Optoeletronic properties of poly(N‐alkenyl‐carbazole)s driven by polymer stereoregularity

Stereoregular polymers like isotactic poly( N ‐butenyl‐carbazole) ( i ‐PBK), isotactic and syndiotactic poly( N ‐pentenyl‐carbazole) ( i ‐PPK and s ‐PPK), and poly( N ‐hexenyl‐carbazole) ( i ‐PHK and s ‐PHK) are synthesized using the stereospecific homogeneous “single site” Ziegler‐Natta (Z‐N) catalysts: rac ‐dimethylsilylbis(1‐indenyl)zirconium dichloride ( 1 )/methylaluminoxane (MAO) and diphenylmethylidene(cyclopentadienyl)‐(9‐fluorenyl)zirconium dichloride ( 2 )/MAO. Catalytic activity is rationalized by density functional theory (DFT) calculations. All synthesized polymers are fully characterized by NMR, thermal, wide‐angle X‐ray diffraction, and fourier transform infrared spectroscopy analysis. Fluorescence measurements on isotactic and syndiotactic polymer films indicate that all polymers give rise to excimers, both “sandwich‐like” and “partially overlapping.” Excimer formation is essentially driven by the polymer tacticity. Isotactic polymers generate both sandwich‐like and partially overlapping excimers, while syndiotactic polymers give rise especially to partially overlapping ones. A theoretical combined molecular dynamics–time dependent DFT approach is also used to support the experimental results.