Drastic Tuning of the Photonic Properties of «(Push–Pull) n » trans ‐Bis(ethynyl)bis(Tributylphosphine)Platinum(II)‐Containing Polymers

The trans ‐Pt(PBu 3 ) 2 Cl 2 complex reacts with 1 equiv. of 2,6‐diethynyl‐ AQ and 2 equiv. of 2‐ethynyl‐ AQ ( AQ = anthraquinone) to form the polymer ( trans ‐Pt(2,6‐diethynyl‐ AQ ) 2 (PBu 3 ) 2 ) n , 1 , and the model compounds, 2 , trans ‐Pt(PBu 3 ) 2 (2‐ethynyl‐ AQ ) 2 (in a 20:1 ratio as trans ‐( 2a ) and cis ‐( 2b ) rotational isomers), respectively. These redox‐active and luminescent materials have been characterized by gel permeation chromatography, thermal gravimetric analysis, X‐ray crystallography, electrochemistry, photophysics, and DFT computations (B3LYP). The typical π,π* T 2 →S 0 phosphorescence centered on the trans ‐Pt(PBu 3 ) 2 (aryl) 2 chromophore, [Pt] , generally encountered for the analogous polymers ( trans ‐Pt(PBu 3 ) 2 (aryl) 2 ‐acceptor) n (acceptor = quinonediimine, QN 2 ; anthraquinone diimine, AQN 2 ), for which the CT T 1 →S 0 emission is silent, has been completely annihilated and replaced by a red‐shifted T 1 →S 0 emission in 1 and 2a , which arise from a triplet charge transfer excited state [Pt] → AQ .