Complex-formation reactions of dicholoro(S-methyl-L-cysteine)palladium(II) with bio-relevant ligands. Labilization induced by S-donor chelates.
The complex-formation equilibria of [Pd(SMC)(H2O)2]+, where SMC = S-methyl-l-cysteinate, with bio-relevant ligands such as amino acids, peptides, dicarboxylic acids and DNA constituents were studied and their formation constants were determined. The binding mode of the ligands containing various functional groups was studied and the speciation diagrams were evaluated. The kinetics of base hydrolysis of amino acid esters bound to [Pd(SMC)(H2O)2]+ was studied in aqueous solution at 25 degrees C and 0.1 M ionic strength. The effect of solvent polarity and temperature on the hydrolysis of coordinated glycine methyl ester was investigated. The activation parameters are evaluated and discussed.
Shehata
Mohamed R
MR
Department of Chemistry, Faculty of Science, Cairo University, Cairo, Egypt.
Shoukry
Mohamed M
MM
Nasr
Fatma M H
FM
van Eldik
Rudi
R
D000596:Amino Acids / Q000737:chemistry; D001665:Binding Sites; D002614:Chelating Agents / Q000737:chemistry*; D003545:Cysteine / Q000031:analogs & derivatives* / Q000737:chemistry; D004247:DNA / Q000737:chemistry; D003998:Dicarboxylic Acids / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D008024:Ligands; D009944:Organoplatinum Compounds / Q000737:chemistry*; D010165:Palladium / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry; D012996:Solutions / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013696:Temperature; D014867:Water / Q000737:chemistry
D000596:Amino Acids; D002614:Chelating Agents; D003998:Dicarboxylic Acids; D008024:Ligands; D009944:Organoplatinum Compounds; D010455:Peptides; D012996:Solutions; D012997:Solvents; D014867:Water; D010165:Palladium; D004247:DNA; D003545:Cysteine; C017507:mecysteine