Columnar discotic Pt(II) metallomesogens as luminescence multifunctional materials with chemo and thermosensor abilities

resumo

A new family of Pt(II) luminescent metallomesogens based on dicatenar pyridylpyrazolate ligands [Pt(pz(R(n,n)py))(2)] (R(n,n) = C6H3(OCnH2n+1)(2), n = 4-18) has been prepared, and their mesomorphic and photophysical properties are described. The compounds were isolated as red (n = 4-8) or yellow (n = 10-18) solids at room temperature, but the first ones were converted to yellow crystals by slow evaporation of a chloroform-acetone mixed solution. All of them behave as discotic liquid crystal materials, exhibiting hexagonal columnar mesophases (Col(h)) in a wide range of temperatures. Photoluminescence studies in the solid state at variable temperatures showed a high emission in the liquid crystalline phase, which was significantly red-shifted with respect to the yellow-green emission of the solid state. This photophysical change was attributed to the formation of aggregates through Pt(d(z)(2))-Pt(d(z)(2)) interactions, thereby giving rise to the metal-metal-to-ligand charge transfers ((MMLCT)-M-3) responsible for the luminescence observed. Taking advantage of these properties we have fabricated polymeric solid supports doped with the platinum complex [Pt(pz(R(10,10)py))(2)], which can be used as temperature sensors for real technological applications. In addition, the Pt-bispyrazolate complexes and their corresponding pyrazole ligands have been proved to be useful as chemosensors towards Pd2+, Zn2+, Cd2+ and Hg2+ metal ions.

palavras-chave

DENSITY-FUNCTIONAL THEORY; EXCITATION-ENERGIES; LIQUID-CRYSTAL; FLUORESCENT CHEMOSENSOR; GEOMETRIC DERIVATIVES; LIVING CELLS; COMPLEXES; PYRAZOLE; HG2+; LIGANDS

categoria

Materials Science; Physics

autores

Cuerva, C; Campo, JA; Ovejero, P; Torres, MR; Oliveira, E; Santos, SM; Lodeiro, C; Cano, M

Grupos

agradecimentos

M. Cano is grateful to the Ministerio de Economia y Competitividad (Spain), project CTQ2011-25172. E. Oliveira acknowledges the post-doctoral grant from Fundacao para a Ciencia e a Tecnologia (Portugal) SFRH/BPD/72557/2010. PROTEOMASS Scientific Society (Portugal) and PROTEOMASS Scientific Society (Spain) are also acknowledged for funding. C. Lodeiro thanks REQUIMTE-FCT PEst-C/EQB/LA0006/2013 for funding. We would like to thank Prof. Guillermo Orellana and Dr Ana Bel en Descalzo for their contribution and help with the lifetime measurement.

Partilhe este projeto

Publicações similares

Usamos cookies para atividades de marketing e para lhe oferecer uma melhor experiência de navegação. Ao clicar em “Aceitar Cookies” você concorda com nossa política de cookies. Leia sobre como usamos cookies clicando em "Política de Privacidade e Cookies".