Melem

Last updated
Melem
Melem Structural Formulae.svg
Names
IUPAC name
11-imino-2,4,6,8,10,12,13-heptazatricyclo[7.3.1.05,13]trideca-1(12),2,4,7,9-pentaene-3,7-diamine
Other names
2,5,8-triamino-heptazine; 2,5,8-triamino-tri-s-triazine; cyamelurotriamide; triamino-s-heptazine; 1,3,4,6,7,9,9b-Heptaazaphenalene-2,5,8-triamine
Identifiers
3D model (JSmol)
27284
ChEBI
ChemSpider
ECHA InfoCard 100.014.657 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 216-122-4
241276
PubChem CID
UNII
  • InChI=1S/C6H6N10/c7-1-10-4-12-2(8)14-6-15-3(9)13-5(11-1)16(4)6/h(H6,7,8,9,10,11,12,13,14,15) X mark.svgN
    Key: YSRVJVDFHZYRPA-UHFFFAOYSA-N
  • C1(=NC2=NC(=N)N=C3N2C(=NC(=N3)N)N1)N
Properties
C6H6N10
Molar mass 218.18 g/mol
Appearancewhite solid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

In chemistry, melem is a compound with formula C
6
N
10
H
6
; specifically, 2,5,8-triamino-heptazine or 2,5,8-triamino-tri-s-triazine, whose molecule can be described as that of heptazine with the three hydrogen atoms replaced by amino groups. It is a white crystalline solid. [1]

Contents

Preparation

Melem can be prepared by thermal decomposition of various C−N−H compounds, such as melamine C3N3(NH2)3, dicyandiamide H4C2N4, ammonium dicyanamide NH4[N(CN)2], cyanamide H2CN2, at 400 to 450 °C. [1] [2]

Structure and properties

Crystal structure

Melem crystallizes in the group P21/c (No. 14), with parameters a = 739.92(1) pm, b = 865.28(3) pm, c = 1338.16(4) pm, β = 99.912(2)°, and Z = 4. The almost-planar molecules are arranged in parallel layers spaced 327 pm apart. The molecule is in the triamino form, rather than one of the possible tautomers. [1]

Thermal decomposition

When heated above 560°, melem transforms into a graphite-like C−N material. [1]

Melemium cations

Melem accepts up to three protons yielding cations called melemium[(NH2)3(C6N7Hx)]x+. Some salts described in the literature are melemium sulfate, [(NH
2
)
3
(C
6
N
7
H
2
)]SO
4
• 2H
2
O
, melemium perchlorate, [(NH
2
)
3
(C
6
N
7
H)]ClO
4
H
2
O
, melemium hydrogensulfate [(NH
2
)
3
(C
6
N
7
H
3
)](HSO
4
)
3
and two melemium methylsulfonates [(NH
2
)
3
(C
6
N
7
H
2
)](SO
3
CH
3
)
2
H
2
O
and [(NH
2
)
3
(C
6
N
7
H)]
[(NH
2
)
3
(C
6
N
7
H
2
)]
(SO
3
CH
3
)
3
H
2
O
. The protons can be inserted in any of the six outer nitrogen atoms of the heptazine core, yielding many tautomers of apparently similar energies. [3]

See also

Related Research Articles

<span class="mw-page-title-main">Amide</span> Organic compounds of the form RC(=O)NR′R″

In organic chemistry, an amide, also known as an organic amide or a carboxamide, is a compound with the general formula R−C(=O)−NR′R″, where R, R', and R″ represent any group, typically organyl groups or hydrogen atoms. The amide group is called a peptide bond when it is part of the main chain of a protein, and an isopeptide bond when it occurs in a side chain, as in asparagine and glutamine. It can be viewed as a derivative of a carboxylic acid with the hydroxyl group replaced by an amine group ; or, equivalently, an acyl (alkanoyl) group joined to an amine group.

