Borinium, a two-coordinated boron cation, is a strong Lewis acid that was thought difficult to prepare due to a lower number of coordinating ligands and susceptibility toward nucleophilic reactions. Recently a dimesityl borinium cation (Mes(2)B(+)) with high thermal stability has been synthesized and characterized by Shoji and co-workers. These findings suggest that, despite being extremely electron-demanding, borinium cations might be stabilized with certain substituted function groups. In the present study, we have studied a series of the borinium cations [X-B-X](+) with different substituted groups using the NBO and the BLW methods. Our computations revealed that both Jr-conjugation and hyperconjugation effects can effectively stabilize substituted borinium cations [X-B-X](+). Substituents such as X = C=CH2 stabilize the borinium center through highly delocalized pi-bonding, involving the formally "empty" boron p(x), and p(y) orbitals. We suggest the borinium cations [X-B-X](+) with X = cyc-N(CH)(2) and especially X = C=CH2 as possible synthetic targets of novel borinium cations.