【作者】 张国梅；

【导师】 刘滇生； 双少敏；

【作者基本信息】 山西大学 ， 无机化学， 2006， 博士

【摘要】 超分子化学是一门处于化学、生命科学、材料科学和信息科学交叉点的新兴学科,它的发展和大环化学密切相关,成为近年来一个研究非常活跃的领域。其中分别具有特殊结构和功能的环糊精和杯芳烃作为超分子化学第二代、第三代主体物质一直是人们研究的热点。而分子识别与组装是超分子化学的核心研究内容,尤其是识别生物分子和离子客体具有非常重要的意义。 本论文具体研究内容简述如下: 1.本文研究了在生理条件下(pH=7.50)中性红与DNA作用方式,并进一步探讨了环糊精与中性红形成的超分子体系与DNA分子的作用,结果表明:NR与DNA相互作用的方式有两种,主要取决于二者之间(NR∶DNA)的摩尔比,即R值。当R>2.5时,NR聚集在DNA分子表面;R<2.5时,NR嵌插到DNA的双螺旋结构中。而当NR-CDs与DNA发生作用时,超分子体系解离,从CDs空腔中释放出来的NR中性型体被DNA质子化形成酸性型体,酸性型体易嵌插到DNA双螺旋中形成DNA加合物。因此NR-CDs超分子组装与DNA的作用形式为嵌插作用。实际上,NR-CDs超分子体系中,环糊精起着一个运载客体分子嵌插到DNA双螺旋结构中。 2.采用荧光光谱法、紫外可见光度法、共振光散射技术研究了藏红T(ST)与DNA及藏红T-环糊精超分子体系与DNA的作用,计算了二者的结合常数和结合位点数。结果表明:通过超分子体系与DNA的作用,证实了低浓度时,DNA与ST的作用方式为DNA诱导ST在其表面进行长距组装,在DNA高浓度下,ST单体分子嵌插在DNA双螺旋中,使其荧光量子产率增加。 3.中性红与杯[4]芳烃磺酸钠形成稳定超分子包合物通过吸收和荧光光谱法得到证实。详细探讨了影响包合过程的因素,包括浓度、pH值、温度的影响,结果表明:二者形成化学计量1∶1包合物,杯[4]芳烃磺酸钠更易于包合中性红的酸性型体。热力学参数表明杯[4]芳烃磺酸钠与中性红形成包合物的主要是焓驱动的,水溶性杯芳烃磺酸钠呈现出小的疏水更多还原

