45 research outputs found
MAPK uncouples cell cycle progression from cell spreading and cytoskeletal organization in cycling cells
Effect of gelatin on the photoinduced electron-transfer reaction of a macrocylic co(III) complex in a network of gelatin hydrogel
Electronic Absorption and Circular Dichroism Spectroscopy of Cu(II) and Pd(II) Complexes with Polyelectrolytes Derived from Amino Acids
Electron-transfer Reactions of Multidentate Ligand Cobalt(III) Complexes. VI. The Effect of the Chelation of Nonbridging Ligands on the Iron(II) Reductions of Chlorocobalt(III) Complexes
CHARACTERISTIC BEHAVIOR OF THE COMPLEXATION OF COPPER(II) WITH POLYMER-BOUND VINYLIMIDAZOLE LIGANDS
CHARACTERISTIC BEHAVIOR OF THE COMPLEXATION OF COPPER(II) WITH POLYMER-BOUND VINYLIMIDAZOLE LIGANDS
CHARACTERISTIC BEHAVIOR OF THE COMPLEXATION OF COPPER(II) WITH POLYMER-BOUND VINYLIMIDAZOLE LIGANDS
Some polymer ligands of N-vinylimidazole-co-N-vinylpyrrolidone (Plm) having different mole fractions of N-vinylpyrrolidone have been prepared. Successive formation constants for the complexation of Cu-II with these Plms in aqueous solutions have been determined by means of spectrum deconvolution at pH 3.5. The present results demonstrate that the successive formation constants are given by K-1=[CuL]/[Cu][L], K-2= [CuL(2)]/[CuL], K-3= [CuL]/[CuL(2)] and K-4 = [CuL(4)]/[CuL(3)] (charge omitted, L = imidazole residue on Plm). The results clearly indicate that the concentration ratio, [CuL] : [CuL(2)] : [CuL(3)] : [CuL(4)], is largely constant for a given Pim when the concentration of imidazole residues is varied. The values of K-2, K-3 and K-4 decrease with increasing mole fraction of vinylpyrrolidone residues (VPRo) in the Plms. The successive formation constants increase in the order K-2 K-3 > K-4) is found for Plm with a VPRo mole fraction of 0.8. Above this VPRo mole fraction, CuL(4) species are rarely formed. These results also suggest that the distributions of Cut, species in Cu-II-Plm solutions can be controlled by adjusting the content of VPRo in the Plm