The adsorption and structure of cyclohexyl isothiocyanate (CHIT) on gold surfaces has been investigated by surface-enhanced Raman scattering (SERS) and scanning tunneling microscopy (STM). Depending on the concentration, the spectral changes of the NCS stretching vibration on gold nanoparticles appeared to be more conspicuous than those of cyclohexyl ring modes. Both equatorial and axial chair conformers of CHIT were found to exist at low bulk concentrations near the monolayer coverage limit, whereas the equatorial chair conformer appeared to be dominant at high bulk concentrations. It was also observed that the ring conversion of equatorial to axial conformers can easily occur at higher temperatures, and the mole fraction of the axial form is assumed to increase with increasing temperature from 30 to 60 degrees C. Alternatively, STM imaging revealed that the adsorption of CHIT molecules on Au(1 1 1) leads to the formation of disordered SAMs with a few vacancy islands, as opposed to the formation of well-ordered self-assembled monolayers (SAMs) by cyclohexanethiols.
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http://dx.doi.org/10.1016/j.jcis.2009.04.036 | DOI Listing |
Heliyon
May 2024
Department of Pharmacology and Therapeutics, Faculty of Veterinary Medicine, Damanhour University, Damanhour, 22511, AlBeheira, Egypt.
A series of six unsymmetrical thiourea derivatives, namely 1-cyclohexyl-3-(pyridin-2-yl) thiourea (), 1-cyclohexyl-3-(3-methylpyridin-2-yl)thiourea (), 1-cyclohexyl-3-(2,4-dimethylphenyl) thiourea (), 1-(4-chlorophenyl)-3-cyclohexylthiourea (), 1-(3-methylpyridin-2-yl)-3-phenylthiourea (), and 1-(3-chlorophenyl)-3-phenylthiourea (), were successfully synthesized via reaction between different amines with isothiocyanates under a non-catalytic environment. Structural elucidation of compounds () was performed using FT-IR and NMR (H and C) spectroscopy. The infrared spectra displayed characteristic stretching vibrations, while the C NMR chemical shifts of the thiourea moiety (C[bond, double bond]S) were observed in the range of 179.
View Article and Find Full Text PDFDrug Test Anal
January 2024
Medicines and Health Products, Scientific Direction Physical and Chemical Health Risks, Sciensano, Brussels, Belgium.
Whipped cream canisters, also known as nitrous oxide whippets, are traditionally used in the culinary arts to prepare food foams. In recent years, however, these gas canisters have been cracked open and inhaled to produce a "legal" high. Users of these whippets have reported the presence of an oily residue containing metallic particles.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
July 2023
School of Chemistry and Chemical Engineering, Chongqing University, Daxuecheng South Rd. 55, Chongqing 401331, China. Electronic address:
The conformational equilibria of cyclohexyl isothiocyanate and its complex with water were studied by microwave spectroscopy combined with theoretical calculations. For the bare cyclohexyl isothiocyanate, the rotational spectra of the two conformers, namely a-trans and e-trans, were measured and analyzed. Additional mono-substituted isotopologues of two C and one S of a-trans and e-trans were also measured, which result in an accurate structural determination of the two conformers.
View Article and Find Full Text PDFInorg Chem
July 2019
College of Chemistry and Chemical Engineering , Southwest University, Chongqing 400715 , China.
Lanthanocene and cerocene alkyl complexes [η-1,3-(MeC)CH]Ln(CHCH--NMe) (Ln = La and Ce ) were obtained from the salt metathesis of {[η-1,3-(MeC)CH]Ln(μ-κ-OSCF)K(THF)}·THF (Ln = La and Ce ) with LiCHCH--NMe. Reactivity of and toward various small molecules provides access to a series of lanthanide derivatives. For example, reactions of and with elemental chalcogens (sulfur and selenium) in 1:1 molar ratio give the lanthanide thiolates {[η-1,3-(MeC)CH]Ln(μ-SCHCH--NMe)} (Ln = La and Ce ) and selenolates {[η-1,3-(MeC)CH]Ln(μ-SeCHCH--NMe)} (Ln = La and Ce ).
View Article and Find Full Text PDFNano Lett
May 2018
CAS Key Laboratory for Biomedical Effects of Nanomaterials & Nanosafety, CAS Center for Excellence in Nanoscience , National Center for Nanoscience and Technology (NCNST), 11 Beiyitiao , Zhongguancun, Beijing 100190 , China.
Combination therapeutic regimen is becoming a primary direction for current cancer immunotherapy to broad the antitumor response. Functional nanomaterials offer great potential for steady codelivery of various drugs, especially small molecules, therapeutic peptides, and nucleic acids, thereby realizing controllable drug release, increase of drug bioavailability, and reduction of adverse effects. Herein, a therapeutic peptide assembling nanoparticle that can sequentially respond to dual stimuli in the tumor extracellular matrix was designed for tumor-targeted delivery and on-demand release of a short d-peptide antagonist of programmed cell death-ligand 1 (PPA-1) and an inhibitor of idoleamine 2,3-dioxygenase (NLG919).
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