水分子夹2,6-二(2-苯并咪唑基)吡啶水合物的晶体结构、氢键和DFT研究

基于实验得到的单晶结构建立了理论计算的结构模型,旨在用计算结果揭示实验所获得结构的微观驱动力,即弱相互作用的重要模式.通过对实验结构的异构化处理,建立异构体模型并进行比对,可以给出实验结构在能量上的优势.采用密度泛函方法对BIPy的2种同晶异形体I(实验获得的单晶结构)和II(根据I的结构设计的异构体)与水分子之间的氢键相互作用进行了计算.结果表明,BIPy-I在能量上具有明显优势,进一步证明了水分子在水分子夹中更适合作为氢键的受体.虽然BIPy-II构型也处于势能面上的稳定点,但是实验无法得到其单晶结构.因此,从BIPy-I构型中所观察到的N-H…O氢键模式是优势作用模式.

Water clip of hydrate of 2,6 bis(benzimidazolyl)pyridine: Crystal structure,hydrogen bonding and DFT studies

Building theoretical structure model based on the single crystal structure obtained by experiments, is conducive to use calculated results to reveal the micro driving forces of single crystal structure, namely, the important weak interaction pattern. Its isomeric structure model has been expediently built by isomerization, and their calculated results expressed in energy can be used to show which is the more advantaged isomer. Density functional theory (DFT) calculations have been performed to explore the hydrogen bonds of two BIPy isomers and their hydrates respectively. The results show that BIPy I has more advantages in terms of energy, although BIPy II is at another stationary point on the potential energy surface. Thus, the water molecule acting as hydrogen bonding acceptor observed in BIPy I, has large tendency to deveop in factual cystal structure, and N—H…O can be deemed as role model.