Bioinorganic Coordination Chemistry
This experiment uses H2TTP made during the last lab and hydrated
copper (II) acetate to convert the H2TTP to Cu(TTP). The reaction
proceeds by being refluxed for 30 minutes. The final product is a
non-iridescent purple color, unlike the vivid, shimmering purple color
of the starting H2TTP.
Thin layer chromatography, or TLC, is used as a prerequisite for
column chromatography. When performing types of chromatography, like
TLC, the polarity of solvents is extremely important. This lab uses
TLC plates, five solvents (hexane, toluene, ethyl acetate,
dichloromethane, and acetone), and small evaporating dishes to
determine which solvent would be best to use in column chromatography.
The least polar solvent is hexane, which has a polarity index of 0.1.
Toluene has a polarity index of 2.4, while ethyl acetate’s is almost
twice that at 4.4. By comparing the polarity indexes, you can tell
what solvent will separate your dots of product on your TLC plates the
best (Skoog 761).
The equipment needed for this experiment is as following: 100 mL round
bottom flask, stir bar, water condenser, hot plate, UV light, Pasteur
pipet, ice bath, separatory funnel, rotary evaporator, evaporating
dish, cotton for filtering, and UV-vis spectrometer.
The chemicals required are: 0.1 g. of H2TTP made previously, 20 mL
N,N-dimethylformamide, 0.16 g. hydrated copper acetate, distilled
water, 75 mL dichloromethane, hexane, toluene, ethyl acetate,
dichloromethane, and acetone for TLC plates.
1. Measure out 0.1 g. of the H2TTP made previously into a 100 mL
round bottom flask with a stir bar.
2. Add 20 mL of N,N-dimethylformamide (a bright blue powder) and let
the solution stir.
3. Add 0.16 g. of hydrated copper (II) acetate, cover with a water
condenser and allow to reflux for 30 minutes.
4. Spot the solution on a TLC plate and check with UV light to see
if there is any red on or around the spot. Add additional copper
(II) acetate and allow to reflux for 10 more minutes if any red is
5. When the reaction is complete, cool in an ice bath for 5-10
minutes then add 50 mL of distilled water.
6. Transfer into a separatory funnel and wash three times with 25 mL
of dichloromethane. Collect the bottom layer each time. Discard
the top layer properly.
7. Pour the collected solution back into the separatory funnel and
add 50 mL of distilled water. Shake. Drain off the bottom
8. Dry the bottom layer using a rotary evaporator.
9. Make five TLC plates spotted on a line drawn near the bottom,
once with the beginning product and once with the final product.