88 (one more CH2, +14).[1]
Both have the same functional group, –OH, which decides the reactions.[1]
CH3: sp3, CH and CH2: sp2[1]
6 C–H + 2 C–C = 8 σ, 1 π[1]
An electron pair donor, with a lone pair of electrons.[1]
sp2, 120°.[1]
The bonding electrons are shared equally, one to each atom, forming two free radicals.[1]
Nucleophilic substitution.[1]
It has one chiral centre and one C=C bond that shows cis–trans isomerism.[1]
Number of stereoisomers = 22 = 4[1]
C4-methylhex-2-ene[1]
2-methylhex-2-ene does not exhibit stereoisomerism.
3-methylhex-2-ene and 5-methylhex-2-ene have only cis and trans isomers: number of stereoisomers = 21.
4-methylhex-2-ene has 22 = 4 stereoisomers.
Cis-trans isomerism occurs when there are 2 different substituents attached to each of the two carbon atoms of a C=C bond, due to its restricted rotation.[1]
Enantiomerism occurs when a molecule is chiral with no plane of symmetry, hence giving rise to a pair of isomers that are non-superposable mirror images. These compounds can rotate the plane of polarised light.[1]
hex-3-ene: geometric (cis-trans) isomerism[1]
[1]
2-bromobutane: optical isomerism[1]
| [1]
NoteShow a tetrahedral shape about the chiral carbon, draw the dash and wedge bonds clearly, and draw the mirror plane between the mirror images.
Molecules A, B and C are stereoisomers. Each molecule has 2 chiral carbon atoms.[1]
As molecules A and B have no plane of symmetry, they are chiral and exist as a pair of enantiomers, which are non-superimposable mirror images. Each enantiomer is optically active and rotates plane polarised light by an equal magnitude but in opposite directions.[1]
Molecule C, which has a plane of symmetry, is achiral (a meso compound). It is superimposable on its mirror image and is optically inactive.[1]