<span class="mw-page-title-main">Aldehyde</span> Organic compound containing the functional group R−CH=O

In organic chemistry, an aldehyde is an organic compound containing a functional group with the structure R−CH=O. The functional group itself can be referred to as an aldehyde but can also be classified as a formyl group. Aldehydes are a common motif in many chemicals important in technology and biology.

A conjugate acid, within the Brønsted–Lowry acid–base theory, is a chemical compound formed when an acid gives a proton to a base—in other words, it is a base with a hydrogen ion added to it, as it loses a hydrogen ion in the reverse reaction. On the other hand, a conjugate base is what remains after an acid has donated a proton during a chemical reaction. Hence, a conjugate base is a substance formed by the removal of a proton from an acid, as it can gain a hydrogen ion in the reverse reaction. Because some acids can give multiple protons, the conjugate base of an acid may itself be acidic.

<span class="mw-page-title-main">Tautomer</span> Isomers of chemical compounds that interconvert

Tautomers are structural isomers of chemical compounds that readily interconvert. The chemical reaction interconverting the two is called tautomerization. This conversion commonly results from the relocation of a hydrogen atom within the compound. The phenomenon of tautomerization is called tautomerism, also called desmotropism. Tautomerism is for example relevant to the behavior of amino acids and nucleic acids, two of the fundamental building blocks of life.

In chemistry, a trimer is a molecule or polyatomic anion formed by combination or association of three molecules or ions of the same substance. In technical jargon, a trimer is a kind of oligomer derived from three identical precursors often in competition with polymerization.

<span class="mw-page-title-main">Cyanuric acid</span> Chemical compound belonging to the class of triazine

Cyanuric acid or 1,3,5-triazine-2,4,6-triol is a chemical compound with the formula (CNOH)3. Like many industrially useful chemicals, this triazine has many synonyms. This white, odorless solid finds use as a precursor or a component of bleaches, disinfectants, and herbicides. In 1997, worldwide production was 160 000 tonnes.

<span class="mw-page-title-main">Triazine</span> Aromatic, heterocyclic compound

Triazines are a class of nitrogen-containing heterocycles. The parent molecules' molecular formula is C3H3N3. They exist in three isomeric forms, 1,3,5-triazines being common.

<span class="mw-page-title-main">Heptazine</span> Chemical compound

Heptazine, or tri-s-triazine or cyamelurine, is a chemical compound with formula C
6
N
7
H
3
, that consist of a planar triangular core group or three fused triazine rings, with three hydrogen atoms at the corners. It is a yellow, weakly fluorescent solid with melting point over 300 °C. It is soluble in organic solvents such as acetonitrile, but is decomposed by water in the presence of light.

<span class="mw-page-title-main">Melon (chemistry)</span>

In chemistry, melon is a compound of carbon, nitrogen, and hydrogen of still somewhat uncertain composition, consisting mostly of heptazine units linked and closed by amine groups and bridges. It is a pale yellow solid, insoluble in most solvents.

<span class="mw-page-title-main">Dimethylamine</span> Chemical compound

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 around 40%. An estimated 270,000 tons were produced in 2005.

<span class="mw-page-title-main">Cyanamide</span> Chemical compound featuring a nitrile group attached to an amino group

Cyanamide is an organic compound with the formula CN2H2. This white solid is widely used in agriculture and the production of pharmaceuticals and other organic compounds. It is also used as an alcohol-deterrent drug. The molecule features a nitrile group attached to an amino group. Derivatives of this compound are also referred to as cyanamides, the most common being calcium cyanamide (CaCN2).

The tropylium ion or cycloheptatrienyl cation is an aromatic species with a formula of [C7H7]+. Its name derives from the molecule tropine from which cycloheptatriene (tropylidene) was first synthesized in 1881. Salts of the tropylium cation can be stable, even with nucleophiles of moderate strength e.g., tropylium tetrafluoroborate and tropylium bromide (see below). Its bromide and chloride salts can be made from cycloheptatriene and bromine or phosphorus pentachloride, respectively.

