The solubility of L-cystine, H2L, as well as the acidic constants have been studied at 25 deg C in different ionic strengths. The media were (0.50, 1.00, 2.00, and 3.00) mol *dm-3 NaClO4. The solubility of H2L was also determined in pure water. The protonation constants of L-cystine, Kn (Hn-1Ln-3 + H+ a HnLn-2) and Kn+2 (H2+n-1Ln-1 + H+ a H2+nLn), in a basic and in a more acid range, respectively, combined with the salting effects of NaClO4 on H2L deduced from the solubility determinations, were processed by the specific ion interaction theory, SIT, to give equilibrium constants at the infinite dilution reference state, log deg K1 ) 9.41 ( 0.05, log deg K2 ) 8.64 ( 0.01, log deg K3 ) 1.61 ( 0.06, and log deg K4 ) 1.36 ( 0.09, as well as specific interaction coefficients, b(L2-, Na+) ) 0.29 ( 0.02, b(HL-, Na+) ) 0.14 ( 0.01, b(H3L+, ClO4 -) ) 0.15 ( 0.01, and b(H4L2+, ClO4 -) ) 0.29 ( 0.02.
Compounds
#
Formula
Name
1
C6H12N2O4S2
3,3'-dithiobis-L-alanine
2
ClNaO4
sodium perchlorate
3
H2O
water
Datasets
The table above is generated from the ThermoML associated json file (link above).
POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied;
the numbers refer to the table of compounds on the left.