Search results
Results from the WOW.Com Content Network
Clar's rule states that for a benzenoid polycyclic aromatic hydrocarbon (i.e. one with only hexagonal rings), the resonance structure with the largest number of disjoint aromatic π-sextets is the most important to characterize its chemical and physical properties. Such a resonance structure is called a Clar structure. In other words, a ...
Phenanthrene is a polycyclic aromatic hydrocarbon (PAH) with formula C 14 H 10, consisting of three fused benzene rings. It is a colorless, crystal-like solid, but can also appear yellow. Phenanthrene is used to make dyes, plastics, pesticides, explosives, and drugs. It has also been used to make bile acids, cholesterol and steroids. [3]
According to one, the relative stability of phenanthrene compared to its isomers can be adequately explained by comparing resonance stabilizations. [8] Another critic argues that the stability of phenanthrene can be attributed to more effective pi-pi overlap in the central double bond; the existence of bond paths is not questioned but the ...
The analogous cyclic system appears to have even more resonance stabilized, as the negative charge can be delocalized across three carbons instead of two. However, the cyclopropenyl anion has 4 π electrons in a cyclic system and in fact has a substantially higher p K a than 1-propene because it is antiaromatic and thus destabilized. [ 3 ]
ortho-Substituted substrates generally give 1-substituted phenanthrenes, unless the substituent is a good leaving group, in which case elimination to form unsubstituted phenanthrene occurs. [11] meta- Substituted substrates give mixtures of 2- and 4-substituted products. Substitution of the exocyclic double bond is well tolerated.
Related: Utah Mom Fled Ethnic Cleansing in Myanmar with Young Family.Then Husband Killed Them in Murder-Suicide. The husband and wife had recently decided to separate at the time of the alleged ...
It has been prepared by oxidation of phenanthrene with chromic acid. [3] It is used as an artificial mediator for electron acceptor/donor in Mo/W containing formate dehydrogenase reduction of carbon dioxide to formate and vice versa. It is a better electron acceptor than the natural nicotinamide adenine dinucleotide (NAD +).
Featuring Lisa Kudrow and Ray Romano, Netflix's new dark comedy "No Good Deed" is "about the highs and lows of searching for a safe, happy home."