Sciencemadness Discussion Board - Rador Labs Challenge 11-12/2014: High Stakes, High Mass

blogfast25, Sb3+ salts are actually quite common, but I'll analyze it.

Not really, and they're not salts in the commonly understood meaning of the term, because they hydrolyse like mad. Certainly SbCl3 can not be seen as a salt, with an MP of 73 C and a BP of 225 C.

In a solution of SbCl3 the concentration of Sb3+ is almost infinitesimally small. Unless the alleged Sb ferrocyanide is extremely insoluble (very low Ks) it would not precipitate in those conditions.

However, the acids of hexacyanoferrate (II) and hexacyanoferrate (III) exist and are water insoluble. The former is H4Fe(CN)6, a white insoluble material that precipitates when HCl (e.g.) is added to a solution of K4Fe(CN)6.

This is the likely cause of the precipitate: H4Fe(CN)6 formed when you added the acidic solution of antimony trichloride to the potassium hexacyanoferrate (II) solution.

You can test this with sodium carbonate, maybe even sodium bicarbonate or strong ammonia, which should dissolve the acid (with CO2 evolution in case of the carbonates).

Quote: Originally posted by deltaH

At 2880 it's a 12W kegging, actually. 12 is the modern understanding. 24 was based on P2O5.24WO3, not PO4.12WO3.

[Edited on 19-11-2014 by blogfast25]

deltaH - 19-11-2014 at 05:31

My bad, you are correct, a little cluck up on my part. It is indeed 12 units.

Actually my brain is soup today because the repeating unit of tungstate is not WO4 but WO3, so that would make my 10 unit molecular weight cut off a little lower at 10*231.8 = 2318, call it 2300, not 2500.

[Edited on 19-11-2014 by deltaH]

aga - 19-11-2014 at 11:59

I have a feeling that the currently Wining submission may well be disallowed on the same Purity basis that people have mentioned about others.

In the fervent hope that may be the case, i scanned through Brauer's Handbuch and found a couple of big fat candidates on pages 326 and 623, of which the 326 compound i think i might be able to do...

The Volatile Chemist - 19-11-2014 at 13:31

I have a feeling that the currently Wining submission may well be disallowed on the same Purity basis that people have mentioned about others.

In the fervent hope that may be the case, i scanned through Brauer's Handbuch and found a couple of big fat candidates on pages 326 and 623, of which the 326 compound i think i might be able to do...

Interesting! Looking forward to their posting.
Might do some acetone derivative complex, dunno...

aga - 19-11-2014 at 14:09

Huh ?
No 'dunno', just Do !

If Praxchys's entry gets disallowed, we're in with a chance !

I get the feeling that my first entry could well be disallowed under the rules, so best have a Plan B.

The Volatile Chemist - 21-11-2014 at 06:37

Huh ?
No 'dunno', just Do !

If Praxchys's entry gets disallowed, we're in with a chance !

I get the feeling that my first entry could well be disallowed under the rules, so best have a Plan B.

Cool. I've been thinking about some complexig ideas, I'll shoot you some potentially interesting inorganic ligand options.

blogfast25 - 21-11-2014 at 13:08

Still waiting for Bismuthate's response... :cool:

aga - 21-11-2014 at 15:18

OK.

So are Rador Labs' members allowed to post submissions, despite having Prior Knowledge, and therefore more time, to investigate/research heavy compounds ?

Surely that would be an Unfair advantage.

blogfast25 - 22-11-2014 at 04:03

OK.

So are Rador Labs' members allowed to post submissions, despite having Prior Knowledge, and therefore more time, to investigate/research heavy compounds ?

I don't really see a problem with it if said member is excluded from adjudication of the winner and if RL in future announces its competition's subject a fortnight or so before opening the competition. The latter would draw more people in, I think...

[Edited on 22-11-2014 by blogfast25]

bismuthate - 22-11-2014 at 04:26

Oh yeah I forgot to post that I decided not to analyze it since I managed to make a larger compound which has been taking quite a while to dry already so it would be a waste.

Also I'm not in it for the prize.

I can still analyze it later if you want, but I've had my hands full recently.
[Edited on 22-11-2014 by bismuthate]

[Edited on 22-11-2014 by bismuthate]

blogfast25 - 22-11-2014 at 05:03

I can still analyze it later if you want, but I've had my hands full recently.

If by 'it' you're referring to the alleged 'antimony hexacyanoferrate(II)' I think you should at least test it with a carbonate to see what happens.

