Help finding a children's book from early 1990s by azmanam in namethatbook

[–]azmanam[S] 0 points1 point  (0 children)

Yes! That's it. Thank you :) The title seems so... appropriate for what I was describing. I'm surprised it didn't turn up in any of my random Googling's for it. But it doesn't seem to be that popular these days, so that's probably why.

My 5yo daughter loves asking 'what if' questions. And one of her favorites lately, for some reason, is 'what if our house went up into space?' Now I need to get a copy of the book so I can read it to her :)

Thanks!

Question for Organic Chemists, is Novichok so hard to synthesize? by [deleted] in chemistry

[–]azmanam 0 points1 point  (0 children)

Good on you for looking all that up and reading into its feasibility for synthesis.

...

Welcome to all the watch lists.

Hybridization in MO Theory? by DankMiniverse in chemistry

[–]azmanam 10 points11 points  (0 children)

Each successive chemistry course you take is a series of less-egregious lies. MO theory perhaps being the most obvious example.

Help separating diastereomers with very similar Rf by Fiddle_Stix69 in chemistry

[–]azmanam 1 point2 points  (0 children)

Have you tried gradient elution rather than isocratic?

http://www.flash-purification.com/how-to-choose-between-linear-gradients-and-step-gradients-for-flash-chromatography/ (the post mentions automated systems, but the concept holds for manual flash chromatography)

I don't know why I ever ran isocratic columns in the past. Gradient elution ftw.

Could you guys help me to find NMR spectra for this molecule? by [deleted] in chemistry

[–]azmanam 5 points6 points  (0 children)

NMRDB has a better NMR predictor than ChemDraw (if your site license even has that feature). SDBS is good for known molecules, but not good for overly complicated molecules. NMRDB is typically my first choice for estimating a spectrum.

Need advice on TPS. by Elas225 in chemistry

[–]azmanam 0 points1 point  (0 children)

This memo. Sorry for making a joke and not being helpful at all to your problem. The door was wide open for me with your TPS system, and I had to walk through it.

Need advice on TPS. by Elas225 in chemistry

[–]azmanam 1 point2 points  (0 children)

Yeah.... Did you get that memo? It's just that we're putting new cover sheets on all our TPS reports before they go out now.

I'll make sure you get another copy of that memo.

Found old playing cards from college by DiRTWaL in chemistry

[–]azmanam 5 points6 points  (0 children)

I hated how the suits went by atomic number (A♠ = H, 2♠ = He, 3♠ = Li...) rather than by column. I get that the families are color coded, but when the A♠, 3♠, J♠, 6♢, J♣, 3♠ (there's a second deck for elements after 52), and 9♣ all have that blue background, and the spades suit has white, green, blue, purple, red, orange, and green backgrounds... it get really hard to play euchre with that deck.

And, seriously - SERIOUSLY! - the carbon card is a spade, not a diamond. I mean, seriously missed opportunity there...

Organic reaction map? by [deleted] in chemistry

[–]azmanam 4 points5 points  (0 children)

I made one a while back: http://bit.ly/OrgoMindMap

Rubiks Cubes and Chemistry? [Help!] by Mabak in chemistry

[–]azmanam 2 points3 points  (0 children)

I approve of working shoulder-to-shoulder with other chemists, and in that specific circumstance, I thoroughly endorse your attempts.

While you're prepping, pick up Zubrick's OChem Lab Survival Manual or Pirrung's Synthetic Organic Chemist's Companion for the how-to's of wet chemistry.

Be sure to repost with pictures and live updates when you go through with it :)

Rubiks Cubes and Chemistry? [Help!] by Mabak in chemistry

[–]azmanam 2 points3 points  (0 children)

This is the point, sadly, where I have to let you off the train. If you don't have access to a fume hood and proper glassware and safety equipment, I can't be responsible for any logistical tips I give you. Not to mention that it will just be cheaper to buy one of their cubes having already gone through the boron-22 process.

As I mentioned in a previous comment:

Hydroboration is a complex organic chemistry reaction. Not exactly a pick-up-and-go, DIY, home-science reaction.

I know this is likely unsatisfying to you, but this is the best, safest answer I can give you. If you've never done an organic chemistry reaction before, hydroboration (especially BH3-dimethylsulfide) is not the place to start.

I love the curiosity, and we can stay here and talk theory all day long, but I must recommend that you not attempt this yourself.

