Tunable energy transfer process in heterometallic MOFs materials based on 2,6-naphtalenedicarboxylate: solid-state lighting and near-infrared luminescence thermometry

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

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-organic frameworks (MOFs) being amongst the most sought-after in recent years. The porosity of Ln-MOFs is often complemented by the luminescence imparted by the metal centers, making them attractive multifunctional materials. Here, we report a class of 3D MOFs obtained from solvothermal reaction between 2,6-naphtalenedicarboxylic acid (H2NDC) and lanthanide chlorides yielding three types 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+. Photoluminescent properties 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 behavior of the isolated MOFs, we introduce the total energy transfer balance model. Therein, the sum of energy transfer rates is considered along with its dependence upon the temperature: sign, magnitude, and variation of this parameter, permitting to afford a thorough interpretation of the observed behavior of the luminescent species of all materials presented here. The combination of novel theoretical and experimental studies presented herein to describe energy transfer processes in luminescent materials can pave the way towards the design of MOF-based chemical and physical sensors working in an optical range of interest for biomedical applications.