Synthesis and Spectroscopy of N_3P_3X_5OCH=CH_2 (X=Cl,F,OCH_3,OCH_2CF_3,N(CH_3)_2) and N_3P_3X_4(OCH=CH_2)_2 (X=Cl,N(CH_3)_2). Correlations of Ultraviolet Photoelectron Spectroscopy and Nuclear Magnetic Resonance Data to Electronic and Geometrical S

摘要

The syntheses of the vinylocycyclotriphosphazene derivatives N_3P_3X_5OCH=CH_2(X=OMe,OCH_2CF_3) and the N_3P_3(NMe_2)_4(OCH=CH_2)_2 isomeric mixture along with improved preparations of N_3P_3X_5OCH=CH_2 (X=F, NMe_2) are reported. The interactions between the vinyloxy function and the cyclophosphazene in these and the previously reported N_3P_3Cl_5(OCH=CH_2) and N_3P_3F_(6-n)(OCH=CH_2)_n (n=1-4) have been examined by ultraviolet photoelectron spectroscopy (UPS) and NMR spectroscopy. The UPS data for the chloro and fluoro derivatives show a strong electron-withdrawing effect of the phosphazene on the olefin that is mediated with decreasing halogen substitution. The ~1H and ~(13)C NMR data for N_3P-3X_5OCH=CH_2(X=F,Cl,OMe,OCH_2CF_3,NMe_2) show significant changes as a function of the phosphazene substituent. There is a linear correlation between and #beta#-carbon chemical shift on the vinyloxy unit and the phosphorus chemical shift at the vinyloxyphosphorus centers. The chemical shifts of the different phosphorus centers on each ring are also related in a linear fashion. These relationships may be understood in terms of the relative electron donor-acceptor abilities of the substituents on the phosphazene ring. The ~1H NMR spectra of the N_3P_3(NMe_2)_4(OCH=CH_2)_2 isomeric mixture allow for assignment of the relative amounts of cis and trans isomers. A model for the observed cis preference in the formation of N_3P_3Cl_4(OCH=CH)_2 is presented.