The activation barrier to axial torsion in 2,2'-bis(diphenylphosphino)biphenyl
After selective deuteration of 2,2'-bis(diphenylphosphino)biphenyl, it was possible to det. the NMR coalescence temp. of the diastereotopic Ph groups. On this basis, a torsional barrier of 22 kcal/mol was calcd. Thus, the bisphosphine, even if it could be resolved into pure enantiomers, would rapidly re-racemize at temps. around or >25 Deg. [on SciFinder (R)]
Keywords: Nuclear magnetic resonance (NMR coalescence temp. of diastereotopic bis(diphenylphosphino)biphenyl); Resolution (of diastereotopic bis(diphenylphosphino)biphenyl); Potential barrier (to axial torsion in bis(diphenylphosphino)biphenyl) ; activation barrier axial torsion diphosphino biphenyl; coalescence NMR temp diastereotopic diphosphino biphenyl
Organometallic and Organometalloidal Compounds
Institut Chimie Organique,Universite Batiment Chimie,Lausanne-Dorigny,Switz.
written in English.
174467-54-0 Role: RCT (Reactant), RACT (Reactant or reagent) (deuterium exchange reaction of); 174467-53-9P Role: PEP (Physical, engineering or chemical process), PRP (Properties), SPN (Synthetic preparation), PREP (Preparation), PROC (Process) (prepn. and temp.-dependent NMR and racemization potential barrier of); 174467-52-8 Role: PEP (Physical, engineering or chemical process), PRP (Properties), PROC (Process) (temp.-dependent NMR and torsional potential barrier of)
Record created on 2006-03-03, modified on 2016-08-08