A series of aliphatic and aromatic thioethers and dithioethers of s-triazine were synthesised to study their thermal properties, in particular the thermally induced thiyl radical generation ability. Four symmetric s-triazine sulfides of the type (RS) C N , namely 2,4,6-tris(phenylthio)- (1), 2,4,6-tris(para-tolylthio)- (3), 2,4,6-tris(ethylthio)- (5) and 2,4,6-tris(tert-butylthio)-1,3,5-triazine (7), as well as four symmetric s-triazine disulfides of the type (RSS) C N , namely 2,4,6-tris(phenyldithio)- (2), 2,4,6-tris(para-tolyldithio)- (4), 2,4,6-tris(ethyldithio)- (6) and 2,4,6-tris(tert-butyldithio)-1,3,5-triazine (8) were synthesised. All compounds were comprehensively characterised by H and C NMR, infrared and Raman spectroscopy as well as elemental analyses. Single-crystal X-ray diffraction analyses of 1, 2 and 5 are discussed. The thermal behaviour was studied by thermogravimetric analyses coupled with mass spectrometry (TGA-MS) and quantum chemical calculations. Limiting oxygen index (LOI) flammability tests showed that the disulfides are the most promising radical generators, and are most likely suitable flame retardants for selected polymers.
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http://dx.doi.org/10.1002/chem.201802427 | DOI Listing |
Redox Biol
December 2024
Department of Chemistry, Brown University, Providence, RI, 02912, USA. Electronic address:
Thiyl radicals are important reactive sulfur species and can cause cis to trans isomerization on unsaturated fatty acids. However, biocompatible strategies for the controlled generation of thiyl radicals are still lacking. In this work, we report the study of a series of naphthacyl-derived thioethers as photo-triggered thiyl radical precursors.
View Article and Find Full Text PDFChemistry
December 2024
School of Marine Science and Technology, Harbin Institute of Technology (WeiHai), Weihai, 264209, China.
Disulfide bonds (S-S) play a critical role in modern biochemistry, organic synthesis and prebiotic chemistry. Traditional methods for synthesizing disulfide bonds often rely on oxygen, alkali, and metal catalysts. Herein, thiol groups involved in amino acids and peptides were spontaneously converted into symmetrical and unsymmetrical disulfide bonds within water microdroplets, without the need for catalysts or oxygen, and under room temperature.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
November 2024
ICBMS, UMR 5246, Universite Claude Bernard Lyon 1, CNRS, INSA, CPE-Lyon, ICBMS UMR 5246, Villeurbanne, F-69100, France.
The recent development of photoredox and energy transfer catalysis has led to a significant expansion of visible-light-driven chemical transformations. These methods have demonstrated exceptional efficiency in converting a wide range of substrates into radical intermediates and generating open-shell catalytic species. However, the simplification of catalytic systems and the direct generation of highly reactive radical organocatalysts through direct visible-light irradiation from stable precatalysts remains largely an unrealized goal.
View Article and Find Full Text PDFInt J Biol Macromol
November 2024
Center for Molecular Science and Engineering, College of Science, Northeastern University, Shenyang 110819, PR China; College of New Energy and Materials, Ningde Normal University, Ningde, Fujian 352100, PR China. Electronic address:
This study introduces an innovative and cost-effective biomass adsorbent, the sulfur/cardanol/potato starch composite (SCP), synthesized through inverse vulcanization for the remediation of mercury-contaminated waters. The SCP was characterized using Scanning Electron Microscopy/Energy Dispersive Spectroscopy (SEM/EDS), Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetric Analysis (TGA) and X-ray Diffraction (XRD) to confirm its composition, morphology, and properties. The adsorption capacity of SCP for Hg(II) was 246.
View Article and Find Full Text PDFNat Commun
October 2024
Department of Physics, University of Hamburg and Center for Free-Electron Laser Science, Hamburg, Germany.
The photolysis of disulfide bonds is implicated in denaturation of proteins exposed to ultraviolet light. Despite this biological relevance in stabilizing the structure of many proteins, the mechanisms of disulfide photolysis are still contested after decades of research. Herein, we report new insight into the photochemistry of L-cystine in aqueous solution by femtosecond X-ray absorption spectroscopy at the sulfur K-edge.
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