Results 251 to 260 of about 82,211 (300)

The13C NMR, UV and IR absorption spectra of pyridinedicarboxylic acids

Chemistry of Heterocyclic Compounds, 1999
The13C NMR, UV and IR absorption spectra of 2,3-, 2,4-, 2,5-, 2,6-, 3,4-, and 3,5-pyridinedicarboxylic acids were recorded and their spectral parameters were assigned. The influence of electronic properties of the substituents on the direction of the chemical shifts is discussed.
L. Wasylina, E. Kucharska, Z. Weglinski, A. Puszko   +3 more
openaire   +1 more source

Theoretical IR, Raman and NMR spectra of 1,2- and 1,3-dimethylenecyclobutane

Vibrational Spectroscopy, 2001
Abstract Equilibrium geometries, rotational constants, harmonic vibrational frequencies, infrared intensities, Raman activities, and 1 H and 13 C NMR spectra were calculated for 1,2-dimethylenecyclobutane and its less stable isomer 1,3-dimethylenecyclobutane by using MP2, DFT (B3PW91), and RHF theoretical methods involving the 6-311++G ∗∗ basis ...
Joanna E Rode, Jan Cz Dobrowolski, Michał H Jamróz, Marek A Borowiak   +3 more
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Experimental and theoretical study on IR and NMR spectra of several tetrachlorinated diphenyl sulfides

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2011
Tetrachlorinated diphenyl sulfides (TCDPSs) are environmentally interesting compounds. In this paper, both experimental and theoretical studies on IR and (1)H NMR as well as (13)C NMR chemical shifts of 4 synthesized TCDPSs have been carried out.
Ruijuan, Qu, Xuesheng, Zhang, Qi, Zhang, Xi, Yang, Zunyao, Wang, Liansheng, Wang   +5 more
openaire   +2 more sources

IR and/or NMR Spectra-Structure Correlations for Organophosphorus Compounds

Applied Spectroscopy, 1988
IR and/or NMR spectra-structure correlations are presented which are useful in the identification of organophosphorus compounds.
openaire   +1 more source

Isolation and Identification of 9-cis Astaxanthin by HPLC, FT-IR, and NMR Spectra

Journal of Applied Spectroscopy, 2021
This study aims to perform a detailed qualitative analysis of astaxanthin isomers. A rapid, open column chromatography method was developed to separate astaxanthin geometrical isomers in gram-scale levels. Chromatographic separation was performed using two silica gel columns with dichloromethane/n-hexane/diethyl ether (2:1:1, v/v/v) as elution system ...
Y. Wang, Y. Wu, T. Wang, D. Qiua
openaire   +1 more source

High-resolution1H NMR and IR spectra of OH-groups of oxide catalysts

Reaction Kinetics and Catalysis Letters, 1985
Chemical shifts in high-resolution PMR spectra of hydroxyl groups of SiO2, Al2O3, aluminosilicate, phosphate and H-ZSM-5 zeolite catalysts have been measured and compared with IR spectroscopic data and proton charges calculated by the MINDO/3 method.
V. M. Mastikhin, I. L. Mudrakovskii, N. S. Kotsarenko, L. G. Karakchiev, A. G. Pelmenshchikov, K. I. Zamaraev   +5 more
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Spectroscopic studies on soil organic fractions i. ir and nmr spectra

Soil Biology and Biochemistry, 1977
Abstract A study has been made using i.r. and n.m.r. spectroscopic techniques to investigate ten different organic fractions extracted in a series of mild organic solvents from a brown soil from Sardinia. The experimental results gave useful information about the nature of the extracted samples, which differ considerably from one another. Some of the
O. Sciacovelli, N. Senesi, V. Solinas, C. Testini   +3 more
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IR and/or NMR Spectra-Structure Correlations for Organonitrogen-Containing Compounds

Applied Spectroscopy, 1988
IR and/or NMR spectra-structure correlations have been developed which aid in the elucidation of molecular structure of organonitrogen-containing compounds.
openaire   +1 more source

NMR, IR and Raman spectra study of the structure of borate and borosilicate glasses

Journal of Non-Crystalline Solids, 1989
Abstract Comparative studies on the IR and NMR of some binary borate systems and ternary borosilicate systems were made. The results of NMR in R 2 OB 2 O 3 , La 2 O 3 B 2 O 3 and Na 2 OB 2 O 3 SiO 2 glass systems were measured and calculated using the phase diagram model.
Tang Yongxing, Jiang Zhonghong, Song Xiuyu   +2 more
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The13C NMR, UV and IR spectra of 2-fluoropyridine methyl derivatives

Chemistry of Heterocyclic Compounds, 1999
13C NMR, UV, and IR spectra of methyl derivatives of 2-fluoropyridine have been recorded. The influence of the substituents on the spectral characteristics of the compounds has been discussed. The electronic spectra have been calculated by a modified INDO method. Transition energies, intensities, and assignments are compared with UV spectra.
A. Puszko, H. Ciurla
openaire   +1 more source