Determination of phthalocyanines energy gaps based on spectroscopic and electrochemical studies and DFT calculations

Abstract

Abstract To determine the energy gaps of four commercially available phthalocyanines spectroscopic and electrochemical studies were carried out. A studied dyes were investigated in solutions, 2D Langmuir layers in water-air interface and form of thin films deposited onto solid substrates. Experimental studies were complemented by DFT calculations performed for isolated molecule and molecule interacting with solvents. Conducted studies allowed to deduce the influence of molecular structure on energy gaps of phthalocyanine. Great compatibility of experimental results and DFT calculations was observed. It was found that the MP2 method results with values of molecular orbitals energies strongly differing from DFT results. The MP2 method results were divergent with experimental results.