enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Nucleophile - Wikipedia

    en.wikipedia.org/wiki/Nucleophile

    In general, in a group across the periodic table, the more basic the ion (the higher the pK a of the conjugate acid) the more reactive it is as a nucleophile. Within a series of nucleophiles with the same attacking element (e.g. oxygen), the order of nucleophilicity will follow basicity.

  3. Nucleophilic substitution - Wikipedia

    en.wikipedia.org/wiki/Nucleophilic_substitution

    The two main mechanisms were the S N 1 reaction and the S N 2 reaction, where S stands for substitution, N stands for nucleophilic, and the number represents the kinetic order of the reaction. [ 4 ] In the S N 2 reaction, the addition of the nucleophile and the elimination of leaving group take place simultaneously (i.e. a concerted reaction ).

  4. List of types of numbers - Wikipedia

    en.wikipedia.org/wiki/List_of_types_of_numbers

    Negative numbers: Real numbers that are less than zero. Because zero itself has no sign, neither the positive numbers nor the negative numbers include zero. When zero is a possibility, the following terms are often used: Non-negative numbers: Real numbers that are greater than or equal to zero. Thus a non-negative number is either zero or positive.

  5. Radical (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Radical_(chemistry)

    The hydroxyl radical, Lewis structure shown, contains one unpaired electron. Lewis dot structure of a Hydroxide ion compared to a hydroxyl radical. In chemistry, a radical, also known as a free radical, is an atom, molecule, or ion that has at least one unpaired valence electron.

  6. Nucleophilic aromatic substitution - Wikipedia

    en.wikipedia.org/wiki/Nucleophilic_aromatic...

    With carbon nucleophiles such as 1,3-dicarbonyl compounds the reaction has been demonstrated as a method for the asymmetric synthesis of chiral molecules. [9] First reported in 2005, the organocatalyst (in a dual role with that of a phase transfer catalyst) is derived from cinchonidine (benzylated at N and O).

  7. Alpha effect - Wikipedia

    en.wikipedia.org/wiki/Alpha_effect

    In 1962, Edwards and Pearson (the latter of HSAB theory) introduced the phrase alpha effect for this anomaly. He offered the suggestion that the effect was caused by a transition state (TS) stabilization effect: on entering the TS the free electron pair on the nucleophile moves away from the nucleus, causing a partial positive charge which can be stabilized by an adjacent lone pair as for ...

  8. Average US rate on a 30-year mortgage falls to 6.89%, third ...

    www.aol.com/average-us-rate-30-mortgage...

    The average rate fell to 6.89% from 6.95% last week, mortgage buyer Freddie Mac said Thursday. A year ago, it averaged 5.9%, Freddie Mac said. Mortgage rates are influenced by several factors ...

  9. Solvent effects - Wikipedia

    en.wikipedia.org/wiki/Solvent_effects

    Protic solvents react with strong nucleophiles with good basic character in an acid/base fashion, thus decreasing or removing the nucleophilic nature of the nucleophile. The following table shows the effect of solvent polarity on the relative reaction rates of the S N 2 reaction of 1-bromobutane with azide (N 3 – ).