Objective

To determine the solubility of phenanthrene-9-carboxaldehnyde and 1-pyrenebutyric acid in DMSO by NMR.

Procedure

Saturated solutions of phenenthrene-9- carboxaldehyde and 1-pyrenebutyric acid were made in dimethylsulfoxide. Inorder to saturate the solutions, after the last addition of solute to DMSO they were vortexed for 10min each. The solutions were left to equilibrate for 4h, they were then centrifuged and the supernatant was decanted in to separate vials. The supernatants (100uL) were then placed into NMR tubes containing 700μl of DMSO-d6 and 10μl of acetonitrile as an internal standard. Proton NMR of the solutions were obtained on a 300MHz Varian Unity Inova instrument.


Results

Phenanthrene-9-carboxaldehyde Sample
HNMR
1-Pyrenebutyric acid Sample
HNMR

Calculations


Discussion

Based on the integrations of aldehyde proton and acetonitrile (internal std.), the solubilty of phenanthrene-9-carboxaldheyde in DMSO is determined to be 0.89M.
Based on the integrations of methylene CH2 at 2.44 PPM and acetonitrile (internal std) the solubility of 1-pyrenebutyric acid in DMSO is determined to be 1.91M

Conclusion


Solubility of the following solutes have been determined successfully.
Solute
Solvent
Solubility
Phenanthrene-9-carboxaldehyde
DMSO
0.89M
1-Pyrenebutyric acid
DMSO
1.91M

Log


2009-02-03

14:00 Made-up saturated solution of phenanthrene-9-carboxaldehyde and 1-pyrenebutyric acid in DMSO (400uL). After the last addition of the solute each solution was vortexed for 10min to ensure saturation. The solutions were left to equilibrate.
18:20 Centrifuged the saturtated solutions and decanted the supernatants in to clean one dram vials.
19:00 Placed DMSO-d6 (700uL) into two clean and dry NMR tubes (1 & 2), added acetonitrile (10uL) to each tube.
19:20 Soon after pipetted out the supernatant from phenanthrene-9-carboxaldehyde (100uL) in to NMR tube 1 and 1-pyrenebutyric acid into NMR tube 2.
20:30 Obtained HNMR of the samples in the NMR tubes 1 and 2 on a 300MHz Varian Unity Inova.