Researcher

David Bulger

Objective

Determine the solubility of 4-pyrenebutanoic acid in DMF and DMSO.

Procedure

Make saturated solutions of 4-pyrenebutanoic acid in DMF and DMSO and determine solubility using SAMS and internal standard (IS) methods.

Results

Pictures

ONSC099-1
ONSC099-2
ONSC099-3
ONSC099-4
ONSC099-5
ONSC099-6
ONSC099-7

Spectra

ONSC099-1
ONSC099-2
Raw JCAMP-DX file for ONSC099-1
Raw JCAMP-DX file for ONSC099-2

Spreadsheet

ONSC099-1
ONSC099-2

Solubilities

Spectrum
Solute Signal Used
Solvent Signal Used
Method
Solvent
Solubility (M)
ONSC099-1
2nd Methylene
Dimethyl
SAMS
DMF
1.86
ONSC099-1
1st Methylene
Dimethyl
SAMS
DMF
1.90
ONSC099-1
Last Aromatic Proton
Dimethyl
SAMS
DMF
1.87
ONSC099-1
2nd Aromatic Proton
Dimethyl
SAMS
DMF
1.65
ONSC099-1
2nd Methylene
Aldehyde
SAMS
DMF
2.45
ONSC099-1
1st Methylene
Aldehyde
SAMS
DMF
2.50
ONSC099-1
Last Aromatic Proton
Aldehyde
SAMS
DMF
2.47
ONSC099-1
2nd Aromatic Proton
Aldehyde
SAMS
DMF
2.23
ONSC099-2
2nd Methylene
Dimethyl
SAMS
DMSO
2.16
ONSC099-2
1st Methylene
Dimethyl
SAMS
DMSO
2.16
ONSC099-2
Last Aromatic Proton
Dimethyl
SAMS
DMSO
2.09
ONSC099-2
2nd Aromatic Proton
Dimethyl
SAMS
DMSO
2.00
ONSCEXP061
2nd Methylene
Dimethyl
SAMS
DMSO
2.13
Spectrum
Solute Signal Used
Internal Standard
Solvent
Solubility (M)
ONSC099-1
2nd Methylene
1,2-dichloroethane
DMF
2.48
ONSC099-1
1st Methylene
1,2-dichloroethane
DMF
2.58
ONSC099-1
Last Aromatic Proton
1,2-dichloroethane
DMF
2.52
ONSC099-1
2nd Aromatic Proton
1,2-dichloroethane
DMF
2.04
ONSC099-2
2nd Methylene
1,2-dichloroethane
DMSO
3.28
ONSC099-2
1st Methylene
1,2-dichloroethane
DMSO
3.27
ONSC099-2
Last Aromatic Proton
1,2-dichloroethane
DMSO
3.07
ONSC099-2
2nd Aromatic Proton
1,2-dichloroethane
DMSO
2.84
ONSCEXP051
2nd Methylene
acetonitrile
DMSO
1.91
[Excellent demonstration of the importance of checking multiple protons with SAMS. Can you provide reasons for preferring one or a few measurements over the others, or would an average be the best measurement the technique can provide? --BH] From what Dr. Bradley has told me, the best measurement first of all does not have any overlapping peaks. In general, methylene singals tend to give better measurements than aromatic or carboxylic acid signals.

Note: Internal Standard signal was not of the highest quality and the IS measurements may be disregarded.

Discussion

Out of all the different solubility measurements, the 2nd methylene signal of the solute and the dimethyl signal of DMF yielded the best peaks. Therefore, those peaks were used to determine the solubility of 4-pyrenebutanoic acid in DMF and DMSO, which was found to be 1.86 M and 2.16 M respectively using the SAMS method. In ONSCEXP061, the solubility in DMSO was found to be 2.13 M using SAMS, which is consistent with the results in this experiment. The IS method could not be used properly, since the 1,2-dichloroethane signal was distorted. However, ONSCEXP051 found the solubility in DMSO using an acetonitrile internal standard to be 1.91 M, which is slightly less than was found in this experiment by SAMS. Overall, the solubility of 4-pyrenebutanoic acid in DMSO is most likely around 1.9-2.2 M and in DMF around 1.6-1.9 M.

Conclusion

Overall, the solubility of 4-pyrenebutanoic acid is estimated to be around 1.9-2.2 M in DMSO and around 1.6-1.9 M in DMF.

Log

16:44 Labeled half-dram vials for DMF (ONSC099-1) and DMSO (ONSC099-2) and weighed
Vial
Mass (g)
ONSC099-1
2.404 1
ONSC099-2
2.397 7
16:47 Added 300 uL of each solvent and weighed
Vials
Mass (g)
ONSC099-1
2.721 8
ONSC099-2
2.775 8
16:51 Added 4-pyrenebutanoic acid, weighed, and vortexed for 10 sec - solid went into solution
Vials
Mass (g)
ONSC099-1
2.908 7
ONSC099-2
2.993 7
17:01 Added 4-pyrenebutanoic acid, weighed, and vortexed for 10 sec
Vials
Mass (g)
ONSC099-1
3.008 7
ONSC099-2
3.206 7
17:11 Photo (ONSC099-1)
17:15 Began sonication (25 degrees Celsius)
17:20 Weighed vials
Vials
Mass (g)
1N
2.419 5
2N
2.400 2
17:23 Prepared NMR tubes (cleaning, drying, cooling)
17:43 Finished sonication (32 degrees Celsius)
17:47 Photo (ONSC099-2)
17:50 Weighed
Vials
Mass (g)
ONSC099-1
3.009 1
ONSC099-2
3.207 2
17:51 Centrifuged for 3 min
17:55 Photo (ONSC099-3)
17:56 Transferred supernatant to corresponding half-dram vials 1A and 2A using Pasteur pipet
17:59 Centrifuged for 3 min
18:07 Photo (ONSC099-4)
18:08 Transferred supernatant to corresponding half-dram vials 1B and 2B using Pasteur pipet
18:11 Centrifuged for 3 min
18:17 Photo (ONSC099-5)
18:18 Added 700 uL of DMSO-d6 to half-dram vials N1 and N2
Vials
Mass (g)
N1
3.278 4
N2
3.255 7
18:26 Added 10 uL of 1,2-dichloroethane to N1 and N2
Vials
Mass (g)
N1
3.291 9
N2
3.268 8
18:30 Added 100 uL of 1B and 2B to corresponding N1 and N2 by inserting the pipet tip beneath the surface of the solution when dispensing contents in order to prevent evaporation and vortexed for 10 sec
Vials
Mass (g)
N1
3.398 1
N2
3.378 1
18:36 Placed in water bath (24.5 degrees Celsius)
18:39 Photo (ONSC099-6)
18:42 Labeled NMR tubes (ONSC099-1 and ONSC099-2)
18:43 Water bath temperature at 23.5 degrees Celsius
18:57 Water bath temperature at 22.8 degrees Celsius
18:58 Removed from water bath
19:00 Vortexed for 30 sec
19:01 Transferred contents of N1 and N2 to corresponding NMR tubes (ONSC099-1 and ONSC099-2) and parafilmed
19:05 Photo (ONSC099-7)
19:30 Collected 500 MHz NMR spectrum (ONSC099-1)
19:45 Collected 500 MHz NMR spectrum (ONSC099-2)

References


Solubility of 4-Pyrenebutanoic Acid in Organic Solvents
Solubility of 4-Pyrenebutanoic Acid in DMF (solubility data viewer)
Solubility of 4-Pyrenebutanoic Acid in DMSO (solubility data viewer)