02097nas a2200181 4500008004100000245010100041210006900142260000800211300001400219490000600233520141200239100002501651700002601676700002901702700002201731700003001753856013201783 2012 eng d00aSupramolecular interaction facilitated small molecule films for organic field effect transistors0 aSupramolecular interaction facilitated small molecule films for  cAPR a1641-16460 v33 aMetalloporphyrins and metal free porphyrins have been explored as active materials in field effect transistors. Amorphous forms of these porphyrins are preferred over their crystalline analogue due to the ease of solution processability. To achieve solution processability, a metalloporphyrin was anchored on a vinyl polymer by taking advantage of the supramolecular interaction between the metal and the pyridine moiety of the polymer. Non covalent bonding was preferred because it provides an opportunity to better manipulate the polymer's properties compared to its covalent bonding analogue. The binding between the porphyrin and the polymer was optimised in solution and the supramolecular complex was spun on various substrates to form thin films. The porphyrin was found to be uniformly distributed throughout the polymer films contrary to the existing approaches, wherein small molecule phase segregates in the polymer film. Field effect transistors were fabricated using the porphyrin-polymer complex and the device parameters were measured at atmospheric condition. The devices annealed at 80 degrees C showed hole carrier mobility of 2.0 x 10(-4) cm(2) V-1 s(-1) with charge trapping at the dielectric semiconductor interface. Furthermore, the high carrier mobility observed at low temperature annealing makes this supramolecular complex an attractive candidate to explore in flexible substrates.1 aArulkashmir, Arulraj1 aMahale, Rajashree, Y.1 aDharmapurikar, Satej, S.1 aJangid, Manoj, K.1 aKrishnamoorthy, Kothandam uhttps://library.ncl.res.in/content/supramolecular-interaction-facilitated-small-molecule-films-organic-field-effect-transistors02439nas a2200265 4500008004100000022001400041245012600055210006900181260007100250300001400321490000600335520144400341653001801785653001301803653003601816653002701852653002001879653001901899100002901918700002501947700001901972700002001991700003002011856013202041 2013 eng d a1944-824400aEnhanced hole carrier transport due to increased intermolecular contacts in small molecule based field effect transistors0 aEnhanced hole carrier transport due to increased intermolecular  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcAUG a7086-70930 v53 a

Small molecules and oligomers can be synthesized with very high purity and precise molecular weights, but they often do not form uniform thin films while processed from solution. Decreased intermolecular contacts between the small molecules are another disadvantage. To increase the intermolecular contacts in small molecules, we have chosen i-indigo, as one of the conjugated molecular units. The electron poor i-indigo has been connected with electron rich triphenylamine to synthesize a donor-acceptor-donor type small molecule. The propeller shaped triphenylamine helps to increase the solubility of the small molecule as well as isotropic charge transport. The intermolecular spacing between the molecules has been found to be low and did not vary as a function of thermal annealing. This implies that the intermolecular contacts between the small molecules are enhanced, and they do not vary as a function of thermal annealing. Organic field effect transistors (OFET) fabricated using a small molecule exhibited a hole carrier mobility (mu) of 0.3 cm(2)/(V s) before thermal annealing. A marginal increase in mu was observed upon thermal annealing at 150 degrees C, which has been attributed to changes in thin film morphology. The morphology of the thin films plays an important role in charge transport in addition to the intermolecular spacing that can be modulated with a judicious choice of the conjugated molecular unit.

10ahole mobility10ai-indigo10aorganic field effect transistor10aquadrupole interaction10asmall molecules10atriphenylamine1 aDharmapurikar, Satej, S.1 aArulkashmir, Arulraj1 aDas, Chayanika1 aMuddellu, Pooja1 aKrishnamoorthy, Kothandam uhttps://library.ncl.res.in/content/enhanced-hole-carrier-transport-due-increased-intermolecular-contacts-small-molecule-based-001648nas a2200217 4500008004100000022001400041245006800055210006800123260006900191300001200260490000800272520091800280653001801198653001301216653001701229653002201246653001601268100002201284700002901306856009501335 2015 eng d a0925-400500aApproach to modulate the sensing range of molecular transducers0 aApproach to modulate the sensing range of molecular transducers aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcSEP a461-4660 v2163 a

