Chem 201 Archive – Alan Shusterman

Month: December 2008

  • Have tunes? Gotta dance?

    Piles of paper surround me. Wrapping paper for presents. Your exams and lab reports. (Not to worry, no one in the family received socks wrapped in a lab report.) And it’s snowing. So what do I do?

    What would anyone do?

    Surf for distractions, of course.

    A student emailed me this song from Science Groove: Hooray for NMR Spectroscopy! (http://www.science-groove.org/Now/Hooray_lofi.mp3)

    I also watched the winners of Gonzo Labs & AAAS/Science magazine 2009 Dance Your Ph.D. Contest. My personal faves: the Sue Lynn Lau & group on the left (good music, joyful sunshine, capoeira moves) and Vince LiCata with red-shirted subunits on center right (watch for Old Man Winter as a cryogenic cooler). Check it out!

    Maybe Reed should have a “Dance Your Non-dance Thesis” contest? (To make this fair, dance majors would have to sing their theses.) Got any nerdy web material to share? Post a comment or just say “hi”.

  • Rate of Nucleophilic Substitution Contest – My Response

    If you recall, the winners of this contest were chosen by pulling cards out of a hat, an unusually large (size 7 3/4″) black top hat. The questions asked by the winners* were:

    1. Fluffy C. – Are the low reactivity of bromocyclohexane and bromocycloheptane towards NaI due to the way the rings fold?
    2. Ross Y. – What is the relationship between angle strain and SN1 reactivity in cycloalkyl bromides?
    3. Kelsey W – Why is 3-bromocyclohexene more reactive than bromocyclohexane towards NaI?

    These are all great questions and none of them have obvious answers so its a good thing I wasn’t forced to answer them on the night of the contest.
    (more…)

  • Cations, crowns, and phase transfer catalysts

    The following images (click image for full-size view) show potential maps (0 –> +1500), ball-and-spoke formulas, and space-filling formulas of

    • (CH3CH2CH2CH2)N+ (top left)
    • PhCH2N(Et)3+ (top center)
    • 18-crown-6(K+) (right)
    • Li+, Na+, K+ (bottom left)

    L35.120808 cations maps.jpgL35.120808 cations ballandspokes.jpgL35.120808 cations spacefillings.jpg
    The potentials surrounding the organic cations are more moderate, but not always for the same reason:

    • The positive charge in the quarternary ammonium ions is formally assigned to N, but N is buried under a blanket of C & H. The map surface lies rather far from N so the potential on the map surface is small.
    • The positive charge in the crown ether complex is assigned to K and this atom is exposed. However, the actual potential is the sum of extreme potentials generated by K and by the surrounding six O and these offset one another.

  • S/P electrophiles & crown ethers

    The PowerPoint slides from today’s lecture can be downloaded here. A couple of comments on each slide … (more…)

  • From O Chem to the Oregonian

    The Oregonian ran an article today titled, “Markets Threaten Oregon University Endowments” (Nov 30, 2008, Metro NW section, B-1). The article profiles Reed College’s finances (which are gloomy, but probably no worse than anyone else’s) and it features a nice picture of students walking away from Eliot Hall.

    What am I saying? These are not just any “students” in the photo, but rather our very own Laurel Oldach pondering a just-completed Chem 201 lecture as she heads across the Blue Bridge.

    LOldach.Oregonian.113008.jpg