Current time in Korea 13:27 Dec 02 (Wed) Year 2020 KCS KCS Publications
KCS Publications
My Journal  Log In  Register
HOME > Search > Browsing(BKCS) > Archives

Bulletin of the Korean Chemical Society (BKCS)

ISSN 0253-2964(Print)
ISSN 1229-5949(Online)
Volume 15, Number 9
BKCSDE 15(9)
September 20, 1994 

Dissociation Kinetics of Linear polyaminopolycarboxylate Complexes of Lanthanides(Ⅲ)
Ki-Young Choi*, Ki Sung Kim, Choon Pyo Hong
The dissociation kinetics of linear polyaminopolycarboxylate complexes of lanthanide ions (Ln3+: Ce3+, Eu3+ and Yb3+) has been studied in an aqueous solution of 0.10 M (NaClO4) at 25.0±0.1℃ using Cu(Ⅱ) ions as a scavenger. The dissociation rates of acid-catalyzed pathway decrease in the order Ln(EPDTA)- > Ln(DPOT)- > In(TMDTA)- > Ln(MPDTA)- > Ln(EDTA)- > Ln(PDTA)- > Ln(DCTA)- according to the present and literature data. An increase in the N-Ln-N chelate ring from 5 to 6 and substitution of two methyl groups, one ethyl and hydroxyl group on a chelate ring carbon of these ligands leads to a decrease in kinetic stabilities of the complexes. The substitution of one methyl group and cyclohexyl ring on a ring carbon, however, results in a significant increase in the kinetic stability of the resulting Ln3+ complexes. Individual reaction steps taking place for each system, with different copper, acetate buffer concentration and pH dependence, are also discussed.
782 - 785
Full Text