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Gutmann, a chemist renowned for his work on non-aqueous solvents, described an acceptor-number scale for solvent Lewis acidity [4] with two reference points relating to the 31 P NMR chemical shift of Et 3 PO in the weakly Lewis acidic solvent hexane (δ = 41.0 ppm, AN 0) and in the strongly Lewis acidic solvent SbCl 5 (δ = 86.1 ppm, AN 100).
The 13 C NMR spectra were recorded at several spectrometers with resonance frequencies ranging from 15 MHz to 100 MHz and a resolution ranging from 0.025 to 0.045 ppm. Spectra were acquired using a pulse flip angle of 22.5 – 45 degrees and a pulse repetition time of 4 – 7 seconds. [4]
The Zeisel determination or Zeisel test is a chemical test for the presence of esters or ethers in a chemical substance. [1] [2] [3] [4]It is named after the Czech chemist Simon Zeisel (1854–1933).
It reacts with acetylacetone in the presence of cesium carbonate to give 3-(4-bromophenylthio)pentane-2,4-dione. 4,4'-Dibromophenyl disulfide is also produced as the intermediate. [5] Like other thiols, it reacts with silver nitrate to produce silver 4-bromothiophenolate. [6]
2,4-Dihydroxybenzoic acid (β-resorcylic acid) is a dihydroxybenzoic acid. As a resorcylic acid, it is one of the three isomeric crystalline acids that are both carboxyl derivatives of resorcinol and dihydroxy derivatives of benzoic acid. [4] Synthesis from resorcinol is via the Kolbe-Schmitt reaction. [5]
Diethylbenzene is used in a mixture with methyl and/or ethyl biphenyls as a low temperature heat transfer fluid. [2] Diethylbenzene is dehydrogenated to give divinylbenzene (DVB): C 6 H 4 (C 2 H 5) 2 → C 6 H 4 (C 2 H 3) 2 + 2 H 2. DVB is used in the production of crosslinked polystyrene. [3]
2,4-Dimethoxybenzaldehyde (DMBA) is a reagent used to specifically quantify phlorotannins. This product reacts specifically with 1,3-and 1,3,5-substituted phenols (e.g., phlorotannins) to form a colored product. [1]
DIPEA is a sterically hindered organic base that is commonly employed as a proton scavenger. Thus, like 2,2,6,6-tetramethylpiperidine and triethylamine, DIPEA is a good base but a poor nucleophile, DIPEA has low solubility in water, which makes it very easily recovered in commercial processes, a combination of properties that makes it a useful organic reagent.