SM's pages are google indexed: it's not good to have ambiguous information to allow to stand without corroboration if that information is out there on the Interwebs.

blogfast25 - 22-11-2014 at 11:01

Afraid not. That's a polymer with n=10000. Mine is a discrete molecule, 10 points for guessing what it is?

[Edited on 18-11-2014 by Oscilllator]

I now know what it is. But I'm not telling, there's $19 at stake, ferg-dsake!

[Edited on 22-11-2014 by blogfast25]

Brain&Force - 22-11-2014 at 11:20

If Rador Labs members win the challenge we're considering rolling the prize over to the next challenge.

Again, this is a test run, so don't be surprised if things get screwy.

aga - 22-11-2014 at 11:28

I agree with Blogfast25's comment that so long as any Radar personnel entering the competition are not part of the Judging process, then that would be fine.

Even Rador people need money,and it;d be a shame to deny them the prize if they won.

Oscilllator - 22-11-2014 at 19:50

Afraid not. That's a polymer with n=10000. Mine is a discrete molecule, 10 points for guessing what it is?

[Edited on 18-11-2014 by Oscilllator]

I now know what it is. But I'm not telling, there's $19 at stake, ferg-dsake!

[Edited on 22-11-2014 by blogfast25]

Shhhhhhhhh

The compound I am thinking of is very easy to make, but I'm finding it nearly impossible to isolate

Texium - 22-11-2014 at 20:33

Quote: Originally posted by Brain&Force

If Rador Labs members win the challenge we're considering rolling the prize over to the next challenge.

Not all of us have been considering that...
Sorry people, but if the compound that I've been working on now ends up winning (which is still doubtful), I'm keeping my winnings, because I have no job and I'm broke! I spent all of my money on chemicals.

blogfast25 - 23-11-2014 at 06:13

The compound I am thinking of is very easy to make, but I'm finding it nearly impossible to isolate

Yup. To be expected. It's a miracle it crystallises at all.

Texium - 23-11-2014 at 09:18

If the compound that you're talking about is what I think you're talking about, well, good luck isolating one pure species of it.

Hmmm, what could it be?

Oscilllator - 23-11-2014 at 19:25

Etaoin Shrdlu - 23-11-2014 at 20:36

Okay, I get it now. Best of luck with the isolation.

Oscilllator - 23-11-2014 at 22:42

I know at least one other member is trying to synthesise this compound and so in the interests of fair play I will disclose that I have successfully used hydrolysed sucrose and sodium metabisulphite to form the complex, forming visually identical products. I don't actually have any of the reagents that published procedures have used, so at this point I'm just mixing together reagents haphazardly to try and get some results.

bismuthate - 24-11-2014 at 04:22

Why not just filter that liquid?

Metacelsus - 24-11-2014 at 09:40

I understand what you're doing now. That's a really clever idea. However, sucrose has a molecular mass of 342.3 grams per mole, so according to the rules of the challenge, you can't use it as a pure starting material; you'd have to get it from an impure source (brown sugar, maybe?).

NexusDNA - 24-11-2014 at 10:31

K. I was going to submit an experiment, but a terrible thing happened to me and I won't be able to do it. My idea was a saccharide poliester (stearic or whatever), around 2500g/mol. Feel free to use it, easy isolations and reactions; isolation of final product is an odyssey. Still, the numbers are getting really huge here! Probably it won't be a winner.

blogfast25 - 24-11-2014 at 10:43

I know at least one other member is trying to synthesise this compound and so in the interests of fair play I will disclose that I have successfully used hydrolysed sucrose and sodium metabisulphite to form the complex, forming visually identical products. I don't actually have any of the reagents that published procedures have used, so at this point I'm just mixing together reagents haphazardly to try and get some results.

Molybdenum Blue. I was thinking of using other reducers too, no reason to believe the prescribed dithionite or hypophosphite are the only potential reducing agents here. QED.

I was messing with some WO3 before (my original target was barium phosphotungstate hydrate, about 4000) and sodium sulphite induced a decidedly strong blue colour into some freshly prepared aqueous WO3 (adding peroxide made the blue disappear again). Like Mo(VI), W(VI) is prone to partial reduction to W(V) and the mixed valence W(V,VI) complexes show charge transfer absorption bands at 745 nm, resulting in intense blue colour. It's what led me onto the Moly Blues.

I won't be entering the race now, as I can't see how 23,000 can be beat. I hope you win, you were the first to have the idea. Isolating it will be a matter of time. Touch wood!

