The synthesis and surface-based self-assembly of thymine-functionalised porphyrins is described. Reaction of 1-formylphenyl-3-benzoyl-thymine with suitable pyrollic species leads to the formation of tetra-(phenylthymine)porphyrin (tetra-TP) or mono-thymine-tri-(3,5-di-tert-butylphenyl)porphyrin (mono-TP). Single crystal X-ray diffraction studies demonstrate the self-association of mono-TP in the solid state through thymine···thymine hydrogen-bonding interactions but in solution this interaction (K d = 6.1 ± 3.0 M–1) is relatively weak in comparison to the heteromolecular interaction between mono-TP and 9-propyladenine (K = 91.8 ± 20.5 M–1). STM studies of the tetratopic hydrogen-bonding tecton, tetra-TP, deposited on an HOPG substrate reveal the formation of an almost perfectly square self-assembled lattice through thymine···thymine hydrogen-bonding. Co-deposition of tetra-TP with 9-propyladenine leads to the adoption of preferable thymine···adenine interactions leading to the formation of a heteromolecular tetra-TP···9-propyladenine hydrogen bonded array including both Watson–Crick thymine···adenine interactions and adenine···adenine hydrogen-bonding. The studies demonstrate a pathway for the self-assembly of tetratopic hydrogen-bonding tectons and the use of preferential heteromolecular thymine···adenine interactions for the disruption of the homomolecular tetra-TP array. Studies of the self-assembly of tetra-TP and 9-propyladenine demonstrate a strong dependence on overall concentration and molar ratio of components indicating the importance of kinetic effects in surface self-assembly processes.
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机译:描述了胸腺嘧啶官能化卟啉的合成和基于表面的自组装。 1-甲酰基苯基-3-苯甲酰基胸腺嘧啶与合适的酚类物质反应导致形成四(苯基胸腺嘧啶)卟啉(tetra-TP)或单胸腺嘧啶三(3,5-二叔丁基苯基苯基)卟啉(单TP)。单晶X射线衍射研究表明,单-TP通过胸腺嘧啶···胸腺嘧啶氢键相互作用而自缔合,但在溶液中这种相互作用(K d = 6.1±3.0 M –1 与单-TP和9-丙基腺嘌呤之间的杂分子相互作用相比,其相对较弱(K = 91.8±20.5 M –1 sup>)。 STM研究沉积在HOPG衬底上的四氢键合四氢键四氢键结构,发现通过胸腺嘧啶···胸腺嘧啶氢键键合形成了几乎完美的正方形自组装晶格。四-TP与9-丙基腺嘌呤的共沉积导致采用优选的胸腺嘧啶···腺嘌呤相互作用,从而导致包括Watson-Crick胸腺嘧啶··的异分子四-TP···9-丙基腺嘌呤氢键阵列的形成·腺嘌呤相互作用和腺嘌呤···腺嘌呤氢键。研究证明了四位氢键结合结构的自组装途径,以及利用优先的异分子胸腺嘧啶···腺嘌呤相互作用来破坏同分子四-TP阵列。对四-TP和9-丙基腺嘌呤自组装的研究表明,强烈依赖于总浓度和组分的摩尔比,这表明在表面自组装过程中动力学效应的重要性。
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