ABSTRACT A new series of di-ynes with extended TT-conjugation through carbazole linker groups in the backbone, 3,6-Bis(trimethylethylethynyl)carbazole la, 3,6-Bis(ethynyl)carbazole 1b, 2,7-bis(trimethylsilylethynyl)carbazole2a, 2,7-bis(ethynyl)carbazole2b, bis(trimethylsilylethynyl)-N-(2-ethylhexyl)carbazole 3a, and 2,7-bis(ethynyl)-N-(2 ethylhexyl)carbazole 3b, has been synthesized and characterized. 2b, 2,7 Reactions of the terminal di-ynes 1b-3b with two equivalents of trans-[(Et3P)2PhPtCl] afford the dinuclear platinum(II) di-ynes, [(Ph)(Et3P)2Pt-C=C-R-C=C-Pt-(PEt3)2Ph] (R = carbazole-3,6-diyl Mi, carbazole-2,7-diyl M2, N-(2-ethylhexyl)carbazole-2,7-diyl M3) in good yields. Organometallic polymers trans-[Pt(P"Buz)2-C=C-R-C=C-] (R = carbazole-3,6 diyl P1 , carbazole-2,7-diyl, P2, N-(2-ethylhexyl)carbazole-2,7-diyi P3) have also been prepared in good yields, in a similar manner to their dinuclear di-ynes by the Cul-catalyzed dehydrohalogenation polycondensation reaction of trans-[(P"Buz)2PtCl2] with one equivalent of 1b-3b. All the new compounds have been characterized by analytical and spectroscopic methods, and the single-crystal X-ray structure of the dinuclear model compound M2 has been determined. All the platinum(II) di-ynes and poly-ynes are soluble in organic solvents and readily cast into films. The materials have high thermal stability and possess interesting photo-physical properties, suitable for application in light emitting devices