Self-Assembly Syntheses, Structural Characterization, and Luminescent Properties of Lanthanide Coordination Polymers Constructed by Three Triazole-Carboxylate Ligands

Abstract

Herein, 15 lanthanide coordination complexes based on three di-, tri-, and tetra-carboxylic ligands with imidazolyl groups have been solvothermally designed, synthesized, and characterized. All the complexes exhibit high thermal stabilities and can remain stable in the open air more than 7 days. Luminescent spectra of Eu3+ and Tb3+ complexes at room temperature indicate that the three carboxylic ligands H2L1, H3L2, and H4L3 are promising potential light sensitizers for lanthanide ions based on their suitable triplet energy levels. Luminescent lifetimes and quantum yields of these compounds were further measured and compared. The correlations between their structural features and photophysical properties are discussed in detail.

Structural Diversity of Three Pyrazoyl–Carboxyl Bifunctional Ligand‐Based Metal–Organic Frameworks: Luminescence and Magnetic Properties

“…These broad bands moderately overlap with the absorption spectrum of H 3 pzbpdc, which also confirms that Hpzbpdc sensitizes Eu III ion through the antenna effect. Meanwhile, no remnant H 3 pzbpdc‐based emission is observed from λ =400 to 450 nm in the emission spectra of 3 ; this implies that the energy adsorbed by the H 3 pzbpdc ligand has transferred to the emitting levels of the Eu III centers efficiently . Notably, in 3 , the phenyl–pyrazoyl groups in Hpzbpdc maintain good planarity with dihedral angles of 4.4 and 4.7°, which result in a conjugated chromophore that plays a crucial role in sensitizing the luminescence of Eu III centers.…”

“…The most typical case is the lanthanide ion, which, because of diffuse interactions and forbidden electronic transitions as a result of Laporte selection rules, usually displays weak emission . To circumvent this problem, the rational design of a suitable chromophoric moiety (often referred to as a conjugated system and antenna) in organic ligands has been adopted . Given that the introduced organic chromophore sensitizes the luminescence of lanthanide ions by means of transferring absorbed energy from the lowest triplet‐energy level of the ligand to metal center.…”

Crystal structure of Bis{1-[(benzotriazol-1-yl)methyl]-1-H-1,3-(2-methyl-imidazol)}diiodidocadmium(II), [Cd(C11H11N5)2I2], C22H22N10I2Cd

“…Coordination compounds have attracted interest for potential applications in various areas [4]. The multidentate Nheterocyclic ligands containing rich coordination sites, such as imidazole, triazole, tetrazole are often employed to produce different polymeric networks due to their various coordination modes [4][5][6][7][8]. Recently, our group synthesized 1-[(benzotriazol-1-yl)methyl]-1-H-1,3-(2-methyl-imidazol)(bmi) and studied its coordination behavior [9][10][11][12].…”

On the Structural Features of Substituted Lanthanide Benzoates

“…On the one hand it allows almost endless possibilities to tune their structures, and, hence, their luminescence properties, while on the other hand it dramatically hampers predicting their structures and even composition (e.g. water content) . This paper aims on the accumulating of the existing structural data of the lanthanide benzoates and the revealing of the general structure–property relationship trends based on this data.…”