Phosphinic and Phosphonic Acids I: Protonation and Complex Formation Equilibria of Some Substituted Ethane-1,1,2-tris-(P-methyl-phosphinie Acids)

Abstract

Protonation constants were determined pH-metrically for 3 selected phosphinic acids of the type CHRP*—CHP*2 (R = phenyl, methyl, t-butyl; P* = CH3P(O)OH). Complex formation equilibria were studied for metal ions Mg(II), Ca(II), Sr(II), Ba(II), Cu(II), Zn(II), Al(III) and Ga(III). Particular strong complex formation was observed for Ga(III).