Synthesis of Poly(arylene vinylene)s Containing Carbazole, Triphenylamine, and Phenothiazine Rings in the Backbone by Cascade Suzuki-Heck Reactions

Abstract

Three new conjugated poly(arylene vinylene) structures containing triphenylamine, carbazole, or phenothiazine as aromatic units in the main chain and connected by vinyl segments have been synthesized by a cascade Suzuki-Heck reactions. The best reaction yields were obtained by coupling of the dibromoarylamines with vinyl segments via Suzuki-Heck reaction cascade using Pd(OAc)₂ as catalyst and triethylamine as solvent. The polymers were obtained as fully or partially soluble materials in chlorinated or aprotic polar solvents. They were characterized by ¹H-NMR, FT-IR, UV-Vis, and photoluminescence spectroscopy. Cyclic voltammetry characteristics were studied in solution and as solid thin films deposited on the electrode surface.

Keywords:

• Arylamines
• carbazole
• optoelectronic properties
• phenothiazine
• poly(arylenevinylene)s
• Suzuki-Heck reaction
• triphenylamine

Acknowledgements

The authors wish to express their gratitude to the Romanian National Authority for Scientific Research (UEFISCSU) for financial support (Grant PN II-IDEI-993, Contract 649/2009).

Notes

A) Using Pd(PPh3)4/ K2CO3/dioxane system. B) Using Pd(AcO)2, P(o-Tol)3/Et3 N/dioxane system. a) Number-average molecular weights. PDI = Mw/Mn.

^a Determined in diluted CHCl₃ solution;.

^b E_g = 1240/ λ _onset obtained from UV-Vis spectra.

E_g = E_HOMO - E_LUMO.