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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).
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]
While 1D NMR is more straightforward and ideal for identifying basic structural features, COSY enhances the capabilities of NMR by providing deeper insights into molecular connectivity. The two-dimensional spectrum that results from the COSY experiment shows the frequencies for a single isotope, most commonly hydrogen (1 H) along both axes.
In chemistry a donor number (DN) is a quantitative measure of Lewis basicity.A donor number is defined as the negative enthalpy value for the 1:1 adduct formation between a Lewis base and the standard Lewis acid SbCl 5 (antimony pentachloride), in dilute solution in the noncoordinating solvent 1,2-dichloroethane with a zero DN.
[2] [3] It can be viewed as benzaldehyde missing one hydrogen. The benzoyl group has a mass of 105 amu. The term "benzoyl" should not be confused with benzyl, which has the formula −CH 2 −C 6 H 5. The benzoyl group is given the symbol "Bz" whereas benzyl is commonly abbreviated "Bn".
This reaction is rapid and stoichiometric, with the addition of one mole of thiol releasing one mole of TNB. The TNB 2− is quantified in a spectrophotometer by measuring the absorbance of visible light at 412 nm, using an extinction coefficient of 14,150 M −1 cm −1 for dilute buffer solutions, [4] [5] and a coefficient of 13,700 M −1 cm −1 for high salt concentrations, such as 6 M ...
2,4-Dihydroxybenzaldehyde or β-resorcylaldehyde is a phenolic aldehyde, a chemical compound with the formula C 7 H 6 O 3. It is an isomer of protocatechuic aldehyde (3,4-dihydroxybenzaldehyde). References
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]