Portal de Periódicos da CAPES

The protonation constants and 31P NMR of tetra-, penta-, hexa- and heptapolyphospates

1982; Elsevier BV; Volume: 1; Issue: 1 Linguagem: Inglês

10.1016/s0277-5387(00)81071-2

1873-3719

Hirohiko Waki, Masao Hatano,

Organophosphorus compounds synthesis

The first and second protonation constants of linear polyphosphates at 25°C and ionic strength 0.1 have been evaluated: log K1 = 8.91, log K12 = 6.13 for P2O74−(P2); log K1 = 8.88, log K12 = 5.86 for P3O105−(P3); log K1 = 8.40, log K12 = 6.58 for P4O136−(P4); log K1 = 8.15, log K12 = 7.03 for P5O167−(P5); log K1 = 8.12, log K12 = 7.16 for P6O198−(P6); log K1 = 8.07, log K12 = 7.18 for P7O229−(P7). The variations of these values with the polyphosphate chain length have been discussed. A simple identification for polyphosphate species utilizing 13P NMR signal ratio of middle to end P has been proposed. By applying a micro ion-exchange technique, a rapid concentration of each polyphosphate and the subsequent preparation of the magnesium salt have been accomplished.