Transition-Metal-Free Homopolymerization of Pyrrolo[2,3-d:5,4-d′]bisthiazoles via Nucleophilic Aromatic Substitution

Abstract

Novel methods to synthesize electron-deficient π-conjugated polymers utilizing transition-metal-free coupling reactions for the use of nonfunctionalized monomers are attractive due to their improved atom economy and environmental prospective. Herein we describe the use of i PrMgCl·LiCl complex to afford thiazole-based conjugated polymers in the absence of any transition metal catalyst, that enables access to well-defined polymers with good molecular weights. The mechanistically distinct polymerizations proceeded via nucleophilic aromatic substitution (SNAr) reaction supported by density functional theory (DFT) calculations. This work demonstrates the first example of fully conjugated thiazole-based aromatic homopolymers without the need of any transition metal catalyst.

Visualizing transport in thiazole flanked isoindigo-based donor–acceptor polymer field-effect transistors

“…13–16 Furthermore, thiazole based materials are emerging as a viable route towards n-type or ambipolar properties in conjugated polymers. 17–19…”

“…[13][14][15][16] Furthermore, thiazole based materials are emerging as a viable route towards n-type or ambipolar properties in conjugated polymers. [17][18][19] An approach for tuning the HOMO-LUMO gap along with facilitating solid state interactions is to replace the sulphur (S) atom in the five-membered ring with heavier atoms such as Se or Te. 20,21 The size of the heteroatom dictates both the solubility and the size of the optical bandgap.…”

Thiazole fused S,N-heteroacene step-ladder polymeric semiconductors for organic transistors

“…22 Another interesting class of fused ladder-type building blocks with promising electronic and optical properties are based on heteroacenes. [23][24][25][26][27][28][29][30][31][32][33][34] Among the various reported building blocks, S,N-heteroacenes consisting of fused thiophene and pyrrole rings, a structural analogue of the electrondonating dithieno[3,2-b:2 0 ,3 0 -d]pyrrole (DTP), unit are of particular interest. [35][36][37][38] Introducing solubilizing substituents on the sp 2 -hybridized nitrogen atom of the pyrrole moiety, enhancing the intramolecular charge transfer (ICT) interactions, and tuning the energy levels are promising strategies for inuencing the properties required to achieve high performance organic thin-lm transistors (OTFTs).…”

“…1 includes fused pyrrolo [3,2-d:4,5-d 0 ]-bisthiazole (PBTz). 34,[44][45][46] In addition, the anking thiazole units can provide potential anchoring points for the formation of non-covalent bonds or can enhance the van der Waals interaction with neighbouring units to further rigidify and coplanarize the conjugated system. 47 Until now there have been no reported examples of thiazole-fused S,N-heteroacene building blocks, which can be attributed to the difficulty in their synthesis.…”

Molecular Tuning in Diaryl-Capped Pyrrolo[2,3-d:5,4-d′]bisthiazoles: Effects of Terminal Aryl Unit and Comparison to Dithieno[3,2-b:2′,3′-d]pyrrole Analogues

“…As such, it is not surprising that the first example of these thiazole species was the DTP analogue pyrrolo[2,3- d :5,4- d ′]bisthiazole (PBTz, Figure 2 ) [ 15 , 16 , 17 ]. Introduced by Heeney and co-workers in 2010 [ 15 ], these new PBTz units have then been applied to both small molecules [ 16 , 18 ] and polymeric materials [ 15 , 19 , 20 , 21 , 22 ].…”