N. Bachelier et Jf. Verchere, FORMATION OF NEUTRAL COMPLEXES OF BORIC-ACID WITH 1,3-DIOLS IN ORGANIC-SOLVENTS AND IN AQUEOUS-SOLUTION, Polyhedron, 14(13-14), 1995, pp. 2009-2017
From solubility measurements in organic media and extraction experimen
ts, the values of the stability constants of neutral 1:1 complexes (HB
L) formed between boric acid (HB) and 1,3-diols (L) have been obtained
in aqueous solution (K-c(w)) and in organic solvents (K-c(s)). The va
lues of the partition coefficients of the diols (P-L) and the complexe
s (P-HBL) between water and the organic solvents have also been calcul
ated. Generally, the addition of a diol to an aqueous solution of bora
x is accompanied by a decrease of pH due to the prevailing formation o
f berate species but, in the case of 2-methyl-2,4-pentanediol, the pH
increased, in agreement with the formation of a single neutral complex
. It is shown that a modification of a previous potentiometric procedu
re yields simultaneously the values of the stability constants of the
neutral and anionic complexes in aqueous solution.