Preparation of η2: η2-o-xylylene complexes of ruthenium(0 )via facile δ-hydrogen abstraction reactions. The crystal and molecular structure of [Ru(CH2C6H4CH2)(PMe2Ph)3]
| Autor: | Michael B. Hursthouse, David J. Cole-Hamilton, S. David Chappell, Anita M. R. Galas |
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| Rok vydání: | 1982 |
| Předmět: | |
| Zdroj: | J. Chem. Soc., Dalton Trans.. :1867-1871 |
| ISSN: | 1364-5447 0300-9246 |
| DOI: | 10.1039/dt9820001867 |
| Popis: | Reactions of cis- or trans-[RuCl2L4](L = PMe2Ph, PMePh2, or PEt3) with o-MeC6H4CH2MgBr produce [R[graphic omitted]H2)L3] as the only isolable product at temperatures down to –30 °C, presumably by δ-hydrogen-abstraction reactions. For L = PMe3 no reaction is observed but [R[graphic omitted]H2)(PMe3)3] may be synthesised from [RuCl2(PMe3)4] and o-MeC6H4CH2Li·tmen (tmen = Me2NCH2CH2NMe2) in toluene. The yellow colour of the complexes, as well as their 1H and 31P n.m.r. spectra and their reaction with CO to give substitution products rather than adducts, suggest a diene like (η2:η2) binding of the xylylene ligand. This is fully confirmed by an X-ray study of [R[graphic omitted]H2)(PMe2Ph)3] which is monoclinic, space group P21/c, with a= 15.919(2), b= 11.643(2), c= 16.674(3)A, β= 104.60(30)°, and Z= 4. The structure was determined with 3 098 observed intensities measured on an automatic diffractometer and refined to an R value of 0.029. The co-ordination geometry can be considered as distorted square pyramidal with the diene molecule occupying two basal sites and bound through its exocyclic double bonds. The C–C distances suggest localisation of bonding in the xylylene ring and the angle between the plane containing Ru,C(1),C(4) and the extension of that of C(1),C(2),C(3),C(4) is 93°, confirming the η2:η2 binding of the xylylene ligand. |
| Databáze: | OpenAIRE |
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