<span class="mw-page-title-main">2-Pyridone</span> Chemical compound

2-Pyridone is an organic compound with the formula C
5
H
4
NH(O)
. It is a colourless solid. It is well known to form hydrogen bonded dimers and it is also a classic case of a compound that exists as tautomers.

In chemistry, an onium ion is a cation formally obtained by the protonation of mononuclear parent hydride of a pnictogen, chalcogen, or halogen. The oldest-known onium ion, and the namesake for the class, is ammonium, NH+4, the protonated derivative of ammonia, NH3.

<span class="mw-page-title-main">Graphitic carbon nitride</span> Class of chemical compounds

Graphitic carbon nitride (g-C3N4) is a family of carbon nitride compounds with a general formula near to C3N4 (albeit typically with non-zero amounts of hydrogen) and two major substructures based on heptazine and poly(triazine imide) units which, depending on reaction conditions, exhibit different degrees of condensation, properties and reactivities.

<span class="mw-page-title-main">Dithiobiuret</span> Chemical compound

Dithiobiuret is an organosulfur compound with the formula HN(C(S)NH2)2. It is a colourless solid that is soluble in warm water and polar organic solvents. It is a planar molecule with short C-S and C-N distances (1.69, 1.38 Å, resp.) indicative of multiple C-S and C-N bonding.

<span class="mw-page-title-main">Hexahydro-1,3,5-triazine</span> Class of chemical compounds

In chemistry, hexahydro-1,3,5-triazine is a class of heterocyclic compounds with the formula (CH2NR)3. Known as aldehyde ammonias, these compounds characteristically crystallize with water. They are reduced derivatives of 1,3,5-triazine, which have the formula (CHN)3, a family of aromatic heterocycles.

Cobalt(III) chloride or cobaltic chloride is an unstable and elusive compound of cobalt and chlorine with formula CoCl
3
. In this compound, the cobalt atoms have a formal charge of +3.

<span class="mw-page-title-main">Cyameluric acid</span> Chemical compound

Cyameluric acid or 2,5,8-trihydroxy-s-heptazine is a chemical compound with formula C
6
N
7
O
3
H
3
, usually described as a heptazine molecule with the hydrogen atoms replaced by hydroxyl groups –OH; or any of its tautomers.

<span class="mw-page-title-main">Hydromelonic acid</span> Chemical compound

Hydromelonic acid, is an elusive chemical compound with formula C
9
H
3
N
13
or (HNCN)
3
(C
6
N
7
)
, whose molecule would consist of a heptazine H3(C
6
N
7
)
molecule, with three cyanamido groups H–N=C=N– or N≡C–NH– substituted for the hydrogen atoms.

References

  1. 1 2 3 4 Jürgens, Barbara; Irran, Elisabeth; Senker, Jürgen; Kroll, Peter; Müller, Helen; Schnick, Wolfgang (2003-08-01). "Melem (2,5,8-Triamino-tri- s -triazine), an Important Intermediate during Condensation of Melamine Rings to Graphitic Carbon Nitride: Synthesis, Structure Determination by X-ray Powder Diffractometry, Solid-State NMR, and Theoretical Studies". Journal of the American Chemical Society. 125 (34): 10288–10300. doi:10.1021/ja0357689. ISSN   0002-7863.
  2. Tamikuni Komatsu (2001)> Komatsu, Tamikuni (2001-01-01). "The First Synthesis and Characterization of Cyameluric High Polymers". Macromolecular Chemistry and Physics. 202 (1): 19–25. doi:10.1002/1521-3935(20010101)202:1<19::AID-MACP19>3.0.CO;2-G. ISSN   1022-1352.
  3. Fabian Karl Keßler (2019), Structure and Reactivity of s-Triazine-Based Compounds in C/N/H Chemistry . Doctoral thesis, Fakultät für Chemie und Pharmazie, Ludwig-Maximilians-Universität München