Carneiro Neto AN, Nasalska J, Gawryszewska P, Trush VA, Sokolnicki J, Malta OL, Legendziewicz J. Intramolecular energy transfer and its influence on the overall quantum yields of Eu
3+ and Tb
3+ chelates with dimethyl(phenylsulfonyl)amidophosphate ligands.
SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024;
324:124875. [PMID:
39137707 DOI:
10.1016/j.saa.2024.124875]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 07/06/2024] [Accepted: 07/22/2024] [Indexed: 08/15/2024]
Abstract
Lanthanide chelates with dimethyl(phenylsulfonyl)amidophosphate (labeled as HSP) and Lewis base ligands (bpy = 2,2;-bipyridine and phen = 1,10-phenanthroline) of formula Na[Ln(SP)4] (1Ln), [Ln(SP)3bpy] (2Ln); [Ln(SP)3phen] (3Ln) (Ln = Eu3+, Gd3+, Tb3+ and Lu3+) were obtained and characterized by the X-ray, photoluminescence spectroscopy at 293 and 77 K as well as by intrinsic (QLnLn) and overall (QLnL) luminescence quantum yields. These phosphors manifest a very strong emission after excitation in the UV range of the molecular singlet states (S1) and two of them have very high QLnL values (Eu3+ and Tb3+ chelates of the type 2Ln and 3Ln). The dynamics of the excited states are discussed based on the intramolecular energy transfer theory, considering the dipole-dipole, the dipole-multipole and the exchange mechanisms. From the calculated energy transfer rates, a rate equation model was constructed and, thus, the theoretical QLnL can be obtained. A good correlation between the experimentally determined and theoretically calculated QLnL values was achieved, with the triplet state (T1) playing a predominant role in the energy transfer process for Eu3+ compounds, while the sensitization for Tb3+ compounds is dominated by the energy transfer rates from the singlet state (S1).
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