Academic Journal
Self-association of organic solutes in solution: a NEXAFS study of aqueous imidazole
| العنوان: | Self-association of organic solutes in solution: a NEXAFS study of aqueous imidazole |
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| المؤلفون: | Thomason, M. J., Seabourne, C. R., Sattelle, B. M., Hembury, G. A., Stevens, J. S., Scott, A. J., Aziz, E. F., Schroeder, S. L. M. |
| المساهمون: | Engineering and Physical Sciences Research Council |
| المصدر: | Faraday Discussions ; volume 179, page 269-289 ; ISSN 1359-6640 1364-5498 |
| بيانات النشر: | Royal Society of Chemistry (RSC) |
| سنة النشر: | 2015 |
| الوصف: | N K-edge near-edge X-ray absorption fine-structure (NEXAFS) spectra of imidazole in concentrated aqueous solutions have been acquired. The NEXAFS spectra of the solution species differ significantly from those of imidazole monomers in the gas phase and in the solid state of imidazole, demonstrating the strong sensitivity of NEXAFS to the local chemical and structural environment. In a concentration range from 0.5 to 8.2 mol L −1 the NEXAFS spectrum of aqueous imidazole does not change strongly, confirming previous suggestions that imidazole self-associates are already present at concentrations more dilute than the range investigated here. We show that various types of electronic structure calculations (Gaussian, StoBe, CASTEP) provide a consistent and complete interpretation of all features in the gas phase and solid state spectra based on ground state electronic structure. This suggests that such computational modelling of experimental NEXAFS will permit an incisive analysis of the molecular interactions of organic solutes in solutions. It is confirmed that microhydrated clusters with a single imidazole molecule are poor models of imidazole in aqueous solution. Our analysis indicates that models including both a hydrogen-bonded network of hydrate molecules, and imidazole–imidazole interactions, are necessary to explain the electronic structure evident in the NEXAFS spectra. |
| نوع الوثيقة: | article in journal/newspaper |
| اللغة: | English |
| DOI: | 10.1039/c5fd00005j |
| الاتاحة: | http://dx.doi.org/10.1039/c5fd00005j http://pubs.rsc.org/en/content/articlepdf/2015/FD/C5FD00005J |
| رقم الانضمام: | edsbas.C42E48DB |
| قاعدة البيانات: | BASE |
| DOI: | 10.1039/c5fd00005j |
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