Co-reporter:Hassan Bohra
Journal of Materials Chemistry A 2017 vol. 5(Issue 23) pp:11550-11571
Publication Date(Web):2017/06/13
DOI:10.1039/C7TA00617A
Organic π-conjugated small molecules and polymers, owing to their light weight, solution processability, mechanical flexibility, and large synthetic variety of finely tunable structures and properties, are promising semiconducting materials for a new generation of optoelectronic devices such as light-emitting diodes (LEDs), field-effect transistors (FETs), photovoltaic devices and sensors. A vast library of π-conjugated systems have been synthesized through conventional tools of coupling (e.g. Suzuki coupling, Stille coupling) and have been used in the fabrication of organic optoelectronic devices. In recent years an emerging synthetic technique called direct C–H arylation has been extensively studied as a facile, atom-efficient and environmentally benign pathway for the synthesis of conjugated polymers and small molecules. C–C bond formation between two heteroaryls can be carried out via the activation of C–H bonds in a transition-metal catalytic cycle, thereby overcoming additional pre-functionalization steps involving toxic reagents. Direct arylation has been applied to a broad range of monomers and its reaction conditions have been optimized to produce defect-free polymers as well as small molecules that exhibit performances comparable with those made from conventional reactions. In this review, we summarize the recent progress in the synthesis of conjugated small molecules, linear polymers and porous polymers by direct C–H arylation. In particular, small molecules and linear polymers based on benzothiadiazole (BT), diketopyrrolopyrrole (DPP), napththalenediimide (NDI), isoindigo (IG), thienoisoindigo (TIIG) and thienothiadiazole (TTD) are discussed in detail. Device performances of some representative polymers synthesized via direct arylation polymerization (DAP) in FETs and bulk heterojunction solar cells are summarized. We finally discuss the present challenges and perspectives of DAP towards future “greener” and more industrially scalable synthesis of π-conjugated semiconducting polymers for a variety of applications.
Co-reporter:Amsalu Efrem, Kai Wang, Mingfeng Wang
Dyes and Pigments 2017 Volume 145(Volume 145) pp:
Publication Date(Web):1 October 2017
DOI:10.1016/j.dyepig.2017.05.040
•Direct arylation polymerization enables facile synthesis of a narrow-bandgap polymer.•Polymers with alternating strong-donor/strong-acceptors are obtained.•The charge transport properties are first examined in field effect transistors.A narrow bandgap D-A conjugated polymer based on 5H-dithieno [3,2-b:2′,3'-d]pyran alternating with 5,6-difluoro-2,1,3-benzothiadiazole (denoted as PDFBT-alt-DTP) was synthesized via direct C-H arylation polymerization (DAP) as an atomically efficient protocol. The optimal reaction condition for the DAP gave the target polymers with moderate number-average molecular weights (Mn) using optimized catalytic condition of Pd2 (dba)3/(o-MeOPh)3P/PivOH/K2CO3 in o-xylene. UV-vis-NIR absorption spectra of the obtained polymers show the presence of aggregation and interchain interaction in thin films. 1H-NMR spectroscopic analysis indicates good C-H selectivity corresponding to an alternating strong-donor-alt-strong-acceptor conjugated backbone. The hole mobility of the resulting polymers in a magnitude of 10−4 cm2V−1s−1 was reached in bottom-gate top-contact field-effect transistors fabricated and tested under ambient conditions.Download high-res image (112KB)Download full-size image
Co-reporter:Hui Liu, Kai Wang, Cangjie Yang, Shuo Huang, Mingfeng Wang
Colloids and Surfaces B: Biointerfaces 2017 Volume 157(Volume 157) pp:
Publication Date(Web):1 September 2017
DOI:10.1016/j.colsurfb.2017.05.080
