Synthesis and Solid-State NMR Studies of P-Vinylbenzylphosphonic Acid

P‐Vinylbenzylphosphonic acid (2) was synthesized and crystallized in two phases A and B. The latter phase was easily converted into the former. Both phases were investigated by IR and solid‐state 31P and 1H NMR spectroscopy, and X‐ray crystallography. The use of recently developed NMR methods has enabled us to increase the usually poor resolution of solid‐state 1H spectra. This gave additional insights on the proton environments. In particular, two dimensional 2D 1H‐31P heteronuclear correlation (HETCOR) experiments, incorporating a Lee–Golburg homonuclear decoupling scheme, allowed description of the mixture of phase A and B. Recent developments of high‐resolution solid‐state NMR techniques have made it a useful tool for the elucidation of crystalline and amorphous structures of materials. The use of these techniques, in particular, allows a more accurate description of the proton environments in solids. P‐Vinylbenzylphosphonic acid (shown here) was synthesized and crystallized in two phases. Its behavior in the solid state was investigated by X‐ray diffraction and solid‐state NMR spectroscopy.