Synthesis and Spectral Characteristics of Copper Complexes Based on Pectin Modified with L-Arginine, L-Alanine, and L-Aspartic Acid

Polymer ligands based on apple pectin modified with amino acids (L-arginine, L-alanine, and L‑aspartic acid) were synthesized and characterized by IR and 13C NMR spectroscopy, polarimetry, viscometry, and elemental analysis. Based on the synthesized polymer ligands, new metal-polymer complexes of copper(II) were synthesized:. The stoichiometry of the resulting metal complexes and the pH ranges of their existence were determined using the spectrophotometric method and elemental analysis data. It has been established that the modification of pectin with amino acids increases the stability of copper-containing polymer complexes compared to their homoligand analogs in a medium simulating gastric juice.