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Diazomethane

Where is the positive charge of central nitrogen located?

It cannot be in the pure p orbital because in that case there will only s-orbital left for hybridization which is not possible. If it's present in the sp hybrid lobe which is also not possile because both sp hybrid orbital are being overlapped and formed sigma bonds with neighbouring atoms.

So in which orbital is this positive charge present?

More detail: In ground state, valence shell electronic configuration of nitrogen was: 2s2 2p3. After internal excitation, it became 2s1 2p4. Two unpaired electrons made π bonds with neighours and the rest one 2s1 and one 2p2 orbitals hybridized to form two sp hybrid orbitals. Now one electron is lost from one of the sp hybrid orbital and so now both sp orbitals have one unpaired electron each. Now both of these hybrid orbitals made sigma bonds with neighbours. After overlapping with neighbours the sp hybrid orbitals cannot contain positive charge.

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"Positive charge being present in an orbital" is weird formulation. Orbitals have zero charge at the best if empty.

But as all 4 orbital pairs contributing to 4 bonds have 2 electrons, it cannot be even said a missing electron in one of them caused the positive charge. It is rather that the middle N provided both electrons for one of its bonds and the other N forms another free electron pair.

By other words, the middle N uses 2 its electrons for the double bond with C and 3 its electrons for the double bond with the other N. The other N formally forms from its 5 electrons the 2 free electron pairs. The remaining unpaired electron and 3 electrons from the middle N form the double N=N bond. This all causes the charge shift.

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