Bolz Ina, Moon Chulsoon, Enkelmann Volker, Brunklaus Gunther, Spange Stefan
Institut für Chemie, Technische Universität Chemnitz, D-09107 Chemnitz, Germany.
J Org Chem. 2008 Jul 4;73(13):4783-93. doi: 10.1021/jo800598z. Epub 2008 Jun 10.
Complex formation of the enolizable chromophor 1-n-butyl-5-(4-nitrophenyl)barbituric acid 1 with multiple binding sites for supramolecular assemblies and its corresponding adducts produced with the Proton Sponge (1,8-bis(dimethylamino)naphthalene), PS) and the adenine-mimetic 2,6-diacetamidopyridine (DAC) have been studied by means of solid-state proton NMR spectroscopy under fast magic-angle spinning, X-ray analysis, and UV/vis spectroscopy. Both NMR data and X-ray results reveal that the enolic chromophor undergoes self-aggregation to hydrogen-bonded dimers which are involved in stacked arrangements. Depending on the nature of the added base, this dimeric assembly is preserved in the formed enolate anion but can be broken in the presence of complementary hydrogen-bonding pattern leading to supramolecular complexes. Molecular recognition of these structural different bases significantly influences the chromophoric pi-system of 1.
可烯醇化发色团1-正丁基-5-(4-硝基苯基)巴比妥酸1具有用于超分子组装的多个结合位点，以及其与质子海绵（1,8-双（二甲氨基）萘，PS）和腺嘌呤模拟物2,6-二乙酰氨基吡啶（DAC）形成的相应加合物，已通过快速魔角旋转下的固态质子核磁共振光谱、X射线分析和紫外/可见光谱进行了研究。核磁共振数据和X射线结果均表明，烯醇式发色团会自聚集形成氢键二聚体，这些二聚体参与堆叠排列。根据所添加碱的性质，这种二聚体组装在形成的烯醇负离子中得以保留，但在存在互补氢键模式的情况下会被破坏，从而导致超分子复合物的形成。这些结构不同的碱的分子识别显著影响了1的发色团π体系。