•Polymeric micelles co-loaded with photothermal agents and anticancer drugs are reported.•Enhanced cancer therapeutic effect was observed under 808-nm laser irradiation.•“Breathing” effect of shrinking/swelling of F127 micelles improves drug release.Polymeric micelles loaded with multiple therapeutic modalities are important to overcome challenges such as drug resistance and improve the therapeutic efficacy. Here we report a new polymer micellar drug carrier that integrates chemotherapy and photothermal therapy in a single platform. Specifically, a narrow bandgap poly(dithienyl-diketopyrrolopyrrole) (PDPP) polymer was encapsulated together with a model anticancer drug doxorubicin (DOX) in the hydrophobic cores of polymeric micelles formed by Pluronic F127, an amphiphilic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer. The PDPP polymer served as an organic photothermal agent that absorbs near-infrared light (700–1000 nm) and transforms into heat efficiently. The dual functional micelles co-loaded with PDPP and DOX in the hydrophobic compartment showed good colloidal stability after being stored at 4 °C at least over two months, and remained visibly stable after 808-nm laser irradiation. The loaded DOX had negligible effect on the size and photothermal property of the micelles. The release of DOX from the micelles could be enhanced by the “breathing” effect of shrinking/swelling of the micelles induced by the temperature change, owing to the thermosensitive nature of the F127 polymers. Importantly, the ternary F127/PDPP/DOX micelles under 808-nm laser irradiation showed enhanced cytotoxicity against cancer cells such as HeLa cells, compared to F127 micelles containing single modality of either PDPP or DOX only.Download high-res image (117KB)Download full-size image
Co-reporter:Tao Jia;Shuo Huang;Cangjie Yang
Journal of Materials Chemistry B 2017 vol. 5(Issue 43) pp:8514-8524
Publication Date(Web):2017/11/08
DOI:10.1039/C7TB01657C
Development of stimuli-responsive drug carriers that can efficiently retain the encapsulated drug during blood circulation and selectively release the drug in disease targets under internal and/or external stimulation is important to minimize the side effects and improve the drug efficacy. Herein, we report a nanoscale polymeric carrier based on robust and pH-responsive unimolecular micelles that are able to carry multiple functional agents such as anticancer drugs and photothermal agents for improved treatment of cancer cells through combinational chemo/photothermal therapy. Specifically, we synthesized three pH-responsive amphiphilic star-like copolymers (denoted as CPDOs), which were facilely synthesized via one-step atom transfer radical polymerization (ATRP) with pH-responsive 2-(diisopropylamino) ethyl methacrylate and hydrophilic poly[(oligo ethylene glycol)methyl ether methacrylate] as co-monomers from the core of heptakis [2,3,6-tri-o-(2-bromo-2-methyl propionyl)-β-cyclodextrin] as the initiator. Then the anticancer drug doxorubicin (DOX) and a narrow-bandgap molecule benzo[1,2-c;4,5-c′]bis[1,2,5]thiadiazole-4,7-bis(9,9-dioctyl-9H-fluoren-2-yl)thiophene (denoted as BBT-2FT) as a near-infrared photothermal agent were co-encapsulated into the CPDO polymers, resulting in stable unimolecular micelles in aqueous media. The tertiary unimolecular micelles loaded with DOX and BBT-2FT showed controllable drug release kinetics and enhanced therapeutic effect against cancer cells under co-stimulation of pH change and 808 nm laser irradiation.
Co-reporter:Shuo Huang, Paul Kumar Upputuri, Hui Liu, Manojit Pramanik and Mingfeng Wang
Journal of Materials Chemistry A 2016 vol. 4(Issue 9) pp:1696-1703
Publication Date(Web):25 Jan 2016
DOI:10.1039/C5TB02367J
Nanoparticles (NPs) with integrated functionalities of targeting, therapy, imaging contrast and biocompatibility have shown promise for application in improved disease diagnosis and therapy. Herein, we report a theranostic agent based on a narrow-bandgap small molecule, benzo[1,2-c;4,5-c′]bis[1,2,5]thiadiazole-4,7-bis(9,9-dioctyl-9H-fluoren-2-yl)thiophene (denoted as BBT-2FT), with the strong absorption of near-infrared (NIR) light. Colloidal nanoparticles composed of BBT-2FT showed a photoacoustic signal intensity ten times higher than that of blood, and high photothermal conversion efficiency (η = 40%) under the irradiation of 808 nm laser light, which killed over 90% of HeLa cells in 10 min.
Co-reporter:Amsalu Efrem, Kai Wang, Prince N. Amaniampong, Cangjie Yang, Sukriti Gupta, Hassan Bohra, Samir H. Mushrif and Mingfeng Wang
Polymer Chemistry 2016 vol. 7(Issue 30) pp:4862-4866
Publication Date(Web):08 Jul 2016
DOI:10.1039/C6PY00719H
Conjugated microporous polymers are synthesized through facile one-step direct arylation polymerization of a single monomer unit, 8,11-dibromodithieno[3,2-a:2′,3′-c]phenazine, without preactivation of C–H bonds using organometallic reagents. The resulting polymers exhibit hierarchical porous structures and a narrow bandgap of 1.5 eV.
