Measuring the solubilities of 10-chloro-9-anthraldehyde; 4-hydroxybenzaldehyde and 4-hydroxy-3-methylbenzaldehyde in ethanol, methanol and THF


Method

Nine 2 mL vials were taken and labelled with the planned contents. Nine 1.6 mL microcentrifuge tubes ("Eppendorfs") were taken, labelled with the planned contents and the masses recorded.
Saturated solutions of 10-chloro-9-anthraldehyde in ethanol, methanol and THF were prepared by adding solid to 750 µL solvent and vortexing each compound for two minutes until deemed saturated. Saturated solutions of 4-hydroxybenzaldehyde in ethanol, methanol and THF by adding solid to 750 µL solvent and vortexing each compound until saturated. Likewise saturated solutions of 4-hydroxy-3-methylbenzaldehyde were prepared in the same way. Full details of the preparation can be found in the experiment log. It was very difficult to see if the solutions of 4-hydroxy-3-methylbenzaldehyde were saturated, without holding up to a strong light as the solution had an appearance similar to coca-cola.
The saturated samples were centrifuged for 1 minute at 13 200 rpm/16 100 rcf in an Eppendorf 5415D centrifuge. 500 µL of each supernatant was added to its respectively labelled eppendorf and the samples dried by speedvac, initially for 3 hours and 15 minutes. The samples had their masses recorded and were returned to speedvac for a further hour to dry to constant mass.
Full details can be found in the spreadsheet at JennyHale-12.

Results

10-chloro-9-anthraldehyde was not very soluble in any of the three solvents, having solubilities of 0.004 M in ethanol, 0.003 M in methanol and 0.076 M in THF. 4-hydroxybenzaldehyde had a solubility of 2.396 M in ethanol, 3.508 M in methanol and comparitively a much lower solubility of 0.909 M in THF. This result seems so much lower that I'm not sure of it's truthfulness.[I agree. If you want to look for patterns put the SMILES of 4-hydroxybenzaldehyde O=Cc1ccc(O)cc1 in the SMARTS box of the web query tool and select THF and you'll see that all derivatives have much higher solubilities JCB] I may repeat that experiment tomorrow to check. 4-hydroxy-3-methylbenzaldehyde has a solubility of 2.146 M in ethanol, 2.782 M in methanol and 3.052 M in THF.

Log

Wednesday 11.02.09 GMT

10.20 - Recorded mass of tubes and prepared experiment.
10.32 - Added 4 narrow spatula scoops of 10-chloro-9-anthraldehyde ("CA") to ethanol. Vortexed sample for 2 minutes in 10 second intervals. Sample saturated.
10.36 - Added 4 narrow spatula scoops of CA to methanol. Vortexed sample for 2 minutes in 10 second intervals. Sample saturated.
10.39 - Added 4 narrow spatula scoops of CA to THF. Vortexed sample for 2 minutes in 10 second intervals. Sample saturated.
10.42 - Added 4 spatula scoops of 4-hydroxybenzaldehyde ("HB") to ethanol. Vortexed sample for 30 seconds in 10 second intervals.
10.44 - Added 4 spatula scoops of HB to ethanol. Vortexed sample for 1 minute in 10 second intervals.
10.47 - Added 4 spatula scoops of HB to ethanol. Vortexed sample for 1 minute in 10 second intervals. Solution was lustrous and translucent - a bit like pearls. Allowed to settle to see what was happening.
10.50 - Added 4 spatula scoops of HB to methanol. Vortexed sample for 10 seconds.
10.52 - Added 4 spatula scoops of HB to methanol. Vortexed sample for 10 seconds.
10.53 - Added 4 spatula scoops of HB to methanol. Vortexed sample for 10 seconds.
10.54 - Added 4 spatula scoops of HB to methanol. Vortexed sample for 2 minutes in 10 second intervals. Solution was lustrous and translucent - a bit like pearls.
10.57 - Added 4 spatula scoops of HB to THF. Vortexed sample for 2 minutes in 10 second intervals. Solution was lustrous and translucent - a bit like pearls.
11.01 - Added 4 narrow spatula scoops of 4-hydroxy-3-methylbenzaldehyde ("HM") to ethanol. Vortexed sample for 1 minute in 10 second intervals.
11.04 - Added 4 narrow spatula scoops of HM to ethanol. Vortexed sample for 20 seconds in 10 second intervals.
11.05 - Added 4 narrow spatula scoops of HM to ethanol. Vortexed sample for 20 seconds in 10 second intervals.
11.07 - Added 4 narrow spatula scoops of HM to ethanol. Vortexed sample for 20 seconds in 10 second intervals.
11.09 - Added 8 narrow spatula scoops of HM to methanol. Vortexed sample for 1 minute in 10 second intervals.
11.11 - Added 4 narrow spatula scoops of HM to THF. Vortexed sample for 10 seconds.
11.12 - Added 4 narrow spatula scoops of HM to THF. Vortexed sample for 10 seconds.
11.14 - Added 4 narrow spatula scoops of HM to ethanol. Vortexed sample for 1 minute in 10 second intervals. Solution saturated.
11.16 - Added 4 narrow spatula scoops of HM to methanol. Vortexed sample for 1 minute in 10 second intervals. Solution saturated.
11.18 - Added 4 narrow spatula scoops of HM to methanol. Vortexed sample for 1 minute in 10 second intervals.
11.20 - Added 4 narrow spatula scoops of HM to methanol. Vortexed sample for 1 minute in 10 second intervals.
11.22 - Added 8 narrow spatula scoops of HM to THF. Vortexed sample for 1 minute in 10 second intervals.
11.24 - Added 4 narrow spatula scoops of HM to methanol. Vortexed sample for 1 minute in 10 second intervals. Solution saturated.
11.26 - Added 4 narrow spatula scoops of HM to THF. Vortexed sample for 1 minute in 10 second intervals.
11.28 - Added 4 narrow spatula scoops of HM to THF. Vortexed sample for 1 minute in 10 second intervals.
11.31 - Added 4 narrow spatula scoops of HM to THF. Vortexed sample for 1 minute in 10 second intervals. Solution saturated.
11.33 - Checked saturation of all solutions.
11.34 - Centrifuged samples for 1 minute. Transferred 500 µL of supernatants to labelled eppendorfs.
11.44 - Started speedvac.
14.59 - Samples removed from speedvac.
15.00 - Sample masses measured.
15.08 - Samples returned to speedvac.
16.08 - Samples removed from speedvac and masses recorded.