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运用量子化学从头算方法,研究了NH2BH2作为质子受体与HCF3,HCCl3,HF,HCl,HCOF和HCOCl作为质子给体形成的双氢键B—H…H—X(X=F,Cl,C).计算结果表明,在所有复合物中,BH键键长增长,伸缩振动频率红移;在HF与HCl的复合物中,XH键键长增长,伸缩振动频率红移;在其他复合物中,XH键键长缩短,伸缩振动频率蓝移.在每个体系中,还存在传统氢键N—H…Y(Y=F,Cl,O).AIM和NBO分析表明,在这些复合物中双氢键是以静电作用为主,振动频率红移蓝移的变化是因为分子间与分子内电子密度转移引起的,可以用Al-abugin的超共轭和重杂化理论进行解释,同时必须考虑分子内超共轭作用.
H-X (X = F, Cl, C, C), which is a hydrogen bond formed by NH2BH2 as proton acceptor and HCF3, HCCl3, HF, HCl, HCOF and HCOCl as proton donors, ). The calculated results show that in all complexes, the bond length of BH increases and the frequency of stretching vibration shifts red. In the complex of HF and HCl, the bond length of XH increases and the frequency of stretching vibration shifts red. In other complexes , The XH bond length is shortened and the stretching vibration frequency is blue shifted. In each system, there are also conventional hydrogen bonds N-H ... Y (Y = F, Cl, O) .AIM and NBO analysis showed that in these complexes The double hydrogen bond is dominated by electrostatic interaction. The change of the red shift of the vibrational frequency due to the shift of the electron density between the molecules and the molecule can be explained by the hyperconjugation and the heavy hybridization theory of Al-abugin. At the same time, Consider intramolecular hyperconjugation.