Tetrakis(methylammonium) hexachloroferrate(III) chloride is a chemical compound with the formula (CH
3NH
3)
4 eCl6l.
Properties
The compound has the form of
hygroscopic
Hygroscopy is the phenomenon of attracting and holding water molecules via either absorption or adsorption from the surrounding environment, which is usually at normal or room temperature. If water molecules become suspended among the substance' ...
orange crystals.
The hexachloroferrate(III) anion is a
coordination complex
A coordination complex consists of a central atom or ion, which is usually metallic and is called the ''coordination centre'', and a surrounding array of bound molecules or ions, that are in turn known as '' ligands'' or complexing agents. M ...
centred on an iron atom in the +3
oxidation state
In chemistry, the oxidation state, or oxidation number, is the hypothetical charge of an atom if all of its bonds to different atoms were fully ionic. It describes the degree of oxidation (loss of electrons) of an atom in a chemical compound. C ...
that is
covalently bound to six chloride atoms arranged
octahedrally around it.
Interstitial
An interstitial space or interstice is a space between structures or objects.
In particular, interstitial may refer to:
Biology
* Interstitial cell tumor
* Interstitial cell, any cell that lies between other cells
* Interstitial collagenase ...
chloride anions are each surrounded by four methylammonium cations, with
hydrogen bond
In chemistry, a hydrogen bond (or H-bond) is a primarily electrostatic force of attraction between a hydrogen (H) atom which is covalently bound to a more electronegative "donor" atom or group (Dn), and another electronegative atom bearing a l ...
-like links between the ammonium cations and the
ligand
In coordination chemistry, a ligand is an ion or molecule (functional group) that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's elect ...
s of the hexachloroferrate(III)
moieties.
Each
CH3NH3)4Clsup>3+ unit balances a
eCl6sup>3–, analogous to how hexachloroferrate(III) forms stable compounds with various large triply-cationic atoms
[ and other triply-cationic complexes.][
]
Synthesis
The compound is synthesised by reacting methylammonium chloride, CH3NH3Cl, with anhydrous iron(III) chloride
Iron(III) chloride is the inorganic compound with the formula . Also called ferric chloride, it is a common compound of iron in the +3 oxidation state. The anhydrous compound is a crystalline solid with a melting point of 307.6 °C. The col ...
and adding hydrochloric acid
Hydrochloric acid, also known as muriatic acid, is an aqueous solution of hydrogen chloride. It is a colorless solution with a distinctive pungent smell. It is classified as a strong acid. It is a component of the gastric acid in the dige ...
with heating. Crystals of the product, which precipitate as the solvent evaporates, are collected and dried using vacuum desiccation
Desiccation () is the state of extreme dryness, or the process of extreme drying. A desiccant is a hygroscopic (attracts and holds water) substance that induces or sustains such a state in its local vicinity in a moderately sealed container.
...
.[
]
Infrared analysis
There is a series of bands from 3129 to 2830 cm−1 that represent stretching modes of the nitrogen–hydrogen bonds. In addition, a distinct peak is found at 2517 cm−1, whereas the corresponding signal for methylammonium chloride is at 2476 cm−1.["methyl ammonium chloride" http://riodb01.ibase.aist.go.jp/sdbs/cgi-bin/direct_frame_top.cgi] The 31 cm−1 shift is due to the coordination of an ammonium hydrogen with the hexachloroferrate(III).
Notes
{{Reflist
Iron complexes
Chloro complexes
Methylammonium compounds
Chlorometallates