# Is a carbon chiral it two of its groups are cis - trans isomers? [duplicate]

For example:

In this image, the two groups sticking to a carbon are cis-trans isomers. So does that make the carbon chiral, exhibiting optical properties?

What if the two groups were both having the same configuration(both cis or both trans), would it then be achiral? Thanks for any help :D

• – user7951 Oct 22 '17 at 9:20
• So it'll exhibit optical properties and will have enantiomers? Thanks. – Cinnamaldehyde Oct 22 '17 at 9:24
• The other posters replied to your main question. I will add a couple of observations. 1) chirality is a property of the whole molecule, not of any of its parts in isolation; thus there are no 'chiral centers' or 'chiral' carbon atoms, there are stereocenters and stereogenic carbon atoms, which may be found in chiral molecules . 2) having stereoisomers, or enantiomers in this case, is not the same as, or automatically implying, displaying optical properties; it is likely to observe distinct optical properties in opposite enantiomers of the same molecule, but not a universal rule. – user6376297 Oct 22 '17 at 13:40

Any time all four groups bonded to carbon are distinct, including any sort of isomeric groups, you have a chiral center. Comments associated with the related question referenced by @Loong indicate that the cis vs trans scenario is even included in the $R$ vs. $S$ naming convention. This case is an $S$ configuration as the cis group takes second place and is counterclockwise from the hydroxyl group in the appropriate view.