Search results
Results from the WOW.Com Content Network
The effect is used in a qualitative way and describes the electron withdrawing or releasing properties of substituents based on relevant resonance structures and is symbolized by the letter M. [2] The mesomeric effect is negative (–M) when the substituent is an electron-withdrawing group, and the effect is positive (+M) when the substituent ...
This can also explain why phosphorus in phosphanes can't donate electron density to carbon through induction (i.e. +I effect) although it is less electronegative than carbon (2.19 vs 2.55, see electronegativity list) and why hydroiodic acid (pKa = -10) being much more acidic than hydrofluoric acid (pKa = 3).
Contributing structures of the carbonate ion. In chemistry, resonance, also called mesomerism, is a way of describing bonding in certain molecules or polyatomic ions by the combination of several contributing structures (or forms, [1] also variously known as resonance structures or canonical structures) into a resonance hybrid (or hybrid structure) in valence bond theory.
The data also show that for these substituents, the meta effect is much larger than the para effect, due to the fact that the mesomeric effect is greatly reduced in a meta substituent. With meta substituents a carbon atom bearing the negative charge is further away from the carboxylic acid group (structure 2b).
Hyperconjugation can be used to rationalize a variety of chemical phenomena, including the anomeric effect, the gauche effect, the rotational barrier of ethane, the beta-silicon effect, the vibrational frequency of exocyclic carbonyl groups, and the relative stability of substituted carbocations and substituted carbon centred radicals, and the thermodynamic Zaitsev's rule for alkene stability.
Jay-Z, the star rapper and entrepreneur whose real name is Shawn Carter, was accused in a lawsuit Sunday of raping a 13-year-old girl in 2000 allegedly along with Sean “Diddy” Combs.
Flames could be seen where a military helicopter made an emergency landing at Camp Pendleton on Friday, causing police to warn drivers of potential traffic delays along Interstate 5. All four crew ...
2.8 grams of fiber. 1.4 gram of protein. To keep it light, skip the heavy cream and opt for coconut milk and low-sodium vegetable broth. The coconut adds a creamy texture and brings out the squash ...