[Edited on 24-11-2014 by blogfast25]

NexusDNA - 24-11-2014 at 11:14

Molybdenum Blue. I was thinking of using other reducers too, no reason to believe the prescribed dithionite or hypophosphite are the only potential reducing agents here. QED.

Hahahaha... btw the terrible thing was reading this page in the wiki.

aga - 24-11-2014 at 12:32

I can't see how 23,000 can be beat.

Add an atom or two of something else ?

bismuthate - 24-11-2014 at 12:35

Make the potassium salt?

blogfast25 - 24-11-2014 at 14:04

Aga and Bismuth: enter the competition through the Big Wheel! But I'm out.

The wheel is an Mo154 structure. One paper claims an Mo358 'sphere' is theoretically possible but no amateur could ever characterise that convincingly, assuming it can be made even...

[Edited on 24-11-2014 by blogfast25]

aga - 24-11-2014 at 14:25

I have part of the workup to my pathetic entry drying in the shed.

If it survives the next 3 or 4 steps, i'll post it anyway, despite the fact it couldn't win.

Who needs transparent aluminium/titanium alloy anyway ?

[Edited on 24-11-2014 by aga]

bismuthate - 24-11-2014 at 14:33

https://www.dropbox.com/sc/viz0y6wu75nzncn/AACv952dt-2bVk9fE...
https://www.dropbox.com/sc/2rcpwpsj1fvuuhy/AABmc5M3_RzP0mmDl...
I've had success in isolating molybdenum blue using sodium thiosulfate, sodium molybdate, and hydrochloric acid. Now read this all the way through. I don't plan on submitting this. I just want to say that I've seen that this compound seems to be ruining the competition. Everybody has seemed to have just given up. I can't stand for that, so not as a Rador Labs member, but as a contestant I say that Molybdenum blue should be disallowed. I don't want this as an official rule, but I would ask that nobody try to make this. I could win now, but it's just much fun this way and I think that should be the point of this competition. Could everybody stop the pursuit of this compound even though this isn't a submission?

blogfast25 - 24-11-2014 at 14:54

Bismuth:

Competitions like this will occasionally turn up these 'spoilers', but that's no reason to ban them.

Banning makes everything contrived and people like Oscillator have already spent considerable time and effort into looking for the highest MW entry possible. I think that should be honoured.

Changing the competition's rules every 5 minutes just because something pops up makes it into a farce, IMHO. Imagine if this had been published a bit more far and wide and 100s of people took part: you'd have a riot on your hands and rightly so IMHO.

[Edited on 24-11-2014 by blogfast25]

Texium - 24-11-2014 at 14:58

While it's definitely true that molybdenum blue is a bit of an easy instant win for those who can get molybdenum fertilizers (assuming there isn't someone else lurking with something even more spectacularly heavy), it would be very unfair to change the rules at this point since some people have already put in a good amount of time and effort, and possibly money if they hadn't previously owned the needed molybdenum compounds. We may run a better version of this competition again sometime in several months, and that should run much more smoothly than this one.

Edit: blogfast replied while I was typing this, we said essentially the same thing.

[Edited on 11-24-2014 by zts16]

bismuthate - 24-11-2014 at 15:06

I'm not banning this. I'm just saying that I can submit it but am choosing not to so that other compounds stand a chance and the competition is more fun. Anybody could still submit it if they want, I just ask that they don't to make the competition more fun. I'm not a member of Rador Labs saying this, just a participant. No rules were changed

aga - 24-11-2014 at 15:21

If you've Made it in relation to this competition, you *have* to submit it, or us noobs will not see how it's made !

Everybody stop panicing !

If Molly Blue is HUGE, groovy.

The POINT is not the $22 (it went up)

The POINT is having some fun, and learning something, so refusing to post MB now would be a severe disappointment to me at least, as it'd be great to see how it's made.

Edit:
a flash of genius: molly blue with a hint of pink ...

[Edited on 24-11-2014 by aga]

bismuthate - 24-11-2014 at 15:28

I just mixed 1g sodium thiosulfate, 2g Sodium molybdate, and 10mL of 39% HCl is water. Then I filtered. Pretty simple actually.

Mailinmypocket - 24-11-2014 at 15:28

Molybdenum blue synthesis shots from a while back

[Edited on 24-11-2014 by Mailinmypocket]

bismuthate - 24-11-2014 at 15:30

When and how did you make it?

