First report of aggregation induced emission (AIE) in NIR-II region of a Pr(III) polymer chain with pyridine-2,6-dicarboxylic acid

The captivating allure of lanthanide complexes, known for their NIR emissions, becomes even more mesmerizing when aggregation occurs, enhancing their luminescent properties. This novel property significantly boosts its potential for applications in theranostics, offering new opportunities for advancements. Complexation of Praseodymium (III) with pyridine-2,6-dicarboxylic acid (dipicH 2 ) led to the formation of transparent green crystals of the 1-D polymer chain of [Pr(dipicH)(dipic)(OH 2 ) 2 ]·4H 2 O ( DPr ), which demonstrates this unique aggregation-induced emission in the NIR region. DipicH 2 being a versatile ligand offering diverse bridging modes in connecting metal centers, numerous complexes of lanthanides exist, displaying aggregation effects in the visible spectrum. Inspite of vast number of complexes, to the best of our knowledge, this is the first report of AIE behavior in lanthanide complexes in the NIR-II region, showcasing the potential applications that may emerge for lanthanide-based materials. Unveiling the unprecedented aggregation-induced emission behavior in the NIR region of the dipicolinic acid based praseodymium complex. Emission spectra and SEM analysis highlight its unique properties, suggesting promising potential for advanced materials science and related fields. • First example of any lanthanide complex exhibiting Aggregation Induced Emission in NIR-2 region in Pr(dipic)(dipicH)(OH 2 ) 2 ·4H 2 O (dipicH 2 = pyridine-2,6-dicarboxylic acid) is being reported.