Effective interplay of donor and acceptor groups for tuning optoelectronic properties in oligothiophene–naphthalimide assemblies

Abstract

In this work, a series of naphthalimide fused thienopyrazine derivatives was designed, and their synthesis and characterization are reported herein. The interaction of this building block with a donor terthiophene...

Synthesis and electronic properties of nitrogen-doped π-extended polycyclic aromatic dicarboximides with multiple redox processes

“…Thus, the t-butyl substituted pyrene-4,5-dione 1 (Scheme 1) has been obtained from pyrene by following the synthetic procedure previously reported by Harris and coworkers 36 while 1,8-naphthalimide derivatives (2-4, Scheme 1) endowed with 1,2-diketone functionalities and different substituents at imide nitrogen have been obtained by using the four-step reaction sequence from acenaphthene previously developed by our group. [37][38][39][40] In order to synthesize the novel family of electron-acceptor π-extended nine-ring-fused systems, we have used the innovative one-pot condensation method of aromatic 1,2diketones recently developed by Zhao and co-workers. 41,42 Thus, diketones 2-4 were selfcondensed in glacial acetic acid in the presence of an excess of ammonium acetate by heating overnight at 110 °C to yield the target molecules (naft-2-4, Scheme 1) after a purification step.…”

“…The limited solubility of naft-2 in dichloromethane in comparison with the parent naft-3 and naft-4 analogues may be responsible for the formation of supramolecular aggregates. 40 In order to confirm this supramolecular aggregation, dilution experiments were carried out in dichloromethane, as depicted in figure S30. When naft-2 solution is diluted enough, an inversion of the structured bands occurs, 44,45 confirming the presence of supramolecular aggregates in solution at concentrations around 10 -4 M and non-aggregated molecular species in solution at 10 -5 M. This study was also accomplished for naft-3 (Figure S29c, S29d) and naft-4 (Figure S29e, S29f) but, in those cases, the presence of longer alkyl chain or 3,5diisopropylphenyl substituent at the imide position do not allow the formation of supramolecular species in dichloromethane solutions.…”

Photocatalytic degradation of organic pollutants through conjugated poly(azomethine) networks based on terthiophene–naphthalimide assemblies

“…2) reveals the characteristic imide signals of the 1,8-naphthalimide moiety at 164.4 ppm, as well as the signal corresponding to the imine carbon at 154 ppm and a signal at 148 ppm which can be assigned to the aromatic carbon neighbouring the nitrogen of the C]N group. The absence of the sp 2 carbons from the NIP3T2CHO 24 aldehyde functionalities above 180 ppm satisfactorily conrms the condensation between the aldehyde and the amine derivatives.…”

“…Both materials show ambipolar redox behaviour in which the reversible reduction processes are characteristic of the naphthalimide unit, while the oxidation processes can be ascribed to the conjugated oligothiophene moiety. [19][20][21][22]24 For NIP3T-ANW, the rst reversible reduction wave (À1.29 V) is shied to less negative values in comparison with NIP-3T (À1.41 V). On the other hand, the rst oxidation half wave potential for NIP3T is observed at +0.41 V and for NIP3T-ANW at +0.44 V. These shis agree with the electron acceptor ability of the imine linker.…”

“…13 In this respect, molecular and polymeric materials based on the combination of oligothiophene 14,15 and naphthalimide moieties 16,17 connected through conjugated linkers have shown to be very effective in order to efficiently tune their frontier orbital levels and produce tunable organic semiconductors with good charge transport properties. [18][19][20][21][22][23][24] As an example, in Fig. 1 is depicted the structure of NIP-3T, an ambipolar organic semiconductor, for which the one-electron HOMO-LUMO excitation consists of the displacement of the electron density from the HOMO, primarily localized on the oligothiophene fragment, to the LUMO, localized on the naphthalimide unit.…”