A Luminescent MOF Based on Pyrimidine-4,6-dicarboxylate Ligand and Lead(II) with Unprecedented Topology

Autor: Laura Razquin-Bobillo, Oier Pajuelo-Corral, Andoni Zabala-Lekuona, Iñigo Vitorica-Yrezabal, Jose Angel García, Jose M. Moreno, Antonio Rodríguez-Diéguez, Javier Cepeda
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: Crystals, Vol 13, Iss 10, p 1490 (2023)
Druh dokumentu: article
ISSN: 2073-4352
DOI: 10.3390/cryst13101490
Popis: In the present work, we report on a 3D MOF of {[Pb5(μ3-OH)(μ3-NO3)3(μ6-pmdc)3]·H2O}n formula (pmdc = pyrimidine-4,6-dicarboxylate) synthesized by an oven-heated, solvent-free procedure. The large connectivity afforded by the three ligands in their coordination to lead(II) ions grows cubic building units characterized by a central Pb atom with an unusual coordination index of 12 and 6 pmdc ligands occupying the faces. These cubic units are linked to one another giving rise to a quite condensed structure that represents an unprecedented topology showing the (4·62)6(43)2(45·610)3(45·68·82)6(46·69)6(612·83) point symbol. The crystalline material has been characterized by routine physico-chemical techniques to confirm its purity, and its thermal behaviour has been also studied by thermogravimetric and thermodiffractometric analyses. The solid presents a greenish blue photoluminescent emission based on pmdc ligands, as revealed by time-dependent density-functional theory (TDDFT) calculations, which is substantially more intense than in the free H2pmdc ligand according to its improved quantum yield. The emissive capacity of the material is further analysed according to decreasing temperature of the polycrystalline sample, finding that sizeable, long-lasting phosphorescence is present.
Databáze: Directory of Open Access Journals