01978nas a2200181 4500008004100000022001400041245016000055210006900215260007100284300001600355490000800371520120400379100002201583700001701605700003101622700002001653856012301673 2010 eng d a1520-610600aN-Type field effect transistors based on rigid rod and liquid crystalline alternating copoly(benzobisoxazole) imides containing perylene and/or naphthalene0 aNType field effect transistors based on rigid rod and liquid cry a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcDEC a16694-167040 v1143 a

The synthesis, characterization, and device studies of poly(benzobisoxazole imide)s containing perylene or naphthalene units in an alternating fashion with the oxazole unit are described. Photoinduced energy transfer and charge separation were studied in methanesulfonic acid (MSA) solution via absorption, excitation, and steady-state fluorescence studies. Excitation of the bisoxazole moiety resulted in enhanced emission from the perylene bisimide unit as a result of FRET (Forster resonance energy transfer). The influence of the imide substitution into the linear chain of poly(benzobisoxazole) (PBO) on its solid-state packing was examined by wide-angle X-ray diffraction (WXRD) analysis. Bottom contact field effect transistors (FET) based on thermally annealed polymer films were fabricated and studied. The polymers showed n-type charge transport and current modulation with an on/off ratio greater than 10(2). It was observed that the FETs consisting of the random copolymer of bisoxazole containing both perylene as well as naphthalene bisimide units had higher performance parameters such as better mobility (mu e) and I(on)/I(off) ratio compared to those of the pristine systems.

1 aKolhe, Nagesh, B.1 aAsha, S., K.1 aSenanayak, Satyaprasad, P.1 aNarayan, K., S. uhttp://library.ncl.res.in/content/n-type-field-effect-transistors-based-rigid-rod-and-liquid-crystalline-alternating-001893nas a2200181 4500008004100000022001400041245014700055210006900202260007700271300001400348490000700362520114000369100001901509700002001528700002001548700001701568856012601585 2013 eng d a1616-301X00aNanostructured crystalline comb polymer of perylenebisimide by directed self-assembly: poly(4-vinylpyridine)-pentadecylphenol perylenebisimide0 aNanostructured crystalline comb polymer of perylenebisimide by d aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcAPR a2033-20430 v233 a

Well defined nanostructured polymeric supramolecular assemblies are formed when an asymmetric perylenebisimide substituted with ethylhexyl chains on one end and functionalized with 3-pentadecylphenol at the other termini (PDP-UPBI) is complexed with poly(4-vinylpyridine) (P4VP) via a non-covalent specific interaction such as hydrogen-bonding. The resulting P4VP(PDP-UPBI)(n) complexes are fully solution processable. The bulk structure and morphologies of the supramolecular film studied using small angle and wide angle X-ray scattering reveals highly crystalline nature of the complex. Thin film morphology of the 1:1 complex analyzed using transmission electron microscopy shows uniform lamellar structures in the domain range of 5-10 nm. A clear trend of improved electrical parameters in P4VP(PDP-UPBI) system compared to pristine (PDP-UPBI) is observed from space charge limited current measurements. In short, a simple and facile method to obtain spatially defined organization of n-type semiconductor perylenebisimide molecules using hydrogen bonding interactions with P4VP as the structural motif is showcased herein.

1 aNarayan, Rekha1 aKumar, Prashant1 aNarayan, K., S.1 aAsha, S., K. uhttp://library.ncl.res.in/content/nanostructured-crystalline-comb-polymer-perylenebisimide-directed-self-assembly-poly4-002917nas a2200265 4500008004100000022001400041245008000055210006900135260007100204300001600275490000600291520199700297653001902294653002102313653003102334653002102365653002202386653004402408100001502452700001802467700001802485700002002503700001702523856011102540 2014 eng d a1944-824400aNanostructured donor-acceptor self assembly with improved photoconductivity0 aNanostructured donoracceptor self assembly with improved photoco a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcNOV a19434-194480 v63 a

Nanostructured supramolecular donor-acceptor assemblies were formed when an unsymmetrical N-substituted pyridine functionalized perylenebisimide (UPBI-Py) was complexed with oligo(p-phenylenevinylene) (OPVM-OH) complementarily functionalized with hydroxyl unit and polymerizable methacrylamide unit at the two termini. The resulting supramolecular complex [UPBI-Py (OPVM-OH)](1.0) upon polymerization by irradiation in the presence of photoinitiator formed well-defined supramolecular polymeric nanostructures. Self-assembly studies using fluorescence emission from thin film samples showed that subtle structural changes occurred on the OPV donor moiety following polymerization. The 1:1 supramolecular complex showed red-shifted aggregate emission from both OPV (similar to 500 nm) and PBI (similar to 640 nm) units, whereas the OPV aggregate emission was replaced by intense monomeric emission (similar to 430 nrn) upon polymerizing the methacrylamide units on the OPVM-OH. The bulk structure was studied using wide-angle X-ray diffraction (WXRD). Complex formation resulted in distinct changes in the cell parameters of OPVM-OH. In contrast, a physical mixture of 1 mol each of OPVM-OH and UPBI-Py prepared by mixing the powdered solid samples together showed only a combination of reflections from both parent molecules. Thin film morphology of the 1:1 molecular complex as well as the supramolecular polymer complex showed uniform lamellar structures in the domain range <10 rim. The donor-acceptor supramolecular complex [UPBI-Py (OPVM-OH)](1.0) exhibited space charge limited current (SCLC) with a bulk mobility estimate of an order of magnitude higher accompanied by a higher photoconductivity yield compared to the pristine UPBI-Py. This is a very versatile method to obtain spatially defined organization of n and p-type semiconductor materials based on suitably functionalized donor and acceptor molecules resulting in improved photocurrent response using self-assembly.

