关键词: SnCNN; 三重键; 势能面; 线性异构体

Abstract:

Triply bonded compounds RE≡CR′ that comprise higher-row elements are known to differ significantly in chemical bonding and reactivity from those of the traditional alkyne species. So they have formed the recent hot topic of the main-group chemistry researches. Unfortunately, these triply bonded species are usually unstable in kinetics towards conversion to doubly bonded SnC(R)R′, making their experimental study rather difficult. To our knowledge, there was only one experiment that indirectly suggested the existence of Sn≡C bonding through the de-nitrogen of ArSnC(N₂)SiMe₃ via spectroscopic technique. Therefore, search of kinetically stabilized Sn≡C compounds still remains a great challenge in main-group chemistry. For this sake, we report a detailed potential energy surface study on the four-atomic molecule [SnCN₂] at the CCSD(T)//B3LYP level. It was shown that the linear isomer SnCNN possesses good thermodynamic and kinetic stability. Structural and bonding analysis indicates that the isomer has a Sn≡C triple bond. Further stabilization of the SnCNN skeleton could be realized via effective coordination by transition-metal carbonyls. Our study is expected to provide theoretical support for future experimental synthesis and characterization of the kinetically stabilized Sn≡C compounds.

Key words: SnCNN; Triple bond; Potential energy surface; Linear isomer