Several
K-benzoyl-
K-phenylhydroxylamine derivatives were synthesized. Their acid dissociation constants, p
Ka, were determined spectrophotometrically. There was a linear relationship between the constants and Hammett′s σ
m values. Furthermore the distribution constants,
KDL, of their reagents between the aqueous and chloroform phases were determined. It was found that both the extraction constants,
Kex, of their copper complexes and the pH values at half extraction, pH
1/2, are practically constant although the p
Ka values decrease because of the electron-withdrawing nature of the substituted group. It cdn be assumed that the values of log
KDC, (where
KDC is the distribution constant of the copper complex) are nearly equal to the values of 2 log
KDL, since the values of log
KDC and log
KDL are proportional to molecular volume on the basis of the regular solution theory; that is, a relationship between
KDC and
KDL can be expressed as follows; log
KDC=2log
KDL+constant. Since the values of
Kex and
KDC KDL-2 for each of the chelates can be regarded as constant, an analogous relationship between
Ka and β
2 can also be derived as follows: logβ
2=2p
Ka+constant.
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