Co-reporter:Hua Jia Diao;Kai Wang;Hong Yan Long;Sing Yan Chew
Advanced Healthcare Materials 2016 Volume 5( Issue 5) pp:529-533
Publication Date(Web):
DOI:10.1002/adhm.201500693
Co-reporter:Amsalu Efrem, Yanlian Lei, Bo Wu, Mingfeng Wang, Siu Choon Ng, Beng S. Ong
Dyes and Pigments 2016 Volume 129() pp:90-99
Publication Date(Web):June 2016
DOI:10.1016/j.dyepig.2016.01.035
•D-A copolymers containing thiophene-fused benzochalcogenodiazole are synthesized.•Optoelectronic properties are tunable by changing the chalcogen atoms.•The chemical structures and phase separation determine device performances.Appositely functionalized dithienobenzo-thiadiazole and dithienobenzo-oxadiazole-monomers were prepared and used in the synthesis of conjugated electron donor-acceptor (D-A) polymers. Detailed systematic investigations were carried out to study the effects of chalcogen atoms and three donor units on the optical and electrochemical properties as well as photovoltaic and field-effect transistor performance of the D-A polymers. All polymers displayed good thermal properties. Polymers containing benzooxadiazole moiety showed deeper LUMO levels as compared to their benzothiadiazole-containing analogues, whereas those derived from weak donor unit exhibited deeper HOMO levels than those with stronger donors. Photovoltaic power conversion efficiency of over 2% and hole field-effect mobility of 2.6 × 10−2 cm2V−1s−1 and on/off ratio of over 105 were obtained. These results demonstrate that dithienobenzo-chalcogenodiazole structures are potentially useful electron acceptor building blocks for the construction of D-A polymers for organic electronics applications.
Co-reporter:Amsalu Efrem, Marc Courté, Kai Wang, Denis Fichou, Mingfeng Wang
Dyes and Pigments 2016 Volume 134() pp:171-177
Publication Date(Web):November 2016
DOI:10.1016/j.dyepig.2016.07.013
•γ-lactone-Pechmann dye as electron acceptor was first introduced to D-A polymers.•D-A polymers with narrow bandgaps and deeper LUMO levels are synthesized.•Side chains affect intermolecular aggregation and charge transport in devices.A new acceptor moiety, γ-lactone-Pechmann dye is synthesized and used in the construction of two new conjugated D-A polymers. The optical and electrochemical characterization shows a broad absorption band extended to 1000 nm and narrow band gaps with deep LUMO energy levels. The chemical structures of the side chains appended from the donor units affect the intermolecular aggregation and the charge transport in thin-film field-effect transistors. The high degree of planarity, low bandgap, and strong electron accepting properties could make γ-lactone-Pechmann dye as a good candidate for the construction of conjugated D-A polymers.
Co-reporter:Hassan Bohra, Jinjun Shao, Shuo Huang, Mingfeng Wang
Tetrahedron Letters 2016 Volume 57(Issue 13) pp:1497-1501
Publication Date(Web):30 March 2016
DOI:10.1016/j.tetlet.2016.02.081
•The first C–H direct arylation based on naphthodithiophenediimide (NDTI) is reported.•NDTI-based D–A and D–A–D small molecules are synthesized and characterized.•NDTI-based D–A alternating copolymers are synthesized and characterized.Naphthodithiophenediimide (NDTI) as a new electron-accepting building block has been used to synthesize narrow bandgap small molecules and polymers for ambi-polar organic field-effect transistors and organic solar cells. Herein, we report the first application of direct arylation coupling to synthesize a series of NDTI-based small molecules and polymers. The regioselectivity was examined in the direct arylation coupling of NDTI with 2-bromo-9,9-dihexylfluorene. Two NDTI-based narrow bandgap polymers, one with benzothiadiazole and the other with 9,9-dioctylfluorene, were synthesized via direct arylation polymerization. The chemical structures and optoelectronic properties of these molecules and polymers were characterized.
Co-reporter:Jing Huang;Kai Wang;Sukriti Gupta;Guojie Wang;Cangjie Yang;Samir H. Mushrif
Journal of Polymer Science Part A: Polymer Chemistry 2016 Volume 54( Issue 13) pp:2015-2031
Publication Date(Web):
DOI:10.1002/pola.28068
ABSTRACT
Thienoisoindigo (TIIG) has emerged as an attractive building block for high-performance organic optoelectronic devices. Here we report the first synthesis of a series of π-conjugated TIIG-based small molecules and alternating copolymers via direct C–H arylation, which enables the efficient synthesis without use of flammable and toxic orgametallic reagents in fewer steps compared Suzuki and Stille coupling. The direct arylation coupling between TIIG and two respective mono-bromo aryl reactants clearly shows that the α-H is more reactive than the β-H in the thiophene unit of TIIG. The high regioselectivity of TIIG monomer warrants the successful synthesis of high-quality alternating copolymers with minimal structural defects. PTIIG-BT polymer synthesized via direct arylation polymerization (DAP) showed comparable molecular weight and hole mobility than the same polymer previously synthesized via Suzuki coupling. Moreover, the two new polymers (PTIIG-TF and PTIIG-2FBT) synthesized via DAP showed hole mobility up to 10−3 cm2 V−1 s−1 in FET devices fabricated and tested under ambient conditions. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 2015–2031
