How Does This Have a Plane of Symmetry?

[MissionStanford]

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My book says this is not a chiral compound because it has no assymetric centers and has a plane of symmetry:

http://cccbdb.nist.gov/gifs/s2398109.gif

It's a cyclobutane molecule with one methyl group on the first carbon and another methyl group on the third carbon, and the methyl groups are in the trans configuration (One's a solid wedge, and the other's on a dashed wedge).

How can there be a plane of symmetry if one's on a dashed wedge and the other a solid wedge?

 

[chlrbwls]

This is because there are no chirality in any of the carbons

also line of symmetry lies with each methyl group directing up and down then the two carbons from the ring create a line of symmetry

from the picture you uploaded turn it 90 degrees with methyl groups going out of the page and into the page

Sent from my SCH-I535 using Tapatalk 2

 

[MissionStanford]

This is because there are no chirality in any of the carbons

also line of symmetry lies with each methyl group directing up and down then the two carbons from the ring create a line of symmetry

from the picture you uploaded turn it 90 degrees with methyl groups going out of the page and into the page

Sent from my SCH-I535 using Tapatalk 2

Sorry, I'm not sure exactly what you mean. What does the fact that there's no chirality in any of the carbons have to do with this? And if I rotate the compound 90 degrees, you're saying the line of symmetry is a line going through the carbons of both methyl groups?

 

[Deadlifts]

Sorry, I'm not sure exactly what you mean. What does the fact that there's no chirality in any of the carbons have to do with this? And if I rotate the compound 90 degrees, you're saying the line of symmetry is a line going through the carbons of both methyl groups?

It actually has two planes of symmetry. One through the C-methyls and one perpendicular to that through the center. Cut the compound in half. Can you move them in space and have identical halves? n-folding.

Perhaps if you build a model of it, you can visualize it better.

http://csi.chemie.tu-darmstadt.de/ak/immel/tutorials/chirality/index.html#achiral

 

[MissionStanford]

It actually has two planes of symmetry. One through the C-methyls and one perpendicular to that through the center. Cut the compound in half. Can you move them in space and have identical halves? n-folding.

Perhaps if you build a model of it, you can visualize it better.

http://csi.chemie.tu-darmstadt.de/ak/immel/tutorials/chirality/index.html#achiral

Thanks for the link. So would it be the same because the carbon with one of the wedges can rotate about its sigma bond to become cis with the other methyl? Unfortunately I don't have a modeling kit, but hopefully I'll be able to get one soon.

 

[Trayshawn]

Plane of symmetry going right through the center from left to right and into and out of the page. Like a table top.