Suspension NMR Spectroscopy of Phosphines and Carbonylnickel Complexes Immobilized on Silica

Abstract

The 31P suspension NMR spectra o f silica-immobilized bifunctional phosphines and their di- and tricarbonylnickel complexes were recorded using conventional high resolution NMR equipment. The practical advantages of suspension NMR spectroscopy, as compared to 31P CP/MAS NMR spectroscopy, are discussed. General tendencies are demonstrated: The suspension NMR signals become broader with increasing solvent viscosity and decreasing solvent polarity. Phenyl groups as spacers lead to broader resonances than alkyl chains. The linewidths increase in the case of chelation.