Solution Thermochemical Study of a Fluorous Tertiary Phosphine Ligand in Rhodium and Ruthenium Systems

Abstract

The enthalpies of reaction of a fluorous tertiary phosphine, P(CH2CH2(CF2)5CF3)3 (PRf3 ) with [Rh(CO)2Cl]2 (1) and Cp‘Ru(COD)Cl (Cp‘ = η5-C5H5 (2), η5-C5Me5 (3)), leading to the formation of RhCl(CO)(PRf3)2 and Cp‘Ru(PRf3)2Cl complexes have been measured by anaerobic solution calorimetry in THF at 30.0 °C. These reactions are rapid and quantitative. The measured reaction enthalpies allow for a quantitative determination of characteristic phosphine steric and electronic parameters associated with this novel tertiary phosphine ligand. Sterically, the P(CH2CH2(CF2)5CF3)3 ligand appears identical to PEt3.

Syntheses and Carbonyliridium Complexes of Unsymmetrically Substituted Fluorous Trialkylphosphanes: Precision Tuning of Electronic Properties, Including Insulation of the Perfluoroalkyl Groups

“…Calorimetric data suggest that phosphane 1 is electronically similar to PMe 2 Ph. [21] The latter gives an iridium complex with an IR ν CO value of 1960 cm Ϫ1 (Nujol), [22] somewhat closer to those of phosphanes 4 and 11 (complexes 18, 17). However, in view of the different steric properties and measurement conditions, we regard this as a good agreement.…”

Synthetic, Thermochemical, and Catalytic Studies Involving Novel R2P(ORf) [R = Alkyl or Aryl; Rf = CH2CH2(CF2)5CF3] Ligands

“… a Enthalpy values are reported with 95% confidence limits. b Taken from refs and a. c Work performed in THF.…”

“…Following a collaboration with Horváth on the determination of stereoelectronic properties of the “ponytail” ligand P(CH 2 CH 2 (CF 2 ) 5 CF 3 ) 3 using a rhodium system (eq 2), we became interested in developing phosphine ligands with tunable stereoelectronic properties to carry out catalysis in nontraditional media We now present the synthesis and catalytic application of an easily accessible, novel class of partially fluorinated “pigtail” ligands which allow regulation of phosphinite and metal center stereoelectronic properties.…”

Additions of PH3 to Monosubstituted Alkenes of the Formula H2CCH(CH2)x(CF2)yCF3: Convenient, Multigram Syntheses of a Family of Partially Fluorinated Trialkylphosphines with Modulated Electronic Properties and Fluorous Phase Affinities

“…Nolan has probed the steric and electronic properties of 1 calorimetrically . Experiments with [Rh(CO) 2 Cl] 2 show that 1 is a poorer donor than P(CH 2 CH 3 ) 3 , and a comparable donor to P(C 6 H 5 )(CH 3 ) 2 .…”