Mailinmypocket - 24-11-2014 at 15:34

About a year ago, something around that. I used the instructions from here http://lambdasyn.org/synfiles/molybdaenblau.htm which are from Brauer.

Instead of sodium molybdate I used molbdenum oxide, zinc and HCl

aga - 24-11-2014 at 15:38

Blue products are forbidden under the local Porn by-laws.

(is mine gonna be blue ? doh !)

bismuthate - 24-11-2014 at 15:38

Ahh you made a very different molybdenum blue from the one I made.

Texium - 24-11-2014 at 16:37

This is not an official submission, but it is my current personal best for heavy compounds. It is disodium copper(II) dichloroisocyanurate. It (I think) has the formula Na₂[Cu(C₃N₃O₃Cl₂)₄] which gives it a mass of 897.3552 g/mol
I made this some time ago, and it isn't the entry that I'm currently working on. I just thought it would be nice to look at something other than molybdenum blue for a bit.

It actually looks even more purple in person. My camera can't handle the purple.

aga - 24-11-2014 at 16:42

Beautiful !

What's the Procedure to make it ?

The Volatile Chemist - 24-11-2014 at 17:15

Wow! That's really pretty!
I'll have to get my game on.
Good luck everyone.

aga - 25-11-2014 at 12:09

The moment you've all been waiting for ...

It's from page 326 of Brauer : Barium Periodate
Ba₃H₄(IO₆)₂
MM 861.9
Sample: 0.92g

To start with, i had some Barium Nitrate, KOH, Bleach, NaOH, KCl (no-sodium salt) and 2g of elemental I₂

Starting with 1g of the I₂, it was calculated that there would be 3.6g of end product. All stoichimetry was worked out from 1g of I₂.

Brauer's called for KClO₃, which was not available, so 1 litre of bleach was boiled down until crystals started to form, then allowed to cool, and 100ml of the supernatant liquid collected. The Crystals are apparently NaCl.

As this was OTC bleach, there were some oils and crud floating on top, so a separatory funnel was used to remove them before filtering.

Then some dissolved, filtered KCl was added, and a precipitate was seen.

After 2 recrystallisations, plate-like crystals of KClO₃ were obtained (they're in the petri dish).

After that, Brauer's was followed.
Especially wonderful was the reaction of KIO₃ + KOH + Cl₂

The liquid is clear to start with, and as Cl2 is pumped through it, Nothing happens until a certain point, after which a worrying Iodine cloud forms, then sparkly blueish crystals of KIO₄ snow out of solution.

Finally those crystals were separated, washed, dissolved in KOH solution and Ba(NO₃)₂ solution was added, at which point white Barium Periodate crystals dropped out of solution.

I only got 0.92g of the theoretical 3.6g (25.6%)
(see dribble on microscope slide)

Who cares ?
I never did most of those procedures before, and it was a blast !

bismuthate - 25-11-2014 at 12:38

Nice. Now I would accept it if it were up to me, but the product must be a dry power. I'm sure it won't take too long to dry. Good job. Try making the copper complex. It's really cool.

aga - 25-11-2014 at 12:41

What's 'THE' copper complex ?

Copper complex with Barium Periodate ?

bismuthate - 25-11-2014 at 12:43

Sorry I meant the copper complex of iodate. I was kinda talking to myself. Sorry
http://woelen.homescience.net/science/chem/exps/CuIII/index....
Here's a synthesis.

Oscilllator - 25-11-2014 at 17:23

Why not just filter that liquid?

Because it didn't have a precipitate yet, silly.

--

An update on my molybdenum blue efforts: I have managed to get a precipitate using hydrolysed sucrose, so all that remains is to filter it, although characterisation will be difficult (anyone have a reference that uses an aldehyde as a reductant?)

I don't know about the use of thiosulphate as a reductant though. Since thiosulphate reacts with acid to give elemental sulfur, the end product will as such be contaminated. If anyone wants to enter a molybdenum blue synthesis that uses thiosulphate, I think that they should have to demonstrate that they have removed any elemental sulfur. This will be extremely difficult, because the sulfur particles formed are extremely small and nearly impossible to filter in my experience.

With regards to the morals of synthesising Molybdenum blue however, I think it is a perfectly fair target because isolating the compound in its pure form is very difficult. Added to this is that I understand there are a number of different similar molybdenum blue compounds, and so the only way you can be reasonably sure you have one of them is if you follow an established procedure and achieve the same results.

