Part 8: The Chem in SpaceChem - Round 3
The Chem in SpaceChem, Round 3Note: As The Chem in Rounds 1 – 4 were written after the tournament, they may refer to later rounds.
6: Hypothetical Synthesis
Inputs: Hypothetite
Outputs: Θ-tetroxide
Well, I have nothing to say about hypothetite. Let’s look at the tetroxide for a moment, though.
Θ-tetroxide
According to Wikipedia, there are only five known substances with this kind of tetroxide structure. These compounds tend to be quite volatile, as all the oxygens pull electrons from the central atom.
Ruthenium tetroxide and osmium tetroxide are rather similar. They melt around or just above room temperature and sublimate/boil easily too, showing these are molecular compounds, not salts. As you’d expect, they are oxidants, and they can be used to oxidize many organic molecules. They dissolve well in carbon tetrachloride. Osmium tetroxide is also used to stain samples for electron microscopy. However, it’s very poisonous and its vapours also stain the human eye, which can lead to blindness.
Iridium oxide is only stable under 6K (close to absolute zero). Xenon tetroxide is a noble gas compound, and you’d expect those to be rather unstable, but it’s stable all the way up to -35.9 °C (-32.6 °F). Above that, it does explode easily.
Feasibility of the reaction
These things don’t exist.
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7: Superhydracetylene
Inputs: Carbon monoxide, Hydrogen dioxide
Outputs: Superhydracetylene, Oxygen
Well, I talked about carbon monoxide (round 5) and oxygen (round 8 and round 2) already. Let’s look at the other compounds.
Hydrogen dioxide, hydroperoxyl radical, perhydroxyl radical, HO2
Melting point: Unknown.
Boiling point: Unknown.
Molecular mass: 33.01 u
Density: Unknown.
Well, I have to say I saw this compound most often in middle school chemistry exams as a wrong way to write the formula of water. But it does actually exist. Wikipedia describes it as the protonated form of so-called the ‘superoxide ion’, O2-. That means it’s structure is like H-O-O• (the dot is denotes an unpaired electron). When dissolved in water, superoxide and water form an equilibrium with this radical and OH-. As a radical, it’s quite reactive and it can act as an oxidant. Radicals are never stable, and certainly not in high concentrations, which is why there’s no melting/boiling point or density known.
HO2 is also photochemically formed in the atmosphere, where it degrades certain organic pollutants. But it also destroys ozone in the ozone layer.
’Superhydracetylene’
Well, this stuff doesn’t exist. You can’t get a double bond on hydrogens. Let’s look at the molecules this stuff was based on instead.
Ethylene, or ethene consists of 2 C’s with a double bond with 4 hydrogens total. The C=C bond has a length of 133.9 pm (picometers). As a simple hydrocarbon, it has many uses in organic chemistry. However, it’s main use is for polymerization to polyethylene (PE). Ethylene is also a plant hormone which, among other things, stimulates ripening of fruit. For this reason, the gas is often added to storages of unripe fruits.
Acetylene or ethyne consists of 2 C’s with a triple bond, which leaves space for only 2 hydrogens. It’s a linear molecule and the triple bond between the C’s has a length of only 120.3 pm, showing that bonds of higher order are stronger, pulling the atoms closer together. As I said in Round 5, one use of this substance is in so-called Reppe chemistry reactions.
Feasibility of the reaction
Feasibility: Low
Well, you can’t ever form that acetylene-like compound from the inputs. What would happen if you put those inputs together? A lot of different reactions at once, forming a lot of rather unstable compounds. The end result would probably include carbon dioxide (a good way to get rid of the excess oxygen), possibly O2 or hydrogen peroxide (in case two of the hydroperoxyl radicals react together). Hydrogen peroxide is itself unstable and forms oxygen and water. The oxygen may react further with left-over carbon monoxide to form more carbon dioxide. And some of the hydrogens might end up on some carbons in all the chaos, but I wouldn’t depend on it.
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Challenge 3: Intro to Templates
Inputs: Maleic Template, Acetaldehyde
Output: Maleic acid
I don’t need to explain why I can’t say anything about the template.
Acetaldehyde, ethanal, CH3CHO
Melting point: -123 °C, -190 °F
Boiling point: 20 °C, 68 °F
Atomic mass: 44.05 u
Density: 0.78 kg/L
Acetaldehyde is one of the simplest aldehydes. An aldehyde is an organic compound with an oxygen atom double-bonded to a C at the end of the carbon skeleton (if the C isn’t at the end, we call the compound a ketone). It occurs a lot in nature (for instance in bread and fruits). It also occurs in the air, especially indoors and near some industries. It’s toxic at higher doses and longer exposure, so it’s considered a pollutant. It’s also a constituent of tobacco smoke. Ethanal is a breakdown product of alcohol in the human body, and it is what what causes the effects of a hangover.
Commercially, acetaldehyde is made by oxidation of ethylene. Alternatively, it can be made out of ethanol (alcohol). In chemistry, it is important to note that just like acetone (see round 7), a small percentage of this compound is in its enol tautomer form (ethenol). The main use of acetaldehyde used to be the production of acetic acid. But there are better ways to do that now, so demand for ethanal is declining. It is still used to produce some other chemicals.
Maleic acid
I talked about this compound in Round 7. My only note is that in this round there’s a double bond missing between the middle two C’s.
Feasibility of the reaction
Feasibility: low
Well, that’s a no, because those template atoms don’t exist. But without them, the template would just be C2O3. There is a hypothetical compound with that formula. It might be a short-lived intermediate in some reactions. It’s called oxalic anhydride and looks like a three-membered -C-O-C- ring with a double bonded O to each C. Even if that compound did exist, it’s structure would be so different from what we need that any reaction towards maleic acid would take a lot of steps.