Exp024

=Objective= To determine the solubility of phenanthrene-9-carboxaldehyde and 1-pyrenebutyric acid in methanol by UV-Vis spectroscopy =Procedure= Saturated solutions of phenanthrene-9-carboxaldehyde and 1-pyrenebutyric acid in methanol were prepared in half dram vials and left to equilibrate for 3 hours. The supernatant from each solution was subjected to dilutions until UV absorbance for them fell under 1.0 absorbance units. Molar absortivity ε values for the compounds were obtained by recordring the UV spectra of there solutions of known concentrations. =Results= [|Saturated solutions] [|024A-2] [|024A-3] [|024B-2] [|024B-3] [|024ACal-1] [|024ACal-2] [|024BCal-1] [|024BCal-2] [|Spreadsheet]

=Discussion=

Table 1 in Methanol ** || **Wavelength (nm) ** || ** ε  cm -1 M -1 ** || As described in Table 1, the molar extinction coefficient of phenanthrene-9-carboxaldehyde in methanol at 250nm was found to be 42935 and at 316nm it was 9382. For 1-Pyrenebutyric acid the molar extinction coefficient at 242 nm was 65728, at 275nm it was 45828 and at 341nm it was determined to be 38459 cm -1 M -1 The following are the concentrations calculated for the solutions (numbers in blue correspond to phenanthrene-9-carboxaldehyde and the ones in green to 1-pyrenebutyric acid. Table 2 = = =Conclusion= Concentration of a saturated solution of Phenanthrene-9-carboxaldehyde in methanol has been determined to be 0.078M Concentration of a saturated solution of 1-Pyrenebutyric acid in methanol has been determined to be 0.022M
 * **Sample ** || **Concentration (mM)
 * Phenanthrene-9-carboxaldehyde || 0.01387 || 250 || 42935.62 ||
 * || 0.01387 || 316 || 9382.316 ||
 * 1-Pyrenebutyric acid || 0.02375 || <span style="color: rgb(45, 149, 24);">242 || <span style="color: rgb(45, 149, 24);">65728.91 ||
 * || <span style="color: rgb(45, 149, 24);">0.02375 || <span style="color: rgb(45, 149, 24);">275 || <span style="color: rgb(45, 149, 24);">45828.41 ||
 * || <span style="color: rgb(45, 149, 24);">0.02375 || <span style="color: rgb(45, 149, 24);">341 || <span style="color: rgb(45, 149, 24);">38459.7 ||
 * Solution || Concentration (mM) ||
 * <span style="color: rgb(0, 10, 255);">ONSC024A-1--- || <span style="color: rgb(0, 10, 255);">77.72 ||
 * <span style="color: rgb(16, 127, 25);">ONSC024B-1--- || <span style="color: rgb(16, 127, 25);">22.7 ||

=Log=

2009-01-13
14:00 Made-up saturated solutions of phenanthrene-9-carboxaldehyde and 1-pyrenebutyric acid in methanol in half dram vials. The vials were vortexed for 8 min each inorder to ensure saturation. The vials were left undisturbed for three hours to equlibrate. 14:20 Temperature in the lab was recorded to be 24C 17:10 Obtained a picture of the saturated solutions after equlibration. 17:45 Dilutions of the saturated solutions were performed as below
 * Solution ID || Description ||
 * **024A-1** || Saturated solution of Phenanthrene-9-carboxaldehyde ||
 * **024A-2** || 100uL 024A-1 in methanol made-up in a 10mL Volumetric flask ||
 * **024A-3** || 100uL 024A-2 in methanol made-up in a 10mL Volumetric flask ||
 * **024B-1** || Saturated solution of 1-Pyrenebutyric acid ||
 * **024B-2** || 100uL 024B-1 in methanol made-up in a 10mL Volumetric flask ||
 * **024B-3** || 100uL 024B-2 in methanol made-up in a 10mL Volumetric flask ||

18:00 Obtained UV spectra of the dilute solutions. 19:30 Weighed 19.6mg phenanthrene-9-carboxaldehyde and dissolved it in methanol, the solution was made-up to the mark in a 100mL Volumetric flask. This solution is **024ACal-1** 20:00 Solution **024ACal-2** was made by dissolving 024ACal-1 (250uL) in methanol in a 10mL volumetric flask. 20:30 Weighed 16.0 mg 1-pyrenebutyric acid and dissolved it in methanol, the solution was made-up to the mark in a 100mL volumetric flask. This solution is **024BCal-1** 20:50 Solution **024BCal-2** was made by dissolving 024ACal-1 (250uL) in methanol in a 10mL volumetric flask. 21:40 Obtained UV spectra of the above solutions.