A functional group is a group of atoms with unique chemical properties. These groups are responsible for the characteristic chemical properties of the molecules they build. Benzyl and phenyl are functional groups and contain benzene rings.
What is a benzyl group?
A benzyl group is a functional group, consisting of a benzene ring and linked to a CH 2 group. Its chemical formula is C 6 H 5 CH 2 -. A benzyl is a monovalent group derived from toluene. The abbreviation "Bn" is used to denote benzyl. For example, benzyl alcohol could be labeled BnOH.
The position of the first C atom bonded to the aromatic ring is described as benzyl. The benzyl position is characterized by enhanced reactivity. This is due to the low dissociation energy of the benzyl CH-bond. The energy required for the dissociation of the benzyl CH bond is 90 kcal/mol, compared to 105 kcal/mol for the methyl CH bond and 101 kcal/mol for the ethyl CH bond.
The aromatic ring has a stabilizing effect on the benzyl group. However, weak CH bonds affect the stability of benzyl radicals. Because of the weaker CH bond, the substituent benzyl shows enhanced reactive free radical halogenation, oxidation, hydrogenolysis, etc.
Compounds containing benzyl groups include benzylmethyl, benzyl bromide, benzyl chloroformate, benzylamine, etc. Benzyl is used as a protecting group for carboxylic acids and alcohols in organic synthesis.
What is phenyl?
Phenyl is a cyclic functional group with the formula C 6 H 5 -. It is a monovalent aryl group, closely related to benzene, and is derived by the removal of an H atom. Phenyl has six carbon atoms attached in a hexagonal ring. One of these atoms is bonded to a substituent and the other five are bonded to hydrogen atoms.
The abbreviation "Ph" is used to denote phenyl. For example, benzene can be represented as PhH.
The dissociation energy of the phenyl CH bond is higher than that of the other CH bonds. The energy required to dissociate a phenyl CH bond is 113 kcal/mol, compared to 105 kcal/mol for a methyl CH bond and 101 kcal/mol for an ethyl CH bond.
The properties of the aromatic molecular orbitals additionally add to the stability of phenyl. Phenyl substances are hydrophobic and tend to resist reduction and oxidation. Compounds containing phenyl groups include triphenylmethane, chlorobenzene, phenol, etc. Compounds containing phenyl are used in pharmaceuticals. For example, atorvastatin is used to lower cholesterol and fexofenadine is used to treat allergies.
Benzyl acetate
Present in the net jasmine oil and essential oil of ylang-ylang and neroli. Floral and fruity aroma (typical of jasmine). (Benzyl acetate is not a terpene derivative, but is present in many essential oils.)
Linalyl acetate (3,7-dimethyl-1,6-octadien-3-yl acetate)
Present in the essential oils of bergamot, lavender, lavandula, spike lavender, happy sage, neroli, and bitter orange leaf. Floral, fruity, sweet, and herbal scent.
Geranyl acetate (trans-3,7-dimethyl-2,6-octadien-1-yl acetate)
Found in many essential oils including geranium, lemongrass, lavender, bitter orange leaf, and sweet marjoram. Fruity, floral, fresh, and rose-like scent.
Citronellol Formate (3,7-dimethyloct-6-ene-1-yl formate)
Present in geranium oil. Fruity, floral, light rose-like aroma.
Properties of esters
Properties commonly associated with esters include.
-Mild action, similar to that of alcohol
-Distinctive sweet, fruity aroma
-Anti-fungal agent
-Anti-inflammatory (medicine)
-Antispasmodic
-Anti-spasmodic
Sedative and nourishing to the nervous system
-Effective against skin rashes.