When are molecules coplanar?

[deleted388502]

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I think I might be confused about the definition of coplanar.

I've read about it in BR in multiple contexts, however coming across it in the context of "in both the E and Z isomers of an alkene, the atoms directly bonded to the alkene carbons are all coplanar."

Can someone maybe just explain what coplanar means/how to tell if a molecule is coplanar?

 

[Beargryllz]

They're on the same plane

I don't know if separate molecules would be considered coplanar. It seems statistically unlikely without some force aligning them

You might be making this more complicated than you need to

I'll add more to that quote

"in ethyne, the hydrogen atoms directly bound to the alkyne carbons are colinear"

The triple bond is linear and all the atoms in ethyne occupy the same line

 

[Teleologist]

The triple bond is linear and all the atoms in ethyne occupy the same line

A line is not a plane.

Coplanar ligands means you can draw a single plane that has contains all the ligands.

 

[Beargryllz]

A line is not a plane.

Coplanar ligands means you can draw a single plane that has contains all the ligands.

I know, I'm making an analogy between alkenes and alkynes making a plane and line respectively

 

[DenTony11235]

I haven't come across the term in any practice test or text, but I can understand why you just wanna know. I go to sleep sometimes ready for the nightmares of an exotic term on the test that I've never seen before.

I don't know the exact definition, but intuitively the term makes sense to me this way: Double bonds are formed from the overlap of p-orbitals between two neighboring carbons. It is a certain orientation in which i guess you can say two p-orbitals eclipse one another in neighboring carbons. This eclipsing, sounds like it'd be like the quality of being coplanar. Therefore, all the other atoms bonded to the two double bonded carbons would be coplanar.

 

[Teleologist]

It is a certain orientation in which i guess you can say two p-orbitals eclipse one another in neighboring carbons. This eclipsing, sounds like it'd be like the quality of being coplanar. Therefore, all the other atoms bonded to the two double bonded carbons would be coplanar.

P-orbitals must be parallel vis-a-vis to allow for effective pi-bonding.

P-orbitals must also be parallel to enable aromaticity (see Huckel's rule). Planarity enables effective electron delocalization.

 

[Chrisz]

P-orbitals must be planar vis-a-vis to allow for effective pi-bonding.

P-orbitals must also be planar to enable aromaticity (see Huckel's rule). Planarity enables effective electron delocalization.

Teleologist, I think you wanna say the p orbitals must be parallel so they can have conjugation in aromatic molecules . P-orbitals parallel so that the atoms are in the same plane.

 

[Teleologist]

Teleologist, I think you wanna say the p orbitals must be parallel so they can have conjugation in aromatic molecules . P-orbitals parallel so that the atoms are in the same plane.

Oops I screwed this one up.