Gaile Anastasija, Belyakov Sergey, Rjabovs Vita Lijs, Mihailovs Igors, Turovska Baiba, Batenko Nelli
Riga Technical University, Faculty of Materials Science and Applied Chemistry, 3/7 Paula Valdena St., Riga LV-1048, Latvia.
Latvian Institute of Organic Chemistry, 21 Aizkraukles St., Riga LV-1006, Latvia.
ACS Omega. 2023 Oct 19;8(43):40960-40971. doi: 10.1021/acsomega.3c07005. eCollection 2023 Oct 31.
Quinones are small redox-active molecules that are able to form intra- and intermolecular interactions both in the solid state and in solution. On the basis of 6-amino-substituted pyrido- and pyrimido-[1,2-]benzimidazole-8,9-diones, weak interactions were investigated by single-crystal X-ray and H NMR spectroscopy methods. Crystallization of quinone derivatives containing a -NH-CH- fragment led to the formation of both chiral and achiral crystals. The presence of two forms with ( form) and without ( form) an intramolecular hydrogen bond was experimentally detected by X-ray crystallography analysis and variable-temperature (VT) H NMR experiments in the cases of pentylamino- and benzylamino-substituted derivatives. Interestingly, the form dominates both in the solid state and in solution.
醌类是具有氧化还原活性的小分子，在固态和溶液中都能形成分子内和分子间相互作用。基于6-氨基取代的吡啶并和嘧啶并-[1,2-]苯并咪唑-8,9-二酮，通过单晶X射线和1H NMR光谱方法研究了弱相互作用。含有-NH-CH-片段的醌类衍生物结晶导致形成手性和非手性晶体。通过X射线晶体学分析和变温（VT）1H NMR实验，在戊基氨基和苄基氨基取代衍生物的情况下，实验检测到存在两种形式，一种具有（α形式）分子内氢键，另一种没有（β形式）分子内氢键。有趣的是，α形式在固态和溶液中都占主导地位。
