[nj_bartel]

I see the azide anion has a net negative charge, but the alkyl azide still has a formal negative charge and a lone pair attached to a linear chain.  Seems like it would be a pretty outstanding nucleophile to me.

[Squirmy]

I believe the terminal nitrogen is still somewhat nucleophilic, just not nearly as much as in the anion.

I suspect if that nitrogen reacts with, say an alkyl halide, it's probably just a reversible process that favors starting material. That is unless some further, favorable process carries it forward

[408]

If it acts as a straight up Nu...would have to form a salt..

It can act as a Nu in situations where the resultant product is not cationic...look at the rxn of alkyl azides with alkyl cyanides giving tetrazoles...In such case aromatization can occur making for a nice thermodynamic driving force.

[nj_bartel]

Thank you!