help with understanding clonazepam structure

[yodermstr]

I know this isn't really harm reduction at all so I felt it was appropriate to put here because I didn't find any rules against this kind of question.
anyway, I've been super interested in the changes in the structure of different drugs of the same class and I was just taking some notes on benzo structures. I apologize I don't know how to put pictures in to show you what I'm talking about but how does the nitrogen branching off the hexagonal carbon ring have 4 bonds? everywhere else I've seen nitrogen only has room for 3 bonds. if someone could help me out or maybe move this to the right area it would be much appreciated.

 

[sekio]

it's a nitro group, the nitrogen has a formal positive charge (e.g. an addtional bond is availiable)

see also, quaternary ammonium compounds and amine salts. nitrogen can have 4 bonds as long as it has a positive charge.