High pressure cyanide exchange study on a square-planar tetracyanometalatecomplex of Pt(II)

Previous studies of cyanide exchange on square planar tetracyanoplatinate c omplex [Pt(CN)(4)](2-) have been undertaken only at a high pH. For a more c omplete Fundamental understanding of this system we extended the investigat ions of these exchanges over a large pH range, NMR kinetics methods (magnet isation transfer, isotopic exchange) proved to be very useful for obtaining quantitative rate data of the cyanide exchange on this complex. In fact it is quite significant that the reactivity of this metal center spans a ca, 9-order of magnitude range as a function of pH. Variable temperature and variable pressure studies were undertaken in aqueo us solutions and the following activation parameters obtained: DeltaH(doubl e dagger) = (25.1 +/- 0.4) kJmol(-1) and activation entropy DeltaS(double d agger)=-(142+/-2) JK(-1)mol(-1) and activation volume DeltaV(double dagger) =-(27+/-2) cm(3)mol(-1).