Reaction #324368

Reaction equation

2,9-dimethyl-1,10-phenanthroline

2-thiophene carboxaldehyde

→

2,9-Bis(2-thiophen-2-yl-vinyl)-[1,10]phenanthroline

Solvents

acetic anhydride

Conditions

Workup

1. 1
   Temperaturewas refluxed for 5 h
2. 2
   Otherto give pale yellow solid
3. 3
   FiltrationThe solid was filtered off under suction
4. 4
   Washthe filter cake was washed with tetrahydrofuran
5. 5
   OtherThis was transferred into a conical flask
6. 6
   Filtrationfiltered off under suction
7. 7
   WashThe solid was again washed with tetrahydrofuran and petroleum ether (40-60° C.)
8. 8
   OtherThe product was dried under vacuum at 80° C. for 8 hours
9. 9
   Otherto give a yellow-orange solid exhibiting intense yellow fluorescence
10. 10
    OtherIts absorption and fluorescence spectra in thin film

Procedure

A mixture of 2,9-dimethyl-1,10-phenanthroline (neocuproine hydrate) (10 g, 0.048 mole) and 2-thiophene carboxaldehyde (9.4 ml, 0.188 mole) in acetic anhydride (15 ml) was refluxed for 5 h. The solution was allowed to cool to room temperature to give pale yellow solid. The solid was filtered off under suction and the filter cake was washed with tetrahydrofuran. This was transferred into a conical flask, stirred with de-ionised water for 15 minutes and filtered off under suction. The solid was again washed with tetrahydrofuran and petroleum ether (40-60° C.). The product was dried under vacuum at 80° C. for 8 hours. Yield: 5.9 g. The product was sublimed to give a yellow-orange solid exhibiting intense yellow fluorescence. Its absorption and fluorescence spectra in thin film and in solution in THF are shown in FIGS. 1 and 2.

Source