A Computational Characterization of Boron−Oxygen Multiple Bonding in HNCH−CHCH−NH−BO

详细信息    查看全文

• 作者：Joseph D. Larkin ; Krishna L. Bhat ; George D. Markham ; Tony D. James ; Bernard R. Brooks ; Charles W. Bock
• 刊名：Journal of Physical Chemistry A
• 出版年：2008
• 出版时间：September 11, 2008
• 年：2008
• 卷：112
• 期：36
• 页码：8446-8454
• 全文大小：227K
• 年卷期：v.112,no.36(September 11, 2008)
• ISSN：1520-5215

文摘

Structures, relative energies, and bonding characteristics for various conformers of 3-imino-N-(oxoboryl)prop-1-en-1-amine, HNCH−CHCH−NH−BO, and the corresponding borocycle (−HNCH−CHCH−NH−B−)O are discussed using results from second-order Møller−Plesset (MP2) perturbation theory with the Dunning−Woon correlation-consistent cc-pVDZ, aug-cc-pVDZ, and cc-pVTZ basis sets. These MP2 results are compared to those from computationally efficient density functional theory (DFT) calculations using the LDA, PBE, TPSS, BLYP, B3LYP, BVP86, OLYP, O3LYP, and PBE1PBE functionals in conjunction with the economical Pople-type 6-311++G(d,p) basis set to evaluate the suitability of these DFT/6-311++G(d,p) levels for use with larger boron-containing systems. The effects of an aqueous environment were incorporated into the calculations using COSMO methodology. The calculated boron−oxygen bond lengths, orbital compositions, and bond orders in all the (acyclic) HNCH−CHCH−NH−BO conformers were consistent with the presence of a boron−oxygen triple bond, similar to that found in H−BO and H₂N−BO. The (−HNCH−CHCH−NH−B−)O borocycle is predicted to be planar (C_2v symmetry), and it is ∼30 kcal/mol lower in energy than any of the (acyclic) HNCH−CHCH−NH−BO conformers; the boron−oxygen bond in this borocycle has significant double bond character, a bonding scheme for which there has been only one experimental structure reported in the literature ().