Tunable Energy-Transfer Process in Heterometallic MOF Materials Based on 2,6-Naphthalenedicarboxylate: Solid-State Lighting and Near-Infrared Luminescence Thermometry

GOMEZ, GERMÁN E.; MARIN, RICCARDO; CARNEIRO NETO, ALBANO N.; BOTAS, ALEXANDRE M. P.; OVENS, JEFFREY; KITOS, ALEXANDROS A.; BERNINI, MARÍA C.; CARLOS, LUÍS D.; SOLER-ILLIA, GALO J. A. A.; MURUGESU, MURALEE

CHEMISTRY OF MATERIALS

AMER CHEMICAL SOC

Lugar: Washington; Año: 2020

0897-4756

Trivalent lanthanide ions (Ln3+) are used to prepare a plethora of coordination compounds; metal-organicframeworks (MOFs) being amongst the most sought-after in recent years. The porosity of Ln-MOFs is often complemented by theluminescence imparted by the metal centers, making them attractive multifunctional materials. Here, we report a class of 3D MOFsobtained from solvothermal reaction between 2,6-naphtalenedicarboxylic acid (H2NDC) and lanthanide chlorides yielding threetypes of compounds depending on the chosen lanthanide: [LnCl(NDC)(DMF)] for Ln3+ = La3+, Ce3+, Pr3+, Nd3+, Sm3+ (type 1),[Eu(NDC)1.5(DMF)]·0.5DMF (type 2), and [Ln2(NDC)3(DMF)2] (type 3) for Ln3+ = Tb3+, Dy3+, Y3+, Er3+, Yb3+. Photoluminescentproperties of selected phases were explored at room temperature. The luminescence thermometry capability of Yb3+-doped Nd-MOF was fully investigated in the 15-300 K temperature range under 365 and 808 nm excitation. To describe the optical behaviorof the isolated MOFs, we introduce the total energy transfer balance model. Therein, the sum of energy transfer rates is consideredalong with its dependence upon the temperature: sign, magnitude, and variation of this parameter, permitting to afford a thoroughinterpretation of the observed behavior of the luminescent species of all materials presented here. The combination of noveltheoretical and experimental studies presented herein to describe energy transfer processes in luminescent materials can pave theway towards the design of MOF-based chemical and physical sensors working in an optical range of interest for biomedicalapplications.