Co-reporter:Cangjie Yang, Hui Liu, Yingdan Zhang, Zhigang Xu, Xiaochen Wang, Bin Cao, and Mingfeng Wang
Biomacromolecules 2016 Volume 17(Issue 5) pp:
Publication Date(Web):March 24, 2016
DOI:10.1021/acs.biomac.6b00092
This article describes molecular design, synthesis and characterization of colloidal nanoparticles containing polycaprolactone-grafted conjugated polymers that exhibit strong far red/near-infrared (FR/NIR) fluorescence for bioimaging. Specifically, we synthesized two kinds of conjugated polymer bottle brushes (PFTBout-g-PCL and PFTBin-g-PCL) with different positions of the hexyl groups on the thiophene rings. A synthetic amphiphilic block copolymer PCL-b-POEGMA was employed as surfactants to encapsulate PFTB-g-PCL polymers into colloidal nanoparticles (denoted as “nanoREDs”) in aqueous media. The chain length of the PCL side chains in PFTB-g-PCL played a critical role in determining the fluorescence properties in both bulk solid states and the colloidal nanoparticles. Compared to semiconducting polymer dots (Pdots) composed of PFTBout without grafted PCL, nanoREDout showed at least four times higher fluorescence quantum yield (∼20%) and a broader emission band centered at 635 nm. We further demonstrated the application of this new class of nanoREDs for effective labeling of L929 cells and HeLa cancer cells with good biocompatibility. This strategy of hydrophobic-sheath segregated macromolecular fluorophores is expected to be applicable to a broad range of conjugated polymers with tunable optical properties for applications such as bioimaging.
Co-reporter:Zhigang Xu, Shiying Liu, Yuejun Kang and Mingfeng Wang
Nanoscale 2015 vol. 7(Issue 13) pp:5859-5868
Publication Date(Web):26 Feb 2015
DOI:10.1039/C5NR00297D
A myriad of drug delivery systems such as liposomes, micelles, polymers and inorganic nanoparticles (NPs) have been developed for cancer therapy. Very few of them, however, have the ability to integrate multiple functionalities such as specific delivery, high circulation stability, controllable release and good biocompatibility and biodegradability in a single system to improve the therapeutic efficacy. Herein, we report two types of stimuli-responsive nonporous silica prodrug NPs towards this goal for controlled release of anticancer drugs and efficient combinatorial cancer therapy. As a proof of concept, anticancer drugs camptothecin (CPT) and doxorubicin (DOX) were covalently encapsulated into silica matrices through glutathione (GSH)-responsive disulfide and pH-responsive hydrazone bonds, respectively, resulting in NPs with sizes tunable in the range of 50–200 nm. Both silica prodrug NPs showed stimuli-responsive controlled release upon exposure to a GSH-rich or acidic environment, resulting in improved anticancer efficacy. Notably, two prodrug NPs simultaneously taken up by HeLa cells showed a remarkable combinatorial efficacy compared to free drug pairs. These results suggest that the stimuli-responsive silica prodrug NPs are promising anticancer drug carriers for efficient cancer therapy.
Co-reporter:Shuo Huang, Shiying Liu, Kai Wang, Cangjie Yang, Yimin Luo, Yingdan Zhang, Bin Cao, Yuejun Kang and Mingfeng Wang
Nanoscale 2015 vol. 7(Issue 3) pp:889-895
Publication Date(Web):17 Nov 2014
DOI:10.1039/C4NR05576D
We report a facile and general strategy for enhancing the photostability of organic fluorophores for bioimaging applications. As a proof of concept, bright and robust fluorescence was observed in solid states of a well-defined synthetic polymer polycaprolactone consisting of di(thiophene-2-yl)-diketopyrrolopyrrole covalently linked in the middle of the polymer chain as a biocompatible and bioresorbable matrix. The nanoparticles prepared through a nanoprecipitation process of these polymers could be internalized by both tumor cells and stem cells with little cytotoxicity. Moreover, these highly fluorescent nanoparticles exhibited significantly enhanced photostability compared to commercial quantum dots or physical blends of dye/polymer complexes in cell imaging and long-term tracing.
Co-reporter:Shuo Huang, Ravi Kumar Kannadorai, Yuan Chen, Quan Liu and Mingfeng Wang
Chemical Communications 2015 vol. 51(Issue 20) pp:4223-4226
Publication Date(Web):03 Feb 2015
DOI:10.1039/C4CC09399B
Photothermal therapy has emerged as a promising tool for treatment of diseases such as cancers. Previous photothermal agents have been largely limited to inorganic nanomaterials and conductive polymers that are barely biodegradable, thus raising issues of long-term toxicity for clinical applications. Here we report a new photothermal agent based on colloidal nanoparticles formed by a small-molecular dye, benzo[1,2-c;4,5-c′]bis[1,2,5]thiadiazole-4,7-bis(5-(2-ethylhexyl)thiophene). These nanoparticles showed strong near-infrared absorption, robust photostability and high therapeutic efficiency for photothermal treatment of cancer cells.
