Vicinal (chemistry)

In the chemical vicinal means (usually abbreviated as VIC, from the Latin vicinus " neighbor" ), two functional groups ( for example, halogens such as fluorine, chlorine or bromine), are attached to two adjacent carbon atoms. In most cases the use of the term vicinal is limited to two identical functional groups.

The term is also used to vicinal description of trisubstituted benzene and of heterocycles. 1,2,3- trimethylbenzene called by such names as vic -trimethylbenzene.

Further, the relative arrangement of two functional groups are geminally and descriptive terms α and β -position.

1H -NMR spectroscopy

In the 1H -NMR spectroscopy is the coupling of two hydrogen atoms, which are located on adjacent carbon atoms, referred to as vicinal coupling. The vicinal coupling constants is referred to as 3J, since the hydrogen atoms on three bonds link each time. As a function of the other substituents, the vicinal coupling constant value between 0 and 20 Hz occupies. The dependence of the vicinal coupling constant of the dihedral angles is described by the Karplus relationship.