Interaction of tricoordinated phosphorus compounds with zeolites

Vapor phase chemisorption of dimethylphosphine (DMP), trimethylphosphine and trimethylphosphite (TMP) in acidic faujasite has been studied with in situ 1R and MAS-NMR techniques. Effects of pore filling on the spectral properties of trimethylphosphine are discussed. Protonation of DMP in a reversible acid-base reaction with dry HY zeolite is indicated by a single P resonance at −56 ppm due to P(CH 3 ) 2 H 2 and by the appearence of different P-H stretching modes. An acid catalyzed Arbuzov rearrangement converts TMP into dimethylmethylphosphonate which splits off methoxy groups upon heat treatment in the zeolite.