02438nas a2200265   4500008004100000022001400041245012600055210006900181260007100250300001400321490000600335520144400341653001801785653001301803653003601816653002701852653002001879653001901899100002901918700002501947700001901972700002001991700003002011856013102041       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<p>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.</p>10ahole mobility10ai-indigo10aorganic field effect transistor10aquadrupole interaction10asmall molecules10atriphenylamine1 aDharmapurikar, Satej, S.1 aArulkashmir, Arulraj1 aDas, Chayanika1 aMuddellu, Pooja1 aKrishnamoorthy, Kothandam  uhttp://library.ncl.res.in/content/enhanced-hole-carrier-transport-due-increased-intermolecular-contacts-small-molecule-based-002117nas a2200301   4500008004100000022001400041245011200055210006900167260000900236300001400245490000600259520110900265653002601374653002901400653001801429653001501447653001901462100001801481700002801499700002201527700002101549700002101570700002101591700002201612700003001634700002301664856012801687       2020                        eng d  a2196-021600aEffect of aromatic rings and substituent on the performance of lithium batteries with rylene imide cathodes0 aEffect of aromatic rings and substituent on the performance of l  cMAR   a1160-11650 v73 a<p>Rylene imides (RIs) are attractive organic battery materials because of the inherent modularity of the molecules. While strong aggregation of RIs is disadvantageous for fast lithium-ion transport in the organic active material, decreasing the solubility of the RIs in battery electrolytes is essential to avoid performance fading. Therefore, the design and synthesis of RIs for lithium batteries is a non-trivial task that must, among other considerations, balance lithium-ion transport in the solid material vs. low solubility by controlling aggregation and packing. We have chosen triphenylamine (TPA) as a substituent which disrupts the aggregation but maintains a low solubility due to increased aromaticity of TPA. We have synthesized three RIs with one, two, and four aromatic units in the core. All of them showed stable specific capacity over 300 charge-discharge cycles. The batteries also showed specific capacities close to their theoretical capacities with 97-99 % coulombic efficiency. The maximum specific energy and specific power were 197 mWh g(-1) and 37 mW g(-1), respectively.</p>
10alithium-ion batteries10aorganic cathode material10arylene imides10asolubility10atriphenylamine1 aAher, Jagdish1 aGraefenstein, Alexander1 aDeshmukh, Gunvant1 aSubramani, Kumar1 aKrueger, Bastian1 aHaensch, Mareike1 aSchwenzel, Julian1 aKrishnamoorthy, Kothandam1 aWittstock, Gunther  uhttp://library.ncl.res.in/content/effect-aromatic-rings-and-substituent-performance-lithium-batteries-rylene-imide-cathodes