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• 作者：A. Sá ; nchez ; R. Jim&eacute ; nez ; F. Ternero ; R. Mesa ; C. A. Piñ ; ero ; F. Muriel ; P. Lopez-Cornejo
• 刊名：Journal of Physical Chemistry B
• 出版年：2007
• 出版时间：September 13, 2007
• 年：2007
• 卷：111
• 期：36
• 页码：10697 - 10702
• 全文大小：74K
• 年卷期：v.111,no.36(September 13, 2007)
• ISSN：1520-5207

文摘

The reaction [Ru(NH₃)₅pz]²⁺ + Co(C₂O₄)₃^3- has been studied in aqueous solutions of p-sulfonatocalix[n]arene (n = 4, 6, and 8). The results are interpreted by using the pseudophase model. Results show that therigidity and/or flexibility of the assembled rings have a great effect on the thermodynamics of inclusion ofthe guest into the host and, therefore, on the kinetics of the electron transfer processes that take place in thesemedia. The obtained results are discussed from the viewpoint of two types of interactions: electrostatic andnonelectrostatic. From surface potential measurements, the guest-host interactions have been demonstratedto be mainly due to nonelectrostatic interactions, although the species are charged. So, the nonelectrostaticcontribution to the equilibrium constant in all the calixarenes studied is 1 order of magnitude higher than theelectrostatic one (K_nel = 144 and 884 mol^-1 dm³ for p-sulfonatocalix[n]arene (n = 4 and 6, respectively) andK_el 10 mol^-1 dm³). Electrostatic interactions also affect the kinetic results.