February 29, 2008

dealing with English

Where has our fearless blogger been off to? At war with the English language.

After a good solid month of struggling with this paper its finally off to the co-authors. All told there is 30 pages of melt-in-your-mouth scientific jargon and nonsensical tables filled with roman numerals, Greek letters, and some special characters that don't even have names. (This is a lie of course, but few people outside chemistry have reasonable cause to know what an angstrom is or what the symbol for it looks like. Many wouldn't know what an ampersand was if not for "Wheel of Fortune")

More to the point, although the paper has not been accepted it is not in danger of being rejected as was the previous paper I wrote. Now it's just a question of where it will be published after its been reviewed etc. etc. Our first try will be to the Journal of the American Chemical Society, which is the most prominent chemistry journal globally. There are those (mostly Europeans) who may contest that Angewandte Chemie should have that title, but most people I know only publish in Angewandte after JACS has rejected their paper.

Actual publication is still a far way off. I suppose I am at the stage that can be considered "2nd draft". There will be a 3rd draft after the co-authors have their say at which point it will be sent to the journal, which will send it out to referees for peer review. After the referees comment on it (assuming it is accepted) there will be a "1st revision" which will be sent back to the journal. The journal typesets the paper at which point it becomes a "Galley Proof" and then publication.

So it would seem that this particular battle with the English language has been won; however, while writing my own paper I have had to spend a lot of unfortunate time reading written reports for the class that I'm TA'ing. This battle has been largely lost I feel, and not solely because of the ESL students. The native speakers have acquired a keen disregard for all things grammatical and pay no mind to spelling or word choice. I try to focus on the English for the written reports because most of the time, their chemistry is even worse. This exercise has been thoroughly demoralizing. I threw away the standard rubric for a much more holistic grading scheme which consisted of "unacceptable" "needs improvement" and "satisfactory". So far only one student in 30 has received a grade of satisfactory.

With all this done I turn my attention to other matters. We have just received shipment of our new belt-drive vacuum pumps, which means that we can begin setting up the new Schlenk lines. Hopefully this will provide some material for the blog (including pictures for those of you who need some breaks from reading.)

February 10, 2008

glassy toluene

Well, the blue crystals didn't diffract. That's not the current problem though.

I'm trying to do low temperature NMR with deuterium enriched samples. This requires adding and removing H2, HD, or D2 gas from a sample in an NMR tube in succession by doing repetitions of degassing. Essentially you remove gas dissolved in a liquid sample by removing the gas in the headspace of the sample, which draws out gas in solution into the headspace. To prevent the solvent from evaporating you need to have it frozen.

The solvent is toluene, which freezes at about -90 C. To degass it you need to freeze it in liquid nitrogen (temperature about -200 C). The quirk is that toluene forms a glass initially when forming a solid and then "cracks" as it cools further. As it cools the solid shrinks, forming a good amount of pressure on the inside, which isn't as cold as the outside closer to the liquid nitrogen. This pressure comes to a head with a loud crack that sounds like breaking glass. Since the toluene is in a glass tube, this makes for some scary moments as your degassing. The toluene in my tube cracked several times, but I was doing a lot of cycles, so I got complacent, and I was just getting to the end of the deuteration, the toluene crack shocked the glass too much and that was the end of that.

That mistake sent me back about four days. I supposed I needed to make some new starting material anyway, but I was hoping to bang out that one last good result.