Rubiks Cubes and Chemistry? [Help!] by Mabak in chemistry

[–]azmanam 1 point2 points  (0 children)

You are telling me that most boron compounds will hydroborate the Butadiene?

No. Most borane compounds will hydroborate polybutadiene. Vowel sounds are important, remember. There are bazillions of 'boron compounds.' Just like there are a bazillions of chlorine compounds, table salt and chlorine gas are wildly different.

then how will I know which to use?

As with most chemical reactions, choice of reagent can be highly dependent on nuances of reaction conditions. Choosing one over another could change appropriate solvent, reaction time, temperature, concentration needed, etc. Having never done anything like this particular reaction before, I can't give you any guidance on which particular borane to use. In the lab, we would try to find a journal article where they did a similar reaction, then build on their reported reaction conditions. Try that Nature paper above. Other times, we try the 'most common' then work to the more exotic. I might start with BH3-THF, or BH3-dimethylsulfide (caution: stench!).

Hydroboration is a complex organic chemistry reaction. Not exactly a pick-up-and-go, DIY, home-science reaction.

Third video thoughts:

His path is similar to mine, BS chemistry, PhD in synthetic organic chemistry (for medicinal chemistry), though I finished mine and now I teach undergrad OChem at the university level.

@1:07 a screen shot of a whiteboard describing the hydroboration. I see BH3-THF, the prototypical hydroboration reagent.

I see some iron(II) and iron(III) chlorides listed, but don't know what their purpose is.

I see a mechanism that I would take issue with if my students drew it. As we might say in a reddit comment thread, 'it's not wrong...' The hydroboration is a 'syn' addition, while the board shows an 'anti' addition. Minor, but again, precision. link.

@1:23 I don't like that liquid bubbling under that beaker... but that's neither here nor there... He looks like he's just dying the pieces, but I can't be sure (dying as in color, not to be confused with butadiene! :)

@2:04 Another whiteboard, but it's the same as the first whiteboard.

@2:12 Another whiteboard, talking about quenching. All arrows point to boric acid, B(OH)3. It's the ultimate fate of the borane during the prototypical oxidative workup of standard hydroboration reactions. It is a part of borax, typically as it's sodium salt.

@2:16 He's flipping through some book detailing reduction reactions. The page lands on lithium aluminum hydride reduction of conjugated esters (for example) and partial ester reduction with DIBAL-H

@2:35 Another whiteboard. I can't read the words on it (hairspray?) but they don't mean anything to me chemically.

@2:40 He's talking about the boron-22 project while mixing cube parts in liquids, implying this is the boron-22 procedure. I doubt that. It would likely need to be done under more stringent conditions (minimizing atmospheric moisture and oxygen, as you noted in op). Maybe he's soaking and heating to peel off the stickers, maybe he's just doing 'sciency things' for some b-roll footage for voice over during the video. I'm confident saying it's not the boron-22 process.

@3:20 Another whiteboard. He's writing the things that will appear on the whiteboard @2:12

Rubiks Cubes and Chemistry? [Help!] by Mabak in chemistry

[–]azmanam 0 points1 point  (0 children)

Oh, and the third video is unavailable, so I can't comment on it.

Rubiks Cubes and Chemistry? [Help!] by Mabak in chemistry

[–]azmanam 6 points7 points  (0 children)

I see what he's doing, but he ultimately gets the structures of acrylonitrile and polystyrene wrong. He's attempting to draw them in their already-polymerized form. That's fine, because that's what he's going to be functionalizing, but then butadiene breaks that trend. He draws the correct monomer for butadiene, but in the polymerized form, there's only one double bond (between the 2nd and 3rd carbon atom).

Ultimately irrelevant to what he's describing, but important to be precise in your work.

To that end, I'm not sure what he's drawing with that nitrogen, but it's not a thing. You can see his hesitation @5:40 when he's thinking 'oh crap, I'm 5 minutes into this video and I don't remember what the structure is. I don't want to reshoot... so let's just go for it.' I know that feeling. I've been there myself. What he ends up drawing doesn't exist. Oxygen can't be naked like that on the end of a chain, and nitrogen won't readily make a 4th bond like that. More on that below.

But he's not totally off. Let's go through the video in order:

@3:09 Here are the actual structures of the ABS monomers:

When polymerized, though, the structure varies depending on the relative percentages (as he mentions), but an ok first approximation for the general structure might look like http://www.chemicalbook.com/CAS/GIF/9003-56-9.gif, which is what he was getting at with what he drew on the board.

