scholarly journals Absorption and Emission Spectra for C60 Anions

1994 ◽  
Vol 14 (1-3) ◽  
pp. 155-160 ◽  
Author(s):  
Tatsuhisa Kato
Keyword(s):  
Absorption Spectrum ◽  
Absorption Band ◽  
Theoretical Analysis ◽  
Room Temperature ◽  
Emission Spectra ◽  
Mirror Image ◽  
Ir Absorption ◽  
Near Ir ◽  
Laser Experiments ◽  
Ir Bands

Absorption spectra are detected for C60− and C602− produced electrolytically in solution at room temperature. Theoretical analysis of the spectrum of C60− by CNDO/S calculations gives an interpretation of the characteristic near-IR bands, the weak visible bands, and the strong bands in the UV region. The emission spectrum of C60− is a mirror image of the near-IR absorption band, and the detection of the emission reconfirms our original assignment of the absorption spectrum. The nature of the spectrum of C602− is characterized by a similar orbital picture to that of C60−. Further laser experiments of significance are proposed.

scholarly journals Local vibrational modes of vacancy-oxygen-related complexes at room temperature

2020 ◽  
Vol 56 (4) ◽  
pp. 480-487
Author(s):  
E. A. Tolkacheva ◽  
V. P. Markevich ◽  
L. I. Murin
Keyword(s):  
Absorption Band ◽  
Room Temperature ◽  
Clear Correlation ◽  
Ir Absorption ◽  
Oxygen Impurity ◽  
Interstitial Oxygen ◽  
Vibrational Modes ◽  
Oxygen Defect ◽  
Absorption Bands ◽  
Local Vibrational Modes

The isotopic content of natural silicon (28Si (92.23 %), 29Si (4.68 %) и 30Si (3.09 %)) affects noticeably the shape of IR absorption bands related to the oxygen impurity atoms. In the present work an attempt is undertaken to determine the positions of local vibrational modes (LVMs), related to quasimolecules 28Si16OS29Si and 28Si16OS30Si (OS – substitutional oxygen atom), for the absorption spectra measured at room temperature. An estimation of the isotopic shifts of corresponding modes is done by fitting the shape of the experimentally measured absorption band related to the vacancy–oxygen center in irradiated Si crystals. The LVM isotope shifts are found to be equal 2,2 ± 0.25 cm–1 for 28Si-16OS29Si and 4,3 ± 0,9 см–1 for 28Si-16OS30Si in relation to the basic band due to 28Si-16OS28Si, and the full width at half maximum of the A-center absorption band (28Si-16OS28Si) is 5,3 ± 0.25 cm–1. By means of infrared absorption spectroscopy a clear correlation between the disappearance of the divacancy (V2) in the temperature range 200–275 ºС and appearance of two absorption bands with their maxima at 825.8 and 839.2 cm–1 in irradiated oxygen-rich Si crystals is found. The band positioned at 825.8 cm–1 is assigned to a divacancy-oxygen defect V2O formed via an interaction of mobile V2 with interstitial oxygen (Oi ) atoms. The 839.2 cm–1 band is much more pronounced in neutron irradiated samples as compared to samples irradiated with electrons. We argue that it is related to a trivacancy–oxygen defect (V3O) formed via an interaction of mobile V3 with Oi atoms.

Observation of a near-IR absorption band of the fluorene excimer by photodissociation spectroscopy

1993 ◽  
Vol 97 (45) ◽  
pp. 11635-11638 ◽  
Author(s):  
Sheng Sun ◽  
Hiroyuki Saigusa ◽  
Edward C. Lim
Keyword(s):  
Absorption Band ◽  
Ir Absorption ◽  
Near Ir

Preparation and Properties of Gadolinium Homoleptic Double-and Triple-Decker Complexes Containing Tetrabenzoporphyrin Ligand

2013 ◽  
Vol 750-752 ◽  
pp. 1816-1821
Author(s):  
Qi Feng Liu
Keyword(s):  
Room Temperature ◽  
Spin Exchange ◽  
Spectroscopic Studies ◽  
Magnetic Interactions ◽  
Antiferromagnetic Coupling ◽  
Ir Absorption ◽  
Magnetic Studies ◽  
Absorption Bands ◽  
Near Ir ◽  
Sandwich Type

Two novel gadolinium sandwich-type complexes containing tetrabenzoporphyrin (TBP) ligands-Gd (TBP)2and Gd (TBP)3were prepared from porphyrin 1 and Gd (acac)3. nH2O under Ar by boiling 1, 2, 4-Tcb for 15~17h and 45~48 h respectively. Their structures are characterized by Uv-Vis, HR-MS and IR. The spectroscopic studies show that their longest-wavelength visible and near-IR absorption bands are obviously red-shifted due to the extension of the π conjugated systems in the TBP ring. The magnetic studies indicate that the observed value of χMT for Gd (TBP)2is close to the combined value of Gd (III) and porphyrin radical anion at room temperature and that antiferromagnetic interaction possibly results from the intramolecular spin exchange between the porphyrin π-radical electron and that the gadolinium f unpaired electrons dominates its magnetic properties over the whole temperature range while there is no magnetic interactions between two Gd (III) ions in Gd (TBP)3in the range from room temperature down to 20K and very weak antiferromagnetic coupling exsits between two Gd (III) ions below 20K.

Factors influencing the tunability of the near-IR absorption band of CuS nanoparticles

2017 ◽  
Vol 123 (8) ◽  
Author(s):  
Delfino Cornejo-Monroy ◽  
Luis A. Martínez-Ortega ◽  
Zaira Y. Castillo-Morán ◽  
Rey D. Molina-Arredondo ◽  
Salvador Noriega ◽  
...  
Keyword(s):  
Absorption Band ◽  
Ir Absorption ◽  
Near Ir ◽  
Factors Influencing

Study of Crystal Yb3+:Ca3Y2(BO3)4

2004 ◽  
Vol 19 (4) ◽  
pp. 1203-1207 ◽  
Author(s):  
Yan Wang ◽  
Chaoyang Tu ◽  
Changcang Huang ◽  
Zhenyu You
Keyword(s):  
Absorption Spectrum ◽  
Absorption Band ◽  
Emission Spectra ◽  
Czochralski Method ◽  
X Ray Diffraction ◽  
Broad Absorption ◽  
Broad Absorption Band ◽  
Orthorhombic System ◽  
X Ray ◽  
Broad Emission

Yb3+-doped single-crystal Ca3Y2(BO3)4 with dimension φ20 × 55 mm was grown by the Czochralski method. The structure of it was determined by x-ray diffraction. It belongs to the orthorhombic system, space group Pnma, with the following parameters: a= 7.1690(4), b = 15.4758(8), c = 8.5587(6) Å, V = 949.55(10)Å3, Mr = 537.51, Z = 2, Dc = 3.8 g/cm3, (MoKa) = 0.71073 Å, F(000) = 508, μ = 6.927 mm-1, final R = 0.0670, and wR = 0.1542 for 2975 independent reflections. The structure of Yb:Ca3Y2(BO3)4 is made up of three set of M-oxygen distorted polyhedrons, and three set of BO3 planar triangles. Ca2+ and Y3+ ions occupy three M sites statistically. Yb3+ ions substitute Y3+ ions to enter these three lattices. The adsorption and emission spectra were measured. It exhibits a broad absorption band ranging from 850 to 1000 nm in the absorption spectrum, which is well matched with the emission wavelength of a laser diode. A broad emission spectrum ranging from 927.95 to 1102.7 nm was observed under the excitation of 895 nm.

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