Brightly Luminescent (TbxLu1-x)2bdc3·nH2O MOFs: Effect of Synthesis Conditions on Structure and Luminescent Properties

Viktor G Nosov; Yulia N Toikka; Anna S Petrova; Oleg S Butorlin; Ilya E Kolesnikov; Sergey N Orlov; Mikhail N Ryazantsev; Stefaniia S Kolesnik; Nikita A Bogachev; Mikhail Yu Skripkin; Andrey S Mereshchenko

doi:10.3390/molecules28052378

Brightly Luminescent (Tb_xLu_1-x)₂bdc₃·nH₂O MOFs: Effect of Synthesis Conditions on Structure and Luminescent Properties

Molecules. 2023 Mar 4;28(5):2378. doi: 10.3390/molecules28052378.

Authors

Affiliations

¹ Saint-Petersburg State University, 7/9 Universitetskaya emb., 199034 St. Petersburg, Russia.
² Federal State Unitary Enterprise "Alexandrov Research Institute of Technology", 72 Koporskoe Shosse, 188540 Sosnovy Bor, Russia.
³ Institute of Nuclear Industry, Peter the Great St. Petersburg Polytechnic University (SPbSU), 29 Polytechnicheskaya Street, 195251 St. Petersburg, Russia.
⁴ Nanotechnology Research and Education Centre RAS, Saint Petersburg Academic University, ul. Khlopina 8/3, 194021 St. Petersburg, Russia.

Abstract

Luminescent, heterometallic terbium(III)-lutetium(III) terephthalate metal-organic frameworks (MOFs) were synthesized via direct reaction between aqueous solutions of disodium terephthalate and nitrates of corresponding lanthanides by using two methods: synthesis from diluted and concentrated solutions. For (Tb_xLu_1-x)₂bdc₃·nH₂O MOFs (bdc = 1,4-benzenedicarboxylate) containing more than 30 at. % of Tb³⁺, only one crystalline phase was formed: Ln₂bdc₃·4H₂O. At lower Tb³⁺ concentrations, MOFs crystallized as the mixture of Ln₂bdc₃·4H₂O and Ln₂bdc₃·10H₂O (diluted solutions) or Ln₂bdc₃ (concentrated solutions). All synthesized samples that contained Tb³⁺ ions demonstrated bright green luminescence upon excitation into the ¹ππ* excited state of terephthalate ions. The photoluminescence quantum yields (PLQY) of the compounds corresponding to the Ln₂bdc₃ crystalline phase were significantly larger than for Ln₂bdc₃·4H₂O and Ln₂bdc₃·10H₂O phases due to absence of quenching from water molecules possessing high-energy O-H vibrational modes. One of the synthesized materials, namely, (Tb_0.1Lu_0.9)₂bdc₃·1.4H₂O, had one of the highest PLQY among Tb-based MOFs, 95%.

Keywords: antenna effect; luminescence; lutetium; metal–organic framework; rare earth; terbium.

Grants and funding

22-73-10040/Russian Science Foundation