Co-reporter:Zhigang Xu, Shiying Liu, Hui Liu, Cangjie Yang, Yuejun Kang and Mingfeng Wang
Chemical Communications 2015 vol. 51(Issue 87) pp:15768-15771
Publication Date(Web):29 Jun 2015
DOI:10.1039/C5CC02743H
Well-defined star-like amphiphilic polymers composed of a β-cyclodextrin core, from which 21 hydrophobic poly(lactic acid) arms and hydrophilic poly(ethylene glycol) arms are grafted sequentially, form robust and uniform unimolecular micelles that are biocompatible and efficient in the delivery of anticancer drugs.
Co-reporter:Cangjie Yang, Quang Thang Trinh, Xiaochen Wang, Yuxin Tang, Kai Wang, Shuo Huang, Xiaodong Chen, Samir H. Mushrif and Mingfeng Wang
Chemical Communications 2015 vol. 51(Issue 16) pp:3375-3378
Publication Date(Web):15 Jan 2015
DOI:10.1039/C4CC09540E
We report a new class of crystallization-induced red-emitting luminogen based on a synthetic biodegradable indigo derivative, Indigoid-B. This compound, upon an ultrasonic treatment, formed well-defined microcrystals that showed striking crystallization-induced emission (CIE) in mixed solvents of tetrahydrofuran–water.
Co-reporter:Xiaochen Wang, Kai Wang and Mingfeng Wang
Polymer Chemistry 2015 vol. 6(Issue 10) pp:1846-1855
Publication Date(Web):16 Dec 2014
DOI:10.1039/C4PY01627K
Thiophene-flanked benzothiadiazole derivatives (DTBTs) have been among the most widely used building blocks for the synthesis of a myriad of high-performance conjugated polymers for applications in optoelectronic devices, sensing and bioimaging. We first report that these building blocks could be synthesized via a facile and straightforward method called direct arylation coupling. Our optimization of Pd2dba3-catalyzed direct arylation coupling gave DTBTs with a comparable yield to that of the Suzuki or Stille coupling reaction. DTBTs were further polymerized with fluorene dibromide via direct arylation polycondensation to give well-defined alternating copolymers. One-pot direct arylation polymerizations were also carried out between benzothiadiazole dibromide, fluorene dibromide and thiophene derivatives, to form DTBT-containing random copolymers. These random copolymers showed typical multichromophore characteristics. The differences in optical properties between the alternating copolymers and random copolymers were evaluated.
Co-reporter:Jinjun Shao, Guojie Wang, Kai Wang, Cangjie Yang and Mingfeng Wang
Polymer Chemistry 2015 vol. 6(Issue 38) pp:6836-6844
Publication Date(Web):07 Aug 2015
DOI:10.1039/C5PY00595G
A series of narrow-bandgap polymers based on an alkyl-thiophene-flanked naphthalene diimide (TNDI) were synthesized through direct arylation polycondensation. The 1H NMR spectra indicate all polymers correspond to an alternating copolymer structure with good regioregularity. Their photophysical, electrochemical, thermal and charge transport properties are characterized. Among all of the synthesized polymers, the copolymer consisting of alternating TNDI and 4,6-di-(2-thienyl)thieno[3,4-c][1,2,5]thiadiazole performs the best among the thin film transistors, with a moderate hole mobility of 4.6 × 10−3 cm2 V−1 s−1 under ambient conditions.
