''N''-Methylmethanimine or ''N''‐methyl methylenimine is a reactive molecular substance containing a methyl group attached to an imine. It can be written as CH₃N=CH₂. On a timescale of minutes it self reacts to form a trimer, of trimethyl 1,3,5-triazinane. ''N''-Methylmethanimine is formed naturally in the Earth's atmosphere, by oxidation of

dimethylamine Dimethylamine is an organic compound with the formula (CH3)2NH. This secondary amine is a colorless, flammable gas with an ammonia-like odor. Dimethylamine is commonly encountered commercially as a solution in water at concentrations up to aroun ...

and

trimethylamine Trimethylamine (TMA) is an organic compound with the formula N(CH3)3. It is a colorless, hygroscopic, and flammable tertiary amine. It is a gas at room temperature but is usually sold as a 40% solution in water. (It is also sold in pressurized ...

, both of which are produced by animals, or burning.

Production

''N''-Methylmethanimine can be produced in two steps from dimethylamine, by first chlorinating the nitrogen atom with solid N-chlorosuccinimide, and then treating with potassium ''tert''-butoxide at 90°C. Also it can be formed directly by thermal decomposition. It can also be prepared from the trimer: 1,3,5-trimethyl-1,3,5-triazinane by heating to . At ,

decomposes into methane and ''N''-methylmethanimine.

Natural occurrence

''N''-Methylmethanimine should be formed in the atmosphere as a result of degradation by oxidation of di- and trimethylamine. These occur at concentrations of a few parts per billion. But ''N''-methylmethanimine cannot be detected. This is likely because it forms the trimer, gets absorbed onto particles, such as cloud droplets, and hydrolyses to form

methylamine Methylamine is an organic compound with a formula of . This colorless gas is a derivative of ammonia, but with one hydrogen atom being replaced by a methyl group. It is the simplest primary amine. Methylamine is sold as a solution in methanol, ...

and

formaldehyde Formaldehyde ( , ) (systematic name methanal) is a naturally occurring organic compound with the formula and structure . The pure compound is a pungent, colourless gas that polymerises spontaneously into paraformaldehyde (refer to section F ...

Properties

The ''N''-Methylmethanimine molecule has ''Cs'' symmetry. The

infrared spectrum Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...

and microwave spectrum have been observed. The bond length for C=N is 1.279 Å, and for the N-C bond it is 1.458 Å. The ∠ C=N-C is 116.6°. The

electric dipole moment The electric dipole moment is a measure of the separation of positive and negative electrical charges within a system, that is, a measure of the system's overall polarity. The SI unit for electric dipole moment is the coulomb-meter (C⋅m). The ...

is 1.53

Debye The debye (symbol: D) (; ) is a CGS unit (a non- SI metric unit) of electric dipole momentTwo equal and opposite charges separated by some distance constitute an electric dipole. This dipole possesses an electric dipole moment whose value is give ...

. When heated to 535°, ''N''-methylmethanimine decomposes to

hydrogen cyanide Hydrogen cyanide, sometimes called prussic acid, is a chemical compound with the formula HCN and structure . It is a colorless, extremely poisonous, and flammable liquid that boils slightly above room temperature, at . HCN is produced on an ...

(HCN) and methane (CH₄). Between 400 and 550°C, the cyclic amine,

aziridine Aziridine is an organic compound consisting of the three-membered heterocycle . It is a colorless, toxic, volatile liquid that is of significant practical interest. Aziridine was discovered in 1888 by the chemist Siegmund Gabriel. Its derivati ...

decomposes to a mixture of ''N''-methylmethanimine and ethylideneimine.

References

{{Reflist Imines