Enhancing the Luminescence of Eu(III) Complexes with the Ruthenocene Organometallic Unit as Ancillary Ligand

resumo

Five novel Eu(III)-beta-diketonate complexes containing ruthenocene ancillary ligands (1,1 '-bis(diphenylphosphoryl)-ruthenocene-RcBPO) were synthesized and characterized. The coordination compounds presented the general formula [Eu(beta-dik)3(RcBPO)], where beta-dik stands for 2-thenoyltrifluoroacetonate (tta), 3-benzoyl-1,1,1-trifluoroacetone (btf), 2-dibenzoylmethanate (dbm), 2-acetyl-1,3-indandionate (aind), and 2-benzoyl-1,3-indandionate (bind), and RcBPO stands for 1,1 '-bis-(diphenylphosphoryl)ruthenocene. The [Eu(aind)(3)(RcBPO)] complex crystallizes in a monoclinic Cc non-centrosymmetric space group with the europium site environment, assuming a bicapped trigonal prism coordination polyhedron with the symmetry point group close to C-2v. Photoluminescent properties for the solid-state samples were described in terms of excitation, emission, lifetime decay curves, and intrinsic and overall quantum yields. The replacement of the two coordinated H2O molecules by the RcBPO ancillary ligand leads to great enhancements of the overall quantum yields (Q(Eu)(L) ), with the minimum increment by a factor of 5 for the case of [Eu(btf)(3)(RcBPO)] and the maximum enhancement of 270 times for the case of the [Eu(dbm)(3)(RcBPO)] complex. In addition, theoretical calculations were carried out to model the spectroscopic properties of the investigated compounds. To obtain theoretical Judd-Ofelt parameters (omega(lambda), lambda = 2, 4, and 6) and intramolecular energy transfer rates, the JOYSpectra web platform was employed using the structure obtained from density functional theory calculations. Hence, a rate equation model provided theoretical overall quantum yields, which are in great agreement with measured data.

palavras-chave

INTRAMOLECULAR ENERGY-TRANSFER; CHARGE-TRANSFER STATE; LANTHANIDE COMPLEXES; SPECTROSCOPIC PROPERTIES; INTENSITY PARAMETERS; MOLECULAR-STRUCTURES; SOLID-STATE; BASIS-SETS; EU3+ ION; COORDINATION

categoria

Chemistry

autores

Moura, JL; Costa, IF; Santos, PRS; Silva, IF; Moura, RT; Neto, ANC; Faustino, WM; Brito, HF; Sabino, JR; Teotonio, EES

Grupos

G2 - Materiais Fotónicos, Eletrónicos e Magnéticos

Projectos

CICECO - Aveiro Institute of Materials (UIDB/50011/2020)

CICECO - Aveiro Institute of Materials (UIDP/50011/2020)

The shape of water: Nanothermometry as a tool to unveil the structure of liquid water and water-based nanofluids (THE SHAPE OF WATER )

agradecimentos

This work was funded by the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPQ) via the project 313195/2018-8 and Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES) via the project 88887.647236/2021-00. It was also developed within the scope of the projects CICECO-Aveiro Institute of Materials (UIDB/50011/2020 and UIDP/50011/2020) financed by Portuguese funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement. A.N.C.N. also thanks FCT project PTCRIS: PTDC/NAN-PRO/3881/2020. R.T.M., Jr. thanks SMU?s Center for Scientific Computing for providing generous computational resources.