We are gonna have a look at -- today, something that's been hitting the headlines. And we're gonna be talking about this compound here, which it rejoices under the acronym: 2,4-DNP. So that translates to 2,4-Dinitrophenylhydrazyne. You've particularly sort of appreciate it because its trivial name is Brady's Reagent but it also rejoices under the trivial name of Bosche's Reagent. Well, I guess, what we'd like to start the story with is taking you way back to the dawn of organic chemistry, in maybe the 1750's through about 1980's. All of the modern techniques that --as a student or as a member of the public that we learn about, before the martyr of modern analytical techniques, are not available. In fact, the only technique that's available is to measure the melting point of your compound, and that kinda could create some difficulties for you. I've got an example here that we can look at this morning. So this is a popular compound. This is a compound of benzene, it's a derivative and it has an aldehyde group on it. But, as you can see, there's gonna be an intrinsic problem with measuring the melting point of Benzaldehyde. It's a liquid. And if melting points are the only thing you can do, you need a way to be sure that everything that is in that aldehyde or carbonyl class (....) solid that you can then even measure the melting point even in 1750 and black the essence of the ladies reagent or DMP something that you can be sure that the correct an aldehyde or ketone with to give you a solid crystalline reagent and back in the day it would come as a solid so what we're going to do now is we're going to look at the original formulation of the BMP Brady's reagent as it was supplied up until I guess probably about a year and a half ago so we're in here so we're going to do a bit of mining because this has been packaged up this is just secondary containment is the plastic outer shell and now we can get through the least in its original form and you can see is the Dean for the dye that the end for the Nitro and there's the piece of the senile hydrazine Pete and Pete gives you the ladies reagent if the compound is formulated correctly it will be completely spaced and very bored we have no need to worry but if it's dry then that's when all the fun and games and excitement starts but I've deliberately selected / compound where I believe it is dry so I'm just going to point that away from me a little bit and just open up gently so the compounds not terribly volatile so I'm handling listen I could but what we're going to do is probably get a sheet of paper in here so that we can put a little bit out so that you can feel and what you should see if you can spoon some out is a highly bright orange now these are not Cristal's these are aggregates where the small little microcrystals of all started to come together as its drying out when it dries out then the region can become more unstable it can suffer an autocatalytic decomposition the order catalysis is where the product of a reaction encourage the reaction to become faster which generally more products so that becomes even faster and of course that's how you get a runaway reaction and that's what we call an explosion and we're going to test out a little bit later but let's actually focus on why the reagents used and why it's useful and let's take you back again to the 1750 and if you remember we had this compound benzaldehyde we're clearly we don't have a solid so we would like to make a solid derivative not we would have to take this solid and we would have to dissolve it and that'll take us a little bit of time so what we're going to do is use the luxury of modern chemistry and what I've done here is actually so influenced me to his one eye pattern so this is just a solution of this orange compound i put it into solution and so what you should see here i hope is that bright or institution come up right okay so we're going to try and turn I've been out of hiding to a into a solid now i just mentioned that canvas like to do all of their reactions in solution so we're going to use methanol we're just going to use that as a solvent for the reaction so we need to get both are orange hydrazine and our carbonyl compound in the same solution so I'm going to take some benadryl divide here and what I'm going to do is to a not terribly stoichiometric reaction clue we're going to take that'll probably about the about 250 200 300 million dancing like that will put that into the solar put the lid back on here and now the high desert very nice smell of almonds but it's like toxic toxic and now we need to switch and see if we can get this to maker of precipitate so let's see benzaldehyde got a mass of about a hundred we're about two million miles in here this is about point two molar so we need a illegal about this with the rate of reaction of DMP o Brady's raging with aldehydes depends on the substrate and it can take anything from instantaneous up to several hours alright so let's just stop there oh look there you go so as you can see we've got almost instantaneous reaction we've produced from our original liquid benzaldehyde a large clump of a bright orange-yellow derivative chemist like to use names to describe the derivative we started with the hydras leave for this derivative of the hydro-zone ok so we've talked a lot about the chemistry of the MP and white really useful but it won't have escaped your attention that in media recently there's been a lot of concern over Brady's reagent pnp as a potential source of the explosion the compound as it was originally formulated damn perfectly safe in the modern version that we've shown you perfectly safe the compound does have a reputation mode for being what is called shock-sensitive meaning that is the compound is subjected to friction or sudden energy through an impact it can detonate that's not so well described actually in the scientific literature and so in the cause of science what we're going to do is try and make a brief investigation of a small and therefore potentially safe scale to indicate what the degree of shock sensitivity is as formulated in wet that shouldn't really be that much shock sensitivity and ladies region but like there's very little data and we're not going to take any chances for I I'm not gonna put on not just a face mask but this is an explosion facemask and it exposed it will protect my face still and I'm gonna gonna lose any fingers so i'm going to go for some protective gloves as well to chest the toxin today we are going to use this highly expensive scientific piece of apparatus available from any good hardware store and we're going to strike the compound not excessively hard because it should lead that if it's going to go so I'm going to give it a light tap and then we'll see 123 that I think it's me missing so we'll do that again 12 three we struck the compound you might want to come in and have a look at back and free here at the black this is where it was struck with a hammer quite vigorously no effect whatsoever you can make the comparison against the material that jumped off the front these are exactly the same color and that's quite a decent strike okay from what we should do now is let's try the compound out and see if it makes a difference so again the literature is not too clear and in view of safety concerns we're going to be a little bit vague about how long we're going to drive is compatible we're going to put it on this hot plate that you can see in the back of the hood you can see the red flashing light indicating that the hot plate is heating and if you look closely at the dials here you can see it said it just over 100 degree C so that should drive offering water and then we'll run our shop test we're gonna put that on the hot plate and now it's my turn the fire code retire to a safe distance ok so we're backing part two of the great shock destination story so while we've been away having a cup of tea what we have left is our hot plate which you can see in the background there and we've been cooking up rtmp so we're at the top here and on 321 this compound is not excessively shock-sensitive ok but what i should add at this point of courses we've done this under very controlled condition was done this with a very small amount of material the compound has a reputation for shock sensitivity therefore there have been detonations in the park clearly we've done this for you today so that you can see and feel confident in that in the chemistry but that i would advise you to take in 14 pound sledge hammers and Dustin's full of this stuff expand very rapidly one of the things that Idol was interesting is that when the bubble catches fire burning gas continues to move up
