An efficient way for the synthesis of covalent Strandberg-type phosphomolybdate compound H6P2Mo5O23

A covalent Strandberg-type phosphomolybdate H 6 P 2 Mo 5 O 23 (EPM) was synthesized by applied ethanediamine (en) as a template agent. Besides, the pH value and Mn 2+ were also the important factors in composing EPM. The structure of EPM was characterized by elemental analyses, X-ray powder diffraction, X-ray photoelectron spectra, IR spectrum, and single-crystal X-ray diffraction. Structural analysis shows that EPM consists a H 6 P 2 Mo 5 O 23 cluster and two en molecules as lattice fillers. As a case of molybdenum oxide, EPM exhibits thermal instability even under low temperature conditions, which is more similar to covalent compound than ionic compound. Graphic abstract A thermo-unstable covalent Strandberg-type precursor was successfully synthesized, and the synthesis method was innovative, involving pH value, catalyst and template synthesis, which provided good synthesis experience for future experiments.