Chiral lanthanide coordination polymers and dinuclear complexes showing high dissymmetry factor and CPL brightness

• Grant number: 25/04124-3
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: May 01, 2025
• End date: April 30, 2029
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Fernando Aparecido Sigoli
• Grantee: Stefano Angerami de Andrade
• Host Institution: Instituto de Química (IQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated research grant: 21/08111-2 - Development of rare earth based light converters: luminescent markers, optical sensors, and amplifiers, AP.TEM

Abstract

Spectroscopists and materials scientists have recently shown great focus on studying the phenomenon of circularly polarized luminescence (CPL) emission, an area of interest mainly for anti-counterfeiting technologies. One of the greatest challenges faced in research is obtaining a high dissymmetry factor |glum|, which measures the deviation of circularly polarized light to the left or right when interacting with chiral systems. Commonly, there is an inversion relationship between the emission quantum yield and the |glum|, where the increase in one comes at the expense of the other. This makes it very difficult to obtain an intense and highly circularly polarized emission, which makes it difficult to observe an intense polarization of the emission. Lanthanide ions have unique spectroscopic properties, one of which is the possibility of obtaining high values of emission quantum yield due to the possibility of obtaining complexes of these ions that present the antenna effect and low emission suppression. The preparation of coordination polymers or dimers containing lanthanide ions, chiral ligands that increase glum, and sensitizing ligands (antennas) that increase quantum yield, is an alternative for obtaining optimized CPL properties. This Project proposes the synthesis of complexes utilizing sensitizing achiral main ligands sided with chiral bridging ligands, while in parallel utilizing chiral main ligands with achiral bridging ligands. This way, we intend to obtain high |glum| values simultaneously to high emission quantum yields, thus unraveling ideal conditions for measuring bright CPL emission.