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On the category of oxidative addition, M. L. H. Green in 1970 reported on the photochemical insertion of tungsten (as a Cp 2 WH 2 complex) in a benzene C–H bond [7] and George M. Whitesides in 1979 was the first to carry out an intramolecular aliphatic C–H activation [8] Fujiwara's palladium- and copper-catalyzed C-H functionalization
For example, the C−H bond length is 110.2 pm in ethane, 108.5 pm in ethylene and 106.1 pm in acetylene, with carbon hybridizations sp 3 (25% s), sp 2 (33% s) and sp (50% s) respectively. To determine the degree of hybridization of each bond one can utilize a hybridization parameter ( λ ).
Cyclohexane-1,2,3,4,5,6-hexol is a family of chemical compounds with formula C 6 H 12 O 6, whose molecule consists of a ring of six carbon atoms, each bound to one hydrogen atom and one hydroxyl group (–OH). There are nine stereoisomers, that differ by the position of the hydroxyl groups relative to the mean plane of the ring.
NOBS is the main bleach activator used in the U.S.A. and Japan. [4] Compared to TAED , which is the predominant bleach activator used in Europe, NOBS is efficient at much lower temperatures. At 20 °C NOBS is 100 times more soluble than TAED in water. [ 5 ]
In the early 1950s, Alexander Todd's group pioneered H-phosphonate and phosphate triester methods of oligonucleotide synthesis. [5] [6] The reaction of compounds 1 and 2 to form H-phosphonate diester 3 is an H-phosphonate coupling in solution while that of compounds 4 and 5 to give 6 is a phosphotriester coupling (see phosphotriester synthesis ...
Tetraacetylethylenediamine, commonly abbreviated as TAED, is an organic compound with the formula (CH 3 C(O)) 2 NCH 2 CH 2 N(C(O)CH 3) 2. This white solid is commonly used as a bleach activator in laundry detergents and for paper pulp. It is produced by acetylation of ethylenediamine.
HO 2 − + RC(O)X → X − + RC(O)O 2 H. The overall reaction of TAED (1) with 2 equivalents of hydrogen peroxide gives diacetylethylenediamine (2) and 2 equivalents of peracetic acid (3): Only the perhydroxyl anion, and not the hydrogen peroxide molecule, reacts with the bleach activator. [4]
Ordinary sulfur (octasulfur, or S 8) is rarely used, despite its low cost, because it is soluble in the polymer. [10] [11] High-temperature vulcanisation with ordinary sulfur leads to rubber supersaturated with S 8, upon cooling this migrates to the surface and crystallises as sulfur bloom. This can cause problems if multiple layers of rubber ...