SCIENTIFIC HIGHLIGHTS

Excimers from Stable and Persistent Supramolecular Radical-Pairs in Red/NIR-Emitting Organic Nanoparticles and Polymeric
06 November 2017
D. Blasi, D. M. Nikolaidou, F.Terenziani,* I. Ratera,* J. Veciana. Phys. Chem. Chem. Phys., 2017,19, 9313-9319. DOI: 10.1039/C7CP00623C


In this work, the luminescence properties of new materials based on open-shell molecular systems are studied. In particular, we prepared polymeric films and organic nanoparticles (ONPs) doped with triphenylmethyl radical molecules. ONPs exhibit uniform size distribution, spherical morphology and high colloidal stability. The emission spectrum of low doped ONP suspensions and low-doped films is very similar to the emission spectrum of TTM in solution, while the luminescence lifetime and the luminescence quantum yield (LQY) are highly increased. Increasing the radical doping leads to a progressive decrease of the LQY and the appearance of a new broad excimeric band at longer wavelengths, both for ONPs and films. Thus, not only the luminescence properties were improved, but also the formation of excimers from stable and persistent supramolecular radical-pairs was observed for the first time. The good stability and luminescence properties with emission in the biological window in the red-NIR region (650-800 nm), together with the open-shell nature of the emitter, make these free-radical excimer-forming materials promising candidates for optoelectronics and bioimaging applications.

 

 

 

Hits: 2756
Oxides for new-generation electronics

Excimers from Stable and Persistent Supramolecular Radical-Pairs in Red/NIR-Emitting Organic Nanoparticles and Polymeric



Also at ICMAB

  • Epitaxial Ferroelectric HfO2 Films: Growth, Properties, and Devices

    Information
    25 May 2021 207 hit(s) Oxides
    About ten years after ferroelectricity was first reported in doped HfO2 polycrystalline films, there is tremendous interest in this material and ferroelectric oxides are once again in the spotlight of the memories industry. Great efforts are being made to understand and control ferroelectric properties. Epitaxial films, which have fewer defects and a more controlled microstructure than polycrystalline films, can be very useful for this purpose. Epitaxial films of ferroelectric HfO2 have been much less investigated, but after the first report in 2015 significant progress has been achieved.
  • Structure and phase transitions in A-site ordered RBaMn2O6(R=Pr,Nd) -perovskites with a polar ground state

    Information
    14 May 2021 225 hit(s) Oxides
    We report here a structural study of RBaMn2O6 (R=La, Pr, and Nd) compounds by means of synchrotron radiation x-ray powder diffraction and Raman spectroscopy. The three compounds are A-site ordered perovskites adopting the prototypical tetragonal structure at high temperature. A ferromagnetic transition is observed in the LaBaMn2O6 sample and the lattice parameters undergo anisotropic changes at TC related to the orientation of the magnetic moments.
  • Tuning the tilting of the spiral plane by Mn doping in YBaCuFeO5 multiferroic

    Information
    23 April 2021 304 hit(s) Oxides
    The layered perovskite YBaCuFeO5 (YBCFO) is considered one of the best candidates to high-temperature chiral multiferroics with strong magnetoelectric coupling. In RBaCuFeO5 perovskites (R: rare-earth or Y) A-site cations are fully ordered whereas their magnetic properties strongly depend on the preparation process. They exhibit partial cationic disorder at the B-site that generates a magnetic spiral stabilized through directionally assisted long range coupling between canted locally frustrated spins.
  • New Sensitive and Selective Chemical Sensors for Ni2+ and Cu2+ Ions: Insights into the Sensing Mechanism through DFT Methods

    Information
    09 April 2021 346 hit(s) Oxides
    We report the synthesis and theoretical study of two new colorimetric chemosensors with special selectivity and sensitivity to Ni2+ and Cu2+ ions over other metal cations in the CH3CN/H2O solution. Compounds (E)-4-((2-nitrophenyl)diazenyl)-N,N-bis(pyridin-2-ylmethyl)aniline (A) and (E)-4-((3-nitrophenyl)diazenyl)-N,N-bis(pyridin-2-ylmethyl)aniline (B) exhibited a drastic color change from yellow to colorless, which allows the detection of the mentioned metal cations through different techniques.
  • Silicon nanowires as acetone-adsorptive media for diabetes diagnosis

    Information
    06 April 2021 456 hit(s) Oxides
    Early detection of diabetes, a worldwide health issue, is key for its successful treatment. Acetone is a marker of diabetes, and efficient, non-invasive detection can be achieved with the use of nanotechnology. In this paper we investigate the effect of acetone adsorption on the electronic properties of silicon nanowires (SiNWs) by means of density functional theory.

INSTITUT DE CIÈNCIA DE MATERIALS DE BARCELONA, Copyright © 2020 ICMAB-CSIC | Privacy Policy | This email address is being protected from spambots. You need JavaScript enabled to view it.