But I think Aga sums it up nicely:

The POINT is having some fun, and learning something
[Edited on 24-11-2014 by aga]

P.S. Don't worry Aga, I'll post my results and method regardless of whether or not I win the competition.

bismuthate - 26-11-2014 at 04:29

Well feel free to make one of them if that's you opinion. Also I used too little acid and the reaction was immediate so no sulphur could have formed.

aga - 26-11-2014 at 05:03

Well, my Barium Periodate dribble dried out overnight into a fine white powder.

It was windy this morning, and it blew away.

bismuthate - 26-11-2014 at 05:33

Oh well. I'll accept it

blogfast25 - 26-11-2014 at 05:43

With regards to the morals of synthesising Molybdenum blue however, I think it is a perfectly fair target because isolating the compound in its pure form is very difficult.

Not from what I've read: they just mixed the chemicals, allowed to stand for 3 days, filtered and washed.

Re. thiosulphate: if the reduction reactions are much faster than the sulphur formation (I believe that is true), sulphur contamination should not be a problem, as all the thiosulphate will preferentially react away in the reduction reactions. I've titrated with thiosulphate in acid conditions w/o any sulphur formation.

bismuthate - 26-11-2014 at 07:40

Yup. That was my reasoning for why there would be no sulfur. Plus I used les than the amount needed. Of the HCl that is

[Edited on 26-11-2014 by bismuthate]

blogfast25 - 26-11-2014 at 07:48

Oh well. I'll accept it

I had made this lovely HMW compound, a wonderful green it was but Freddy the Duck ate it. Can I submit too?

[Edited on 26-11-2014 by blogfast25]

bismuthate - 26-11-2014 at 09:27

Yup.

Just kidding.

But I'm accepting his because I saw the pic earlier.

[Edited on 26-11-2014 by bismuthate]

Texium - 26-11-2014 at 09:40

Yeah, really since it wasn't as heavy as the current frontrunner anyway, the rules don't need to be so strict. Only on compounds that are challenging the current heaviest one. I think I'll make a publicly viewable Google doc with the current leaderboard.

Edit: Here is the link: https://docs.google.com/document/d/1XSsPWkPlc9ZYOOliBgl4HP9p...

Still actually only 4 entries currently

[Edited on 11-26-2014 by zts16]

aga - 26-11-2014 at 11:59

As ever, Aga is the Four runner.

deltaH - 26-11-2014 at 22:57

If moly blues are allowed, then it's not necessarily a guaranteed win, because there are MANY compounds in that class, some with very high molecular mass and others, less so. It can still be very much a contest and I am sure we have not seen the end of moly blues here.

For those who have struggled to obtain moly blue crystals... they take a very long time to crystallise (some big ones... 2 weeks while covered), simple because of the size of the things, it's a kinetic issue... but crystallise they certainly do and without the need to do anything fancy. In fact, they crystallise so well that one can perform single crystal x-ray diffraction (to prove its structure) on an individual crystal, as was done in one paper I read with one version of a moly blue on the high end side (MW between 50000 - 100000... not saying exactly in case someone intends to enter that particular one).

That said, as I've written about earlier, I personally don't think moly blues should be allowed under the original rules because it's an inorganic macromolecular polymer by IUPAC definitions (since it is made up predominantly of a molybdate monomer).

Yet, I think under the spirit of all-things-groovy, moly blues might be declared fair game by the powers that be

That's half the fun of such a contest... who knows

bismuthate - 29-11-2014 at 18:00

Ammonium Phosphomolybdate
1876.35 g/mol
(NH4)3PMo12O40
First prepare a 8M solution of Nitric acid from nitric acid made from ammonium nitrate and sulphuric acid.
Pour 40mL into a beaker.
Dissolve 3.5g of sodium molybdate (fertilizer) in this.
Dissolve 5g of hardware grade TSP in it.
Prepare a solution of 3g of ammonium nitrate cold pack beads in 20mL of water.
Mix the two solutions.
Heat it.
Filter and dry the rather beautiful yellow precipitate.
12(NH4)2MoO4 + H3PO4 + 21HNO3 ==>(NH4)3PMo12O40 + 21NH4NO3 + 12H2O
https://www.dropbox.com/s/vuxozjjsaj9jfjo/Photo%20Nov%2029%2...
https://www.dropbox.com/s/c1hlk3wy6dvaya8/Photo%20Nov%2027%2...
https://www.dropbox.com/s/uzag4yr6ahysir1/Photo%20Nov%2022%2...
sorry about poor pic quality. My lighting sucks.

