Carbene tetrel-bonded complexes

• DOI: 10.1007/s11224-016-0890-y
• Publication Date: 2016-12-02T01:14:12Z
• Authors: Mingxiu Liu; Qingzhong Li; Wenzuo Li; Jianbo Cheng
• Keywords: 01 natural sciences; 0104 chemical sciences

An ab initio calculation has been carried for the carbene tetrel bonded complexes CH3Y∙∙∙CH2 (Y = F, CN, NC, and NO2), CH3F∙∙∙CZ2 (Z = Cl and CH3), XH3F∙∙∙CF2 (X = C, Si, Ge, and Sn), SiF4∙∙∙CF2, and XH3F∙∙∙NHC (N-heterocyclic carbene), where carbene is treated as a Lewis base and XH3Y is a Lewis acid. Formation of the tetrel bond is mainly attributed to charge transfer from the lone pair on the C atom in the carbene toward the σ* X–Y orbital and also the σ* X–H one in the strong tetrel bond. The carbene tetrel bond is strengthened/weakened by the electron-withdrawing group in the tetrel donor/acceptor and enhanced by the methyl group in C(CH3)2. NHC forms a stronger carbene tetrel bond in XH3F∙∙∙NHC (X = Si, Ge, and Sn) where it exceeds that of the majority of H-bonds. Interestingly, the tetrel bond becomes stronger in the order of X = C < Ge < Sn < Si in XH3F∙∙∙NHC and the largest interaction energy occurs in SiH3F∙∙∙NHC, amounting to −103 kJ/mol. The carbene tetrel bond can be strengthened by cooperative effect with the N∙∙∙M interaction in trimers H2C∙∙∙CH3CN∙∙∙M (M = CH3CN, HCN, ICN, SbH2F, LiCN, and BeH2) and has doubled in H2C∙∙∙CH3CN∙∙∙BeH2.