The Schiff bases of N

N′-bis(salicylidene)-1

4-diaminobenzene (L

1

)

4-[2-(hydroxy-1-naphthalen-1-ylmethylene)-amnio]-benzoic acid (L

2

) and 4-(benzylidene-amino)-benzoic acid (L

3

) are synthesized and characterized by

1

H NMR

IR

UV

and elemental analysis. The results of fluorescent spectra indicate that the Schiff bases of L

1

L

2

and L

3

possess strong luminescent properties. The excitation spectra of the Schiff bases have many fine characteristic excitation peaks and the maximal excitation wavelengths are 468 nm. The fluorescent lifetime experiments indicate that the lifetimes of the Schiff bases of L

1

L

2

and L

3

are 199

199

and 214 ns

respectively. The sequence of the fluorescent intensity of the fine powder Schiff bases is listed as L

1

>

L

2

>

L

3

but the sequence of the ethanol solutions of Schiff bases is just reverse. The quantum yields of the ethanol solutions of L

3

L

2

and L

1

are 0.60

0.56 and 0.0086. The luminescent intensities of nanosized supramolecular materials that the guests of Schiff bases are encapsulated in the non-poplar channels of (CH

3

)

3

Si-MCM-41 are stronger than that of the composites encapsulated in the polar channels of MCM-41. The results show that the lipophilic channels of host are more favourable to fluorescence of the guest Schiff base molecule than the hydrophilic channels. Comparing with the excitation and emission peaks of the guest Schiff bases

the emission peaks of nanosized supramolecular materials shift generally blue. The excitation wavelengths of (CH

3

)

3

Si-MCM-41-L

1

(CH

3

)

3

Si-MCM-41-L

2

MCM-41-L

2

and MCM-41-L

3

are 529

507

507 and 505 nm (red shift)

respectively. The excitation wavelengths of MCM-41-L

1

and (CH

3

)

3

Si-MCM-41-L

3

are the same as that of the guest Schiff bases. The lifetimes of (CH

3

)

3

Si-MCM supramolecular systems with L

1

L

2

and L

3

as guest has obvious change

but that of MCM-41 supramolecular systems with L

1

L

2

and L

3

as the guest keep almost unchanged

comparing with the guests of the schiff bases molecules. The experimental results of fluorescent lifetime show that the selectivity between the host and the guest exists obviously.