Texium - 30-11-2014 at 12:13

Nice job! The color of it reminds me of cadmium sulfide. It seems like your procedure and product are completely legit this time, so it looks like with that you're currently in the lead.

unionised - 30-11-2014 at 12:29

Surely I'm not the only one looking at that and thinking of the next row of the periodic table?
http://www.endmemo.com/chem/compound/nh4_3w12po403h2o.php
A heavier counter-ion and you could break the 3000 mark.

Incidentally, if anyone tries this starting with tungsten metal and dissolving it in molten NaOH/NaNO3 please beware that the reaction is rather violent.
Also if you ppt the WO3. n (H2O) with acid, remember the NOx fumes are nasty

Texium - 30-11-2014 at 12:31

Surely I'm not the only one looking at that and thinking of the next row of the periodic table?

Yep, I was just looking at that too.

I have something better though, if I can pull it off in the next week or two.

Brain&Force - 30-11-2014 at 15:42

Aren't we going to have weekly/biweekly updates in the thread regarding the current winner and prize?

Texium - 30-11-2014 at 15:56

We should, but Praxichys seemed to be the one doing that, and he seems to have mysteriously disappeared...
As of today, the competition is halfway over.

Brain&Force - 30-11-2014 at 16:15

I think that's his trademark

he's done that in several other threads.

[Edited on 1.12.2014 by Brain&Force]

Praxichys - 1-12-2014 at 06:44

Quote: Originally posted by Brain&Force

I think that's his trademark

he's done that in several other threads.

Haha, I suppose it is.

Sadly, chemistry is only my hobby, and I am often very busy with things like fixing the house, tending to the lady, business travel, etc. and I do not always have time to respond or follow things up at the speed I would like. With the recent holiday, things have been especially crazy. Many of you probably noticed that I have been quite absent from Skype for the last week, and the TEMPO synth that I am working on is at a TEMPO-rary standstill. (Ha!)

I do read SM daily, and although my focus on chemistry (and video making) will continue to come in bursts, I have no plans to quit. I will try to be on Skype tonight!

The pot is now $24.

Oh, and if there is money involved (or shipping things), it will happen on time, guaranteed. Those things have much higher priority than simple discussion. I think the 30-ish people here who ordered mercury can testify to that.

blogfast25 - 1-12-2014 at 10:02

Surely I'm not the only one looking at that and thinking of the next row of the periodic table?

Surely not. It's been discussed above: the P12WO3 compounds. I was going to prepare the barium hydrate of it but to me the Moly Blues should rightfully win, so I won't be entering anything.

I think Bismuth hasn't made enough of the compound, by the rules?

bismuthate - 1-12-2014 at 11:49

It was over .5g so it passes and anybody could still submit a molybdenum blue if they want.

unionised - 1-12-2014 at 12:31

Unless someone can convince me otherwise I think that the molybdenum blue is a polymer (and a poorly defined one at that.)
I can't see how anyone is going to meet the requirement of this rule
"You must have the exact molecular weight."
with the sort of mess you get from Mo Blues and such.
It may well be mainly the "big wheel" but what evidence is that that you don't have a whole mess of impurities?
However, I don't really care- I'm not entering, just puzzled as to how someone intends to measure the degree of polymerisation.

[Edited on 1-12-14 by unionised]

Mesa - 1-12-2014 at 13:03

I can't say much for Mo compounds as I've had no reason to study them, but many of the W compounds can be isolated or prepared in a relatively pure form.

[Edited on 1-12-2014 by Mesa]

blogfast25 - 2-12-2014 at 13:58

1. Unless someone can convince me otherwise I think that the molybdenum blue is a polymer (and a poorly defined one at that.)

2. I can't see how anyone is going to meet the requirement of this rule
"You must have the exact molecular weight."
with the sort of mess you get from Mo Blues and such.

It may well be mainly the "big wheel" but what evidence is that that you don't have a whole mess of impurities?

3. However, I don't really care- I'm not entering, just puzzled as to how someone intends to measure the degree of polymerisation.

[Edited on 1-12-14 by unionised]

1. I don't think it's a polymer. Look at the formulas that describe it. It's similar but not exactly a polymer, IMHO...

2. How is anyone going to prove their compound is the exact molecular weight? No one is, Mo Blues or other.

You claim the Mo Blues are a "sort of mess". That's not what I've read at all.

