6272-94-2Relevant articles and documents
Black hybrid iodobismuthate containing linear anionic chains
Kotov, Vitalii Yu.,Ilyukhin, Andrey B.,Korlyukov, Alexander A.,Smol'Yakov, Alexander F.,Kozyukhin, Sergey A.
, p. 6354 - 6363 (2018)
Three hybrid 1,1′-(1,n-alkanediyl)bis(4-methylpyridinium) iodobismuthates 1-3 were prepared by a facile solution route and showed thermal stability in air up to 230 °C. The structures of solids 1 and 3 contain zero-dimensional anions, and the structure of 2 contains one-dimensional linear anionic chains [BiI5]n2n-. Photoluminescence (PL) in the spectral range between 600 and 750 nm was observed for 1 and 2. DFT calculations and optical studies confirmed that compounds 1-3 are semiconductors with band gaps of 1.73-2.10 eV, which correspond with their intense black (for 2) or red (for 1 and 3) colors. The optical absorption of 2 in the red spectral range is primarily due to charge transfer from the I5p orbitals at the top of the valence band to the Bi6p orbitals at the bottom of the conduction band.
Synthesis, thermal stability, crystal structure and optical properties of 1,1′-(1,n-alkanediyl)bis(4-methylpyridinium) bromobismuthates
Kotov, Vitalii Yu.,Ilyukhin, Andrey B.,Simonenko, Nikolai P.,Kozyukhin, Sergey A.
, p. 122 - 126 (2017/09/11)
Four hybrid 1,1′-(1,n-alkanediyl)bis(4-methylpyridinium) bromobismuthates, namely (PiC2)2Bi2Br10 (1), PiC4(H5O2)BiBr6·2H2O (2), (PiC5)2Bi2Br10 (3) and (PiC6)2(H5O2)Bi2Br11 (4), were prepared by a facile solution method. The crystal structures of 1 and 3 contain zero-dimensional Bi2Br10 anion units. A 2-D network structure consisting of {H5O2}[BiBr6]·2H2O interconnected by hydrogen bonds was found in 2 and a 1-D network structure consisting of {H5O2}[Bi2Br11] was observed in 4.
Kinetics and mechanism of the formation of N-vinyl pyridinium cations in elimination reactions in aqueous base
Bunting, John W.,Toth, Andrea,Kanter, James P.
, p. 1195 - 1203 (2007/10/02)
The rates of the elimination reactions of N-(2-bromoethyl) pyridinium cations (1) and N,N'-ethylene bispyridinium dications (3) to give the corresponding N-vinyl pyridinium cations (2) have been measured spectrophotometrically in basic aqueous solutions (ionic strength 0.1, 25 deg C) for a variety of substituents in the pyridine rings of each of these classes of pyridinium cation.The reaction kinetics are first order in 1 or 3 and first order in hydroxide ion.Bronsted-type plots of the second-order rate constants (kOH) as a function of the basicity (as pKBH) of the corresponding substituted pyridine are nonlinear for each of 1 and 3 and can be interpreted in terms of E1cb reaction mechanism.For 1, the Bronsted-type plot displays two distinct ''concave down'' linear regions; rate-determining deprotonation for pKBH > 5.16 (slope = -0.30), and a change in rate-determining step to bromide ion departure for pKBH > 5.16 (slope -0.58).For 3, the Bronsted-type plot appears to be smoothly curved for symmetrically disubstituted bispyridinium dications, as a consequence of the multiple substituent effects upon each step of the E1cb reactions of these dications.However, log kOH for 3 is a smooth linear function of the previously reported log kOH for the E1cb reactions of N-(2-cyanoethyl) pyridinium cations over a range in which a change in rate-determining step has been directly demonstrated for these latter cations.Thus a change in rate-determining step as a function of pyridine basicity is also required within the E1cb mechanism for 3.The E1cb reactions of 1 are approximately 104-fold faster than the corresponding hydroxide ion catalyzed E2 eliminations from 2-phenylethyl bromides that are isoelectronic with 1.
