Photoluminescent Lanthanide(III) Coordination Polymers with Bis(1,2,4-Triazol-1-yl)Methane Linker

Abstract

A series of new lanthanide(III) coordination polymers with the general formula [Ln(btrm)2(NO3)3]n, where btrm = bis(1,2,4-triazol-1-yl)methane and Ln = Eu3+, Tb3+, Sm3+, Dy3+, Gd3+ were synthesized and characterized by IR-spectroscopy, elemental, thermogravimetric, single-crystal, and powder X-ray diffraction analyses. Europium(III), samarium(III), terbium(III), and gadolinium(III) coordination polymers demonstrate thermal stability up to 250 °C, while dysprosium(III) is stable up to 275 °C. According to single-crystal X-ray diffraction analysis, the ligand exhibits a bidentate-bridging coordination mode, forming a polymeric chain of octagonal metallocycles. The photoluminescence of the free ligand in the polycrystalline state is observed in the ultraviolet range with a quantum yield of 13%. The energy transfer from the ligand to the lanthanide ions was not observed for all obtained coordination polymers. However, there are sharp bands of lanthanide(III) ions in the diffuse reflectance and excitation spectra of the obtained compounds. Therefore, Ln(III) luminescence arises, most probably, from the enhancement of f-f transition intensity under the influence of the ligand field and non-centrosymmetric interactions.

Synthesis, Structure and Magnetic Properties of Low-Dimensional Copper(II) trans-1,4-cyclohexanedicarboxylate

“…Metal-organic coordination polymers (MOCPs) have attracted significant research attention due to their broad structural design [1][2][3] and targeted modulation of properties that is possible by varying functional metal centers [4], organic ligands [5], and guest substrates [6]. Polynuclear and polymeric blocks consisting of unpaired electron-rich metal ions can present valuable magnetic properties (such as ferro- [7], antiferro- [8], and ferrimagnets [9], as well as slow magnetic relaxation [10,11]), complex luminescence patterns [12,13], redox behavior [14], and unique chemical bonding features [15]. In particular, such metal centers are of interest for the synthesis of MOCPs with designable and unique properties and unveil the usage of coordination polymers in diverse magnetic materials [16], in highly efficient luminophores and sensors [4,17], for data storage [18], and for production of multifunctional and "smart" materials [19].…”

A Series of Novel 3D Coordination Polymers Based on the Quinoline-2,4-dicarboxylate Building Block and Lanthanide(III) Ions—Temperature Dependence Investigations

“…Lanthanide coordination entities are attractive because of their interesting physicochemical features and numerous applications as so-called new materials. The reason for this is that the luminescence of the lanthanides is unique with their sharp emission bands and higher lifetimes of the excited states [33][34][35][36][37] in the visible (Sm, Eu, and Tb) and NIR region (Pr, Nd, Ho, Er, and Yb) [38][39][40]. In particular, the luminescence of lanthanides in the NIR range is very attractive because of their potential applications in the medical field as luminescent probes, in telecommunication, and in photonic devices such as light-emitting diodes [34][35][36][37][41][42][43][44].…”

Recent Developments in Multifunctional Coordination Polymers

“…Their utility as excellent catalysts has been demonstrated in CO 2 cycloaddition reactions with epichlorohydrin under ambient CO 2 pressure and solvent-free conditions. Moreover, the effective application of a diverse range of coordination polymers and metalorganic frameworks in many cutting-edge domains of materials science is only continuing to expand [65][66][67][68][69][70][71][72][73][74][75][76][77][78][79][80].…”