Transduction occurs upon binding of an analyte with a transducer. Specific binding involves the design and synthesis of receptors that is non trivial. Indeed, the task of designing a receptor for the smallest anion fluoride is very challenging. Herein, we take advantage of the basicity of fluoride ions that has affinity toward acidic proton. A commercially available 6-bromoisatin can sense fluoride ion in the concentration range of 0.5-3.9 ppm. Although the sensor is reaction based, the response is rapid. To further increase the linear range, dibromoisoindigo was synthesized. The linear range of this transducer was found to be between 0.5 ppm and 10.4 ppm. The transducer can be regenerated by adding proton source such as trifluoroacetic acid. Thus, transducers with variable sensing range have been designed and synthesized using acid base interaction. (C) 2015 Elsevier B.V. All rights reserved.

10aAcidic proton10aBasicity10aFluoride ion10aReversible sensor10aTransducers1 aJain, Bhanprakash1 aDharmapurikar, Satej, S. uhttps://library.ncl.res.in/content/approach-modulate-sensing-range-molecular-transducers-001448nas a2200169 4500008004100000245011300041210006900154260000800223300001200231490000800243520079400251100002601045700002901071700002601100700002301126856012901149 2017 eng d00aInfluence of thermocleavable functionality on organic field-effect transistor performance of small molecules0 aInfluence of thermocleavable functionality on organic fieldeffec cJUN a139-1450 v6783 aDiketopyrrolopyrrole based donor-acceptor-donor conjugated small molecules using ethylene dioxythiophene as a donor was synthesized. Electron deficient diketopyrrolopyrrole unit was substituted with thermocleavable (tert-butyl acetate) side chains. The thermal treatment of the molecules at 160 degrees C eliminated the tert-butyl ester group results in the formation of corresponding acid. Optical and theoretical studies revealed that the molecules adopted a change in molecular arrangement after thermolysis. The conjugated small molecules possessed p-channel charge transport characteristics in organic field effect transistors. The charge carrier mobility was increased after thermolysis of tert-butyl ester group to 5.07 x 10(-5) cm(2)/Vs. (C) 2017 Elsevier B.V. All rights reserved.1 aMahale, Rajashree, Y.1 aDharmapurikar, Satej, S.1 aChini, Mrinmoy, Kumar1 aVenugopalan, Vijay uhttps://library.ncl.res.in/content/influence-thermocleavable-functionality-organic-field-effect-transistor-performance-small02034nas a2200289 4500008004100000022001400041245010900055210006900164260000800233490000800241520101300249653001001262653008901272653002401361653002101385653001301406653001401419653001901433653001601452653001601468653002601484100002901510700002501539700002601564700002601590856012801616 2017 eng d a0021-899500aSynthesis of amphiphilic isoindigo co-polymers for organic field effect transistors: A comparative study0 aSynthesis of amphiphilic isoindigo copolymers for organic field  cNOV0 v1343 a

In this work, the amphiphilic isoindigo (am-iInd) based conjugated polymers namely poly(am-iInd-DT) and poly(am-iInd-TT) and their regular counterpart poly(reg-iInd-DT) and poly(reg-iInd-TT) were synthesized to compare their opto-electronic and charge transport properties. They were used to fabricate organic field effect transistors. Charge transport properties in conjugated polymers depend upon intermolecular interaction which is strongly affected by the nature of side chains. The amphiphilic nature of the conjugated polymers has little impact on the charge transport properties. The charge carrier mobility of amphiphilic conjugated polymers was comparable with the regular polymers except poly(reg-iInd-DT) which can be correlated by X-ray diffraction and thin film morphology. (c) 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45461.

