scholarly journals Effect of High Pressure on the Molecular Structure andπ-Electrons Delocalization of Canthaxanthin as Revealed by Raman Spectra

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Shun-li Ou-Yang ◽  
Nan-nan Wu ◽  
Yan-jie Tian
Keyword(s):  
Molecular Structure ◽  
High Pressure ◽  
Raman Spectra ◽  
Main Chain ◽  
Resonance Raman Spectroscopy ◽  
Electron Delocalization ◽  
Frequency Multiplication ◽  
Experimental Conditions ◽  
Band Frequency

The effect of high pressure on the molecular structure andπ-electron delocalization of canthaxanthin was studied byin situresonance Raman spectroscopy. Changes in the characteristic band frequency and the pressure of canthaxanthin were described. The effect of pressure onπ-electron delocalization was also discussed. Results show that the characteristic bands of canthaxanthin increase and reach high wavenumbers. The correlations between Raman frequency of the three main bands and pressure are listed as follows:ν1(C=C) = 3.43P+ 1512.3,ν2(C-C) = 3.29P+ 1156.1, andν3(CH3) = 2.16P+ 1006.3. The frequency multiplication of canthaxanthin changes as pressure is altered. The pressure effect on theν1(C=C) mode is more susceptible than on theν2(C-C) mode, which can be explained by the fact that theβ-ring twists to a larger angle from the plane of the conjugated main chain under high pressure, leading to a lower degree of theπ-electrons delocalization. The Raman spectra are recovered after the compression-decompression cycle indicating the canthaxanthin has no evident phase change under our experimental conditions.

In situ high pressure Raman spectra of Ba3(VO4)2

1997 ◽  
Vol 102 (8) ◽  
pp. 569-574 ◽  
Author(s):  
Andrzej Grzechnik ◽  
Paul F. McMillan
Keyword(s):  
High Pressure ◽  
Raman Spectra

Single Crystal Growth of High-Pressure Phases of Ice and Salt Hydrate Far Below the Original Melting Point by Mixing Alcohol: Crystal Structure Determination of Magnesium Chloride Heptahydrate

2020 ◽  
Author(s):  
Keishiro Yamashita ◽  
Kazuki Komatsu ◽  
Hiroyuki Kagi
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Crystal Growth ◽  
Single Crystal ◽  
Room Temperature ◽  
Growth Technique ◽  
Salt Hydrate ◽  
X Ray

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.

scholarly journals Cover Picture: A Versatile Ambient‐to‐High‐Pressure Reaction Transmission Cell for in situ/operando Infrared Spectroscopic Investigations (Chemistry ‐ Methods 7/2021)

2021 ◽  
Vol 1 (7) ◽  
pp. 305-305
Author(s):  
Jana Weiß ◽  
Christine Rautenberg ◽  
Thomas Rall ◽  
Christoph Kubis ◽  
Evgenii Kondratenko ◽  
...  
Keyword(s):  
High Pressure ◽  
Spectroscopic Investigations ◽  
Infrared Spectroscopic ◽  
High Pressure Reaction

Nitroethane at high density: an experimental and computational vibrational study

2021 ◽  
Vol 23 (15) ◽  
pp. 9325-9336
Author(s):  
Akio Yoshinaka ◽  
Serge Desgreniers ◽  
Anguang Hu
Keyword(s):  
High Pressure ◽  
Raman Spectra ◽  
Vibrational Spectra ◽  
Unit Cell ◽  
High Density ◽  
Monoclinic Unit Cell ◽  
Vibrational Study

Raman and IR vibrational spectra confirm two molecular units associated with the monoclinic unit cell of nitroethane under high pressure. Raman spectra are extremely sensitive to predicted effects of unit cell distortion due to changes in H-bonding.

scholarly journals A Versatile Ambient‐to‐High‐Pressure Reaction Transmission Cell for in situ/operando Infrared Spectroscopic Investigations

2021 ◽  
Vol 1 (7) ◽  
pp. 308-314
Author(s):  
Jana Weiß ◽  
Christine Rautenberg ◽  
Thomas Rall ◽  
Christoph Kubis ◽  
Evgenii Kondratenko ◽  
...  
Keyword(s):  
High Pressure ◽  
Spectroscopic Investigations ◽  
Infrared Spectroscopic ◽  
High Pressure Reaction

scholarly journals Structural Characterization of Heterodinuclear ZnII-LnIII Complexes (Ln = Pr, Nd) with a Ring-Contracted H2valdien-Derived Schiff Base Ligand

2021 ◽  
Author(s):  
Shabana Noor ◽  
Richard Goddard ◽  
Fehmeeda Khatoon ◽  
Sarvendra Kumar ◽  
Rüdiger W. Seidel
Keyword(s):  
Molecular Structure ◽  
Schiff Base ◽  
Structural Characterization ◽  
Schiff Base Ligand ◽  
Crystal And Molecular Structure ◽  
X Ray ◽  
X Ray Crystallography ◽  
Imidazoline Ring

AbstractSynthesis and structural characterization of two heterodinuclear ZnII-LnIII complexes with the formula [ZnLn(HL)(µ-OAc)(NO3)2(H2O)x(MeOH)1-x]NO3 · n H2O · n MeOH [Ln = Pr (1), Nd (2)] and the crystal and molecular structure of [ZnNd(HL)(µ-OAc)(NO3)2(H2O)] [ZnNd(HL)(OAc)(NO3)2(H2O)](NO3)2 · n H2O · n MeOH (3) are reported. The asymmetrical compartmental ligand (E)-2-(1-(2-((2-hydroxy-3-methoxybenzylidene)amino)-ethyl)imidazolidin-2-yl)-6-methoxyphenol (H2L) is formed from N1,N3-bis(3-methoxysalicylidene)diethylenetriamine (H2valdien) through intramolecular aminal formation, resulting in a peripheral imidazoline ring. The structures of 1–3 were revealed by X-ray crystallography. The smaller ZnII ion occupies the inner N2O2 compartment of the ligand, whereas the larger and more oxophilic LnIII ions are found in the outer O2O2’ site. Graphic Abstract Synthesis and structural characterization of two heterodinuclear ZnII-LnIII complexes (Ln = Pr, Nd) bearing an asymmetrical compartmental ligand formed in situ from N1,N3-bis(3-methoxysalicylidene)diethylenetriamine (H2valdien) through intramolecular aminal formation are reported.

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