Co-reporter:Kai Wang;Guojie Wang
Macromolecular Rapid Communications 2015 Volume 36( Issue 24) pp:2162-2170
Publication Date(Web):
DOI:10.1002/marc.201500377
Co-reporter:Zhigang Xu, Shiying Liu, Yuejun Kang, and Mingfeng Wang
ACS Biomaterials Science & Engineering 2015 Volume 1(Issue 7) pp:585
Publication Date(Web):May 21, 2015
DOI:10.1021/acsbiomaterials.5b00119
This article presents a novel glutathione (GSH)-responsive poly(ethylene glycol)-b-polycarbonate-b-poly(ethylene glycol) triblock copolymer that self-assembles into micellar nanoparticles and simutaneously carry hydrophobic anticancer drugs such as doxirubicin. These drug-loading micelles show glutathione-triggered decomposition that leads to controlled drug release and cytotoxicity to cancer cells. This polymeric drug-carrier system integrates features of facile synthesis, stimuli-responsive drug release, good biocompatibility, and relatively low toxicity of the dissociated segments, thus representing a promising anticancer drug carrier for potential clinical applications.Keywords: cancer; controlled release; micelles; nanomedicine; polymer
Co-reporter:Kai Wang;Yimin Luo;Shuo Huang;Hongbin Yang;Bin Liu
Journal of Polymer Science Part A: Polymer Chemistry 2015 Volume 53( Issue 8) pp:1032-1042
Publication Date(Web):
DOI:10.1002/pola.27531
ABSTRACT
Well-defined 1,4-diketo-3,6-di(thiophen-2-yl)pyrrolo[3,4-c]pyrrole (DTDPP) labeled polycaprolactones (PCL) with different chain lengths were synthesized and characterized. The effect of polymer chain lengths on the optical properties of DTDPP in solid states was studied by UV-Vis absorption spectroscopy as well as steady-state and dynamic fluorescence spectroscopies. Our results indicate that when the PCL side chain is extended to a certain length, the intermolecular aggregation of DTDPP units can be reduced significantly due to segregation effect of PCL. This approach offers a new facile strategy to address the common problem of aggregation-caused quenching existing in organic fluorophores. These highly fluorescent biodegradable PCL polymers may find broad biomedical applications such as fluorescence-based bioimaging and tissue engineering. © 2015 Wiley Periodicals, Inc. J. Polym. Sci. Part A: Polym. Chem. 2015, 53, 1032–1042
Co-reporter:Xiaochen Wang and Mingfeng Wang
Polymer Chemistry 2014 vol. 5(Issue 19) pp:5784-5792
Publication Date(Web):17 Jun 2014
DOI:10.1039/C4PY00565A
This article describes the synthesis of donor–acceptor (D–A) type copolymers based on benzo[1,2-b:4,5-b′]dithiophene and 2,1,3-benzothiadiazole via direct-arylation cross-coupling polycondensation. To achieve high performance polymerization, we have systematically investigated the reaction factors including catalysts, solvents, ligands, bases, additives, concentration of reactants and phase transfer agents. In particular, 1,2-dimethylbenzene (ODMB), as a nonpolar high boiling point solvent, is a superior medium to perform this direct-arylation polymerization. In this nonpolar aromatic solvent, Pd2dba3/(o-MeOPh)3P, accompanied with a base potassium carbonate and an additive pivalic acid, serves as an efficient catalyst system to obtain high-quality polymers. Our optimized condition gave the polymer with a weight-average molecular weight (Mw) as high as 60 kg mol−1 in nearly quantitative yield and excellent C–H selectivity.
Co-reporter:Mingfeng Wang and Fred Wudl
Journal of Materials Chemistry A 2012 vol. 22(Issue 46) pp:24297-24314
Publication Date(Web):24 Aug 2012
DOI:10.1039/C2JM33756H
Solar cells involving organic small molecules and polymers have attracted intense attention from chemists, physicists and materials scientists in the past decade. Efforts in materials synthesis and device processing have led to significant improvement of the power conversion efficiency, approaching 10%. In organic solar cells (OSCs), the morphology and the interface of the donor–acceptor (D–A) heterojunctions play a critical role in determining the device efficiency. In this article, we highlight recent progress on both materials synthesis and self-assembly and lithography techniques toward ordered nanostructures and well-defined D/A interfaces that are expected to enhance the performance of OSCs.
Co-reporter:Cangjie Yang, Xiaochen Wang, Zhigang Xu, Mingfeng Wang
Sensors and Actuators B: Chemical (June 2017) Volume 245() pp:845-852
Publication Date(Web):June 2017
DOI:10.1016/j.snb.2017.01.147
Co-reporter:Hassan Bohra and Mingfeng Wang
Journal of Materials Chemistry A 2017 - vol. 5(Issue 23) pp:NaN11571-11571
Publication Date(Web):2017/05/02
DOI:10.1039/C7TA00617A
Organic π-conjugated small molecules and polymers, owing to their light weight, solution processability, mechanical flexibility, and large synthetic variety of finely tunable structures and properties, are promising semiconducting materials for a new generation of optoelectronic devices such as light-emitting diodes (LEDs), field-effect transistors (FETs), photovoltaic devices and sensors. A vast library of π-conjugated systems have been synthesized through conventional tools of coupling (e.g. Suzuki coupling, Stille coupling) and have been used in the fabrication of organic optoelectronic devices. In recent years an emerging synthetic technique called direct C–H arylation has been extensively studied as a facile, atom-efficient and environmentally benign pathway for the synthesis of conjugated polymers and small molecules. C–C bond formation between two heteroaryls can be carried out via the activation of C–H bonds in a transition-metal catalytic cycle, thereby overcoming additional pre-functionalization steps involving toxic reagents. Direct arylation has been applied to a broad range of monomers and its reaction conditions have been optimized to produce defect-free polymers as well as small molecules that exhibit performances comparable with those made from conventional reactions. In this review, we summarize the recent progress in the synthesis of conjugated small molecules, linear polymers and porous polymers by direct C–H arylation. In particular, small molecules and linear polymers based on benzothiadiazole (BT), diketopyrrolopyrrole (DPP), napththalenediimide (NDI), isoindigo (IG), thienoisoindigo (TIIG) and thienothiadiazole (TTD) are discussed in detail. Device performances of some representative polymers synthesized via direct arylation polymerization (DAP) in FETs and bulk heterojunction solar cells are summarized. We finally discuss the present challenges and perspectives of DAP towards future “greener” and more industrially scalable synthesis of π-conjugated semiconducting polymers for a variety of applications.
