INFRARED SPECTRA OF XANTHATE COMPOUNDS: II. ASSIGNMENT OF VIBRATIONAL FREQUENCIES

1961 ◽  
Vol 39 (4) ◽  
pp. 745-754 ◽  
Author(s):  
L. H. Little ◽  
G. W. Poling ◽  
J. Leja
Keyword(s):  
Chain Length ◽  
Infrared Spectra ◽  
Alkali Metals ◽  
Hydrocarbon Chain ◽  
Vibrational Frequencies ◽  
Vibrational Modes ◽  
Metal Atoms ◽  
Copper And Zinc ◽  
Hydrocarbon Chain Length ◽  
Stretching Vibrations

Discrepant interpretations regarding the frequency of the C=S stretching mode are reviewed and assignments of frequencies for the vibrational modes of the xanthate group, [Formula: see text] are presented.A band at 1020–1070 cm−1 is assigned to the C=S stretching mode. Bands at 1200 cm−1 and 1110–1140 cm−1 are ascribed to the stretching vibrations of the C—O—C linkage.The effects of the alkyl hydrocarbon chain length and of metal atoms (alkali metals, copper, and zinc) in displacing some of the frequencies are recorded.

scholarly journals Structure and Interdigitation of Chain-Asymmetric Phosphatidylcholines and Milk Sphingomyelin in the Fluid Phase

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1441
Author(s):  
Moritz P. K. Frewein ◽  
Milka Doktorova ◽  
Frederick A. Heberle ◽  
Haden L. Scott ◽  
Enrico F. Semeraro ◽  
...  
Keyword(s):  
Chain Length ◽  
Hydration Shell ◽  
Fluid Phase ◽  
Hydrocarbon Chain ◽  
Specific Model ◽  
Glycerol Backbone ◽  
Membrane Composition ◽  
Membrane Structures ◽  
Hydrocarbon Chain Length ◽  
Dynamics Simulations

We addressed the frequent occurrence of mixed-chain lipids in biological membranes and their impact on membrane structure by studying several chain-asymmetric phosphatidylcholines and the highly asymmetric milk sphingomyelin. Specifically, we report trans-membrane structures of the corresponding fluid lamellar phases using small-angle X-ray and neutron scattering, which were jointly analyzed in terms of a membrane composition-specific model, including a headgroup hydration shell. Focusing on terminal methyl groups at the bilayer center, we found a linear relation between hydrocarbon chain length mismatch and the methyl-overlap for phosphatidylcholines, and a non-negligible impact of the glycerol backbone-tilting, letting the sn1-chain penetrate deeper into the opposing leaflet by half a CH2 group. That is, penetration-depth differences due to the ester-linked hydrocarbons at the glycerol backbone, previously reported for gel phase structures, also extend to the more relevant physiological fluid phase, but are significantly reduced. Moreover, milk sphingomyelin was found to follow the same linear relationship suggesting a similar tilt of the sphingosine backbone. Complementarily performed molecular dynamics simulations revealed that there is always a part of the lipid tails bending back, even if there is a high interdigitation with the opposing chains. The extent of this back-bending was similar to that in chain symmetric bilayers. For both cases of adaptation to chain length mismatch, chain-asymmetry has a large impact on hydrocarbon chain ordering, inducing disorder in the longer of the two hydrocarbons.

scholarly journals Effect of Hydrocarbon Chain Length of Amphiphilic Ruthenium Dyes on Solid-State Dye-Sensitized Photovoltaics

Nano Letters ◽  
2005 ◽  
Vol 5 (7) ◽  
pp. 1315-1320 ◽  
Author(s):  
Lukas Schmidt-Mende ◽  
Jessica E. Kroeze ◽  
James R. Durrant ◽  
Md. K. Nazeeruddin ◽  
Michael Grätzel
Keyword(s):  
Solid State ◽  
Chain Length ◽  
Hydrocarbon Chain ◽  
Dye Sensitized ◽  
Hydrocarbon Chain Length ◽  
Ruthenium Dyes

Cation exchange in synthetic manganates: II. The structure of an alkylammonium-saturated phyllomanganate

