رسالة جامعية
Experimental and Ab initio studies of intramolecular Ph/Cl exchange on Wilkinson’s catalyst and ligand-centered electrochemistry of ligand substituted metal carbonyls (M = Cr, Mo, W, Ir)
| العنوان: | Experimental and Ab initio studies of intramolecular Ph/Cl exchange on Wilkinson’s catalyst and ligand-centered electrochemistry of ligand substituted metal carbonyls (M = Cr, Mo, W, Ir) |
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| المؤلفون: | Igartúa-Nieves, Elvin |
| المساهمون: | Cortés-Figueroa, José E., College of Arts and Sciences - Sciences, Santana-Vargas, Alberto, Meléndez-Martínez, Enrique, Rivera-Pagán, José A., Cádiz-García, Mayra E., Department of Chemistry, Martínez-Iñesta, María M. |
| سنة النشر: | 2012 |
| المجموعة: | Digital Institutional Repository @UPR (University of Puerto Rico - DiRe.UPR) |
| مصطلحات موضوعية: | Intramolecular Ph/Cl exchange, Wilkinson’s catalyst, Electrochemical detection, C60-Piperidine Adduct, Ligand substituted metal carbonyls, Metal carbonyls, Voltammetry, Fullerenes--Oxidation, Reduction (Chemistry) |
| الوصف: | Cyclic voltammetry measurements on (η2 -C60)M(CO)5 complexes (M = Cr, Mo, W) and on (C5H10N)3(H)3C60 in dichloromethane showed three C60-centered and reversible reduction/oxidation waves. The E1/2 values of these waves are shifted to positive values relative to the corresponding uncoordinated C60 values. A Jahn -Teller type effect due to C60 spherical surface distortion promoted by C60-metal π-backbonding may explain the observed positive shifts. The complex Ir(CO)(PPh3)2(Cl)(C60) was spectroscopically detected in C60-saturated liquid solutions. Instead, the species Ir(CO)(PPh3)2(Cl)(C60 n- ) (n = 4, 5, 6) were detected electrochemically. Results suggest that electrochemically produced C60 4- and C60 5- displace acetonitrile from Ir(CO)(PPh3)2(Cl)(CH3CN) forming Ir(CO)(PPh3)2(Cl)(C60 4- ) and Ir(CO)(PPh3)2(Cl)(C605- ) followed by one-electron electrochemical reductions forming Ir(CO)(PPh3)2(Cl)(C60 5- ) and Ir(CO)(PPh3)2(Cl)(C606- ), respectively. The Wilkinson’s catalyst when dissolved in benzene or C6D6 under nitrogen or under high vacuum undergoes a series of unreported reactions at room temperature. The species (Ph3P)2Rh(η 2 -(C6H4PPh2))(Ph)(H), Ph-C6D5 and (Ph3P)3Rh(D) were detected in addition to expected formation of the cloro-bridged (Ph3P)4Rh2(μ-Cl)2. The mechanistic description of the reactions based on the behavior of its fluoro-congener, kinetics experiments, and ab initio computational studies, involves reversible intramolecular P-Ph/Rh-Cl exchange on the catalyst producing the non-steady-state intermediate cis-(Ph3P)2Rh(Ph)(Ph2PCl) via metal-phosphido formation. Intermolecular PPh3/PPh2Cl exchange on cis-(Ph3P)2Rh(Ph)(Ph2PCl) produces (Ph3P)3Rh(Ph), that in turn undergoes cyclometalation, solvent oxidative addition and reductive elimination producing Ph-C6D5. ; Medidas de voltametría cíclica en los complejos de (η 2 -C60)M(CO)5 (M = Cr, Mo, W) y en (C5H10N)3(H)3C60 en diclorometano demostraron tres ondas reversibles de oxidación/reducción centradas en C60. Los valores de E1/2 de éstas ondas se ... |
| نوع الوثيقة: | doctoral or postdoctoral thesis |
| وصف الملف: | application/pdf |
| اللغة: | English |
| العلاقة: | https://hdl.handle.net/20.500.11801/345Test |
| الإتاحة: | https://doi.org/20.500.11801/345Test https://hdl.handle.net/20.500.11801/345Test |
| حقوق: | © 2012 Elvin Igartúa-Nieves ; All rights reserved |
| رقم الانضمام: | edsbas.306EF33A |
| قاعدة البيانات: | BASE |
| الوصف غير متاح. |