Organic Chemistry Lab 318 Spring, 2012

DUE DATES Today –At beginning of lab – Synthesis of di-t-Bu-biphenyl Report –Spectroscopy Problem Set, Part II, 4. –at end of lab -- copy of laboratory notebook pages for today's experiment (do not turn in your pre-lab notes or in-class notes) Next Week (after Spring Break) –At beginning of lab - Identification of Unknown Report –Spectroscopy Problem Set, Part II, 5.

Report from last week Notice that the graded parts correspond to the explicit instructions on my web page and the Manual for writing this report. The instructions tell you what to turn in (example – the literature IR and NMR and to mark them) The instructions tell you how to do something (example – citing references; strong acid calculations) If you have questions about how it was graded, please ask.

Report for next week –Please follow the instructions for writing an “Identification of Unknown” report in the Manual and on my lab web site. –Refractive Index: Experimental vs. literature. Experimental determined at r.t.; literature value reported for some temperature. You correct your experimental value to the temperature reported in the literature. It may or may not be 20 deg. Always report the experimental refractive index at both r.t. and corrected to the literature temperature.

In the mass spectrum and the IR, there are indications of the presence of a nitrogen atom. Circle/label and explain what part(s) of each spectrum provides this information.

singlet Integration 3 : 3 : 3 multiple H's absorbing and splitting How many different (non-equivalent) carbon atoms are apparently in the molecule? What groups are indicated by the two C-NMR absorptions at 19.9 and 20.6 ppm? Are there any aromatic C’s or H’s present? Indicate on each spectrum where you could find absorptions due to aromatic substructure. What functional group(s) are part of the compound (other than CH’s)? (See IR on previous page.) What functional group(s) are part of the compound (other than CH’s)? (See IR on previous page.) What are the hydrocarbon group(s) that are absorbing upfield in the H- NMR? Refer back to your answer from C-NMR.

In Lab Today Finish Identification of Unknown experiment if necessary –Determine boiling point by simple distillation –Test for water solubility and relative density –Take refractive index –Take IR Empty and clean Nitration product vial Go to NMR Center to take an NMR of your unknown Waiting to use NMR or for others to finish? –Access on-line chemical property databases –Begin a search for your unknown