MACROMOLECULES-METAL ION COMPLEXES .7. ELECTRON-SPIN RESONANCE STUDY OF POLY (ALPHA-L-GLUTAMIC ACID)-COPPER(II) AND POLY(ACRYLIC ACID)-COPPER(II) COMPLEXES IN THE FROZEN STATE WITH EMPHASIS ON THE COMPLEX SPECIES

ESR spectra of Cu(II) in the presence of poly(sodium α-L-glutamate) (poly(Glu)) and poly(sodium acrylate) (poly(Acr)) were measured in frozen aqueous solutions at various degrees of neutralization (α) (0.2-1.0), pH 3-11 at room temperature, and at various molar mixing ratios of polymer residue to cupric ion (8-64). The parallel hyperfine constants, g, values, line widths, and line heights of the polyanion-Cu(II) complexes were determined by means of computer simulation of the observed ESR spectra. The Cu(II)-residue complexes of two different classes (classes 1 and 2) were concluded to exist in the poly(Acr)-Cu(II) system. In the poly(Glu)-Cu(II) system, the Cu(II)-residue complex containing one ligand nitrogen atom (class N) was found to exist in addition to the same complexes of classes 1 and 2 as found in the poly(Acr)-Cu(II) system. The magnetic parameters of the Cu(II)-residue complexes were compared with those of Cu(II)-glutarate and -malonate complexes. The Cu(II)-complex species of Cu(COO)42- and Cu(COO)3- were assigned to class 1 and the species of Cu(COO)2 to class 2. The Cu(II)-residue complex of class N was found to be the Cu(NH)(COO)2. © 1979, American Chemical Society. All rights reserved.