What type of interaction is depicted by the dashed line?

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2 Answers
Apr 29, 2017

The image is slightly misleading in that the interaction is actually between the second carboxylate oxygen and one of the amine hydrogens.

It is in part a hydrogen-bonding interaction, where the carboxylate oxygen is the hydrogen-bond acceptor, and the amine hydrogen is the donor.

https://upload.wikimedia.org/

It is also an ion-pairing interaction, between the partially-positive hydrogens as a group and the partially-negative oxygen.

Apr 29, 2017

Electrostatic Physical Bond. As shown, most likely 'Hydrogen-Bonding' between electronegative nitrogen and the electropositive carbon center of the carbonyl carbon of the carboxyl group.

Explanation:

There are three types of bonding in nature; physical, chemical and nuclear bonds. Physical bonds are weak electrostatic interactions (i.e., +/- attractions) between elemental structures. Chemical bonds are strong interactions from ion interactions or electron orbital interactions. Nuclear bonds are the strongest bonds involving neutron/proton/electron interactions at the nuclear level.

Within the 'Physical Bonds' classification is the 'Hydrogen-Bonding' which is a special case of dipole-dipole interaction between highly electronegative N, O, or Halogen (F, Cl, Br. I) in which one of the interacting elements is also covalently bonded to a highly electronegative element. By convention, this is typically represented by a dotted line between interacting elements.

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