Chemical insertion of anthracene moiety into the backbone of a newly synthesized oligophenylene (OMPA): effect on the photo-physical properties

The newly synthesized oligo[4-(methoxyphenyl) acetonitrile] (OMPA) was chemically modified by Knoevenagel condensation of OMPA oligomer with 9-anthraldehyde. The obtained oligomer is named OMPA-ANTH. Vibrational, optical, and thermodynamic properties of OMPA-ANTH oligomer were investigated using FT-IR, ultraviolet–visible (UV–vis), steady-state and time-resolved photoluminescence spectroscopies, and thermogravimetric analysis (TGA). The chemical insertion of the anthracene group into the OMPA backbone induces a decrease of the optical bandgap and the energy gap (Eg = EHOMO-ELUMO) with significant modification in their observed optical properties. The decay of modified OMPA (OMPA-ANTH) in solution or condensed state is slower than that of pure OMPA, showing a change of the photo-generated species with longer lifetime upon chemical modification.