【Abstract】 Supramolecular chemistry is a novel intersection discipline of chemistry, life science, material science and informatics. Its development is close related to the macrocyclo-chemistry and has been stirring field in recent years. As host molecules of the second and third generation of supramolecular chemistry, cyclodextrins and calixarene with unique structure and function respectively are the current interest hottopic. Recognition and assembly of molecular are the important content of the supramolecular chemistry, especially recognition and sensing of biological molecule and ion. The major contents in this dissertation are described as follows:1. DNA assembling to neutral red (NR) and cyclodextrins (CDs)-NR inclusion complex has been investigated by means of absorption, fluorescence and resonance light scattering (RLS) technique. Depending on the molar ratio R of NR: DNA, the binding of NR with DNA involved in two processes at pH 7.50 and ionic strength 0.0045. The first process occured in R>2.5, where the neutral form of NR with one positive charge was predominant, and DNA was a polyanion. Moreover, enhanced RLS was observed, indicating the aggregation of NR in neutral form on the molecular surface of DNA. The second process occured in R<2.5, where the binding of NR to DNA leaded to extensive NR protonation even at pH 7.50, meanwhile DNA also protonates, and that a protonated NR with two positive charges (the acidic form of NR) could form DNA adducts with a binding mode different from that of the unprotonated form (the neutral form of NR). The results were also illustrated by the CDs-NR supramolecular system. The experimental data showed that NR-CDs decomposed when it bound to DNA. Thus, the decomposed NR was also protonated to form DNA adducts with intercalative mode. In fact, CDs played a role to carry guest molecule to intercalate DNA. A related mechanism is proposed.2. The interactive models of ST with double stranded DNA have been studied by means of the inclusion action of CDs supramolecular system. Through thechanges of absorption, fluorescence and resonance light scattering (RLS) spectra, the intrinsic binding constant (K) and the binding number (n) of ST with DNA and inclusion complexes with DNA was obtained in the case of 20 m mol/L Tris-HCl buffer solution (pH 7.2). According to the experimental results, it could be inferred that the interactive model of ST with DNA was: in low ratio of ST to DNA, the ST must intercalate into DNA and improve the fluorescence quantum yield of ST while in high ratio of ST to DNA, ST interacts with DNA by long range assembly. The small molecules are very important probes for studying the structure and function of nucleic acid, and the results can offer necessary information for understanding the cause of some diseases and curative mechanism of some drugs, especially anticancer ones.3 The formation of the inclusion complex of neutral red (NR) with 4-sulfocalixarene was studied by fluorescence and absorption spectroscopy and the binding constant (K) of the inclusion complexes were obtained. Experimental conditions including concentrations of 4-sulfocalixarene, media acidity and temperature were investigated for the inclusion formation in detail. The results suggested that 4-sulfocalixarene was more suitable for inclusion of the acid form of NR. The complexation thermodynamic parameters indicate that the complexation of NR with 4-solfuocalixarene is mainly driven by the favorable change in enthalpy. The soluble 4-sulfocalixarene has slight hydrophobic function. Electrostatic interaction of the guest’s (NR) cationic moiety with sulfonates of the host (4-sulfocalixarene) is the mainly impetus of recognition. The related mechanism is proposed to explain the inclusion process.4. A plasticized poly (vinyl chloride ) optode membrane incorporated with a calix[6]arene hexaester ,a H~+-selective chromoionophore(3,3,’5,5’-tetramethyl-N,N-dibenzylbenzidine, TMB, a novel synthetical cationic dye), and a lipophilic potassium tetrakis (4-chlorophenyl )borate (KTpC1PB) was used as a sensing device for the indirect optical determination of potassium ion. It exhibited a reversible response to potassium ion in pH=4HC1 in the concentration range from l.OxlO’6 to l><10’2 M. The linear range was from 1.53xlO"5 to 3.20* 10"3 M. The proposed optode sensor exhibited a fast response of less than 1 min, good repeatability (n = 7, R.S.D = 3.62 %) at 5xlO"5M, and long-term stability with 92 % of its initial sensitivity after 1 months of storage. The selectivity of the potassium-selective membrane allows its application for detection of potassium concentration in real sample analysis. The result was satisfactory compared with atomic absorption spectrometry (AAS).5. A new calixarene-porphyrin supramolecular sensitizer for zinc ion has been proposed based on the porphyrin fluorescence intensity increasing.In aqueous solution, the fluorescence intensity of meso-tetrakid (4-N-methyl-pyridiniumyl)porphyrin (TMPyP) decreasing by forming a 4-solfuocalixarene-TMPyP inclusion complex. Furthermore, the formation of a supramolecular complex causes a remarkable increase of the porphyrin metalation rate following the porphyrin fluorescence emission increase with increasing the concentration of zinc ion. With the optimum conditions desceibed, The linear range was from 1.0 X 10"6 to 3.5 X 10"5mol/L and the relative standard deviation (R.S.D.) is 2.6% (10 |jl mol/L). The proposed method is simple, rapid and selective and can determinate Zn2+ without organic solevent.6. Using sodium dodecylsulfate as a protective medium, the selective recognition of Cu2+ is realized based on fluorescence quenching of TMPyP. The linear range was from 5.2 X 10~6~ 3.3 X 10"4mol/L. The limit of detection is 7.63 X 10’ mol/L (S/N=3), and the precision is evaluated as the relative standard deviation (R.S.D.) in five replicates of a sample containing 10 u, mol/L of Cu2+, and the results is 1.5%. The system could be potentially used for rapid determination of Cu2+in water samples.更多还原