Temperature Dependence of the Luminescence Spectra of Copper(II) Mesoporphyrinate in a Polystyrene Film and on the Surface of Microparticles of Al2O3

Abstract

Copper(II) diethyl mesoporphyrinate (CuMP), as well as luminescent materials based on it, namely, films of CuMP in polystyrene and microparticles of aluminum oxide covered by a layer of CuMP, is obtained. An analysis of the change in the photoluminescence spectra of the new materials in a range of temperatures of 77–298 K is conducted. It is found that, upon varying temperature in the photoluminescence spectra of CuMP in polystyrene, the ratio of the intensities of phosphorescence from the triplet electron levels 2T1 and 4T1 changes and a shift of the spectra according to the Stokes law is observed. A change in the ratio of the intensities of emission from the levels 2T1 and 4T1 is also observed in the luminescence spectra of CuMP adsorbed on the surface of microparticles of Al2O3 upon varying temperature; however, an anti-Stokes shift of phosphorescence from the level 2T1 is observed at the same time. An analysis of the kinetics of decay of the phosphorescence spectra of the CuMP dye in composite materials that possess the properties of luminescent temperature sensors is conducted.