1459-93-4Relevant articles and documents
Berson,Salomon
, p. 4620 (1971)
Surface-enhanced infrared absorption of DMIP on gold-germanium substrates coated by self-assembled monolayers
Domingo,García-Ramos,Sánchez-Cortés,Aznarez
, p. 419 - 427 (2003)
Gold islands coated with self-assembled monolayers of three enough different thiols - thiophenol, propanethiol and octadecanethiol - are shown to enable the detection of molecules without polar groups, such as dimehylisophthalate (DMIP), using Surface enhanced infrared absorption (SEIRA). Binding of thiols was studied using SERS and SEIRA. The careful comparison of the transmission and p-polarized external reflection SEIRA spectra of DMIP taken using the modified substrates, with the corresponding spectra taken on the uncoated gold-Ge and bare Ge and CaF2 surfaces, has allowed to elucidate the role played by the underlayer substrate and the different thiols in the total observed enhancement effect. Furthermore, the DMIP orientation with respect to the gold surface for each thiol-coating has also been deduced, confirming that the surface selection rule in our case applies both to reflection and transmission SEIRA spectra. No SERS spectra of DMIP, either on the modified or on the uncoated gold substrates, were revealed.
Electrochemical Reduction of Pyridine- and Benzene-Substituted n-Alkyl Esters and Thioic S-Esters in Acetomtrile
Webster, Richard D.,Bond, Alan M.
, p. 1779 - 1787 (1997)
Bulk controlled potential electrolysis experiments have been performed on a wide range of n-alkyl- substituted esters and thioic S-esters of pyridine and benzene in dry acetonitrile with tetraalkylammonium salts as the supporting electrolyte. In most cases, the bulk one-electron reduction of oxygen esters results in unstable or semistable radicals being formed that decompose via loss of the alkyl radical to leave the carboxylate anion in high yield (ca. 70-100%). Benzoate and dinicotinate esters are the exception to this where the final decomposition products are numerous and complicated. For the thioic S-esters, two types of decomposition mechanism have been identified as operating depending on the stability of their anion radicals. Thioic S-ester radical anions that are very unstable (lifetimes in the order of several milliseconds) decompose with loss of the thiolate ion to leave a neutral acyl radical that undergoes aromatic substitution reactions with other acyl radicals to form, among other products, γ-lactones. Thioic S-esters radical anions that are stable for many minutes to hours ultimately decompose via reaction with molecular oxygen to form carboxylate anions.
Novel Isophthalohydrazide-cDB24C8 cryptand derivative for the selective recognition of fluoride ion: An experimental and DFT study
Bora, Sankar Jyoti,Dutta, Rakesh,Kalita, Dhruba Jyoti,Chetia, Bolin
, p. 225 - 231 (2018)
A highly selective and sensitive novel Isophthalohydrazide-cDB24C8 cryptand derivative was developed for fluoride recognition at a very low concentration of 2.31 × 10?10 M. The binding was established by UV–Vis, fluorescence and 1H NMR titration. The receptor formed very strong H-bonded complex with fluoride, furnished a sharp new UV–Vis absorption peak at 280 nm which was also supported by the DFT-study. The fluorescence emission spectra showed large quenching up to 79.13% upon addition of fluoride.
Br?nsted acid-catalyzed chlorination of aromatic carboxylic acids
Yu, Zhiqun,Yao, Hongmiao,Xu, Qilin,Liu, Jiming,Le, Xingmao,Ren, Minna
supporting information, p. 685 - 689 (2021/04/09)
The chlorination of aromatic carboxylic acids with SOCl2 has been effectively performed by reacting with a Br?nsted acid as the catalyst. Based on this discovery, an efficient catalytic method that is cheaper than traditional catalytic methods was developed. 20 substrates were chlorinated offering excellent yields in a short reaction time. And the SOCl2/Br?nsted acid system has been used in a larger scale preparative reaction. A dual activation mechanism was proposed to prove the irreplaceable system of SOCl2/Br?nsted acid.
Mild Copper-Catalyzed Addition of Arylboronic Esters to Di- tert -butyl Dicarbonate: An Easy Access to Methyl Arylcarboxylates
Xu, Jin-Di,Su, Xiao-Bo,Wang, Cai,Yao, Li-Wei,Liu, Jing-Hui,Hu, Guo-Qin
supporting information, p. 833 - 837 (2021/02/26)
An efficient copper-catalyzed addition of arylboronic esters to (Boc) 2O was developed. The reaction can be conducted under exceedingly mild conditions and is compatible with a variety of synthetically relevant functional groups. It therefore represents a useful alternative route for the synthesis of methyl arylcarboxylates. A preliminary mechanistic study indicated the involvement of an addition-elimination mechanism.