Benzophenone is a diphenyl ketone, represented by the chemical formula C13H10O. The IUPAC name for benzophenone is diphenylmethanone. It is frequently used in the chemical industry as a flavoring agent, a fragrance enhancer, a UV-light protectant in cosmetics, etc.

Is Benzophenone polar or non-polar?

Benzophenone (C13H10O) is a polar molecule overall. It consists of a polar C=O bond lying in between two non-polar benzene rings, one on each side.

C-C, C=C, C-H and C=O are the four main types of chemical covalent bonds present in a benzophenone molecule.

The C-C or C=C bond is purely non-polar as zero, or no electronegativity difference is present between two identical carbon atoms.

A C-H bond is slightly polar (almost non-polar) as per Pauling’s electronegativity scale, as an electronegativity difference of only 0.35 units is present between a carbon and a hydrogen atom.

Contrarily, a high electronegativity difference of 0.89 units is present between the covalently bonded carbon and oxygen atoms in the C=O bond of benzophenone. Thus, the C=O bond (also called the carbonyl functional group) is strongly polar.

Oxygen being highly electronegative, attracts the nearby C-C and C-H electrons as well, in addition to attracting the C=O bonded electrons.

The charged electron cloud stays non-uniformly spread over benzophenone overall. Thus, benzophenone is a polar molecule (net μ > 0).

Benzophenone uses

Benzophenone is used as a flavour ingredient, a fragrance enhancer, a perfume fixative and an additive for plastics, coatings and adhesive formulations; it is also used in the manufacture of insecticides, agricultural chemicals, hypnotic drugs, antihistamines and other pharmaceuticals. Benzophenone is used as an ultraviolet (UV)-curing agent in sunglasses, and to prevent UV light from damaging scents and colours in products such as perfumes and soaps. Moreover, it can be added to plastic packaging as a UV blocker, which allows manufacturers to package their products in clear glass or plastic rather than opaque or dark packaging. It is also used in laundry and household cleaning products.

Benzophenone is widely used as a photoinitiator for inks and varnishes that are cured with UV light. In addition to being a drying catalyst, benzophenone is an excellent wetting agent for pigments; it can also be used in printing to improve the rheological properties and increase the flow of inks by acting as a reactive solvent.