Co-reporter:Mingfeng Wang and Fred Wudl
Journal of Materials Chemistry A 2012 - vol. 22(Issue 46) pp:NaN24314-24314
Publication Date(Web):2012/08/24
DOI:10.1039/C2JM33756H
Solar cells involving organic small molecules and polymers have attracted intense attention from chemists, physicists and materials scientists in the past decade. Efforts in materials synthesis and device processing have led to significant improvement of the power conversion efficiency, approaching 10%. In organic solar cells (OSCs), the morphology and the interface of the donor–acceptor (D–A) heterojunctions play a critical role in determining the device efficiency. In this article, we highlight recent progress on both materials synthesis and self-assembly and lithography techniques toward ordered nanostructures and well-defined D/A interfaces that are expected to enhance the performance of OSCs.
Co-reporter:Cangjie Yang, Quang Thang Trinh, Xiaochen Wang, Yuxin Tang, Kai Wang, Shuo Huang, Xiaodong Chen, Samir H. Mushrif and Mingfeng Wang
Chemical Communications 2015 - vol. 51(Issue 16) pp:NaN3378-3378
Publication Date(Web):2015/01/15
DOI:10.1039/C4CC09540E
We report a new class of crystallization-induced red-emitting luminogen based on a synthetic biodegradable indigo derivative, Indigoid-B. This compound, upon an ultrasonic treatment, formed well-defined microcrystals that showed striking crystallization-induced emission (CIE) in mixed solvents of tetrahydrofuran–water.
Co-reporter:Zhigang Xu, Shiying Liu, Hui Liu, Cangjie Yang, Yuejun Kang and Mingfeng Wang
Chemical Communications 2015 - vol. 51(Issue 87) pp:NaN15771-15771
Publication Date(Web):2015/06/29
DOI:10.1039/C5CC02743H
Well-defined star-like amphiphilic polymers composed of a β-cyclodextrin core, from which 21 hydrophobic poly(lactic acid) arms and hydrophilic poly(ethylene glycol) arms are grafted sequentially, form robust and uniform unimolecular micelles that are biocompatible and efficient in the delivery of anticancer drugs.
Co-reporter:Shuo Huang, Paul Kumar Upputuri, Hui Liu, Manojit Pramanik and Mingfeng Wang
Journal of Materials Chemistry A 2016 - vol. 4(Issue 9) pp:NaN1703-1703
Publication Date(Web):2016/01/25
DOI:10.1039/C5TB02367J
Nanoparticles (NPs) with integrated functionalities of targeting, therapy, imaging contrast and biocompatibility have shown promise for application in improved disease diagnosis and therapy. Herein, we report a theranostic agent based on a narrow-bandgap small molecule, benzo[1,2-c;4,5-c′]bis[1,2,5]thiadiazole-4,7-bis(9,9-dioctyl-9H-fluoren-2-yl)thiophene (denoted as BBT-2FT), with the strong absorption of near-infrared (NIR) light. Colloidal nanoparticles composed of BBT-2FT showed a photoacoustic signal intensity ten times higher than that of blood, and high photothermal conversion efficiency (η = 40%) under the irradiation of 808 nm laser light, which killed over 90% of HeLa cells in 10 min.
Co-reporter:Shuo Huang, Ravi Kumar Kannadorai, Yuan Chen, Quan Liu and Mingfeng Wang
Chemical Communications 2015 - vol. 51(Issue 20) pp:NaN4226-4226
Publication Date(Web):2015/02/03
DOI:10.1039/C4CC09399B
Photothermal therapy has emerged as a promising tool for treatment of diseases such as cancers. Previous photothermal agents have been largely limited to inorganic nanomaterials and conductive polymers that are barely biodegradable, thus raising issues of long-term toxicity for clinical applications. Here we report a new photothermal agent based on colloidal nanoparticles formed by a small-molecular dye, benzo[1,2-c;4,5-c′]bis[1,2,5]thiadiazole-4,7-bis(5-(2-ethylhexyl)thiophene). These nanoparticles showed strong near-infrared absorption, robust photostability and high therapeutic efficiency for photothermal treatment of cancer cells.
