And if you haven't heard of Things I Won't Work With, it's an (infrequently updated) blog by a research chemist on substances frightening enough that he doesn't want to be in the same lab as them. A common thread is compounds that would *really* prefer to be nitrogen gas and will energetically turn into such if given the slightest opportunity.
http://blogs.sciencemag.org/pipeline/archives/category/things-i-wont-work-with