question_answer

Which of the following is a pair of geometric isomers?

(i)
(ii)
(ii)
(iv)

A)  (i) and (ii)         

B)  (i) and (in)

C)  (i) and (iv)         

D)  (ii) and (iii)

Correct Answer: C

Solution :

When all the groups attached to the double bonded carbon atoms are different, these exists E?Z type geometrical isomerism. When the heavier groups are present at the same side of double bonded carbon atoms, the configuration is Z and when present at the opposite sides, the configuration is E. The configuration of, \[(C{{H}_{3}}>H;\,Br>Cl)\] is Z. Thus, its E form is Hence, (i) and (iv) are E ? Z type geometrical isomers.