Synthesis and crystal structure of a novel compound: [H3PMo12O40][CO(NH2)2]3·5H2O

The 13C NMR spectra, both in DMSO solution and in the solid state of four cinnamic acids (p-methoxy, p-hydroxy, p-methyl, p-chloro) and their corresponding methyl esters have been recorded. The two main results in the solid state are: (i) the only significant difference between acids and esters chemical shifts concerns the C=O group which, on average, appears at 173 ppm in the acids and 168 ppm in the esters; (ii) the signals of the ortho and meta carbons both in the acids and the esters are splitted. The two `anomaliesʹ disappear in DMSO solution. These observations can be rationalized using simple GIAO/B3LYP/6-31G* calculations.