10adonor-acceptor10ahydrogen bonding10aoligo(p-phenylenevinylene)10aPerylenebisimide10aphotoconductivity10asupramolecular polymeric nanostructures1 aSaibal, B.1 aAshar, A., Z.1 aDevi, Nandini1 aNarayan, K., S.1 aAsha, S., K. uhttp://library.ncl.res.in/content/nanostructured-donor-acceptor-self-assembly-improved-photoconductivity-002718nas a2200169 4500008004100000245012700041210006900168260000800237300001600245490000700261520208000268100002202348700001802370700002002388700001702408856012302425 2014 eng d00aNaphthalene diimide copolymers with oligo(p-phenylenevinylene) and benzobisoxazole for balanced ambipolar charge transport0 aNaphthalene diimide copolymers with oligopphenylenevinylene and  cMAR a2296–23050 v473 a

A series of alternating and random donor (D)–acceptor (A) copolymers based on naphthalene diimide (NDI) as the acceptor and oligo(p-phenylenevinylene) (OPV) or benzobisoxazole (BBO) as the strong and weak donor, respectively, were designed and synthesized by Suzuki coupling and Horner–Wadsworth–Emmons polymerization. The effect of the varying donor strength of OPV and BBO on the photophysical, electrochemical, and semiconducting properties of the polymers was investigated. Absorption and emission spectra recorded for dilute chloroform solution and thin film showed increased intramolecular charge transfer for NDI-alt-OPV polymer compared to NDI-alt-BBO polymer. Cyclic voltammetry studies along with DFT (density functional theory) studies at the B3LYP/6-31g* level gave insight into the energy level (HOMO/LUMO) and molecular orientation of donor and acceptor along the polymer backbone. NDI-alt-OPV polymer exhibited rigid coplanar structure with extended π-conjugation which induced backbone planarity and crystallinity to the polymer. The inherent poor solubility of the NDI-alt-BBO prevented further device characterization of this polymer. Random copolymer having maximum 30% incorporation of BBO comonomer in NDI-r-OPV/BBO was found to be soluble for further characterization. Compared to NDI-alt-OPV, lowering of both energy levels LUMO (∼0.2 eV) and HOMO (∼0.5 eV) was observed for both NDI-alt-BBO and the NDI-r-OPV/BBO. Bottom gate–top contact organic field effect transistors (OFETs) of NDI-alt-OPV exhibited balanced ambipolar charge transport with average electron and hole mobility of 3.09 × 10–3 cm2 V–1 s–1 and 2.1 × 10–3 cm2 V–1 s–1, respectively, whereas the random copolymer incorporating both OPV and BBO units NDI-r-OPV/BBO showed dominant n-type charge transport with moderate 4 × 10–4 cm2 V–1 s–1 average electron mobility. The present work thus highlights the structure–property relationship and the electronic tunability required in this class of NDI-based polymers to produce ambipolar transistors.

1 aKolhe, Nagesh, B.1 aAshar, A., Z.1 aNarayan, K., S.1 aAsha, S., K. uhttp://library.ncl.res.in/content/naphthalene-diimide-copolymers-oligop-phenylenevinylene-and-benzobisoxazole-balanced02107nas a2200181 4500008004100000022001400041245012400055210006900179260000800248300001200256490000700268520145700275100002001732700001501752700002401767700001701791856011701808 2018 eng d a0024-929700aNaphthalene diimide copolymers by direct arylation polycondensation as highly stable supercapacitor electrode materials0 aNaphthalene diimide copolymers by direct arylation polycondensat cFEB a954-9650 v513 a

Conjugated donor-acceptor copolymers based on naphthalene diimide (NDI) as acceptor and thiopheneterminated oligophenylenevinylene as donor moieties (P-1 and P-2, respectively) were synthesized using the direct (hetero) arylation (DHAP) polymerization route. Nitrile groups were introduced at the vinylene linkage in one copolymer (P-2) to fine-tune its electrochemical properties. Both polymers show) pi-pi* transition in the 300-480 nm region and intramolecular charge transfer (ICT) from thiophene to NDI in the 500-800 nm region in the absorption spectra. P-2 exhibits a blue-shifted intramolecular charge transfer (ICT) band in the absorption spectrum as well as a lower reduction potential in the cyclic voltammogram compared to the analogous polymer without the nitrile substitution (P-1). The two polymers were evaluated as type III supercapacitor materials by preparing composite electrodes with carbon nanotubes (CNTs) and employing 0.5 M H2SO4 as the electrolyte. Their performance was compared with that of P(NDI2OD-T2) as a reference polymer. The polymer P-2 based supercapacitor exhibits a specific capacitance of 124 F/g with excellent stability up to 5000 cycles with almost 100% retention of the initial capacitance in the potential window of -0.7 to 0.5 V. Compared to P-2, P-1 exhibits a specific capacitance of 84 F/g, while the corresponding value for the reference polymer P(NDI2OD-T2) is 61 F/g under identical conditions.

1 aSharma, Sandeep1 aSoni, Roby1 aKurungot, Sreekumar1 aAsha, S., K. uhttp://library.ncl.res.in/content/naphthalene-diimide-copolymers-direct-arylation-polycondensation-highly-stable