摘要
为了探明四氮唑体系质子传导速率与分子间氢键强度的关系,采用密度泛函理论,在B3LYP/6-311++G(2d,2p)水平下对四氮唑二聚体N_4CH_2-N_4CH_3进行了几何结构优化和频率分析,重点分析了能量相对较低的8种二聚体的结构、能量、自然键轨道(NBO)和电荷转移量,并采用QST_2方法在B3LYP/6-31+G(d)水平下研究了8种二聚体间质子传递的动态过程,发现了6种过滤态,计算了其传递能垒.结果表明,四氮唑与质子化的四氮唑阳离子通过N…H—N氢键形成分子间相互作用较强的二聚体N_4CH_2-N_4CH_3,N…H—N氢键表现出明显的红移特征;N…H—N氢键相互作用稳定化能主要是N原子孤对电子轨道与N—H键反键轨道之间的相互作用;N…H—N氢键强度是影响质子传递能垒大小的主要因素,即直接影响着四氮唑体系中质子的传导速率.
The geometric optimization and harmonic vibrational frequency for tetrazole dimers were carried out by DFT at B3LYP/6-311 ＋＋ G（2d,2p） level, in order to explore the relationship between the proton conduc- ting and intermolecular hydrogen bond strength of tetrazole system. The structures, energy, natural bond orbit- als and charge transfer of eight main N4CH2-N4CH3 dimers were investigated. And then, the QST2 method was employed in studying the dynamic process of proton transfer among the eight dimers at B3LYP/6-31 ＋ G （d） level. There were six transition states in the proton transfer processes among eight tetrazole dimers, and their energy barriers were also calculated. The results showed that the N--＇H--N hydrogen bonds of tetrazole dimers were the bridges which connected tetrazole and tetrazlium, and these hydrogen bonds showed strong in- termolecular interactions and obvious red-shift characteristics. The interaction between the lone-electron pair orbital of atom N and the anti-bonding orbital of N--H was the main source of the stabilization energy. The strength of hydrogen bond was one of main factors affecting the proton transfer reaction＇ s energy barrier, which may directly affect the proton transfer rate of tetrazole system.
出处
《郑州大学学报（工学版）》
CAS
北大核心
2016年第3期27-31,共5页
Journal of Zhengzhou University（Engineering Science）
基金
河南省国际合作交流计划项目(104300510009)
