Formal charge is not always a reliable guide to electron density. You are right that the H in NaH is nucleophilic. In case of alcohol, an Alkene would be formed.
Great Job! They are all electrophilic. And the empty p orbital of BH3 is electrophilic. Yes, there are. Many molecules can be both nucleophiles and electrophiles. How they behave, determines whether they are electrophile or neutrophile.
If water is reacted with an neutrophile, the water will behave as a electrophile. This suggests that water can behave an a nucleophile. However in practice diethylamine is an extremely poor electrophile. The only way to make it behave like an electrophile is to add a Lewis acid to the nitrogen or to convert it into an alkylammonium salt with something like CH3I, which will make the nitrogen a much better leaving group. Your email address will not be published.
Save my name, email, and website in this browser for the next time I comment. Notify me via e-mail if anyone answers my comment. This site uses Akismet to reduce spam. Learn how your comment data is processed. Next Curved Arrows for reactions. There are very few exceptions! Polar Aprotic? Are Acids! What Holds The Nucleus Together? Basicity — Master Organic Chemistry. Do you mean Lewis bases…? Thanks for the information, it helped me complete my assignment. Is there are any compounds which are electro and nucleophile both.
Nucleophiles and electrophile have charges but how they have got such names. A nucleophile when the bond being made is a covalent bond in the product. Let us take a closer look at related concepts and terminology. One of the key principles of organic chemistry is that molecules with electron-rich areas partial or full negative charge , generally lone pairs of electrons or in some cases specific bonds such as the pi bonds of alkenes, have important and characteristic patterns of reactivity.
Such electron-rich species are described by three different but related terms depending on the type of bond being made and this can be confusing at first. Different terms can be used to describe the same molecule and the correct term is chosen based on the type of bond being made. Quick summary An electron-deficient molecule is called: A Lewis acid when the bond being made is a dative or coordinate bond in other words relatively weak so that it repeatedly forms and dissociates at or near room temperature.
An electrophile when the bond being made is a covalent bond in the product. Molecules with electron-deficient areas partial or full positive charge also have important and characteristic patterns of reactivity. These molecules either have an atom with an unfilled valence a B or C atom with only 6 electrons in its valence shell or atoms of low electronegativity such as H or C atoms adjacent to an electronegative atom such as N, O or a halogen.
Such electron-deficient species are also described by three different but related terms depending on the type of bond being made. Examples Study the following examples to help solidify your understanding of the concepts described above. The first three examples show the same electron rich ammonia molecule reacting in three different contexts. In the first example, ammonia is a Lewis base because it is reacting with the Lewis acid BF3 to form a new coordinate bond in the product Lewis acid-Lewis base complex.
In the third example, a new bond is being made in the first step of the amide formation reaction mechanism. Note that in the context of the high energy reaction intermediate being formed in the step shown, the new N-C bond is formed reversibly, but in the final amide product, the new bond is covalent. In the fourth example, the relatively electron-rich pi bond of the alkene is making a new bond to bromine in the first step of an electrophilic addition reaction.
Note that a lone pair on bromine simultaneously makes a second new bond with the alkene to give the three-membered ring reaction intermediate. Also notice that the Br2 is an electrophile because it has a relatively weak bond between the Br atoms due to the presence of so many lone pairs that repel each other. The most general description of an electron-rich species is as a Lewis base Section 4.
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