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Compared to amines, amides are very weak bases. While the conjugate acid of an amine has a pK a of about 9.5, the conjugate acid of an amide has a pK a around −0.5. Therefore, compared to amines, amides do not have acid–base properties that are as noticeable in water. This relative lack of basicity is explained by the withdrawing of ...
Amine. In chemistry, amines (/ ə ˈ m iː n, ˈ æ m iː n /, [1] [2] UK also / ˈ eɪ m iː n / [3]) are compounds and functional groups that contain a basic nitrogen atom with a lone pair.Formally, amines are derivatives of ammonia (NH 3 (in which the bond angle between the nitrogen and hydrogen is 107°), wherein one or more hydrogen atoms have been replaced by a substituent such as an ...
Both are major contributors to the overall structure, so much so that the amide bond between the carbonyl carbon and the amide nitrogen has significant double bond character. The energy barrier for rotation about an amide bond is 75–85 kJ/mol (18–20 kcal/mol), much larger than values observed for normal single bonds.
If it is at a higher energy level, it is said to be excited, or any electrons that have higher energy than the ground state are excited. Such a species can be excited to a higher energy level by absorbing a photon whose energy is equal to the energy difference between the levels. Conversely, an excited species can go to a lower energy level by ...
Structures of three kinds of amides: an organic amide (carboxamide), a sulfonamide, and a phosphoramide. In chemistry, the term amide (/ ˈ æ m aɪ d / or / ˈ æ m ɪ d / or / ˈ eɪ m aɪ d /) [1] [2] [3] is a compound with the functional group R n E(=O) x NR 2, where x is not zero, E is some element, and each R represents an organic group or hydrogen. [4]
Amidines are much more basic than amides and are among the strongest uncharged/unionized bases. [6] [7] Protonation occurs at the sp 2-hybridized nitrogen. This occurs because the positive charge can be delocalized onto both nitrogen atoms. The resulting cationic species is known as an amidinium ion [8] and possesses identical C-N bond lengths.
If the three R groups attached to the nitrogen are all unique, then the amine is chiral; whether it can be isolated depends on the free energy required for the molecule's inversion. Pyramidal inversion in nitrogen and amines is known as nitrogen inversion . [ 8 ]
In organic chemistry, amine value is a measure of the nitrogen content of an organic molecule. [1] Specifically, it is usually used to measure the amine content of amine functional compounds. [ 2 ] It may be defined as the number of milligrams of potassium hydroxide (KOH) equivalent to one gram of epoxy hardener resin.