Synthesis of poly[methyl(phenyl)silanediyl] containing 1,3,4-oxadiazole electron-transporting moieties

Summary

The new oxadiazole derivative containing amino group, 2-(4-aminophenyl)-5-(biphenyl-4-y1)- 1,3,4-oxadiazole (Oxad-NH₂), was synthesized and attached to formylated poly[methyl(phenyl)silanediyl] (PMPSi) by acid-catalyzed condensation of the aldehyde with the amino group yielding a Schiff base. The aldehyde groups were incorporated into the parent PMPSi by the reaction with dichloromethyl methyl ether in the presence of Lewis acid (SnCl₄). GPC analyses before and after modification reaction revealed that the attachment of Oxad-NH₂ proceeded without degradation of the silicon backbone. We reached 75 % conversion of aldehyde groups to oxadiazole Schiff base. The condensation reaction was followed and the prepared compounds and polymers were characterized by ¹H NMR, UV-vis, FT IR, GPC and elemental analyses. Fluorescence behavior of oxadiazole-modified PMPSi was studied in tetrahydrofuran. Broad emission band with maximum at 440 nm was observed. Fluorescence quantum yield of modified polysilanes increases with the increasing content of the attached oxadiazole moiety.