Week 6: Crystallization of Complex

Last week, I mentioned my attempts to synthesize a pure product from my coordination reaction.  This week, I toyed with many different solvents in order to find the perfect combination for crystallization via slow diffusion.  This technique works by dissolving the product of a reaction in a certain solvent, and then slowly adding a second solvent on top of it.  The two solvents must be miscible, but the second solvent must not dissolve the complex.  When the two progressively mix together, the product then crashes out in a crystal formation.  This week was used to find solvents that did not dissolve my complex.  The two that do not are pentanes and hexanes. I then needed to test the different solvents with pentanes and hexanes.  After much trial and error, I tried an acetone/pentanes and acetone/hexanes mix.  I am hoping to discover crystals in my vial when I go in for my last week supported by the Charles Center.

[Read more…]

Week 5: Generation of Hydrogen

In my previous post, I touched on the efficiency of the iron catalyst I have been studying, but I also mentioned that I need to ensure that my catalyst was actually generating hydrogen. This week, I introduced my complex into an environment containing a sacrificial donor of electrons (triethylamine), a proton source (water), a chromophore (fluorescein), and a solvent (ethanol).  Six different test tubes were prepared.  They were then illuminated in a controlled environment.  This experiment was purely used to see if any hydrogen was generated at all.  So, instead of taking many measurements of hydrogen gas in the test tube every few hours, which can be useful to measure the robustness of a catalyst as well as measure reaction rates, I took one after 24 hours of illumination.  The experiment was successful; I observed hydrogen generation from each test tube by collecting samples and analyzing them via gas chromatography.  This proves that my catalyst is, in fact, producing hydrogen and at an efficient rate.  However, the catalyst I used was impure, and the turnover number (moles of hydrogen per mole of catalyst) was relatively low.  The next step is finding ways to ensure crystallization of my catalyst after synthesis.  While I have made strides in increasing my ligand yield, it is still less than half of what I should be synthesizing.

Into the Woods, and the Start of New Adventures

IMG_7349 IMG_7359

[Read more…]

Painting Painting Painting

And yet again a wonderful week interning for the Colonial Williamsburg Foundation has flown by! Laura gave me a small research assignment just so she could double check some previous research she has already done. This past week I focused on analyzing how the American Revolution affected painting in the colonies. Where there any trends? New artists? What about this conflict changed the world of painting in America?

[Read more…]

Parks Rx: Weeks 4-5

Over weeks four and five of the Park Rx project, a lot of progress has been made. In this relatively short time period, we have gotten 3 doctors on board with the project, as well as launching a public website and finish editing our website for doctor’s use.

[Read more…]