Cu K-edge EXAFS on Copper(I) Complexes Containing Dihydridobis(3-nitro-1,2,4-tryazol-1-yl)borate and Bis(1,2,4-triazol-1-yl)acetate Ligand: Evidence for the Cu-O Interaction

X-ray absorption spectroscopy (XAS) has been used to probe the local structure of copper(I) complexes containing the dihydridobis(3-nitro-1,2,4-triazol-1-yl)borate and the bis(1,2,4-triazol-1-yl)acetate ligands. The material is polycrystalline and no crystal structure is available in the literature. The EXAFS analysis has permitted the identification of the local environment of the copper site. Copper is found to be 4-fold coordinated with two sets of Cu-N and Cu-P interactions describing a quasi-planar figure. An additional coordination is revealed for the copper(I) complex of bis(1,2,4-triazol-1-yl)acetate due to the interaction of the copper with the acetate of the scorpionate ligand. XANES spectra of the studied samples show a resolved pre-edge peak at about 8983 eV which is assigned to the 1s -> 4p transition, whose intensities can be explained considering the copper in a 4-fold coordination.