A New Series of Conjugated Platinum‐co‐Poly(p‐phenylenebutadiynylene)s Polymers: Syntheses and Photophysical Properties

An efficient route is developed to synthesize a series of platinum‐co‐poly(p‐phenylenebutadiynylene)s (Pt‐co‐PPBs) polymers by stoichiometric mixing of poly(p‐phenylenebutadiynylene)s (PPBs) and platinum bis‐phosphine dichlorides. This synthetic route involves two steps; first, oxidative coupling of diterminal phenyleneethynylenes (PEs) gives low‐molecular‐weight PPBs oligomers H? C?C? (Ph(OR)₂ ? C?C? C?C)_n ? Ph(OR)₂ ? C?CH (R = C₄H₉ 1 , R = C₈H₁₇ 2 , R = C₁₂H₂₅ 3 ) (M_n = 1000–3000, degrees of polymerization, P_n(M_n) = 4–6 ), which have bifunctional alkynyl end groups, and in the second step, these organic oligomers are allowed to react with trans‐[(PⁿBu₃)₂PtCl₂] to form newly designed Pt‐co‐PPBs (R = C₄H₉ 4 , R = C₈H₁₇ 5 , R = C₁₂H₂₅ 6 ) polymers. The yield of 4–6 varies from good (63%) to high (76%) with high molecular weights (M_n) ranging from 52 738 to 74 212, and this methodology tolerates different alkoxy substituted PPBs. These new organometallic polymers contain platinum to phenylenebutadiynylene (PB) ratio of 1:4 to 1:6 and are solution processable. Polymer 4 displays fluorescence at room temperature and fluorescence and phosphorescence at low temperature in thin film, which would be useful for studying the triplet emission in these polymers.