It was observed that, for low values of H2PP molar fraction in the mother solution, semitransparent gels, similar to that of nanosized ZrP, were obtained after 1 day of solution, the just formed gel turned into a white precipitate after 1 day. The conditions for the direct precipitation of the ZrP(PP)x compounds and their composition are reported in Table 2. In all cases, the overall (P/Zr) molar ratio in the solids, determined by ICP analysis, was around 1.95.