@article { ISI:000380038000012, title = {Site-selective synthesis and characterization of BODIPY-acetylene copolymers and their transistor properties}, journal = {Journal of Polymer Science Part A-Polymer Chemistry}, volume = {54}, number = {13}, year = {2016}, month = {JUL}, pages = {1978-1986}, publisher = {WILEY-BLACKWELL}, address = {111 RIVER ST, HOBOKEN 07030-5774, NJ USA}, abstract = {

To study the effect of site-selective copolymerization of borondipyrromethene (BODIPY) with acetylene on the structural and optoelectronic properties, three copolymers P1-P3 were synthesized by the Sonogashira cross-coupling of BODIPY units with diacetylene and bromine capping through all the possible linkages: alpha-alpha (P1), alpha-beta (P2), and beta-beta (P3). The optoelectronic properties of the polymers were investigated systematically to understand the effect of site-selective polymerization. The HOMO levels of the polymers were significantly tuned from P1 to P3 with negligible change in the LUMO levels. Broadening of absorption spectra from P3 to P1 was observed because of increase in the extent of conjugation. Additionally, the charge transport properties of these polymers in organic thin-film transistors (OTFTs) revealed that P1 and P3 exhibited only p-type mobility, whereas P2 exhibited electron mobility. Notably, the further investigations of the surface morphology of polymer films by atomic force microscopy (AFM) unveiled that comb like nanostructural arrangements in P3 was beneficial for the charge-carrier mobility over the circular arrangements in P1 and P2. (C) 2016 Wiley Periodicals, Inc.

}, keywords = {acetylene, BODIPY, DFT, low-band gap}, issn = {0887-624X}, doi = {10.1002/pola.28064}, author = {Debnath, Sashi and Singh, Saumya and Bedi, Anjan and Krishnamoorthy, Kothandam and Zade, Sanjio S.} } @article {48290, title = {Organic field effect transistors comprising copolymers synthesized without structure-directing moieties with enhanced carrier mobility}, journal = {ACS Applied Electronic Materials}, volume = {5}, year = {2023}, month = {APR}, pages = {2338-2344}, type = {Article}, abstract = {

Conjugated materials are synthesized by C-C bond formation reactions. Trimethyltin and boronic acid are two widely used structure-directing moieties. While using the ethynyl moiety as a part of the monomer, additional structure-directing moieties are not needed. However, ethynylene will be part of the conjugated material. Often, the polymers with an ethynylene moiety negatively impact the polymers{\textquoteright} properties. However, the ethynylene moiety could minimize the dihedral angle if the monomer has steric functionalities. For example, BODIPY is an attractive monomer due to its high molar extinction coefficient, partial quinoidal character, and high quantum yield. However, materials based on BODIPY exhibited poor charge carrier mobility due to steric hindrance generated by four methyl groups. Herein, we copolymerize BODIPY with ethynylene comprising i-indigo and thieno-i-indigo. The copolymer with thieno-i-indigo showed increased molecular weight and significantly reduced band gap compared to the copolymer with i-indigo. The copolymer with i-indigo showed immeasurably low hole transport mobility. On the other hand, the copolymer with thieno-i-indigo exhibited 0.003 cm2V(-1) s(-1). These measurements were made using field effect transistors. We also measured the charge carrier mobility using the space charge-limited current method. Both copolymers exhibited a mobility of 10(-3) cm(2) V-1 s(-1).

}, keywords = {acetylene linkage, BODIPY, field effect transistor, iso-indigo, Sonogashira coupling, thienoisoindigo}, doi = {10.1021/acsaelm.3c00160}, author = {Swain, Gitanjali and Javaregowda, Bharathkumar H. and Dambhare, Neha V. and Krishnamoorthy, Kothandam} } @article {49026, title = {Visible light and pH-responsive star copolymer and doxorubicin-polymer conjugate micelles for combination drug delivery and bioimaging}, journal = {Journal of macromolecular science part A- pure and applied chemistry}, volume = {61}, year = {2024}, month = {FEB }, pages = {105-116}, type = {Article}, abstract = {

Amphiphilic 3-arm star copolymer containing visible light-cleavable BODIPY group and pH-responsive imine bonds at the junction of hydrophilic poly(ethylene glycol) (PEG) and two poly(epsilon-caprolactone) (PCL) arms was synthesized by the combination of ring-opening polymerization (ROP) and click chemistry. The formation and stimuli-responsive disruption of micelles were analyzed using dynamic light scattering and transmission electron microscopy. Dual stimuli-responsive release of anticancer drugs Doxorubicin (Dox) and Camptothecin (CPT) from the micelles was studied. Micellar assemblies containing Dox conjugated to PEG-BODIPY through imine bonds were prepared and controlled release of Dox in response to visible light and pH was shown. CPT and Dox-loaded star copolymer micelles as well as CPT loaded Dox-conjugated micelles were used in cellular uptake studies on MDA-MB 231 cells, and the synergistic effect of the two stimuli on the release of the two drugs was demonstrated inside the cells. Micellar assemblies also showed excellent bioimaging properties in the cellular uptake studies. [GRAPHICS]

}, keywords = {BODIPY, drug conjugate, micelles, pH-responsive, visible light-responsive}, issn = {1060-1325}, doi = {10.1080/10601325.2024.2302857}, author = {Basutkar, Nitin B. and Surapaneni, Sai Geetika and Alam, Md. Shafi and Ambade, Ashootosh V.} }