Potentiometric determination of stepwise stability constants of zirconium, thorium and uranium chelates of asparagine and glutamine.

The metal chelates of Zr(IV), Th(IV) and U(VI) with asparagine and glutamine have been studied potentiometrically. Stepwise stability constants in 0.1 M sodium perchlorate at 25 degrees are as follows. Asparaginate chelates-log K(1) 8.80, log K(2) 6.25 for Zr, log K(1) 6.79, log K(2) 6.16 for U, log K(1) 8.28, log K(2) 7.77 and log K(3) 7.72 for Th. Glutaminate chelates-log K(1) 8.75, log K(2) 6.10 for Zr, log K(1) 6.63, log K(2) 6.22 for U, log K(1) 8.30, log K(2) 7.61 and log K(3) 7.55 for Th.

Potentiometric determination of stepwise stability constants of vanadium, molybdenum and tungsten chelates formed with asparagine and glutamine.

The metal chelates of V(IV), Mo(VI) and W(VI) formed with asparagine and glutamine have been studied potentiometrically. Stepwise stability constants in O.1M sodium perchlorate at 25 degrees C are reported as follows. Asparagine chelates--log K(1)K(2) 14.50 and log K(3) 4.04 for V, log K(1) 8.06, log K(2) 7.29 and log K(3) 3.45 for Mo, and log K(1) 5.84, log K(2) 5.11 and log K(3) 3.30 for W. Glutamine chelates--log K(1)K(2) 14.45, and log K(3) 4.07 for V, log K(1) 7.90, log K(2) 6.93, and log K(3) 3.35 for Mo, and log K(1) 5.76, log K(2) 5.09 and log K(3) 3.20 for W.