Drawing isomers for C6H12BrCl (1 Viewer)

[vds700]

This is part of a report I have to do, but it specifies that you cannot have "geometrical" and "optical" isomers, I tried googling these terms, but can't understand what they mean. Could someone give a simple explanation or say whether its OK just to move the Br and Cl around to different carbons in the chain to get a few different isomers


Thanks.

 

[Affinity]

have a look at http://en.wikipedia.org/wiki/Geometric_isomerism

for example.. 1,2 dichloroethene would have 2 geometric isomers

H     Cl
  \   /
   C=C
  /   \
Cl     H

Cl     Cl
  \   /
   C=C
  /   \
H      H

Notice how they are different.

an optical isomer is harder to draw here... but imagine a Carbon attom attached to one of each of F, Cl, H and Br (not sure if you can get such thing, but suppose you can) these 4 are arranged in a tetrahedron. there are two ways to orient them if you think carefully.

Try building some molecue models and you will see why.
EDIT: wiki has the same example:
http://en.wikipedia.org/wiki/Optical_isomer

 

[vds700]

have a look at http://en.wikipedia.org/wiki/Geometric_isomerism

for example.. 1,2 dichloroethene would have 2 geometric isomers

H     Cl
  \   /
   C=C
  /   \
Cl     H

Cl     Cl
  \   /
   C=C
  /   \
H      H

Notice how they are different.

an optical isomer is harder to draw here... but imagine a Carbon attom attached to one of each of F, Cl, H and Br (not sure if you can get such thing, but suppose you can) these 4 are arranged in a tetrahedron. there are two ways to orient them if you think carefully.

Try building some molecue models and you will see why.
EDIT: wiki has the same example:
http://en.wikipedia.org/wiki/Optical_isomer

ok so just to clarify, in your example, each carbon had a chlorine but in the first one, they are on opposite sides of the double bond and in the 2nd one, they are on the same side of the double bond. And optical isomers have a carbon attahced to a F, Cl, Br and H.

Thanks for your help.

 

[minijumbuk]

lol, don't you just swap the position of some atoms? xD

 

[vds700]

lol, don't you just swap the position of some atoms? xD

yeah but i just wasn't sure about geometrical and optical isomers, this Q is worth 2 marks in my assessment, so i dont want to screw it, thats all.

 

[vds700]

I would be very grateful if someone ccould quickly check I've named these correctly and they are not geometrical or optical isomers. Thanks so much.

 

[Affinity]

those are fine, but you should have 18 altogether.

 

[vds700]

those are fine, but you should have 18 altogether.

18 isomers u mean? :O

The question says "Identify and name examples of isomers (excluding geometrical and optical) for C6H12BrCl" 2 marks/30 for the report.

so i kinda assumed 3 would be enough, or am i wrong?

 

[Affinity]

there are 18 isomers.. maybe your teacher is not asking for all..

 

[vds700]

there are 18 isomers.. maybe your teacher is not asking for all..

No i dont think so, it just says examples so yeah, i reckon 3 should be OK.

Thanks so much for your help.

 

[xiao1985]

there are 18 isomers.. maybe your teacher is not asking for all..

Picking bone from egg eh? Actually there's more than 18, keep coutning affinity ^^

@vds: you are right, those are examples of (constitutional isomers)

 

[Affinity]

oh beh the different carbon chains lemme count again

Lol.. yeah Xiao's the expert here on chem, hows your research going at the moment