Premise

It seems that most people i know have had some contact with AMC’s crime drama Breaking Bad. This 5 season spectacular follows the misadventures of terminal cancer patient Walter White (Bryan Cranston) and perpetual burnout Jessie Pinkman ( Aaron Paul), following their forays and mixed success in the meth business.

Walter White was once a talented chemist, he graduated with a PhD in chemistry from the California Institute of Technology and contributed to research on proton radiography that won a Nobel Prize.

Throughout the saga Walt’s expertise in chemistry helps him out of many potentially deadly situations. In one of these scenarios (S1E6: “A crazy handful of Nothin”) , an unhinged drug kingpin, Tuco Salamanca, has hospitalized Jessie refusing to pay $35,000 for the methamphetamine which Walt had synthesized for distribution. Understandably, Walt is annoyed about the situation and visits Tuco’s headquarters demanding retribution for the beating of Jessie and his stolen product.

“Let me get this straight.. I steal your dope, I beat the piss out of your mule boy, and then you walk in here and bring me more meth?”

“You got one part of that wrong. This is not meth,”

Walt then throws the mystery material to the floor. The ensuing explosion blows out the windows, sending shards of glass, splintered wood and air conditioning units tumbling to the street below, causing passers-by to scatter in terror. Walt proceeds to explain to Tuco that the crystalline material is fulminated mercury and secures the $35,000 for the meth and $15,000 as compensation for Jessie.

History

The explosive properties of fulminated mercury have been known since the 17th century with mixtures of “spiritus vini” with mercury in “aqua fortis” known to explode. The English chemist , Edward Howard (1774-1816), isolated mercury fulminate by treating a solution of mercury in nitric acid with ethanol.



Mercury fulminate was widely used as a primary explosive for nearly 100 years, with annual production in early 20th century Germany reaching 100,000 kg/yr. Most notably, the wide application of dynamite was only possible with the use of mercury fulminate (Hg(CNO)2) as a primary explosive to guarantee ignition.

Chemistry

The crystal structure of Mercury Fulminate has been determined by X-ray diffraction. It crystallizes in an orthorombic cell, with the space group cmce a=5.35 b=10.45 c=7.56. Each mercury atom is surrounded by two carbon atoms. The measured positions and bond lengths confirm a molecular structure of O−N≡C−Hg−C≡N−O.

The thermal decomposition of (Hg(CNO)2) can begin at temperatures as low as 100 C, though proceeds at a much higher rate with increasing temperatures. Pressure changes, vibrations and shock can also lead to decomposition . Example decomposition pathways follow:

4 Hg(CNO) 2 → 2 CO 2 + N 2 + HgO + 3 Hg(OCN)CNHg(CNO) 2

→ 2 CO + N + HgO + 3 Hg(OCN)CNHg(CNO) Hg(CNO) 2 → 2 CO + N 2 + Hg

→ 2 CO + N + Hg 2 Hg(CNO)2 → 2 CO2 + N2 + Hg + Hg(CN)2

Walt previously explains to his class how rapid chemical reactions which produce gases can cause otherwise harmless substances to explode.

Disputed Effects

The effect of the single crystal of fulminated mercury on Tuco’s office have been subject to some controversy.

“You got balls. I’ll give you that.”

The “Mythbusters” recently tested a number of Breaking Bad related experiments. The first of these was testing the volatility of Hg(CNO)2 with changes in pressure. 5g was placed inside a pumpkin (with a squib), with the detonation of the squib the gourd was blown to smithereens.

http://dsc.discovery.com/tv-shows/mythbusters/videos/breaking-bad-special-mercury-fulminate.htm

Due to the first success, they then went big by building a replica of Tuco’s office, complete with windows, desk and dummies. To prevent anyone from getting blown up in the name of mythbusting, star Grant Imahara created a robot with a throwing arm to play Walt, and programmed it to toss 50g of Hg(CNO)2 (the same amount used by Walt) at a speed of 60 MPH so it would hit the floor at about the same speed the average human can throw. But there was no explosion. The speed of the robots arm was then increased to a “superhuman” speed, which also did nothing.. Finally they increased the amount to 250g, which caused a massive explosion, destroying room and mannequin alike. That would have been a short series for sure.

Another anomaly is the appearance of Hg(CNO)2 which from a number of sources is described as a “Grey, Pale Brown, or White Crystalline solid”, whereas the crystals seen on the show are large clear crystals, similar in appearance to methamphetamine. However this may be a testament to Walt’s skills as a chemist, being able to grow very large crystals.

In conclusion the effect of Mercury fulminate seen in Breaking Bad probably would not have had the same effect as the real version. Though a potent explosive in higher quantities the amount used (50g) probably would not have been able to disable gangbangers or even ignite without a significant stimulus. We’ll see if Mr White gets it right next time…

References