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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: kaji on August 18, 2021, 07:26:38 AM

Title: Why doesn't N4H4 look like this?
Post by: kaji on August 18, 2021, 07:26:38 AM
Why doesn't N4H4 look like this? Each N would have a lone pair.
Title: Re: Why doesn't N4H4 look like this?
Post by: jeffmoonchop on August 18, 2021, 01:51:15 PM
Is this a homework question? Why do you think?
Title: Re: Why doesn't N4H4 look like this?
Post by: kaji on August 22, 2021, 01:45:04 AM
It's not, I am preparing for an exam, and I was asked to draw N4H4. And I came up with this solution, and don't know why it is wrong. Could I ask for a hint? There are 24 valence electrons, each N and H fulfill the octet rule so Idk what's wrong.
Title: Re: Why doesn't N4H4 look like this?
Post by: Orcio_87 on August 22, 2021, 04:34:43 AM
Looks like N has a sp2 configuration (hybridization). On each N atom there is pair of electrons which occupies pi orbital perpendicular to the plane.

While maybe they will form two bonding and two anti-bonding orbitals, repulsion of the electrons will be higher than in H2N-N=N-NH2.

Furthermore - N-N-N angles are tightened from 120 to 90°.
Title: Re: Why doesn't N4H4 look like this?
Post by: Borek on August 24, 2021, 05:33:59 PM
Seems like this is actually one of several theoretically possible structures, at least as predicted by QM calculations.