Title: Influence of the structure modification of lanthanide chelates with N - (diphenylphosphoryl)pyrazine-2-carboxamide on brilliant tunable luminescence
Abstract:
Lanthanide coordination compounds with high quantum efficiency and brightness of emission are still desirable due to the possibilities of numerous applications ranging from biomedical diagnostics to photonic devices and solar energy conversion. The proper design of organic ligands plays a crucial role in optimizing the photophysical properties of lanthanide coordination compounds and makes them effective molecular converters of electromagnetic radiation.
We present a series of photostable lanthanide compounds in which N (diphenylphosphoryl)pyrazine-2-carboxamide plays the role of a perfect sensitizer for the emission of various lanthanide ions in the solid state and a polymer matrix (PMMA). The structure of the ligand was carefully designed to minimize the multiphonon quenching of lanthanide emission and to increase the efficiency of the intersystem crossing. The crystal structure of lanthanide compounds is characterized by high stiffness due to its architecture. This with a well fulfilled condition of resonance between the ligand triplet state and excited lanthanide levels translated to very high overall quantum yield (Q_Eu^L = 98 %, Q_Tb^L = 98 %, Q_Sm^L = 11 %, Q_Dy^L = 17 %).
Biography:
Paula Gawryszewska is D.Sc. Eng. at the Faculty of Chemistry, University of Wroclaw. She received her M. Sc. in Wroclaw University of Science and Technology. In 1998 she received a PhD in Faculty of Chemistry at the University of Wrocław in the group of prof. Janina Legendziewicz. Then she spent 6 months (1998/1999) at Michigan Technological University (MTU) in the group of prof. James Riehl, where she dealt with polarized luminescence of racemic mixtures of lanthanide complexes. In the USA she stayed twice more on short stays in 1999 and 2014 in MTU and University of Minnesota Duluth (prof. J. Riehl). Her scientific interests include coordination chemistry, luminescent materials, energy transfer in lanthanide compounds, plasmon-enhanced fluorescence.