scholarly journals Recent Advances in IR and UV/VIS Spectroscopic Characterization of the C76and C84Isomers of D2Symmetry

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Tamara Jovanović ◽  
Đuro Koruga ◽  
Branimir Jovančićević

The stable isomers of the higher fullerenes C76and C84with D2symmetry as well as the basic fullerenes C60and C70were isolated from carbon soot and characterized by the new and advanced methods, techniques, and processes. The validity of several semiempirical, ab initio, and DFT theoretical calculations in predicting the general pattern of IR absorption and the vibrational frequencies, as well as the molecular electronic structure of the C76and C84isomers of D2symmetry, is confirmed, based on recent experimental results. An excellent correlation was found between the previously reported theoretical data and the recently obtained experimental results for these molecules over the relevant spectral range for the identification of fullerenes. These results indicate that there are no errors in the calculations in the significant spectral regions, the assumptions that were based on previous comparisons with partial experimental results. Isolated fullerenes are important for their applications in electronic and optical devices, solar cells, optical limiting, sensors, polymers, nanophotonic materials, diagnostic and therapeutic agents, health and environment protection, and so forth.

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Tamara Jovanović ◽  
Djuro Koruga ◽  
Aleksandra Mitrović ◽  
Dragomir Stamenković ◽  
Gordana Dević

The only stable isomer of the higher fullerene C76 of D2 symmetry was isolated from carbon soot by the new and advanced extraction and chromatographic methods and processes. Characterization of the isolated C76-D2 was performed by the IR(KBr) and UV/VIS method in the absorption mode. All of the experimentally observed infrared and electronic absorption bands are in excellent agreement with the theoretical calculations for this fullerene. The molar absorptivity ε and the integrated molar absorptivity Ψ of the observed entire new series of various characteristic, both deconvoluted and convoluted IR absorption bands of the C76-D2 isomer, in different integration ranges were determined. In addition, the molar extinction coefficients of its UV/VIS absorption bands were determined. The obtained novel IR and UV/VIS spectroscopic parameters are significant for the quantitative assessment of C76-D2. All the presented data are important both for its qualitative and quantitative determination, either in natural resources on Earth and in space or in artificially synthesized materials, electronic and optical devices, optical limiters, sensors, polymers, solar cells, nanophotonic lenses, diagnostic and therapeutic agents, pharmaceutical substances, for targeted drug delivery, incorporation of metal atoms, in biomedical engineering, industry, applied optical science, batteries, catalysts and so forth.


2008 ◽  
Vol 22 (15) ◽  
pp. 1487-1495 ◽  
Author(s):  
YEXIA FAN ◽  
HONGTAO LI ◽  
LIANCHENG ZHAO

Congruent Ce (0.1 wt %): Cu (0.05 wt %): LiNbO 3 single crystals doped with 0, 1, 3, 4, 5, 6 mol% MgO respectively were grown by the Czochrolski method in air along the C direction. The inductively coupled plasma optical emission/mass spectrometry (ICP-OE/MS), the X-ray powder diffraction (XRD), the differential thermal analysis (DTA), the ultraviolet-visible (UV-Vis) absorption spectra and the infrared (IR) absorption spectrum were measured and discussed in terms of the spectroscopic characterization and the defect structure of the Mg:Ce:Cu:LiNbO 3 crystals. The results indicated that the Mg:Ce:Cu:LiNbO 3 crystal grown from the congruent composition melt showed large [ Li ]/[ Nb ] ratios, which was closer to stoichiometry, an increase in the Curie temperature and a non-linear shift in the absorption edge with MgO concentration increasing. The threshold concentration of MgO in Mg:Ce:Cu:LiNbO 3 of nearly 5.52 mol% was estimated.


2010 ◽  
Vol 63 (12) ◽  
pp. 1634 ◽  
Author(s):  
Patrik Neuhaus ◽  
Stefan Henkel ◽  
Wolfram Sander

The elusive diradicals α,2- and α,4-didehydrotoluene 1 and 3, have been generated by photolysis of matrix-isolated 2-iodobenzyl iodide 7 and 4-iodobenzyl iodide 8, respectively. Diradical 3 could also be synthesized by flash vacuum thermolysis of 8, with subsequent trapping of the products in argon at 5 K. The diradicals in their triplet ground states were characterized by electron paramagnetic resonance spectroscopy. The triplet ground states were in accordance with previous theoretical calculations for these species.


2013 ◽  
Vol 21 (1) ◽  
pp. 64-74 ◽  
Author(s):  
T. Jovanovic ◽  
Dj. Koruga ◽  
B. Jovancicevic ◽  
V. Vajs ◽  
G. Devic

2014 ◽  
Vol 148 (3) ◽  
pp. 744-750
Author(s):  
Kornelia Lewandowska ◽  
Boleslaw Barszcz ◽  
Andrzej Graja ◽  
Sun Young Nam ◽  
Yi-Seul Han ◽  
...  

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