PURPOSE OF THE EXPERIMENT

In this laboratory you and a partner will obtain the infrared spectrum of both a known and an unknown compound. You are to identify all major peaks in spectrum of the known compound by consulting tables provided. For the unknown, you are to search for important peaks and make as many assertions about the identity of the unknown as you can. You will NOT be able to identify the molecule completely. Instead, you will simply suggest classes of compounds to which your unknown might belong.

GENERAL PROCEDURE

1. Restore the spectrometer to its initial condition as follows:
   
   

   Press	Identification
   Shift	White button
   Restore	Red button
   Setup	Grey softkey 2
   Factory	Grey softkey 1

   
   
2. Obtain the "mini-cell" holder and two AgCl cells. Clean the cells with acetone and wipe on Kimwipes to dry. Be certain that the cells are dry. Being careful not to touch the cells with your fingers, place two cells into the mini-cell holder (without any sample), tighten the top onto the mini-cells and place sample holder on adapter. Record the background spectrum of the empty cell and air as follows:
   
   

   Press	Identification
   Backg	Grey button
   Scan	Green button
   4	Grey softkey 2

   ...wait
   
   
3. Remove the empty cells from the holder, taking care not to touch them with your fingers. Place one cell into the holder, flat side up, then place about 1 drop of liquid to be analyzed onto the cell. Place the other cell onto the pile, flat side down. Tighten the top onto the mini-cell and place sample holder on adapter. Record the sample spectrum as follows:
   
   

   Press	Identification
   X	Grey button
   Scan	Green button
   4	Grey softkey 2

   ...wait
   
   
4. Once the raw spectrum is obtained you may expand the peaks to fill the full screen as follows:
   
   

   Press	Identification
   Abex	Grey button
   Execute	Grey softkey 7

   
   
5. Obtain the exact position of the major peaks in your spectrum as follows. Press the white Shift button followed by the white right arrow button. Press the left arrow or right arrow to move the vertical cursor from one peak to the next. When the cursor stops at a peak of interest press Shift Mark. Move to the next peak of interest, mark and continue until all peaks of interest have been marked. Be sure to press the Shift button before each Mark or the button will not perform the desired function.

6. Plot the marked spectrum by placing a piece of paper into the plotter (make sure that the paper is lined up against the left side of the paper tray), verify that the plotter is turned on, then press the green button labeled Plot on the spectrometer.

   Note: While waiting for your plot to be completed, you may proceed to the next step. Once the spectrum is recorded, the sample no longer needs to remain in the spectrometer.

7. If you have another sample to run, clean the cells with acetone, air dry and continue as in step 3; otherwise, clean the cells and store them in their light-tight container.