Investigating local coordination and electronic nature of Cu centers in the copper complexes having aspartic and glutamic acids

Abstract

X‐ray absorption fine structure (XAFS) at the Cu K‐edge in copper complexes of L‐aspartic acid (asp) and L‐glutamic acid (glu), namely, [Cu(L‐asp)(H2O)].H2O (1) and [Cu(L‐glu)(H2O)].H2O (2) have been investigated using synchrotron radiation. Though, the crystal structure of both of the complexes 1 and 2 have been studied earlier using x‐ray crystallography, it was considered worthwhile to study the coordination geometry and electronic nature of Cu metal center using XAFS. EXAFS analysis indicated that Cu has distorted tetragonal pyramidal and distorted octahedral coordination in complexes, respectively. The XANES spectra have been simulated for the Cu center in the complexes and compared with the experimental XANES spectra. Further, p‐DOS and d‐DOS calculated simultaneously for absorbing Cu metal center have been correlated with the features and shape of the simulated XANES spectra as well as the experimental spectra.