The reaction of M(CO) 3 (Ph 2 PCH 2 CH 2 PPh 2 ) (M = Fe, Ru) with parahydrogen: probing the electronic structure of reaction intermediates and the internal rearrangement mechanism for the dihydride products
| Autor: | Robin N. Perutz, Jose M. Goicoechea, Jeremy N. Harvey, Cyril Godard, John P. Dunne, Roger J. Mawby, Philip Callaghan, Michael K. Whittlesey, Georg Müller, John P. Lowe, Simon B. Duckett, Danièle Schott, Rinaldo Poli |
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| Přispěvatelé: | Department of Chemistry [York, UK], University of York [York, UK], Department of Chemistry [Bath], University of Bath [Bath], University of Bristol [Bristol], Laboratoire de chimie de coordination (LCC), Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2004 |
| Předmět: |
010405 organic chemistry
Hydride Chemistry Ligand Reaction intermediate Nuclear magnetic resonance spectroscopy 010402 general chemistry Spin isomers of hydrogen 01 natural sciences Transition state 0104 chemical sciences Inorganic Chemistry NMR spectra database [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry Crystallography [CHIM.COOR]Chemical Sciences/Coordination chemistry Singlet state |
| Zdroj: | Dalton Transactions Dalton Transactions, 2004, 20, pp.3218-3224. ⟨10.1039/B407457B⟩ Dalton Transactions, Royal Society of Chemistry, 2004, pp.3218-3224. ⟨10.1039/B407457B⟩ |
| ISSN: | 1477-9226 1477-9234 |
| DOI: | 10.1039/B407457B⟩ |
| Popis: | The photochemical reaction of Ru(CO)(3)(dppe) and Fe(CO)(3)(dppe)(dppe = Ph(2)PCH(2)CH(2)PPh(2)) with parahydrogen has been studied by in situ-photochemistry resulting in NMR spectra of Ru(CO)(2)(dppe)(H)(2) that show significant enhancement of the hydride resonances while normal signals are seen in Fe(CO)(2)(dppe)(H)(2). This effect is associated with a singlet electronic state for the key intermediate Ru(CO)(2)(dppe) while Fe(CO)(2)(dppe) is a triplet. DFT calculations reveal electronic ground states consistent with this picture. The fluxionality of Ru(CO)(2)(dppe)(H)(2) and Fe(CO)(2)(dppe)(H)(2) has been examined by NMR spectroscopy and rationalised by theoretical methods which show that two pathways for ligand exchange exist. In the first, the phosphorus and carbonyl centres interchange positions while the two hydride ligands are unaffected. A second pathway involving interchange of all three ligand sets was found at slightly higher energy. The H-H distances in the transition states are consistent with metal-bonded dihydrogen ligands. However, no local minimum (intermediate) was found along the rearrangement pathways. |
| Databáze: | OpenAIRE |
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