# Does 1,3‐dichloroallene show geometrical isomerism? [duplicate]

Since the attached groups are present in different planes, $$\ce{ClCH=C=CHCl}$$ should not show geometrical isomerism, but my book say that it does. Why?

• You are right, there is no cis-/trans- isomerism for allenes to speak of. Probably a typo, or the book author considers enantiomeric forms geometrical isomerism too. Feel free to provide an exact quote from your textbook alongside with bibliographical data. – andselisk Apr 6 '19 at 7:28
• Enantiomerism is a geometrical isomerism.It is so obvious that I do not check any definition. Just it is that often we intend geometrical isomerism as E/Z isomerism. Even more, isomerism of whatever forms implies a different geometry of stable molecules, though I would never call two chain isomers as geometric, as in this case it would bring more confusion than information. – Alchimista Apr 6 '19 at 8:01
• @AbhishekKumar The compound shows axial chirality and hence has two enantiomers. – Soumik Das Apr 6 '19 at 8:26

Left-handed molecule $$\qquad ~~~~~\qquad$$ Right-handed molecule