MIST ER Laboratory

Bologna, Italy

MIST ER Laboratory

Bologna, Italy
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Durso M.,CNR Institute for Organic Syntheses and Photoreactivity | Gentili D.,CNR Institute of Nanostructured Materials | Bettini C.,MIST ER Laboratory | Zanelli A.,CNR Institute for Organic Syntheses and Photoreactivity | And 10 more authors.
Chemical Communications | Year: 2013

The synthesis and characterization of two thieno(bis)imide based n-type semiconductors with electron mobilities of up to 0.3 cm2 V -1 s-1 are described. The relationships between the electronic features of the π-inner core and the functional properties of the new materials are also discussed. © 2013 The Royal Society of Chemistry.


Zambianchi M.,CNR Institute for Organic Syntheses and Photoreactivity | Favaretto L.,CNR Institute for Organic Syntheses and Photoreactivity | Durso M.,CNR Institute for Organic Syntheses and Photoreactivity | Bettini C.,MIST ER Laboratory | And 11 more authors.
Journal of Materials Chemistry C | Year: 2015

2,3-Thieno(bis)imide (N) ended oligomers are emerging as valuable molecular materials for applications in organic electronics. Here, we report the synthesis and characterization of three new 2,3-thieno(bis)imide ended oligothiophenes (T) bearing unsaturated ethylene (E), azomethine (I) and ethinyl (A) inner bridges (NTE, NTI and NTA, respectively). The effect of the unsaturated bridge on the π-conjugation extent, molecular conformation and overall aromaticity is related to the functional optoelectronic and morphological properties and compared to the properties of the linear analogue (NTT) with a bithiophene inner moiety. Optical spectroscopy and cyclovoltammetry analysis show a strong red shift of the absorption and an increased energy band gap on going from NTI and NTE to NTA. The HOMO level decreases in the order NTE > NTI > NTA. Moreover, while the LUMO of NTE and NTA have almost the same energy, NTI has a LUMO energy about 0.1 eV lower, likely due to the electron withdrawing effect of the azomethine moiety. Morphological investigation of solution cast thin deposits shows that the unsaturated bridges promote the formation of concomitant polymorphs with the simultaneous presence of microcrystals with different morphology and fluorescence properties. Moreover, irreversible conversion of one polymorph to the other was achieved by thermal treatments for NTA and NTE and by exploiting this feature, we realized a time temperature integrator (TTI) device based on NTE material. This device allowed to monitor temperature evolutions in the range between RT and 200 °C by means of a red to yellow fluorescence switch that was detectable by optical microscopy. This journal is © The Royal Society of Chemistry 2015.


Melucci M.,CNR Institute for Organic Syntheses and Photoreactivity | Durso M.,CNR Institute for Organic Syntheses and Photoreactivity | Bettini C.,CNR Institute for Organic Syntheses and Photoreactivity | Bettini C.,MIST ER Laboratory | And 12 more authors.
Journal of Materials Chemistry C | Year: 2014

The relationships between the molecular structure, packing modalities, charge mobility and light emission in organic thin films is a highly debated and controversial issue, with both fundamental and technological implications in the field of organic optoelectronics. Thieno(bis)imide (TBI) based molecular semiconductors provide an interesting combination of good processability, tunable self-assembly, ambipolar charge transport and electroluminescence, and are therefore an ideal test base for fundamental studies on the structure-property correlation in multifunctional molecular systems. Herein, we introduce a new class of thieno(bis)imide quaterthiophenes having alkyl side chains of different shapes (linear, cyclic, branched) and lengths (C1-C8). We found that contrarily to what is generally observed in most molecular semiconductors, the length of the alkyl substituent does not affect the optical, self-assembly and charge transport properties of TBI materials. However, different electroluminescence powers are observed by increasing the alkyl side, this suggesting a potential tool for the selective modulation of TBI functionalities. A deep experimental and theoretical investigation on this new family of TBI materials is provided. This journal is © the Partner Organisations 2014.

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