Synthesis of Polydiacetylenes from Novel Monomers Having Two Diacetylene Units Linked by an Arylene Group

Abstract

Three novel monomers 4BCMU4A(Ar) with chemical structures of R-C≡C-C≡C-Ar-C≡C-C≡O-R, where R=−(CH2)4-OCONHCH2COOC4H9 and Ar=1,4-phenylene (Ph) or 2,3,5,6-tetrafluoro-1,4-phenylene (PhF) or 4,4′-biphenylene (Biph), were synthesized. 4BCMU4A(Ph) was found to be stable for solid-state polymerization, although 4BCMU4A(PhF) and 4BCMU4A(Biph) could be polymerized by UV or γ-ray irradiation. The polymerization for two polymerizable monomers was investigated in detail mainly by solid-state 13C NMR. The polymerization of 4BCMU4A(PhF) and 4BCMU4A(Biph) took place by 1,4-addition reaction at one of the butadiyne moieties in the monomer to give single chain-type polydiacetylenes with the respective butadiynylaryl moiety as a side chain and ladder-type ones were not obtained. High crystallinity was confirmed for these polymers by X-Ray diffraction. Polydiacetylene obtained from 4BCMU-4A(PhF) was found to be dispersed in organic solvent. Visible absorption spectra of this polymer in dispersion state with different compositions of solvents and in amorphous state were investigated in comparison with the spectrum in the crystalline state.