Тіон-тіольна таутомерія тіосечовинних лігандів на поверхні кремнезему
Quantum chemical calculations of the IR spectra of the thione and thiol forms of N, N'-dimethylthiourea and silica surface fragment with composition (HO)3SiCH2NHC(S)NHCH3 (density functional theory method, B3LYP/6-31G (d, p)) make it possible to fix indicator absorption bands of the tautomers....
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| Date: | 2015 |
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| Main Authors: | , , , |
| Format: | Article |
| Language: | English |
| Published: |
Chuiko Institute of Surface Chemistry National Academy of Sciences of Ukraine
2015
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| Subjects: | |
| Online Access: | https://www.cpts.com.ua/index.php/cpts/article/view/329 |
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| Journal Title: | Chemistry, Physics and Technology of Surface |
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Chemistry, Physics and Technology of Surface| Summary: | Quantum chemical calculations of the IR spectra of the thione and thiol forms of N, N'-dimethylthiourea and silica surface fragment with composition (HO)3SiCH2NHC(S)NHCH3 (density functional theory method, B3LYP/6-31G (d, p)) make it possible to fix indicator absorption bands of the tautomers. The presence of absorption bands at 1586 cm-1 (or 1607 cm-1 in the case of surface fragment) reveals the thione form whereas appearance of the intensive absorption bands at 1714 (1707)cm -1 indicates the occurrence of the thiol form. The results of quantum chemical calculations on the total energy of the transition complex in vacuum at T = 298 K and on the activation energy values of thione-thiol tautomeric transition between different conformations of the cluster models have shown a decrease in the activation barrier due to the grafting of thiourea groups on silica surface. The configurations of the transition complexes were also determined. |
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