Clay Minerals ◽  
1986 ◽  
Vol 21 (5) ◽  
pp. 957-964 ◽  
Author(s):  
E. Paterson ◽  
D.R. Clark ◽  
D. Russell ◽  
R. Swaffield
Keyword(s):  
Chain Length ◽  
Photoelectron Spectroscopy ◽  
Hydrocarbon Chain ◽  
Exchange Capacity ◽  
Basal Spacing ◽  
Water Molecules ◽  
Interlayer Water ◽  
X Ray ◽  
Alkyl Chains ◽  
Hydrocarbon Chain Length

AbstractA synthetic phyllomanganate saturated with a series of primary alkylammonium cations has been examined using XRD, chemical analysis and X-ray photoelectron spectroscopy. A linear relationship exists between the basal spacing of the saturated alkylammonium-manganate and the hydrocarbon chain length in the interlayer, and from the gradient it is concluded that the alkyl chains are perpendicular to the manganate sheet. This orientation is a function of both the charge density and the presence of a layer of water molecules immediately adjacent to the manganate basal surfaces. Evacuation results in the loss of this interlayer water and the structure of the organo-manganate is considerably disrupted. The extent to which the interlayer arrangement can be reinstated by rehydration is dependent on the chain length of the saturating organo-cation. For cations of chain length > C6 the C contents suggest that cation in excess of the exchange capacity is present in the interlayer, but the absence of any compensating anion and the release of amine on evacuation suggests that the excess C arises from the presence of free amine.

scholarly journals Inactivation of Protein Tyrosine Phosphatases by Peracids Correlates with the Hydrocarbon Chain Length

2015 ◽  
Vol 36 (3) ◽  
pp. 1069-1083 ◽  
Author(s):  
Alicja Kuban-Jankowska ◽  
Magdalena Gorska ◽  
Jack A. Tuszynski ◽  
Cassandra D. M. Churchill ◽  
Philip Winter ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Enzymatic Activity ◽  
Chain Length ◽  
Active Site ◽  
Protein Tyrosine Phosphatases ◽  
Hydrocarbon Chain ◽  
Inhibitory Effect ◽  
Tyrosine Phosphatases ◽  
Medium Chain ◽  
Hydrocarbon Chain Length

Background/Aims: Protein tyrosine phosphatases are crucial enzymes controlling numerous physiological and pathophysiological events and can be regulated by oxidation of the catalytic domain cysteine residue. Peracids are highly oxidizing compounds, and thus may induce inactivation of PTPs. The aim of the present study was to evaluate the inhibitory effect of peracids with different length of hydrocarbon chain on the activity of selected PTPs. Methods: The enzymatic activity of human CD45, PTP1B, LAR, bacterial YopH was assayed under the cell-free conditions, and activity of cellular CD45 in human Jurkat cell lysates. The molecular docking and molecular dynamics were performed to evaluate the peracids binding to the CD45 active site. Results: Here we demonstrate that peracids reduce enzymatic activity of recombinant CD45, PTP1B, LAR, YopH and cellular CD45. Our studies indicate that peracids are more potent inhibitors of CD45 than hydrogen peroxide (with an IC50 value equal to 25 nM for peroctanoic acid and 8 µM for hydrogen peroxide). The experimental data show that the inactivation caused by peracids is dependent on hydrocarbon chain length of peracids with maximum inhibitory effect of medium-chain peracids (C8-C12 acyl chain), which correlates with calculated binding affinities to the CD45 active site. Conclusion: Peracids are potent inhibitors of PTPs with the strongest inhibitory effect observed for medium-chain peracids.

scholarly journals Effect of Hydrocarbon Chain Length of Disubstituted Triphenyl-amine-Based Organic Dyes on Dye-Sensitized Solar Cells

2011 ◽  
Vol 115 (44) ◽  
pp. 22002-22008 ◽  
Author(s):  
Qiong-Yan Yu ◽  
Jin-Yun Liao ◽  
Shi-Ming Zhou ◽  
Yong Shen ◽  
Jun-Min Liu ◽  
...  
Keyword(s):  
Solar Cells ◽  
Chain Length ◽  
Organic Dyes ◽  
Dye Sensitized Solar Cells ◽  
Hydrocarbon Chain ◽  
Dye Sensitized ◽  
Hydrocarbon Chain Length ◽  
Sensitized Solar Cells
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