![Benzo[2,1-b:3,4-b']dithiophene-4,5-dione](/data/chemimg/1467500/24243-32-1.png)
![Benzo[2,1-b:3,4-b']dithiophene-4,5-dione](/data/chemimg/1467500/24243-32-1_b.png)
![Poly[oxy(1-oxo-1,6-hexanediyl)]](http://img.cochemist.com/ccimg/25300/25248-42-4.png)
![Poly[oxy(1-oxo-1,6-hexanediyl)]](http://img.cochemist.com/ccimg/25300/25248-42-4_b.png)
![[2]Benzopyrano[6,5,4-def][2]benzopyran-1,3,6,8-tetrone, 4,9-dibromo-](/data/chemimg/1015800/83204-68-6.png)
![[2]Benzopyrano[6,5,4-def][2]benzopyran-1,3,6,8-tetrone, 4,9-dibromo-](/data/chemimg/1015800/83204-68-6_b.png)
![Pyrrolo[3,4-c]pyrrole-1,4-dione, 3,6-bis(5-bromo-2-thienyl)-2,5-dihydro-2,5-bis(2-octyldodecyl)-](/data/chemimg/139000/1260685-63-9.png)
![Pyrrolo[3,4-c]pyrrole-1,4-dione, 3,6-bis(5-bromo-2-thienyl)-2,5-dihydro-2,5-bis(2-octyldodecyl)-](/data/chemimg/139000/1260685-63-9_b.png)
![Benzo[lmn][3,8]phenanthroline-1,3,6,8(2H,7H)-tetrone, 4,9-dibromo-2,7-bis(2-octyldodecyl)-](/data/chemimg/139000/1100243-35-3.png)
![Benzo[lmn][3,8]phenanthroline-1,3,6,8(2H,7H)-tetrone, 4,9-dibromo-2,7-bis(2-octyldodecyl)-](/data/chemimg/139000/1100243-35-3_b.png)
![Dithieno[3,2-e:2',3'-g]-2,1,3-benzothiadiazole](/data/chemimg/154400/1256138-50-7.png)
![Dithieno[3,2-e:2',3'-g]-2,1,3-benzothiadiazole](/data/chemimg/154400/1256138-50-7_b.png)
![Poly[2,7-(9,9-di-octyl-fluorene)-alt-4,7-bis(thiophen-2-yl)benzo-2,1,3-thiadiazole]](/data/chemimg/133300/782469-77-6.png)
![Poly[2,7-(9,9-di-octyl-fluorene)-alt-4,7-bis(thiophen-2-yl)benzo-2,1,3-thiadiazole]](/data/chemimg/133300/782469-77-6_b.png)
![Benzo[1,2-b:4,5-b']dithiophene, 4,8-bis[(2-hexyldecyl)oxy]-](/data/chemimg/154400/1254985-73-3.png)
![Benzo[1,2-b:4,5-b']dithiophene, 4,8-bis[(2-hexyldecyl)oxy]-](/data/chemimg/154400/1254985-73-3_b.png)
![2,5-Bis(2-ethylhexyl)-3,6-di(thiophen-2-yl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione](http://img.cochemist.com/ccimg/1185900/1185885-86-2.png)
![2,5-Bis(2-ethylhexyl)-3,6-di(thiophen-2-yl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione](http://img.cochemist.com/ccimg/1185900/1185885-86-2_b.png)
![2H-Pyran, 2-[(11-bromoundecyl)oxy]tetrahydro-](http://img.cochemist.com/ccimg/52100/52056-69-6.png)
![2H-Pyran, 2-[(11-bromoundecyl)oxy]tetrahydro-](http://img.cochemist.com/ccimg/52100/52056-69-6_b.png)
![Pyrrolo[3,4-c]pyrrole-1,4-dione, 2,5-dihydro-2,5-bis(2-octyldodecyl)-3,6-di-2-thienyl-](/data/chemimg/139000/1267540-02-2.png)
![Pyrrolo[3,4-c]pyrrole-1,4-dione, 2,5-dihydro-2,5-bis(2-octyldodecyl)-3,6-di-2-thienyl-](/data/chemimg/139000/1267540-02-2_b.png)
![2,5-Bis(trimethylstannyl)thieno[3,2-b]thiophene](http://img.cochemist.com/ccimg/470000/469912-82-1.png)
![2,5-Bis(trimethylstannyl)thieno[3,2-b]thiophene](http://img.cochemist.com/ccimg/470000/469912-82-1_b.png)
![4,7-dibromobenzo[1,2-c:4,5-c']bis([1,2,5]thiadiazole)](http://img.cochemist.com/ccimg/165700/165617-59-4.png)
![4,7-dibromobenzo[1,2-c:4,5-c']bis([1,2,5]thiadiazole)](http://img.cochemist.com/ccimg/165700/165617-59-4_b.png)
