Article

Synchrotron X-ray, Photoluminescence, and Quantum Chemistry Studies of Bismuth-Embedded Dehydrated Zeolite Y

International Center for Young Scientists, 1-2-1 Sengen, Tsukuba-city, Ibaraki 305-0047, Japan.
Journal of the American Chemical Society (Impact Factor: 11.44). 02/2012; 134(6):2918-21. DOI: 10.1021/ja211426b
Source: PubMed

ABSTRACT For the first time, direct experimental evidence of the formation of monovalent Bi (i.e., Bi(+)) in zeolite Y is provided based on the analysis of high-resolution synchrotron powder X-ray diffraction data. Photoluminescence results as well as quantum chemistry calculations suggest that the substructures of Bi(+) in the sodalite cages contribute to the ultrabroad near-infrared emission. These results not only enrich the well-established spectrum of optically active zeolites and deepen the understanding of bismuth related photophysical behaviors, but also may raise new possibilities for the design and synthesis of novel hybrid nanoporous photonic materials activated by other heavier p-block elements.

0 Followers
 · 
136 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: The series of quantum chemical calculations for model molecular system, consisted of monocation Me+ (Bi+ or alkali metal cations), surrounded by two weakly coordinating BF4- anions were performed. It was demonstrated, that in this model system, the Me+-BF4- distances, which corresponds to ground state electronic energy minimum are in good correlation with the values of Shannon crystal ionic radii for corresponding monocations. Taking advantage of this correlation it is possible to estimate the unknown crystal ionic radius of Bi+ monocation from CASSCF/Spin–orbit CI calculations for Bi+-containing model system. The estimated value of crystal ionic radius places the bismuth monocation in size near Rb+. The isomorphous substitution of Bi+ for K+, Rb+, Cs+ is possible in different crystal hosts.
    Computational and Theoretical Chemistry 08/2013; 1017:159–161. DOI:10.1016/j.comptc.2013.05.020 · 1.37 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The photophysical properties of Bi82+ and Bi53+ polycations stabilized by [AlCl4]- have been studied experimentally and theoretically. The obtained product was thoroughly evaluated by powder X-ray diffraction and photoluminescence spectroscopy, making it clear that both Bi82+ and Bi53+ contribute to the observed broad near-infrared emission. Furthermore, it was revealed that Bi82+ polycation mainly results in the emission peaking at ca. 1180 nm, while Bi53+ the longer-wavelength emission. The following quantum chemistry calculation on Bi82+ polycation helps us attribute some observed excitation bands in the visible spectral range to specific electronic transitions of bismuth polycations. It is believed that systematical investigation of structural and luminescent properties as well as detailed quantum chemistry calculation of molecular crystals containing such kinds of bismuth units allows us to obtain a clearer picture on bismuth-related photophysical behaviors, which not only serve to solve the confusions on the luminescence origin of bismuth in other material systems such as bulk glasses, glass fibers and conventional crystals, but also is helpful to develop novel applicable broadband tunable laser mediums.
    Journal of Materials Chemistry 02/2012; 22(25). DOI:10.1039/C2JM30251A · 7.44 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: For the first time, we report that a single crystal of (K-crypt)2Bi2 containing [Bi2]2+ displays ultra-broad near-infrared photoluminescence (PL) peaking at around 1190 nm and having a full width at the half maximum of 212 nm, stemming from the inherent electronic transitions of [Bi2]2+.The results not only add to the number of charged Bi species with luminescence, but also deepen the understanding of Bi-related near-infrared emission behavior and lead to the reconsideration of the fundamentally important issue of Bi-related PL mechanisms in some material systems such as bulk glasses, fibers, and conventional optical crystals.
    Journal of Materials Chemistry 05/2012; 22(38). DOI:10.1039/C2JM34101H · 7.44 Impact Factor