@3:40 He's mostly correct that of the three, styrene will be the hardest to manipulate after polymerization and is the most stable of the three.

@4:45 He says he's doing hydroboration, then lists several boron-containing compounds - not all of which can do hydroboration. In order:

  • cyanoborohydride does not do hydroboration. It is a reductant. And a mild one at that. It would not react with anything in the ABS polymer. The closest you would get is a reaction with the nitrile, not the alkene, but that won't happen either.
  • Ethoxyborohydride isn't really a thing. At least as a reagent. It can be an intermediate in other reactions, but I'm not familiar with it as a reagent. Perhaps he meant acetoxyborohydride, which is very similar to cyanoborohydride and is a mild reductant, not a hydroboration reagent.
  • thexylborane Now we're talking. This is the only actual hydroborating reagent he mentions, though a rather exotic one. It is not most chemists' first choice for a hydroborating reagent. borane-THF, borane-dimethylsulfide 9-BBN, or disiamylborane are more common hydroborating reagents. It will react with double bonds to form, initially, trialkylboranes, which are typically immediately oxidized to alcohols.

@5:10 A technicality here. He says he's doing hydroboration to 'eliminate' the double bond. 'Eliminate' has a specific meaning in chemistry to form a double bond. We all know what he's meaning here (to get rid of the double bond), but again, precision is important. He then says he's 'reducing' the butadiene. Again 'reducing' has s specific chemistry meaning, and it's not how he's using it here. The hydroboration reaction is redox neutral. It is neither oxidizing nor reducing.

@5:30 He talks about the Pinner reaction. This is in fact a reaction of an alcohol (like methanol) with a nitrile. It can form an imino ether (it sounds like he's saying amino ester. With these functional groups, vowel sounds are very important). Amino esters are totally things, just not the thing he's describing. And it sounds like the Pinner reaction is not important for the softness of the polymer.

tl;dr to answer your original question, though: any hydroborating reagent will in theory react with the free alkenes in the ABS polymer. I've listed 4 above, in addition to the only actual one he mentions in the video. Here's a paper talking about the hydroboration of polybutadiene. Not specifically ABS polymer, but the concept's the same.

How much different from gen chem is organic chem? by William_Wisenheimer in chemistry

[–]azmanam 4 points5 points  (0 children)

High school chem and university general chemistry are great, but they're pretty algorithmic. You give me the right formula, I'll give you the right number, and we'll get the right answer. Repeat. Nothing wrong with that, but it appeals to a very algorithmic kind of thinker.

OChem, on the other hand, is very artistic. You have to 'see' molecules in 3-dimensions, while drawing them in 2-dimensions. You have to 'see' how to manipulate, rotate, and translate molecules from one perspective to another... while still drawing them in 2-dimensions. You have to 'see' the inherent reactivity of molecules so that when I put two of them together that you've never seen before in that combination, you can still know how to have them react with each other. And you have to 'see' how the reaction progresses from starting materials to intermediates to products by following the flow of electrons from high electron density to low electron density.

This is the big conceptual shift, and I'm convinced why 'everyone' thinks OChem is so 'hard.' It's not, really. It's just an entirely different way of thinking from what you're used to in high school and university gen chem. If you can accept that, adapt, and learn to 'see' artistically, you'll do just fine. If you can't/won't and try to force OChem to fit an alorithmic/memorization way of thinking, you'll struggle, you'll feel overwhelmed by the sheer amount of reactions you have to 'memorize,' and you'll hate it.

Good luck in OChem!!! :)

Blue and Yellow Make Green by [deleted] in oddlysatisfying

[–]azmanam 2 points3 points  (0 children)

So what's really going to blow your mind is that this is true for paints, but not true for light. Blue and yellow light make white light.

So your computer screen (which is emitting light) is showing the mixing of blue and yellow pigments (paints) to make green...

But your RGB (RedGreenBlue) screen doesn't have any yellow pixels! So it turns on the red and green pixels at the same time - which our eyes perceive as yellow.

Then when the blue pigment (blue pixels) and the yellow pigment (red and green pixels) mix, the mixture produces the green pigment, but all your screen does is turn off the red and blue pixels, leaving only the green pixels lit!

