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Equilibrium investigation of complex formation reactions involving copper(II), nitrilo-tris(methyl phosphonic acid) and amino acids, peptides or DNA constitutents. The kinetics, mechanism and correlation of rates with complex stability for metal ion promoted hydrolysis of glycine methyl ester
- Source :
-
Journal of Coordination Chemistry . 9/20/2006, Vol. 59 Issue 14, p1541-1556. 16p. 1 Diagram, 5 Charts, 6 Graphs. - Publication Year :
- 2006
-
Abstract
- The complex formation reactions of [Cu(NTP)(OH 2 )] 4- (NTP  =  nitrilo-tris(methyl phosphonic acid)) with some selected bio-relevant ligands containing different functional groups, are investigated. Stoichiometry and stability constants for the complexes formed are reported. The results show that the ternary complexes are formed in a stepwise mechanism whereby NTP binds to copper(II), followed by coordination of amino acid, peptide or DNA. Copper(II) is found to form Cu(NTP)H n species with n   =  0, 1, 2 or 3. The concentration distribution of the various complex species has been evaluated. The kinetics of base hydrolysis of glycine methyl ester in the presence of copper(II)-NTP complex is studied in aqueous solution at different temperatures. It is proposed that the catalysis of GlyOMe ester occurs by attack of OH - ion on the uncoordinated carbonyl carbon atom of the ester group. Activation parameters for the base hydrolysis of the complex [Cu(NTP)NH 2 CH 2 CO 2 Me] 4- are, ΔH ±   =  9.5  ±  0.3  kJ  mol -1 and ΔS ±   =  -179.3  ±  0.9  J  K -1   mol -1 . These show that catalysis is due to a substantial lowering of ΔH ± . [ABSTRACT FROM AUTHOR]
- Subjects :
- *COPPER
*AMINO acids
*PEPTIDES
*METAL ions
*HYDROLYSIS
*GLYCINE
Subjects
Details
- Language :
- English
- ISSN :
- 00958972
- Volume :
- 59
- Issue :
- 14
- Database :
- Academic Search Index
- Journal :
- Journal of Coordination Chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 22769749
- Full Text :
- https://doi.org/10.1080/00958970600561399