Objective

To determine the solubility of Phenanthrene-9-carboxaldehyde and the Ugi product 214C in methanol and THF by NMR spectroscopy.

Procedure

Saturated solution of pheanthrene-9-carboxaldehyde in methanol (300uL) is transferred in to clean and dry NMR tube, which is then left in an oven maintained at 67C until most of the solvent has evaporated. Then Chloroform-D (300uL) is added to the NMR tube containing the residue after evaporation. This is followed by addition of acetonitrile (10uL) as an internal standard. Concentration of the aldehyde is obtained by integrating the aldehyde peak (~10 ppm) against the methyl peak (2.0 ppm) of acetonitrile.


Results

Phenanthrene-9-Carboxaldehyde
HNMR
027A
027B
027C
027D
027E
027F
Spreadsheet

Discussion

[Why are you evaporating the methanol? If you do that you don't need an NMR - you can just use a balance. JCB]- The reason why have been evaporating methanol, in effect to suppress its signature peak which in turn would make the solute peaks magnified. But I do understand that it does not make sense when compared to the gravimetric method. Therefore I have redone these measurements without evaporating methanol.
During the measurements, when CDCl3 (co-solvent) was added to the saturated solution, no precipitation of solute was observed.
ID
Solute
Solvent
Saturated Soln Conc (mM)
27C
Phenanthrene-9-carboxaldehyde
methanol
7.2
27D
Phenanthrene-9-carboxaldehyde
THF
629
27E
Ugi product 214C
methanol
6.8
27F
Ugi product 214C
THF
352.3

Conclusion

Solubility of Phenanthrene-9-carboxaldehyde and the Ugi product (214C) has been determined in methanol and THF.
[The value for phenanthrene-9-carboxaldehyde in THF was marked as DONOTUSE because value in EXP060 is much higher - this experiment uses less vortexing time and is not as simple JCB]

Log

2009-10-16

10:00 Made a saturated solution of phenanthrene-9-carboxaldehyde in methanol by vortexing it for 7min, this is ONSC027-1
10:40 Transferred 300uL of the saturated solution to a clean and dry NMR tube.
10:45 Placed the NMR tube into a heated oven maintained at 67C
13:45 Removed the NMR from the oven and noticed that almost all the solvent (methanol) had evaporated
14:00 Added CDCl3 (300uL) followed by Acetonitrile (10uL)
15:00 Obtained a proton NMR spectrum with 800 scans.
20:00 Another saturated solution of phenanthrene-9-carboxaldehyde was made in methanol (600uL) by vortexing it for 10min...the solution was further sonicated for 1h. This solution was left in the hood for equlibration.

2009-10-17

13:00 The solid had setteled down at the botton of the vial; transferred 300uL of the supernatant from the vail in to a clean and dry NMR tube. The tube was left in an oven at 70C for 2 h.
15:00 When almost all methanol has evaporated from the NMR tube, CDCl3 (700uL) and acetonitrile (10uL, 0.19mmoles) was added to the NMR tube.
15:40 Obtained a HNMR of the solution on a 500MHz varian inova.

2009-10-19

10:30 Made-up saturated solutions of Phenanthrene-9-carboxaldehyde in methanol (Solution 027C,) and THF (Solution 027D) by vortexing each for 5min. The aldehyde was readily soluble in THF,.
11:20 Made-up saturated solutions of the ugi product 214C in methanol (Solution 027E) and THF (Solution 027F)
13:00 Centrifuged the vials, the supernatant from each solution was transferred to clean and dry NMR tubes. 027C (400uL); 027D (200uL), 027E (300uL) and 027F (100uL).
13:30 To each NMR tube CDCl3 (700uL) was added followed by Acetonitrile (10uL).
14:40 Obtained HNMR of each sample on a Varian Inova 300MHz instrument.