Preparation of supramolecular - MOF systems containing rare earth ions and their photoluminescent properties investigation

• Grant number: 13/07521-6
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Effective date (Start): July 01, 2013
• Effective date (End): March 31, 2018
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Hermi Felinto de Brito
• Grantee: Cesar dos Santos Cunha
• Host Institution: Instituto de Química (IQ). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated scholarship(s): 16/03640-9 - High-throughput investigation of new rare earth-doped bismuth-based metal-organic frameworks (MOFs), BE.EP.DD

Abstract

Despite the study of photoluminescence of supramolecular Metal Organic Framework (MOFs) systems has attracted the attention of the scientific community it remains underexplored. One of the main important characteristics of this material in terms of luminescent device application it is their higher emission quantum yield and life time compared with precursors complexes in solution due to rigidity imposed by their structures. In this project porous MOFs crystals are synthesized by the hydrothermal method and in ambient conditions. These MOFs systems can be represented as M3(BTC=1,3,5-benzeno-tricarboxilato)2 e (HPA-ácido fosfotungistico-H3PW12O40)@M3(BTC)2 where M correspond to divalent metallic ions: Zn2+, Ca2+, Ba2+, Sr2+ and Cd2+, doped with trivalent rare earth ions (TR3+: Sm3+, Eu3+, Gd3+, Dy3+, Tb3+ and Tm3+). In this case, the TR3+ ions are incorporated within the MOFs, in the following ways: I) during the synthesis and II) through ion exchange by suspending the crystals in solution containing rare earths ions. The information about the structure and anisotropy of the materials are obtained using the techniques like elemental analysis (CHN), x-ray diffraction - powder method (PXRD), small-angle x-ray scattering (SAXS), termoanalyzes (DTG/DTA/DSC), scanning electron microscopy (SEM) and extended x-ray absorption fine structure (EXAFS).The photoluminescent properties of the materials are studied using the excitation and emission spectra of the MOFs. Also are determined the life time of the emitting level, quantum efficiency, emission quantum yields, experimental intensities parameters, spontaneous emission coefficients and monochromatic character by the color coordinates. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

CÉSAR S. CUNHA; OSCAR L. MALTA; HUAYNA TERRASCHKE; HERMI F. BRITO. Photoluminescent Investigation of the Doping Site of Eu3+-Doped [Zn3(BTC)2·12H2O] Metal-Organic Framework Prepared by Microwave-Assisted Hydrothermal Synthesis. Journal of the Brazilian Chemical Society, v. 31, n. 11, p. 2409-2420, 2020-10-30. (16/03640-9, 13/07521-6)

CUNHA, C. S.; KOEPPEN, M.; TERRASCHKE, H.; FRIEDRICHS, G.; MALTA, O. L.; STOCK, N.; BRITO, H. F.. Luminescence tuning and single-phase white light emitters based on rare earth ions doped into a bismuth coordination network. JOURNAL OF MATERIALS CHEMISTRY C, v. 6, n. 46, p. 12668-12678, DEC 14 2018. (16/03640-9, 13/07521-6)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

CUNHA, Cesar dos Santos. Photoluminescent emission color tuning of the coordination network [Bi(HPyr)] doped with RE3+ ions. 2018. Doctoral Thesis - Universidade de São Paulo (USP). Conjunto das Químicas (IQ e FCF) (CQ/DBDCQ) São Paulo.