Resumen: Ethylene insertion into Rh–H bonds in complexes bearing an anionic fac-triphosphane ligand gives hydrido complexes, ß-agostic species, or noninteracting ethyl derivatives depending on the reaction conditions. Several chemical equilibria between these species have been analyzed by NMR and DFT calculations, which revealed that they are mainly controlled by the entropy. Moreover, ß-agostic species were found to be lower in enthalpy than the corresponding hydride–ethylene complexes, probably due to the steric pressure exerted by the bulky fac-triphosphane ligand. Idioma: Inglés DOI: 10.1021/acs.organomet.6b00036 Año: 2016 Publicado en: Organometallics 35, 5 (2016), 799-808 ISSN: 0276-7333 Factor impacto JCR: 3.862 (2016) Categ. JCR: CHEMISTRY, ORGANIC rank: 12 / 59 = 0.203 (2016) - Q1 - T1 Categ. JCR: CHEMISTRY, INORGANIC & NUCLEAR rank: 8 / 46 = 0.174 (2016) - Q1 - T1 Factor impacto SCIMAGO: 1.723 - Inorganic Chemistry (Q1) - Physical and Theoretical Chemistry (Q1) - Organic Chemistry (Q1)