Solving the P-O/P-OH Riddle: Direct Synthesis and Neutron Diffraction Characterization of Dianionic Dithiophosphonates

Abstract

We report the first definitive neutron diffraction study aimed at resolving the P–OH/P=O structural ambiguity in metal dithiophosphonates. The small NH4 counterion forces a rare syn-configuration via an extended hydrogen-bonding network. Neutron analysis definitively confirmed the fully deprotonated P=O moiety, thus confirming the formation of a dianionic dithiophosphonate, a versatile synthon in homoleptic and heteroleptic coordination environments.