Cis- vs Trans- bonds

[Ryan Juncker 3D]

Do we need to know the difference between Cis- and Trans- bonds for test 2 this week? And if so can someone please elaborate on it.

[Sophia Shaka 3L]

Dr. Lavelle did mention the concept before the content cutoff for Test 2, so I think we should know it. From what I understand of the example given in class, the cis molecule has a less symmetric Lewis structure you could say, with the same atoms or functional groups on the same side of the molecule. In class this caused the molecule to have dipoles that do not cancel, making it a polar molecule, whereas the trans structure was more symmetric, with dipole moments that cancelled, making the molecule nonpolar.

[Justin Quan 4I]

To add on, a Cis- molecule is a polar molecule that has polar bonds with dipoles that do not cancel, while a Trans- molecule must have zero electric dipole moment which is possible if it contains non -polar bonds, or polar bonds with dipoles that cancel.

[chrisleung-2J]

In addition, the Cis- and Trans- forms of molecules are able to exist when there is a double bond present between two atoms, separating each side of the molecule, due to each form having a distinct structure since the molecule cannot rotate about the central bond (usually a C=C bond).

[Minh Ngo 4G]

It’s fair game since he did talk about it in class. Cis means the dipole moment cant cancel each other out while trans they do

[Dan M -3E]

It wasn't on that test but I'd guess we might have to know it for the final.