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deltaH
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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]
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phlogiston
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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.
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"If a rocket goes up, who cares where it comes down, that's not my concern said Wernher von Braun" - Tom Lehrer |
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blogfast25
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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.
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aga
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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]
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unionised
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Quote: Originally posted by blogfast25  |
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?
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blogfast25
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| Quote: Originally posted by unionised | | [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?
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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.
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unionised
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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...
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blogfast25
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| Quote: Originally posted by unionised | 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.
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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.
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bismuthate
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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 .
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j_sum1
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| Quote: Originally posted by bismuthate | | 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.)
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Texium
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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.
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Etaoin Shrdlu
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| 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.
| Quote: Originally posted by blogfast25 | | 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. |
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]
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bismuthate
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Pours starch into a beaker*
Tada!
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blogfast25
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| 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.
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aga
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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.
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smaerd
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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.
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unionised
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| Quote: Originally posted by blogfast25 | | Quote: Originally posted by unionised | 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.
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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. |
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]
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blogfast25
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| Quote: Originally posted by unionised |
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?
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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]
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bismuthate
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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.
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Tsjerk
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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.
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Tsjerk
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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.
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unionised
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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]
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Etaoin Shrdlu
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| Quote: Originally posted by unionised | | 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.
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The RNA isn't a starting material, it's the 'product' of an extraction and so well within the rules.
"Another way to enter is to just extract the heaviest compound possible. However, you cannot react the extracted compound with anything."
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aga
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Is anyone going to dispute my claim to victory ?
I'd like to be the Disputed winner now please.
Undisputed isn't much fun.
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bismuthate
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I recently synthesized H2. It weighed in at -1g on my scale. It should be beating your entry.
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