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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(NH 3 (in which the bond angle between the nitrogen and hydrogen is 107°), wherein one or more hydrogen atoms have been replaced by a substituent such as an ...
The high energy electronic state, 2 A 1, has the two electrons in the p-orbital and the unpaired electron in the sp 2 orbital (σ type radical). [4] [5] Nitrogen centered compounds, such as amines, are nucleophilic in nature. This character is also seen in amino radicals, which can be considered to be nucleophilic species. [4] [5]
The term dipolar bond is used in organic chemistry for compounds such as amine oxides for which the electronic structure can be described in terms of the basic amine donating two electrons to an oxygen atom. R 3 N → O. The arrow → indicates that both electrons in the bond originate from the amine moiety. In a standard covalent bond each ...
The chemistry involved in the amine treating of such gases varies somewhat with the particular amine being used. For one of the more common amines, monoethanolamine (MEA) denoted as RNH 2, the acid-base reaction involving the protonation of the amine electron pair to form a positively charged ammonium group (RNH + 3) can be expressed as: RNH 2 ...
The lone electron pair on the nitrogen delocalizes into the pi system of the benzene ring. This is responsible for nitrogen's weaker basicity compared to other amines. Missing in such an analysis is consideration of solvation. Aniline is, for example, more basic than ammonia in the gas phase, but ten thousand times less so in aqueous solution. [21]
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 ...
Ethylamine like some other small primary amines is a good solvent for lithium metal, giving the ion [Li(amine) 4] + and the solvated electron. Such solutions are used for the reduction of unsaturated organic compounds, such as naphthalenes [11] and alkynes.
The substituent R next the amine methylene bridge is an electron-withdrawing group. The original 1928 publication by Thomas S. Stevens [2] concerned the reaction of 1-phenyl-2-(N,N-dimethylamino)ethanone with benzyl bromide to the ammonium salt followed by the rearrangement reaction with sodium hydroxide in water to the rearranged amine.