That would be my reaction if asked to take a look at the structures in this new paper in JACS. As the authors, who tiptoe gingerly every morning into the State Key Laboratory of Explosion Science and Technology in Beijing put it:
“The larger the number of directly linked nitrogen atoms, the more difficult the compound is to synthesize. The difficulties in synthesizing and handling polynitrogen compounds are a direct consequence of their high endothermicities; a further complication is the almost complete absence of methodology for preparing such compounds.”
Every word of that is true, and doesn’t it just sound appealing? Here, go invent some completely new chemistry in order to make some compounds that are just trembling with the desire to explode. And if the reactions don’t work? No prob: all the side products will probably be horribly explosive, too. Good luck determining just which one of them it was that demolished your hood!
But hold on. At first glance, this structure is terrifically unappealing, unless your chemical sensibilities are bent the right way, in which case, there’s not much hope for you. The beast has eight nitrogens in a row, which I believe ties the current record. What’s startling about the compound is that it’s weirdly stable: it doesn’t decompose until nearly 194 degrees C, which is quite bizarre. You’d think, by looking at it, that it would hop up and do its big death scene at about one-tenth that temperature. I mean, I’ve made potential drug candidates that fell apart at lower temperatures than that. (The amount of electron delocalization this compound has probably keeps its personality from coming through).
The other odd thing about this one is that it changes color on exposure to light. That central double bond will flip around to cis instead of trans, which changes the color of the crystals from yellow to blue. (I remember making a photochromic compound of this sort in an undergrad experiment, which I believe was some sort of Chichibabin pyridine thingie; it sure as heck wasn’t this!) Exposing this sort of structure to UV light also isn’t the first thing I’d want to do, either – the fact that it’ll reversibly go through a transition like that also points to its mild, friendly nature.
But heck, we can fix that: hang some nitro groups off of it, guys! Put some more nitrogens in those rings! Go for the record! Surely the State Key Laboratory of Explosion Science can make some compounds that, you know, explode. Look, guys, I’ve had Chinese colleagues that seemed to have no problem making things that blew up. (To be sure, I’ve known people from a number of different backgrounds who had that talent; it springs up everywhere) So I know that you can do it.
I can’t even decide whether to put this in the “Things I Won’t Work With” category at all, since it looks like I could not only work with it, but beat on it with a ball-peen hammer. What kind of polyaza compounds are people turning out these days, anyway?