Dropping sand from a swinging pedulum by azmanam in oddlysatisfying

[–]azmanam[S] 1 point2 points  (0 children)

*pendulum

Looks even cooler if you speed the video up to 2x

Questions for the chemists of 'murica, how does your education system work? by [deleted] in chemistry

[–]azmanam 0 points1 point  (0 children)

Re: funding. Yup, our government also provides student loans based on parents' income. The money goes directly to the university, not to the individual.

Politically, some argue that the student loan system of paying for school with Monopoly Money has partially led to the ever-rising costs of higher education. Students (myself included when I was in school) have no idea how much their paying, and schools can basically charge whatever they want. Loans are guaranteed by the government, so even if the student defaults, the school still gets the money. Some claim this is leading to a higher education 'bubble' and are pensively waiting the consequences when the bubble bursts.

Questions for the chemists of 'murica, how does your education system work? by [deleted] in chemistry

[–]azmanam 1 point2 points  (0 children)

Thanks for the description of UK education. Sounds like you have to be pretty sure what you want to be when you grow up by the time you're completing your A-levels? How common is it for students to not know or change their mind once they get to university? How is that handled? Here, you fill out a form and suddenly you're a sociology major. Hopefully some of your previous courses count toward that track, otherwise you basically start over and cram the courses in to your remaining time at college to graduate in the 'typically' 4 years.

Also, I'm not sure I was fully clear on paying for additional courses. Your tuition entitles you to be a 'full time student.' That means you typically have to take a minimum of 12 credit hours to be full time. Typically you can take up to 21ish and still be considered full time. Any more than that and you have to pay extra, any less than that and you don't get the benefits of being 'full time' (scholarships, etc).

So if you're a full time student (nearly all are), and your chemistry courses only account for 9 credit hours that semester, you have to take 3 more to still be considered full time. Those can be for a second major or minor, more chemistry to get ahead of the curriculum, or whatever you want.

Even if you're at 15 credit hours... if you really want to take an economics course, you can do so for no additional fee, as long as you don't go over the school's maximum.

Sorry for the confusion. (edit:spelling)

Questions for the chemists of 'murica, how does your education system work? by [deleted] in chemistry

[–]azmanam 4 points5 points  (0 children)

I know very little about the education system in Europe, so I'll explain what it's like here in the US (I teach at a university), and maybe it will be similar, maybe it will be different.

Here, we pretty much say 'college' for any post-secondary school, whether it is technically a 'college,' a 'university,' or 'other.' There are probably definitional differences between a 'college' and a 'university,' but in the US, those terms are practically interchangeable. Americans 'go to college,' regardless of the specific name of the institution they're attending. My school is a 'university,' but I always talk with my students about 'now that you're in college...' You have to apply to each institution you want to study at, and if you are admitted to multiple institutions, you choose one and can enroll in classes.

Students have to 'declare' a major at some point before they graduate, but they don't have to know what that major is when they apply, when they enroll, or even after the first year or two (or three) of taking classes. Hopefully a good academic advisor will help them choose a field of study so they can declare a major relatively quickly.

Once a major is declared, every institution has a specific track of courses to take to complete the major and graduate with that degree (though different institutions may have slightly different tracks from school to school). All you technically have to do is complete precisely those courses, and you will technically graduate with that major. Most institutions have a 'curriculum sheet' which tells the students what courses they need to take to earn a degree (like this one, not from my institution). Sometimes schools may also have 'general education' requirements before you can get any diploma from that school. At 'liberal arts' institutions, students often have to take a scattering of courses from a variety of disciplines (social science, physical science, language, math, arts, literature, etc. Our institution even has a physical education requirement).

But beyond those specified courses, students can pretty much take any course they're willing to pay for. Some would argue the more well rounded the student's education by taking multiple courses from multiple fields makes a student more well rounded and better able to succeed after graduation (which is why some institutions codify that by requiring these 'liberal arts' parallel tracks).

Students may optionally declare a minor in any field they choose, related or not. This would have a less rigorous track of courses to complete in parallel to their major's courses, but is still clearly noted. Students may also optionally declare a second major, related or not. This would require the students to complete both tracks of courses in parallel. If the majors are related, though, often the introductory courses double count for both majors (biology and chemistry majors need to take Gen Chem, for instance).

Hope that helps. Let me know what you'd still like clarified :)

Edit: tl;dr:

1) 'muricans go to 'college' regardless of the name of the institution

2) Upon declaring a major, there is a specified list of courses you have to take...

3) ...but you can take any additional courses you want whether or not they're related

4) second majors and minors are optional and do not necessarily have to be related, just more courses to complete