Department of Chemistry, Kansas State University, Manhattan, KS 66506, USA.
Molecules. 2021 Jul 7;26(14):4125. doi: 10.3390/molecules26144125.
In order to explore how specific atom-to-atom replacements change the electrostatic potentials on 1,3,4-chalcogenadiazole derivatives, and to deliberately alter the balance between intermolecular interactions, four target molecules were synthesized and characterized. DFT calculations indicated that the atom-to-atom substitution of Br with I, and S with Se enhanced the σ-hole potentials, thus increasing the structure directing ability of halogen bonds and chalcogen bonds as compared to intermolecular hydrogen bonding. The delicate balance between these intermolecular forces was further underlined by the formation of two polymorphs of 5-(4-iodophenyl)-1,3,4-thiadiazol-2-amine; Form I displayed all three interactions while Form II only showed hydrogen and chalcogen bonding. The results emphasize that the deliberate alterations of the electrostatic potential on polarizable atoms can cause specific and deliberate changes to the main synthons and subsequent assemblies in the structures of this family of compounds.
为了探索特定的原子取代如何改变 1,3,4-杂二唑衍生物上的静电势，并刻意改变分子间相互作用的平衡，合成并表征了四个目标分子。DFT 计算表明，用 I 取代 Br，用 Se 取代 S 增强了 σ-hole 势能，从而增强了卤键和硫键的结构导向能力，与分子间氢键相比。这些分子间力之间的微妙平衡进一步强调了 5-(4-碘苯基)-1,3,4-噻二唑-2-胺的两种多晶型物的形成；形式 I 显示了所有三种相互作用，而形式 II 仅显示氢键和硫键。结果强调，对可极化原子上的静电势的刻意改变可以导致该类化合物结构中主要单体和后续组装体的特定和刻意变化。
