Dyes and dyeing organic chemistry lab report

Thanks to Prof. Handy for sharing his protocol.

Aurone Dye Lab

Aurones are a small sub-family of the flavonoids that are of interest in the Handy research group.

They have been known for some time and are most commonly found in the flowers of plants that

produce yellow flowers, such as cosmos and snapdragons. Indeed, they are the compounds that

are responsible for this yellow coloration. At the same time, they are present in very small

quantities, which has made their study rather difficult. Several groups have developed synthetic

routes to these types of compounds and have thus enabled the study of their biological properties.

A number of interesting activities have been reported, including anti-cancer, anti-fungal, anti-

inflammatory, and anti-tuberculosis. One aspect that really has not been studied, however, is

their ability to function as dyes. In this experiment, you will synthesize an aurone analog

(variation) in the presence of a fabric strip using an unusual solvent system (a so-called deep

eutectic solvent) for both the aurone synthesis and the fabric dying (in situ dying). We will examine

the final, rinse fabric strips for both the color of the dye and which types of fabrics it dyes best.

Procedure:

Week 1 –

You will select an aldehyde to use in the aurone synthesis (basically a variation of an aldol

condensation, but under very mild conditions) and you will prepare the choline chloride/urea

deep eutectic solvent.

marina elkommos
For the choline chloride/urea solvent: weigh into a vial (provided) 20 mmol of chloride chloride

and 40 mmol of urea. Then heat the mixture in a sand bath for roughly 1 hour at 80°C (shaking

occasionally). Once liquefied, add 0.10 mmol of rodhamine and 0.10 mmol of your aldehyde

and a stir bar. Shake, then label your vial and give it to the instructor who will keep it at 50°C for

the rest of the week.

Week 2 –

Cool your reaction to room temperature (it will likely already be cool) and note the color of the

solution. Dilute the mixture with roughly 15 mL of water, add the fabric strip and heat at 80°C

for about an hour. Decant the water, then wash the fabric strip with water until the wash is clear

(likely roughly 5 times with about 20 mL each time). Let the fabric strip dry off on a paper towel

for a bit, then set it on a new paper towel and let it air dry for roughly 10 minutes. We will

compare all of the strips for variation in color and dying efficiency.

POST LAB

Write the lab report as usual including:

Abstract: summary of the procedure with comments about color and dying efficiency

Introduction: background of the reaction with one reference that is NOT an online source. Use

pubmed or scifinder.

Discussion: Table of reagents, mechanism, details about the color of the fabric strip with a

sketch, picture optional. Calculations for the number of moles and gram used in the procedure

Experimental: brief description of the procedure. Use Passive form.

Conclusion: statement about the final result