Evaluating stereoelectronic properties of bulky dialkylterphenyl phosphine ligands

The stereoelectronic properties of a series of sterically hindered phosphines containing a terphenyl substituent, PRAr’ (R = alkyl; Ar’ = CH-2,6-Ar), have been evaluated by various methods. Their σ-donating capacity has been assessed on the basis of the carbon monoxide stretching frequencies in benc...

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Detalhes bibliográficos
Autores: Marín, Mario, Moreno, Juan J., Alcaide, María M., Álvarez, Eleuterio, López-Serrano, Joaquín, Campos, Jesús, Nicasio, M. Carmen, Carmona, Ernesto
Tipo de documento: artigo
Estado:Versión aceptada para publicación
Data de publicação:2019
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositório:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/204270
Acesso em linha:http://hdl.handle.net/10261/204270
Access Level:Acceso aberto
Palavra-chave:Bulky phosphine
Ligand parameterization
Tolman
Selenides
Buried volume
Terphenyl
Descrição
Resumo:The stereoelectronic properties of a series of sterically hindered phosphines containing a terphenyl substituent, PRAr’ (R = alkyl; Ar’ = CH-2,6-Ar), have been evaluated by various methods. Their σ-donating capacity has been assessed on the basis of the carbon monoxide stretching frequencies in benchmark iridium [IrCl(CO)(PRAr’)] and rhodium [Rh(acac)(CO)(PRAr’)] (acac = acetylacetonate) complexes, as well as by measuring P–Se scalar coupling constants (J) for the corresponding phosphine selenides (Se=PRAr’). In turn, the steric profile of terphenyl phosphines has been gauged by calculating Tolman Cone Angle (TCA), ligand shielding (G) and percent buried volume (%V) parameters. These calculations have been carried out from both X-ray diffraction and DFT-optimized structures. We have also examined several of the widely used biaryl phosphines for comparative purposes.