Chemical Bonding and Molecular Structure

Cyanogen is the chemical compound with the formula (CN)₂. It is a colourless, toxic gas with a pungent odour. The molecule is a pseudohalogen. Cyanogen molecules consist of two CN groups — analogous to diatomic halogen molecules, such as Cl₂, but far less oxidizing.

Disilane is a chemical compound with chemical formula H₆Si₂. It is the only two silicon silane that is an aliphatic hydrosilicon. At standard temperature and pressure, disilane is a colourless, acrid gas. Disilane and ethane have similar structures, although disilane is much more reactive.

Antimony pentafluoride is the inorganic compound with the formula SbF₅. This colourless, viscous liquid is a valuable Lewis acid and a component of the superacid fluoroantimonic acid, the strongest known acid. It is notable for its Lewis acidity and its ability to react with almost all known compounds.

Iodine heptafluoride is the compound IF7. It has an unusual pentagonal bipyramidal structure, as predicted by VSEPR theory. The molecule can undergo a pseudorotational rearrangement called the Bartell mechanism, which is like the Berry mechanism but for a hepta coordinated system.

Barbituric acid is an organic compound based on a pyrimidine heterocyclic skeleton. It is an odourless powder soluble in water. Barbituric acid is the parent compound of barbiturate drugs, although barbituric acid itself is not pharmacologically active.

All of the above contain halogens.

Decabromodiphenyl ether is a brominated flame retardant which belongs to the group of polybrominated diphenyl ethers (PBDEs).

Methylamine is an organic compound with formula CH₃NH₂. This colourless gas is a derivative of ammonia, but with one H atom replaced by a methyl group. It is the simplest primary amine.

Diethylenetriamine (DETA) is a colourless hygroscopic liquid , soluble in water and polar organic solvents. It is a structural analogue of diethylene glycol. Its chemical properties resemble those of ethylene diamine, and it has similar uses. It is a weak base and its aqueous solution is alkaline.

Dichlorodifluoromethane is a chlorofluorocarbon halomethane (CFC), used as a refrigerant and aerosol spray propellant.

Ethylenediaminetetraacetic acid, widely abbreviated as EDTA is a polyamino carboxylic acid and a colourless, water-soluble solid. It is widely used to dissolve limescale. Its usefulness arises because of its role as a hexadentate ligand and chelating agent, i.e., its ability to sequester metal ions such as Ca²⁺ and Fe³⁺.

The trigonal planar is a molecular geometry model with one atom at the centre and three atoms at the corners of a triangle, called peripheral atoms, all in one plane. In an ideal trigonal planar species, all three ligands are identical and all bond angles are 120°, e.g. boron trifluoride (BF₃), formaldehyde (H₂CO), phosgene (COCl₂), and sulfur trioxide (SO₃).

A borane is a chemical compound of boron and hydrogen. The boranes comprise a large group of compounds with the generic formulae of BxHy. These compounds do not occur in nature. Many of the boranes readily oxidise on contact with air, some violently.

Boron trichloride, BCl₃ is a valuable reagent in organic synthesis. It is a starting material for the production of elemental boron. It is also used in the refining of aluminium, magnesium, zinc and copper alloys to remove nitrides, carbides, and oxides from molten metal.

Cadmium telluride (CdTe) is a crystalline compound formed from cadmium and tellurium. It is used as an infrared optical window and a solar cell material. It is usually sandwiched with cadmium sulfide to form a p-n junction photovoltaic solar cell.