Synthesis, Structure, and Comparative Analysis of Photo- and Electroluminescence Spectra of Vanadyl Mesoporphyrinate in PVK:PBD Composite

Abstract

By reacting the free base of mesoporphyrin methyl ester with an excess of vanadyl sulfate, the corresponding vanadyl mesoporphyrinate was obtained with high yield. The resulting compound’s structure was established using EAS and mass spectrometry. Photoluminescence and electroluminescence spectra of vanadyl mesoporphyrinate in a PVK:PBD composite at the temperature of 25°C were analyzed. Based on the luminescence decay kinetic curves, it was established that the complex exhibits only phosphorescent emission. The vanadyl mesoporphyrinate photoluminescence and electroluminescence spectra shape are identical, indicating an identical ratio of intensities of ⁴T₁–²S₀ and ²T₁–²S₀ emission transitions during both photoexcitation and electroexcitation of vanadyl mesoporphyrinate molecules. It was found that at 1 and 5 wt % of vanadyl mesoporphyrinate in the PVK:PBD composite, no aggregation of vanadyl mesoporphyrinate occurs. This indicates that the resulting complex may have use as a dopant in the light-emitting layer of red and near-IR OLEDs.