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A hydroxide ion acting as a nucleophile in an S N 2 reaction, converting a haloalkane into an alcohol. In chemistry, a nucleophile is a chemical species that forms bonds by donating an electron pair. All molecules and ions with a free pair of electrons or at least one pi bond can act as nucleophiles. Because nucleophiles donate electrons, they ...
This is because α-nucleophiles showing the α-effect have smaller HOMO(nucleophile)-LUMO(substrate) gap, in other words, high HOMO energy level that allows more orbital interaction. Examples of α-nucleophiles with α-effects are shown in Figure 4. The α-nucleophiles have smaller HOMO lobes than the parent normal nucleophile. Figure 4.
The name of a clade is conventionally a plural, where the singular refers to each member individually. A unique exception is the reptile clade Dracohors, which was made by haplology from Latin "draco" and "cohors", i.e. "the dragon cohort"; its form with a suffix added should be e.g. "dracohortian".
The nucleophile is polarised and oriented by the base, which is itself bound and stabilised by the acid. [24] Catalysis is performed in two stages. First, the activated nucleophile attacks the carbonyl carbon and forces the carbonyl oxygen to accept an electron pair, leading to a tetrahedral intermediate. The resulting build-up of negative ...
DNA is a long polymer made from repeating units called nucleotides. [ 6 ] [ 7 ] The structure of DNA is dynamic along its length, being capable of coiling into tight loops and other shapes. [ 8 ] In all species it is composed of two helical chains, bound to each other by hydrogen bonds .
Juglone is an example of such a molecule inhibiting the growth of other plant species around walnut trees. [ citation needed ] The aquatic vascular plant Myriophyllum spicatum produces ellagic , gallic and pyrogallic acids and (+)- catechin , allelopathic phenolic compounds inhibiting the growth of blue-green alga Microcystis aeruginosa .
The structure of a nitrile: the functional group is highlighted blue. In organic chemistry, a nitrile is any organic compound that has a −C≡N functional group.The name of the compound is composed of a base, which includes the carbon of the −C≡N, suffixed with "nitrile", so for example CH 3 CH 2 C≡N is called "propionitrile" (or propanenitrile). [1]
In animals, the plasma membrane is the outer boundary of the cell, while in plants and prokaryotes it is usually covered by a cell wall. This membrane serves to separate and protect a cell from its surrounding environment and is made mostly from a double layer of phospholipids , which are amphiphilic (partly hydrophobic and partly hydrophilic ).