3. That's point 2. really. If someone prepared Ba P12WO3 hydrate would we believe his claims for MW? How would he prove it? How about degree of hydration for instance?

deltaH - 3-12-2014 at 06:09

Exactly why I suggested people work from a publication, preferably one where that compound has been characterised. If you repeat their methodology and get a similar result, it is far more believable.

Crystalline materials of the moly blues family are well know even in the 50000 < 100000amu range and have been characterised with single crystal x-ray diffraction, so they are not always a mess, however, I agree with unionised on his other point about them being polymers.

[Edited on 3-12-2014 by deltaH]

phlogiston - 3-12-2014 at 07:27

A very recent publication in JACS, perhaps interesting to some of you:

J. Am. Chem. Soc., (2014), 136 (48), pp 16732–16735

Quote:

The modular synthesis of a defined, rigid molecular spoked wheel structure with the sum formula C₁₈₇₈H₂₆₈₂ and a diameter of about 12 nm is described. The attached 96 dodecyl side chains provide the solubility of the 25 260 Da compound in common organic solvents. At the octanoic acid/highly oriented pyrolytic graphite interface, the molecules self-assemble to form an ordered 2D lattice, which is investigated by scanning tunneling microscopy, displaying their structure with submolecular resolution.

blogfast25 - 3-12-2014 at 09:50

Quote: Originally posted by deltaH

[...] however, I agree with unionised on his other point about them being polymers.

Whatever. I detest Mankind's philatelist tendencies to try and put everything in a little box. It's petty and doesn't enlighten in any real sense of the word.

aga - 3-12-2014 at 10:50

Excellent reasoning.

So only my entry is valid, as it was produced by a published method, and the powder got blown away by the wind, proving it indeed be a highly pure powder of amazing weight, albeit lighter than my wind.

Therefore i proclaim myself the undisputed winner (i'm not disputing it).

[Edited on 3-12-2014 by aga]

unionised - 3-12-2014 at 10:52

Quote: Originally posted by deltaH

[...] however, I agree with unionised on his other point about them being polymers.

Whatever. I detest Mankind's philatelist tendencies to try and put everything in a little box. It's petty and doesn't enlighten in any real sense of the word.

So, in order to avoid splitting the word into "meets the rules" and " doesn't meet the rules" you would like to remove the rules?

blogfast25 - 3-12-2014 at 11:34

[So, in order to avoid splitting the word into "meets the rules" and " doesn't meet the rules" you would like to remove the rules?

I've already indicated my opposition to the 'no polymers' rule. Unnecessary and limiting for no good reason.

This competition is low on science but high on entertainment.

Looks like someone's gonna win with a compound that's a standard test for phosphates. But hey, at least it's not a polymer!

Honestly... what a farce.

unionised - 3-12-2014 at 11:39

There's at least 2 reasons for avoiding polymers.
You almost always get mixtures and it's often very difficult to measure the molecular weight (in particular, most polymers don't even have just one average MW.

Now, just as soon as I can synthesise a decent sized diamond...

blogfast25 - 4-12-2014 at 13:07

There's at least 2 reasons for avoiding polymers.
You almost always get mixtures and it's often very difficult to measure the molecular weight (in particular, most polymers don't even have just one average MW.

Except: they're not good reasons. Say P.Olymer synths a PP with Ziegler Natta of average 25,000, lower limit say 10,000 which beats the runner up pants down. Yet P. gets disqualified for producing a polymer? In a competition about high MWs that's oxymoronic.

Any characterisation problems are the competitor's concerns, not the organising committee's.

bismuthate - 4-12-2014 at 14:29

If the each molecule has a differing formula you don't really have a single absolute compound. It would be like allowing network solids. That's also I large series of repeating units .

j_sum1 - 4-12-2014 at 16:21

If the each molecule has a differing formula you don't really have a single absolute compound. It would be like allowing network solids. That's also I large series of repeating units .

I submit a networked molecule of NaCl.
Molecular mass 6 713 214 368 921 042 617.83924

(I really think that polymers are rightly disallowed on the grounds that they do not have a definite mass and are invariably impure molecular mixtures.)

Texium - 4-12-2014 at 16:42

Yes, and the rule about not allowing polymers (despite being ill-defined at first) has been around since the start. It's certainly not something that is going to change.
Possibly, there could be a challenge at some point dedicated to making interesting polymers (winner determined by popular vote). I have not brought this up yet with everyone else though, it's just an idea that I had after reading some of this.

