Lanthanide(III) Thiosemicarbazone Complexes: Synthesis and Emission Properties with Preliminary Polymer Film Investigations
摘要
Ligand L, 2-((2-hydroxynaphthalen-1-yl)methylene)-N’-(-(2-hydroxynaphthalen-1-yl)methylene)hydrazine-1-carbothiohydrazide, synthesized through the condensation reaction of thiocarbohydrazide and o-hydroxy naphthaldehyde, characterized. Lanthanide complexes of the ligand L such as C1 (L-Nd3+), C2 (L-Gd3+) and C3 (L-Yb3+) were synthesised with co-ligand 1,10-phenanthroline. The photoluminescence properties of the synthesized complexes, including ligand-centred emission and metal-centred NIR emission, HR-ESI mass spectra, EPR spectra were also recorded. Complex C2 exhibited room-temperature phosphorescence spanning the UV to red spectral regions, attributed to ligand-centred (IL) triplet states. As these triplet emissions are observable under ambient conditions, they hold promise for various practical applications. Detailed investigations were conducted on the photoluminescence properties, including lifetime decay measurements. Additionally, the luminescence stability in a lanthanide-polymer composite (PMMA polymer film) was examined, showing enhanced emission within the polymer matrix.