Structure and catalytic properties of dimeric copper(II) acetato complexes encapsulated in zeolite-Y

摘要: Dimeric copper acetate and chloroacetate complexes (CuAc CuClAc, respectively), were encapsulated in zeolite-Y by the flexible ligand synthesis method. Spectroscopic techniques (FT-IR, diffuse reflectance UV-visible, EPR) thermal analysis provide convincing evidence for formation of acetato-bridged dimeric copper(II) supercages zeolite-Y. The effects encapsulation on geometric, magnetic, spectral, catalytic properties are examined. separation (†ν) between ν as (COO − ) s bands FT-IR spectra changes from 182 to 213 cm −1 CuAc 185 205 CuClAc upon corresponds syn-syn mode coordination bridging carboxylato groups. Variable temperature EPR studies (77–298 K) indicate an antiferromagnetic interaction two Cu(II) ions dimers. magnitude exchange molecular symmetry both change a consequence encapsulation. Cu-Cu dimer decreases encapsulation, 2.64 2.40 A 2.92 2.73 CuClAc. catalyze o -hydroxylation phenols catechols additional oxidation -benzoquinone oxygen. turnover frequency phenol conversion increases significantly Due enhanced binding strength lability Cu-phenolate Cu-dioxygen bonds modified trans-axialligand effect accounting reactivity complex.