Slater Anna G, Hu Ya, Yang Lixu, Argent Stephen P, Lewis William, Blunt Matthew O, Champness Neil R
School of Chemistry , University of Nottingham , University Park , Nottingham , NG7 2RD UK . Email:
The Department of Chemistry , University College London (UCL) , London , WC1H 0AJ , UK . Email:
Chem Sci. 2015 Feb 1;6(2):1562-1569. doi: 10.1039/c4sc03531c. Epub 2014 Dec 11.
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--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 ( = 6.1 ± 3.0 M) is relatively weak in comparison to the heteromolecular interaction between mono-TP and 9-propyladenine ( = 91.8 ± 20.5 M). 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.
本文描述了胸腺嘧啶功能化卟啉的合成及其基于表面的自组装。1-甲酰基苯基-3-苯甲酰基胸腺嘧啶与合适的吡咯类物质反应，生成四（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）卟啉（mono-TP）。单晶X射线衍射研究表明，mono-TP在固态中通过胸腺嘧啶···胸腺嘧啶氢键相互作用发生自缔合，但在溶液中，与mono-TP和9-丙基腺嘌呤之间的异分子相互作用（K = 91.8 ± 20.5 M）相比，这种相互作用（K = 6.1 ± 3.0 M）相对较弱。对沉积在HOPG衬底上的四配位氢键构筑单元tetra-TP进行STM研究，揭示了通过胸腺嘧啶···胸腺嘧啶氢键形成几乎完美的方形自组装晶格。tetra-TP与9-丙基腺嘌呤共沉积导致优先形成胸腺嘧啶···腺嘌呤相互作用，从而形成包括沃森-克里克胸腺嘧啶···腺嘌呤相互作用和腺嘌呤···腺嘌呤氢键的异分子四（tetra-TP）···9-丙基腺嘌呤氢键阵列。这些研究证明了四配位氢键构筑单元自组装的途径，以及利用优先的异分子胸腺嘧啶···腺嘌呤相互作用破坏同分子tetra-TP阵列。对tetra-TP和9-丙基腺嘌呤自组装的研究表明，其强烈依赖于组分的总浓度和摩尔比，这表明动力学效应在表面自组装过程中的重要性。
