Organometallic polymer light-emitting diodes derived from a platinum(II) polyyne containing the bithiazole ring

The synthesis, thermal, and photoluminescence properties of novel platinum metallopolyynes of bithiazole derivatives trans-[-Pt(PR₃) ₂-C≡C-Ar-C≡C-]_n (Ar = 4,4′-dibutyl-2, 2′- bithiazole-5,5′-diyl P1; 4,4′-dinonyl-2,2′- bithiazole-5,5′-diyl P2) and their molecular model complexes are described. The structural properties of the dinuclear model compound for PI have been examined by X-ray crystallography. In view of the electron-donating and electron- with-drawing nature of the thiazole rings in the main chain, a strong π-conjugated system that features unique donor-acceptor interactions is created, which results in optical bandgaps of 2.40 eV. The optical gap of the polymer is notably reduced as compared to that for the more electron-rich bithienyl analogue. Multi-layer polymer light-emitting diodes have been fabricated with the metallopolymer as the emitting layer, which give a green light color with the Commission Internationale de L'Eclairage (CIE) chromaticity coordinates of (0.26, 0.58) at 8 V.