10aAlkyl10aApplications; Conducting polymers; Copolymers; Optical and Photovoltaic applications10aconjugated polymers10aHigh-performance10amobility10aPackaging10aSemicondoctors10aSide-chains10aSolar-cells10aThin-film Transformer1 aDharmapurikar, Satej, S.1 aArulkashmir, Arulraj1 aMahale, Rajashree, Y.1 aChini, Mrinmoy, Kumar uhttps://library.ncl.res.in/content/synthesis-amphiphilic-isoindigo-co-polymers-organic-field-effect-transistors-comparative01364nas a2200157 4500008004100000245011900041210006900160260000800229300001000237490000800247520074200255100002600997700002901023700002601052856012801078 2018 eng d00aChemical oxidative and solid state synthesis of low molecular weight polymers for organic field effect transistors0 aChemical oxidative and solid state synthesis of low molecular we cMAR a48-540 v6963 aSolution processability of the precursor molecules is a major issue owing to their limited solubility for the synthesis of conjugated polymers. Therefore, we favour the solvent free solid state chemical oxidative polymerization route for the synthesis of diketopyrrolopyrrole (DPP) based donor-acceptor (D-A) type conjugated polymers. D-A type polymer Poly(S-OD-EDOT) which contains DPP coupled with EDOT donor units is synthesized via solid state polymerization method. The polymer is employed as an active layer for organic field-effect transistors to measure charge transport properties. The Polymer shows good hole mobility 3.1 x 10(-2) cm(2) V-1 s(-1), with a on/off ratio of 1.1 x 10(3). (C) 2018 Elsevier B.V. All rights reserved.1 aMahale, Rajashree, Y.1 aDharmapurikar, Satej, S.1 aChini, Mrinmoy, Kumar uhttps://library.ncl.res.in/content/chemical-oxidative-and-solid-state-synthesis-low-molecular-weight-polymers-organic-field02039nas a2200181 4500008004100000245012900041210006900170260000800239300001000247490000800257520133100265100002901596700002801625700002001653700002201673700003001695856013201725 2018 eng d00aDihedral angle control to improve the charge transport properties of conjugated polymers in organic field effect transistors0 aDihedral angle control to improve the charge transport propertie cMAR a51-580 v6953 aDiketopyrrolopyrrole (DPP) and i-Indigo (i-Ind) are two monomers that are widely explored as active materials in organic field effect transistor and solar cells. These two molecules showed impressive charge carrier mobility due to better packing that are facilitated by quadrupoles. We hypothesized that the copolymers of these monomers would also exhibit high charge carrier mobility. However, we envisioned that the dihedral angle at the connecting point between the monomers will play a crucial role in packing as well as charge transport. To understand the impact of dihedral angle on charge transport, we synthesized three copolymers, wherein the DPP was sandwiched between benzenes, thiophenes and furans. The copolymer of i-Indigo and furan comprising DPP showed a band gap of 1.4 eV with a very high dihedral angle of 179 degrees. The polymer was found to pack better and the coherence length was found to be 112 angstrom. The hole carrier mobility of these polymer was found to be highest among the synthesized polymer i. e. 0.01 cm(2)/vs. The copolymer comprising benzene did not transport hole and electrons. The dihedral angle at the connecting point between i and Indigo and benzene DPP was 143 angstrom, which the packing and consequently charge transport properties. (C) 2018 Elsevier B. V. All rights reserved.1 aDharmapurikar, Satej, S.1 aChithiravel, Sundaresan1 aMane, Manoj, V.1 aDeshmukh, Gunvant1 aKrishnamoorthy, Kothandam uhttps://library.ncl.res.in/content/dihedral-angle-control-improve-charge-transport-properties-conjugated-polymers-organic-field01567nas a2200265 4500008004100000022001400041245012800055210006900183260000800252300001100260490000800271520066400279653003100943653001400974653001300988653000901001653002001010100002901030700002701059700001801086700002401104700002101128700002601149856012601175 2021 eng d a0009-261400aSignificance of secondary forces toward improving the charge carrier mobility of Isoindigo based conjugated small molecules0 aSignificance of secondary forces toward improving the charge car cJUL a1386210 v7743 a

The charge carrier mobility of conjugated small molecules (CSMs) depends on the intermolecular interactions and morphology. Herein, we report the synthesis of CSMs having different side chains. Hydrogen bonding, lipophilic imbalance and van der Waals interactions are imparted through the asymmetric substitution of Isoindigo. The secondary forces impact thin film morphology, and charge carrier mobility. The CSMs having van der Waals interaction further shows higher charge carrier mobility as a function of improved morphology, and increased temperature. The highest mobility of 0.15 cm2/Vs has been achieved for CSMs with van der Waals interaction.

10aConjugated small molecules10aIsoindigo10amobility10aOFET10aSecondary force1 aDharmapurikar, Satej, S.1 aKashmir, Arulraj, Arul1 aKumari, Tanya1 aKalalawe, Virbhadra1 aKanetkar, Maruti1 aChini, Mrinmoy, Kumar uhttps://library.ncl.res.in/content/significance-secondary-forces-toward-improving-charge-carrier-mobility-isoindigo-based