Browsing by Author "Raj, Ankit"

Now showing 1 - 4 of 4

Linear, mixed-valent homocatenated tri-tin complexes featuring Sn-Sn bonds
(2020-06-25)
Chang, Wei-Chieh
;
Raj, Ankit
;
Hiramatsu, Hirotsugu
;
Li, Han-Jung
;
Ziegler, Micah S.
A series of tri-tin complexes((LSn)-Sn-Ph)(3)Xwith triple-decker structures (L-Ph= 2,5-di(o-pyridyl)-3,4-diphenylpyrrolate; X = Cl, AlCl4, OTf, and PF6) was synthesized by reducingL(Ph)SnClwith (LiBBu3H)-Bu-s and subsequent reactions. Structural characterization of((LSn)-Sn-Ph)(3)Clrevealed a Sn-Sn-Sn core, and DFT calculations suggest that its HOMO is primarily sigma-bonding along the tri-tin framework.((LSn)-Sn-Ph)(3)Clreacts with W(CO)(5)THF to afford((LSn)-Sn-Ph)(2)(W(CO)(5))(2)andL(Ph)SnCl, implying that((LSn)-Sn-Ph)(3)Clmay exhibit dynamic behavior in solution.
Polarizability tensor invariants of H-2, HD, and D-2
(2018-03-14)
Raj, Ankit
;
Hamaguchi, Hiro-o
;
Witek, Henryk A.
;
應用化學系
;
應用化學系分子科學碩博班
We report an exhaustive compilation of wavelength-dependent matrix elements over the mean polarizability ((alpha) over bar) and polarizability anisotropy (gamma) operators for the rovibrational states of the H-2, HD, and D-2 molecules together with an accompanying computer program for their evaluation. The matrix elements can be readily evaluated using the provided codes for rovibrational states with J = 0-15 and v = 0-4 and for any laser wavelengths in the interval 182.25-1320.6 nm corresponding to popular, commercially available lasers. The presented results substantially extend the scope of the data available in the literature, both in respect of the rovibrational transitions analyzed and the range of covered laser frequencies. The presented detailed tabulation of accurate polarizability tensor invariants is essential for successful realization of our main long-term goal: developing a universal standard for determining absolute Raman cross sections and absolute Raman intensities in experimental Rayleigh and Raman scattering studies of molecules. Published by AIP Publishing.
Toward standardization of Raman spectroscopy: Accurate wavenumber and intensity calibration using rotational Raman spectra of H-2, HD, D-2, and vibration-rotation spectrum of O-2
(1970-01-01)
Raj, Ankit
;
Kato, Chihiro
;
Witek, Henryk A.
;
Hamaguchi, Hiro-o
;
交大名義發表
Wavenumber and intensity calibration of a Raman spectrometer is performed with the use of pure rotational Raman bands(Delta nu = 0, Delta J = +/- 2) of H-2, HD, D-2, and vibration-rotation Raman bands (Delta nu = 1, Delta J = +/- 2) of O-2 as primary standards. Wavenumber calibration is based on reference transition wavenumbers available from accurate theoretical and experimental results. Intensity calibration is based on ratios of accurate theoretical Raman intensities for transitions from common rotational states to eliminate temperature effects. Polarization dependence is corrected to ensure that all of these bands have the correct depolarization ratio, rho = 0.75. The calibrated Raman spectrometer is used to measure standard Raman spectra of carbon tetrachloride, benzene, cyclohexane, toluene, and benzonitrile, for which the relative Raman intensities and depolarization ratios are determined with carefully estimated uncertainties. Vibrational frequencies of indene used for routine wavenumber calibration are updated.
Vibration-rotation interactions in H-2, HD and D-2 : centrifugal distortion factors and the derivatives of polarisability invariants
(1970-01-01)
Raj, Ankit
;
Witek, Henryk A.
;
Hamaguchi, Hiro-o
;
應用化學系
;
應用化學系分子科學碩博班
We report the correction factors for centrifugal distortion in Raman intensities for pure rotation (O0- and S0-branch) and vibration-rotation (O1- and S1-branch) transitions in the ground electronic state of H-2, HD and . These factors are presented for 52 selected excitation wavelengths and for the initial rotational states, . This data is useful in applications of intensity calibration of spectrometers and the spectroscopy of flames. The classical treatment of centrifugal distortion involved the expansion of polarisability anisotropy (gamma) over the internuclear distance, while assuming the diatomic molecule behaves as a harmonic oscillator. Here, this approximation of polarisability invariants as a Taylor series expansion is tested, revealing that truncation up to the second-order derivatives of mean polarisability () and polarisability anisotropy (gamma) gives faithful representations, yielding accurate expectation values with error , for the ground rovibrational state and for the fundamental transition. [GRAPHICS] .