Dynamic covalent chemistry, with its ability to correct synthetic dead-ends, allows for the synthesis of elaborate extended network materials in high yields. However, the limited number of reactions amenable to dynamic covalent chemistry necessarily confines the scope and functionality of materials synthesized. Here, we explore the dynamic and self-correcting nature of nucleophilic aromatic substitution (SAr), using ortho-aryldithiols and ortho-aryldifluorides that condense to produce redox-active thianthrene units. We demonstrate the facile construction of two-, three- and four-point junctions by reaction between a dithiol nucleophile and three different model electrophiles that produces molecules with two, three and four thianthrene moieties, respectively, in excellent yields. The regioselectivity observed is driven by thermodynamics; other connections form under kinetic control. We also show that the same chemistry can be extended to the synthesis of novel ladder macrocycles and porous polymer networks with Brunauer-Emmett-Teller surface area of up to 813 m g.

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Two new diketopyrrolopyrrole-based π-conjugated copolymers (PDPP6T and PDPP7T) have been synthesized by Stille coupling polymerization of 3,6-bis(5′bromo-[2,2′-bithiophen]-5-yl)-2,5-bis(2-octyldodecyl)pyrrolo-[ 3 , 4 -c ] p y r r o l e -1 , 4 ( 2 H , 5 H ) -d i o n e w i t h α , α ′ -b i s-( t r i m e t h y l s t a n n y l ) -b i t h i o p h e n e a n d α , α ′ -b i s -(trimethylstannyl)-terthiophene, respectively.The impressive high mobility of 3.94 cm 2 V −1 s −1 for the polymer with sextetthiophene (6T) and of 2.82 cm 2 V −1 s −1 for polymer with septetthiophene (7T) is acquired. It is found that the introduction of longer β-unsubstituted oliogothiophene unit in DPP-based copolymers has a great influence on the molecular weight and solubility of the DPP-oligothiophene copolymers that finally affects the organic thin-film transistor (OTFT) performances, indicating that a suitable number of thiophene group in β-unsubstituted oligothiophene exists for such a kind of copolymer to exhibit the best OTFT performances. This work also reveals the significance in the design of D−A copolymers for OTFTs through regulating the balance between π−π stacking of intermolecular chains and molecular weight as well as solubility of the rigid main chain.

Donor-acceptor type polymers bearing diketopyrrolopyrrole and 3,4-ethylenedioxythiophene units are reported. The polymers are green and exhibit very low band-gaps (1.19 eV) with strong and broad absorption (maxima of about 830 nm) in the near infrared (NIR) region in their neutral film states. The polymers display color changes between dark green and light blue with exceptional optical contrasts in the NIR regions of up to 78 and 63% as thin films and single-layer electrochromic devices, respectively. Fast switching, good stabilities as well as high coloration efficiencies (743-901 cm 2 C 21 ) were also observed. The polymers could also be potentially used as photovoltaic material, with a power conversion efficiency of up to 1.68%. V C 2015 Wiley Periodicals, Inc. J.