Niu Zhihao, McDowell Sean A C, Li Qingzhong
The Laboratory of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Yantai University, Yantai 264005, China.
Department of Biological and Chemical Sciences, The University of the West Indies, Cave Hill Campus, Bridgetown BB11000, Barbados.
Molecules. 2023 Oct 14;28(20):7087. doi: 10.3390/molecules28207087.
The tetrel bond between PhXFY(TF) (T = C and Si; X = Cl, Br, and I; Y = F and Cl) and the electron donor MCN (M = Li and Na) was investigated at the M06-2X/aug-cc-pVDZ level of theory. As the electronegativity of the halogen atom X increases, the strength of the tetrel bond also increases, but as the electronegativity of the halogen atom Y increases, the strength of the tetrel bond decreases. The magnitude of the interaction energy in most -CF complexes was found to be less than 10 kcal/mol, but to exceed 11 kcal/mol for PhClFCl(CF)⋯NCNa. The tetrel bond is greatly enhanced when the -SiF group interacts with LiCN or NaCN, with the largest interaction energy approaching 100 kcal/mol and displaying a covalent Si⋯N interaction. Along with this enhancement, the Si⋯N distance was found to be less than the X-Si bond length, the -SiF group to be closer to the N atom, and in most -SiF systems, the X-Si-F angle to be less than 90°; the -SiF group therefore undergoes inversion and complete transfer in some systems.
在M06 - 2X/aug - cc - pVDZ理论水平下，研究了PhXFY(TF)（T = C和Si；X = Cl、Br和I；Y = F和Cl）与电子给体MCN（M = Li和Na）之间的四元键。随着卤素原子X电负性的增加，四元键的强度也增加，但随着卤素原子Y电负性的增加，四元键的强度降低。发现大多数-CF配合物中相互作用能的大小小于10 kcal/mol，但对于PhClFCl(CF)⋯NCNa，其相互作用能超过11 kcal/mol。当-SiF基团与LiCN或NaCN相互作用时，四元键大大增强，最大相互作用能接近100 kcal/mol，并表现出共价Si⋯N相互作用。随着这种增强，发现Si⋯N距离小于X - Si键长，-SiF基团更靠近N原子，并且在大多数-SiF体系中，X - Si - F角小于90°；因此，-SiF基团在某些体系中会发生反转和完全转移。
