Shi Haijie, Wang Fengdi, Chen Wei, Tang Shuwei, Zhang Wanqiao, Li Wenliang, Sun Hao, Zhang Jingping, Wang Rongshun
Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Renmin Road 5268, Changchun, Jilin 130024, P.R. China; National & Local United Engineering Lab for Power Battery, Northeast Normal University, Renmin Road 5268, Changchun, Jilin 130024, P.R. China.
Institute of Functional Material Chemistry, Faculty of Chemistry, Northeast Normal University, Renmin Road 5268, Changchun, Jilin 130024, P.R. China.
J Mol Graph Model. 2015 Jun;59:31-9. doi: 10.1016/j.jmgm.2015.03.004. Epub 2015 Apr 3.
The heterocyclic urea of deazapterin (DeAPa) and its protomeric conformers (b, c) with different substituents are selected as the building block for a series of dimers in different configurations. The stabilities of all dimers in various conditions have been investigated by density functional theory. Homodimer of b has more stability than other dimers. Topological analyses certify the coexistence of intermolecular with intramolecular H-bonds. Investigations into frequency demonstrate that all H-bonds show an evident red shift in their stretching vibrational frequencies. Electron donating substituents can provide favorable free energies of the dimer. Solvent effect computations suggest that the dimerization can be favored in weakly polar solvents, such as toluene and chloroform. UV-visible spectra exhibit obvious difference of maximum absorption wavelengths between monomers and dimers, thus may have potential applications for identifying intermolecular H-bonds and calculating association constant of DeAP equilibrium systems in experiments.
选择脱氮蝶呤（DeAPa）的杂环脲及其具有不同取代基的质子异构体（b、c）作为一系列不同构型二聚体的构建单元。通过密度泛函理论研究了所有二聚体在各种条件下的稳定性。b的同二聚体比其他二聚体更稳定。拓扑分析证实了分子间氢键与分子内氢键共存。频率研究表明，所有氢键在其伸缩振动频率上都有明显的红移。给电子取代基可以提供有利的二聚体自由能。溶剂效应计算表明，在弱极性溶剂（如甲苯和氯仿）中有利于二聚化。紫外可见光谱显示单体和二聚体之间最大吸收波长存在明显差异，因此在实验中可能具有识别分子间氢键和计算DeAP平衡体系缔合常数的潜在应用。
