Results 261 to 270 of about 82,211 (300)

Analysis of NMR and FT-IR spectra on the bis(substituted cyclopentadienyl)dichlorides of titanium and zirconium

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2008
The NMR and FT-IR spectra of 10 (etaC6H9CRR'-Cp)2MCl2 (M=Ti, Zr) were measured. Results indicate that the metal atom formed bond combination with the center of cyclopentadienyl. NMR spectra move to high field when electronegativity decreases. The electronegativity difference of Ti and Zr mainly influences their IR spectra at the far-infrared range. The
Jianbo, Zhang, Zhenqiang, Xu, Yueru, Zong, Zhenhua, Xu, Shoushan, Chen   +4 more
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13C NMR, 1H NMR and IR spectra of a series of monochloroesters of aliphatic short chain carboxylic acids

Tetrahedron, 1981
Abstract 13 C chemical shifts for 14 isomeric monochloroesters of aliphatic carboxylic acids from propanoic acid to hexanoic acid have been determined. Comparisons are made with the literature values for methyl monochloro-octanoate isomers. Substituent effects for all positions are given.
Maija T. Pitkänen, Ilpo O.O. Korhonen, Jorma N.J. Korvola   +2 more
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NMR and IR spectra-structure correlations for carbonyl containing compounds in various solvents

Journal of Molecular Structure, 1996
Abstract The δ 13 CO chemical shifts and the carbonyl stretching frequencies ν CO are affected by their physical surroundings, and information about the chemical structure can be obtained by study of δ 13 CO and ν CO in various solvents or solvent systems.
R.A. Nyquist, R. Streck, G. Jeschek
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Multimodal Machine Learning for Molecular Identification Based on IR, Raman, and NMR Spectra

The Journal of Physical Chemistry Letters
Accurate molecular structure recognition is vital in chemistry and drug discovery, yet single-spectrum methods often struggle with limited accuracy and robustness. Here, we present a multimodal machine learning framework based on our previously developed TranSpec to integrate IR, Raman, and NMR spectra for precise structure prediction.
Sheng Wu, Shengjiao Ji, Mingzhi Yuan, Jun Jiang, Yi Luo, Wei Hu   +5 more
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Coordination Properties of Magnesium in Chlorophyll from IR and NMR Spectra

1968
The infrared (IR) and nuclear magnetic resonance (NMR) spectra of chlorophyll are best interpreted on the basis that the central magnesium atom of the chlorophyll always has a coordination number larger than 4. In electron-donor solvents, chlorophyll exists as monomer, with solvent molecules filling the axial position(s).
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Structure, IR, and NMR spectra of tetrakis(4-methyl piperidinedithiocarbamate) dimercury(II)

Journal of Crystallographic and Spectroscopic Research, 1988
The compound C14H24HgN2S4 was prepared and characterized by means of X-ray, IR, and NMR measurements. The crystals are monoclinic, space group P21/c, (No. 14) witha=8.697(2),b=19.156(3),c=12.098(2) A,β=108.14(1)° andZ=4. The structure was solved by the heavy-atom method, and least-squares refinement of structural parameters led to a conventionalR ...
Adriano Benedetti, Antonio C. Fabretti, Carlo Preti   +2 more
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Hydrogen bonding of N-methylacetamide in CDCl3 solution studied by NMR and IR spectra

Spectrochimica Acta Part A: Molecular Spectroscopy, 1994
Abstract The amide proton NMR chemical shifts have been widely used for the determination of the population fraction of the non-hydrogen-bonded states in studies of hydrogen bonding in peptides and proteins. However, in such works the determination of the limiting chemical shifts for the fully hydrogen-bonded state and for the non-hydrogen-bonded ...
Minoru Akiyama, Toshiaki Ohtani
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Density functional theory study on lactides: Geometries, IR, NMR and electronic spectra

Journal of Molecular Structure: THEOCHEM, 2007
Abstract Density functional theory (DFT) has been used to determine the equilibrium geometries, IR, total energies and NMR chemical shifts of various kinds of lactides. According to the calculations, besides l -lactide and d -lactide, three kinds of meso-lactides have been obtained: meso-i-lactide, meso-α-lactide and meso-β-lactide.
Wenpeng Wu, Wenbin Li, Lianbin Wang, Puyu Zhang, Jinglai Zhang   +4 more
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Reactions of O-silyl selenocarboxylates; IR and NMR spectra of heteroatom-substituted selenocarboxylates

Journal of the Chemical Society, Perkin Transactions 1, 1994
O-Silyl selenocarboxylates 1 react readily with acyl chlorides to give selenoanhydrides. Attempts to synthesize unsymmetrical selenoanhydrides selectively gave mixtures of the desired products with symmetrical selenoanhydrides. Ph3GeCl, Ph3SnCl, Ph3PbCl, Ph2PCl and Ph2AsCl were treated with 1 to give the corresponding selenocarboxylates containing a Se–
Hideki Kageyama, Kenji Kido, Shinzi Kato, Toshiaki Murai   +3 more
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Experimental and theoretical studies on compositions, structures, and IR and NMR spectra of functionalized protic ionic liquids

Physical Chemistry Chemical Physics, 2016
DMCEAP and DMEOAP are composed of neutral and ionized species in the liquid phase as investigated through experimental spectroscopy and DFT calculations.
Yingna, Cui, Jingmei, Yin, Changping, Li, Shenmin, Li, Ailing, Wang, Guang, Yang, Yingping, Jia   +6 more
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