Transcript DUE DATES - George Mason University

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.
19
literature n D = 1.4521
22
experimental n D = 1.4502
exp'tl corrected to literature temperature of 19o = 1.4502 + 3(0.000045) = 1.4516
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.
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.)
singlet
What functional group(s) are part of the
compound (other than CH’s)? (See IR
on previous page.)
Integration
3
What are the hydrocarbon group(s)
that are absorbing upfield in the HNMR? Refer back to your answer from
C-NMR.
singlet
multiple H's absorbing and splitting
:
3
: 3
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