abstract
Trivalent lanthanide ions (Ln(3+)) are used to prepare a plethora of coordination compounds, with metal-organic frameworks (MOFs) being among 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 three-dimensional (3D) MOFs obtained from a solvothermal reaction between 2,6-naphthalenedicarboxylic acid (H2NDC) and lanthanide chlorides, yielding three types of compounds depending on the chosen lanthanide: [LnCl(NDC)-(DMF)] for Ln(3+) = La3+, Ce3+, Pr3+, Nd3+, Sm3+ (type 1), [Eu(NDC)(1.5)(DMF)]center dot 0.5DMF (type 2), and [Ln(2)(NDC)(3)(DMF)(2)] for Ln(3+) = Tb3+, Dy3+, Y3+, Er3+, Yb3+ (type 3). 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 on the temperature-the 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 toward the design of MOF-based chemical and physical sensors working in an optical range of interest for biomedical applications.
keywords
METAL-ORGANIC FRAMEWORKS; BUILDING UNITS; COORDINATION-COMPOUNDS; TOPOLOGICAL ANALYSIS; CRYSTAL-STRUCTURES; EMISSION; NANOPARTICLES; POLYMERS; SERIES; NETS
subject category
Chemistry; Materials Science
authors
Gomez, GE; Marin, R; Neto, ANC; Botas, AMP; Ovens, J; Kitos, AA; Bernini, MC; Carlos, LD; Soler-Illia, GJAA; Murugesu, M
our authors
Albano Neto Carneiro Neto
Junior Researcher
Alexandre Manuel Pedroso Botas
Post-Doc Fellowship
Luís Carlos
Full professorGroups
G2 - Photonic, Electronic and Magnetic Materials
G3 - Electrochemical Materials, Interfaces and Coatings
acknowledgements
This study was supported by the MINCyT-uOttawa Project Optomagnetic Metal-Organic and Metal-Metalloporphyrin Frameworks Ot/14/03 (Ministerio de Ciencia, Tecnologia e Innovacion Productiva-University of Ottawa) and by MinCyT-ANPCyT projects PICT 2015-3526, PICT 20174651, and PICT 2018-04236. We are grateful to the University of Ottawa, Natural Sciences and Engineering Research Council of Canada, and the Canada Foundation for Innovation. G.E.G. thanks to CONICET (Consejo Nacional de Investigaciones Cientificas y Tecnicas) for the financial support and Carolina Cerizola for her unconditional support.