NC2S+离子的结构和稳定性的理论研究

在密度泛函和从头算理论水平下计算了单重态的NC2S+离子的结构、能量、光谱以及稳定性. 在B3LYP/6-311G(d)水平下, 得到8个异构体, 它们由15个过渡态相连接. 在CCSD(T)/6-311+G(2df)//QCISD/6-311G(d)+ZPVE水平下, 得到能量最低的异构体是直线型的具有1Σ电子态的NCCS+(1)(0.0 kJ/mol), 其次是直线型的异构体CNCS+(2)(54.8 kJ/mol). 两个低能量的异构体1和2及另外一个高能量的直线型异构体CCNS+(3)(323.8 kJ/mol)都具有相当大的动力学稳定性, 这三个异构体在具备一定条件的实验室和星际条件下是可以进行观测的. 分析了这3个异构体的成键性质.

Theoretical Study on Structures and Stability of Ion NC2S+

The structures, energetics, spectroscopies, and stabilities of the singlet NC2S+ system were explored with density functional theory and ab initio method. At the B3LYP/6-311G(d) level, eight isomers were located, which are connected with 15 interconversion transition states. At the CCSD(T)/6-311+G(2df)//QCISD/6-311G(d)+ZPVE level, the lowest-lying isomer is linear NCCS+ 1(0.0 kJ/mol)with 1Σ state followed by linear CNCS+ 2(54.8 kJ/mol). Two low-lying isomers 1, 2 and another high-lying species CCNS+ 3(323.8 kJ/mol) with a linear structure possess considerable kinetic stability. All the three isomers should be experimentally or astrophysically observable. The bonding natures of isomers 1, 2 and 3 were also analyzed.