A core-extended naphthalene diimide as a p-channel semiconductor

Abstract

A novel naphthalene diimide with a fully conjugated, extended π-core was synthesized in a one-pot, two-step reaction. This organic semiconductor exhibits ambipolar transport properties with a large hole mobility of 0.56 cm(2) V(-1) s(-1) and a current on/off ratio of 10(6) in bottom-gate, top-contact thin-film transistors prepared by vacuum deposition.

Thiophene-Fused Naphthalene Diimides: New Building Blocks for Electron Deficient π-Functional Materials

“…This in turn affords an opportunity to finely tune the HOMO while keeping the LUMO almost intact or only slightly altered. 35 Among such cNDIs, thiophene-fused ones, 4,5,9,10-naphtho[2,3-b:6,7-b¤]dithiophene diimides (NDTI, 1) 39 and 4,5,8,9-naphtho[2, 3-b]thiophene diimides (NTI, 2, Figure 1), with α-and β-unsubstituted thiophenes, 40 are attractive archetypical structures for electron-deficient building blocks for the following reasons: (i) they have a planar and rigid structure over the whole π framework, beneficial for favorable intermolecular π-π overlap in the solid state and therefore carrier transport, (ii) the vacant thiophene α-positions can be modified and enable further π-extension and incorporation into the backbone structures of conjugated oligomers and polymers while maintaining good coplanarity. Although tetracyano-substituted NDTI derivatives and benzo-annulated NDTIs were reported in 2011 32 and 2013 34 respectively, α-,β-unsubstituted NDTIs have remained unknown until the report of their synthesis and characterization in 2013.…”

“…28, 29 The lateral extension of the π-conjugation system based on NDI, on the other hand, has been examined with the inclusion of fused aromatic rings, such as benzene, 30,31 thiophene, 32 thiazole, 33 benzo[b]thiophene, 34 benzo[b]pyrrole, 35,36 quinoxaline, 37,38 and so on ( Figure 1). This approach, in contrast to the former vertical extension, is an interesting way to control the electronic structure of the resulting core-extended NDI (cNDI) derivatives; the LUMO of the system tends to localize on the NDI skeleton, whereas the highest molecular orbital (HOMO) tends to delocalize in the lateral direction through the naphthalene 2-, 3-, 6-, and 7-carbon atoms.…”

Synthesis and Characterization of Alternating Polymers Incorporating Boron-Chelated Heterochrysene Units

“…In the past decades, π-conjugated derivatives have attracted significant interests in organic light-emitting diodes, field effect transistors, photovoltaic cell and fluorescent probes due to their unique characteristics such as high brightness, tunable emission, stability against photobleaching and high photon-emission rates [1][2][3][4][5][6][7][8]. In the early 1960s, Clar developed the first synthetic acene as a kind of π-conjugated derivative [9][10][11].…”

N,N′-Bis(2-cyclohexylethyl)naphtho[2,3-b:6,7-b′]dithiophene Diimides: Effects of Substituents

“…In contrast to the former vertical π-extension, the latter approach is a promising way of controlling the electronic structure of the resulting core-extended NDI derivatives because the lowest unoccupied molecular orbital (LUMO) of the system tends to localize on the NDI skeleton, i.e., the vertical molecular axis, whereas the highest occupied molecular orbital (HOMO) tends to delocalize in the lateral direction through the naphthalene 2-, 3-, 6-, and 7-carbon atoms. This affords an opportunity to finely tune the HOMO while keeping the LUMO almost intact or only slightly altering it [15]. Naphtho [2,3-b:6,7-b′]dithiophene-4,5,9,10-tetracarboxylic diimide (NDTI, Figure 1d) is an example of core-extended NDI derivatives.…”

“…On the one hand, the optical properties of the rylene diimide-based system can be tuned by the central rylene moiety [5,6], i.e., increasing the number of naphthalene moieties (Figure 1b) can drastically alter the absorption range from ultraviolet to visible and to the infrared region. On the other hand, the lateral extension of the π-conjugation system based on NDI, the smallest rylene diimide molecule, has also been examined by fusing different aromatic rings, such as benzene [7][8][9], thiophene [10], thiazole [11], benzo [b]thiophene [12], quinoxaline [13,14], benzo [b]pyrrole [15], and so on ( Figure 1c). In contrast to the former vertical π-extension, the latter approach is a promising way of controlling the electronic structure of the resulting core-extended NDI derivatives because the lowest unoccupied molecular orbital (LUMO) of the system tends to localize on the NDI skeleton, i.e., the vertical molecular axis, whereas the highest occupied molecular orbital (HOMO) tends to delocalize in the lateral direction through the naphthalene 2-, 3-, 6-, and 7-carbon atoms.…”