超分子体系中的分子识别研究23.多胺修饰β-环糊精及其铜配合物与萘衍生物的包结配位作用

Studies on Molecular Recognition in Supramolecular Systems 23. The Inclusion Complexation of Naphthalene Derivatives by Polyamine Modified (3 - Cyclodextrins and Their Complexes with Copper ( II )

用荧光光谱滴定法测定了单-[6-(二乙烯三胺)-6-脱氧]-β-环糊精(1)、单-[6-(三乙烯四胺)-6-脱氧]-β-环糊精(2)及其铜配合物(3,4)与一系列萘衍生物在磷酸缓冲溶液(pH7.2,0.lmol·dm^(-3)中,25℃时形成超分子体系的稳定常数,并与母体β-环糊精的配位能力进行了比较.化学计量法表明,四种化学修饰β-环糊精与萘衍生物形成了1:1的超分子配合物.从尺寸适合、几何互补及多点识别等方面讨论了主体化合物对模型底物的分子选择性键合能力.结果表明,疏水相互作用、范德华力、静电相互作用及氢键等多种非共价键弱相互作用协同贡献于超分子配合物的形成,主-客体间的结构匹配在分子受体选择性键合底物形成超分子配合物中起重要作用.

Spectrofluorometric titrations have been performed to determine the stability constants of inclusion complexation for mono [ 6 - ( diethylenetriamino) - 6 - deoxy ] - (3 - cyclodextrin (1), mono [ 6 -(triethylenetetraamino) - 6 - deoxy] - (3 - cyclodextrin (2) and their copper ( II ) complexes with a series of naphthalene derivatives in phosphate buffer solution (pH 7.2, 0.1 mol·dm-3) at 25℃. The complex abilities of chemically modified cyclodextrins (1 ~ 4) were compared with that of native β - cyclodextrin. The supramolecular system stoichiometry is 1 : 1 for the inclusion complexation of all naphthalene derivatives with four chemically modified β - cyclodextrins (1 ~ 4). The selective binding abilities of host compounds with model substrates are discussed from the viewpoint of size/shape - fitting, geometry compensation and multiple recognition. The results obtained indicate that several noncovalent weak forces, including hydrophobic, van der Waals, electrostatic and hydrogen bonding interactions, cooperatively contribute to the formation of supramolecular complexes. The structural matching between host and guest plays a crucial role in selectively binding substrates to form supramolecular complexes.