This is a lab experiment designed to cover an array of techniques, including metal complex synthesis, spectroscopy and electrochemistry. Overall, the goal is to synthesize the metal complex Ru(bpy)32+, exchange the counter ion to demonstrate changes in solubility, absorbance and emission properties (including excited state quenching through energy and electron transfer, and ground state oxidation), as well as cyclic voltammetry of the complex. It is a three week lab: Week 1 - Synthesis of the complex; Week 2 - Electronic spectroscopy of the complex; Week 3 - Electrochemistry of the complex.
After this laboratory experiment is complete a student should be able to explain "What are the possible processes that can occur when a molecule absorbs light?" In addition, they should be able to explain the many ways in which electron transfer can occur and different methods of studying electron transfer.
Chemicals: Ruthenium trichloride; 2,2'-bipyridine; NaOH pellets; 31% phosphinic acid; KCl; acetone; ammonium hexafluorophosphate; ether; hydroquinone; quinone; ammonium cerium(IV) nitrate; acetonitrile; tetrabutylammonium hexafluorophosphate; ferrocene Supplies/Equipment: round bottom flask; reflux condenser; hose adapter; stir bar; hot plate; filter; beaker; nitrogen or argon line; IR spectrophotometer; UV/Visible spectrophotometer; Fluorimeter; disposable fluorimeter cells; 5 mL volumetric flasks; potentiostat
I have done this laboratory experiment twice. The experiment can be mixed and matched depending upon what you want to do!
There are a series of questions at the end of the lab that students must address in a full written paper. I have students write a paper in JACS format (the other labs taught in the semester, students write communications in JACS format).
Overall, student's reports have been good in this area. The course is a writing intensive course. What I've found is that the students perform better when writing their reports as they go through the weeks (as opposed to those students who wait until the last minute and generally forget what they've done). I have not tried this, but I will most likely have students write sections of the paper each week so they get more feedback from me in the process.