Etaoin Shrdlu - 4-12-2014 at 16:52

Quote: Originally posted by zts16

Yes, and the rule about not allowing polymers (despite being ill-defined at first) has been around since the start. It's certainly not something that is going to change.

The definition laid out stated a polymer was made up of indefinitely repeating units. Crystallized moly blue does not fit this definition because the units repeat a pretty definite number of times.

The good reason is that I would crosslink an entire beaker full of resin. I was going to do it as a joke when the idea for this competition was just starting to kick around but alas I was anticipated.

[Edited on 12-5-2014 by Etaoin Shrdlu]

bismuthate - 4-12-2014 at 18:27

Pours starch into a beaker*
Tada!

blogfast25 - 5-12-2014 at 10:48

Quote: Originally posted by j_sum1

(I really think that polymers are rightly disallowed on the grounds that they do not have a definite mass and are invariably impure molecular mixtures.)

It's perfectly possible to produce polymer with very narrow molecular weight distribution and extremely well defined structure.

To be honest, I've stopped caring.

Bring on as many petty rules as you want, it doesn't make the science any more interesting, quite the opposite. QED as far as I'm concerned. Yawn.

aga - 5-12-2014 at 11:22

Ah c'mon !

It's a First Stab at a Competition, not a violation of Human Rights.

No need to be so damning.

The lessons learned should produce a better rule-set next time.

smaerd - 6-12-2014 at 07:47

Awe shoot I recently made a compound with a MW of about 1200g/mol. But It started out of range for the contest hehehe. Hmm, maybe I'll try this with something else.

unionised - 6-12-2014 at 09:28

It's a bit like entering the 100 metres sprint, but using a motorbike.
If the point is to get from a to b in a hurry then a motorbike is great, but that's not the point here.
Of course, you are welcome to set up a competition for the highest MW polymer. (Or, if you like, a motorbike race)
Good luck with the judging.
On a practical note, how do you think you can guarantee a lower limit of MW range on a polymer?

[Edited on 6-12-14 by unionised]

blogfast25 - 6-12-2014 at 10:04

It's a bit like entering the 100 metres sprint, but using a motorbike.

On a practical note, how do you think you can guarantee a lower limit of MW range on a polymer?

Or is it a bit like asking the faster runners to run without shoes, so as not to 'disadvantage' these poor slower ones? Do you want potentially great science or mediocrity for the sake of 'fairness'? No holds barred leads potentially to the former.

Molecular weight distribution determination is standard fair for polymer producers. From it the lower limit can be known.

Molecular weight determination of many high MW compounds is outside the capability envelope of most here. Are we going to exclude those who don't present full characterisations? What's good for the goose is good for the gander.

[Edited on 6-12-2014 by blogfast25]

bismuthate - 6-12-2014 at 10:31

Ok make a polymer with an exact formula. That will help your case be more reasonable.
In the mean time I'll submit my one mole block of iron.

Tsjerk - 6-12-2014 at 10:59

Extract 23S rRNA from E. coli. Not excluded by the rules, but having a strictly defined molecular structure with a MW of 990.000 g/mol.

Very possible to do in a home lab and up to +95% purity.

Tsjerk - 6-12-2014 at 11:01

Extract 23S rRNA from E. coli. Not excluded by the rules, but having a strictly defined molecular structure with a MW of 990.000 g/mol.

Very possible to do in a home lab and up to +95% purity.

unionised - 6-12-2014 at 11:12

OK the rules say you can extract something as a starting material as long as it has a mass less than 500. So the RNA is about 2000 fold too big.

How much does a custom peptide synthesiser cost?
"Or is it a bit like asking the faster runners to run without shoes, so as not to 'disadvantage' these poor slower ones? Do you want potentially great science or mediocrity for the sake of 'fairness'? No holds barred leads potentially to the former.

Molecular weight distribution determination is standard fair for polymer producers. From it the lower limit can be known."
The point isn't to get from A to B, it's to get there in accordance with the rules.
You may not have noticed, but the rules of pretty much any game make it harder and more interesting.

Also, since they force you into thinking of unconventional solutions to the problem, they improve the intellectual content of the work done.

for example,, while I'm in 2 minds about whether the Mo blue is a polymer or not, at least including it for discussion led me to some interesting stuff about big Mo clusters.
If it was just a matter of "search the web for the heaviest protein you can find" it's not interesting at all.

[Edited on 6-12-14 by unionised]

Etaoin Shrdlu - 6-12-2014 at 14:43