Effect of peripheral substitution on spectral and catalytic properties of copper phthalocyanine complexes

The effect of peripheral substitution on the spectral and catalytic propert ies of copper phthalocyanine complexes has been investigated. The complexes were characterized by elemental analysis, FT-IR, UV-VIS and electron param agnetic resonance (EPR) techniques. The EPR spectra of solid samples were b road due to intermolecular spin-spin interactions while the frozen H2SO4 so lutions showed well resolved hyperfine and superhyperfine features due to c opper and nitrogen nuclei, respectively. The unpaired electron occupies a 3 d(x2-y2) orbital of copper(II). The ground state molecular orbital coeffici ents were estimated from the spin Hamiltonian parameters. The activity for epoxidation of styrene was more for complexes with electronegative substitu ents. The enhanced activity of substituted CuPc complexes has been correlat ed to the electronic and molecular structure parameters. (C) 2001 Elsevier Science B.V. All rights reserved.