I was doing an exercise with formal charges on anions and it occurred to me that the issues with incomplete octets could be solved with sharing 1 electron between constituent atoms of the ion. To illustrate:
This would be the Lewis structure of a resonance form of the nitrite ion, without bringing in an electron from an external source to complete Nitrogen's octet. Nitrogen basically needs to fill it's octet, so it becomes charged -1 by bringing an electron in from another source.
My question - could the octet be completed if one of the Oxygen atoms shared one of its electrons with the Nitrogen? Like in a dative bond where oxygen contributes its pair of electrons, instead in this case it just donates a single electron? This would satisfy all octets without needing to have an 'extra' electron. What is the need for covalent bonds to share pairs of electrons? Can't covalent bonds exist where only 1 electron is shared between molecules? After all, NaCl is a case where a single electron is used in a ionic bond rather than a covalent bond, so what's the issue with using a single electron in covalent bond?