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 P1 have been examined by X-ray crystallography. In view of the electron-donating and electron- withdrawing nature of the thiazole rings in the main chain, a strong pi-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.