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The initial investigation of the catalytic activity of DBA dianions was reported by Lorbach et al. [13] Due to the delocalization of these extra electrons in the aromatic system, the DBA dianion is formally isoelectronic with anthracene and should be able to react with dienes in a [4+2] fashion (Diels-Alder reaction). Subjecting the DBA dianion ...
The chromate and dichromate ions are fairly strong oxidizing agents. Commonly three electrons are added to a chromium atom, reducing it to oxidation state +3. In acid solution the aquated Cr 3+ ion is produced. Cr 2 O 2− 7 + 14 H + + 6 e − → 2 Cr 3+ + 7 H 2 O ε 0 = 1.33 V. In alkaline solution chromium(III) hydroxide is produced.
[3] The second family of reagents are salts, featuring the pyridinium cation (C 5 H 5 NH +). pyridinium dichromate (PDC) is the pyridium salt of dichromate, [Cr 2 O 7] 2-. pyridinium chlorochromate (PCC) is the pyridinium salt of [CrO 3 Cl] −. These salts are less reactive, more easily handled, and more selective than Collins reagent in ...
A dianion is an anion with a net charge of −2. While there exist many stable molecular dianions, such as BeF 4 2− and MgF 4 2− , [ 1 ] thus far no stable atomic dianion has been found: Electron shielding and other quantum mechanical effects tend to make the addition of another electron to an atomic anion unstable.
Pert Plus (also known as Pert 2 in 1) is an American brand of shampoo and conditioner (2-in-1) products owned by Sodalis USA (formerly High Ridge Brands LLC). It was introduced in 1987 by Procter & Gamble as a reformulation of Pert shampoo introduced in 1980. [ 1 ]
The FDA’s recent ban on Red Dye No. 3, set to take effect by 2027 for foods and 2028 for drugs, marks a significant step in addressing safety concerns over artificial food dyes in the U.S. food ...
Strontium chromate is approximately 30 times more soluble in water at 100 °C than at room temperature. Therefore, the yellow strontium chromate can be suspended in a hot solution of a soluble sulfate to digest until fully converted to the much less soluble and white strontium sulfate, leaving the chromate or dichromate in solution.
Allura Red AC is a popular dye used worldwide. Annual production in 1980 was greater than 2.3 million kilograms. [5] It was introduced as a replacement for amaranth in the United States.