Equilibrium behavior and proton transfer kinetics of the dioxotetracyanometalate complexes of molybdenum(IV), tungsten(IV), technetium(V), and rhenium(V): carbon-13 and oxygen-17 NMR study

C-13 NMR spectroscopic studies on the (MO2(CN)4)(n+2)(-) complexes of the Mo(IV), W(IV), Te(V) and Re(V) systems yield pKa values that agree well with previously determined dissociation constants for the systems. 0-17 line broadening NMR methods yield the reaction kinetics for proton transfer of the systems. The study results indicate that the complexes have enriched oxo sites due to water/hydroxide exchange and subsequent proton transfer.