1088205-02-0Relevant articles and documents
Intersystem Crossing in Naphthalenediimide–Oxoverdazyl Dyads: Synthesis and Study of the Photophysical Properties
Hussain, Mushraf,Taddei, Maria,Bussotti, Laura,Foggi, Paolo,Zhao, Jianzhang,Liu, Qingyun,Di Donato, Mariangela
, p. 15615 - 15627 (2019)
Oxoverdazyl (Vz) radical units were covalently linked to the naphthalenediimide (NDI) chromophore to study the effect of the radical on the photophysical properties, especially the radical enhanced intersystem crossing (REISC), which is a promising approach to develop heavy-atom-free triplet photosensitizers. Rigid phenyl or ethynylphenyl linkers between the two moieties were used, thus REISC and formation of doublet (D1, total spin quantum number S=1/2) and quartet states (Q1, S=3/2) are anticipated. The photophysical properties of the dyads were studied with steady-state and femtosecond/nanosecond transient absorption (TA) spectroscopies and DFT computations. Femtosecond transient absorption spectra show a fast electron transfer (1→D0 decay, and the slow decay component (2.0 μs; 20 %) to the Q1→D0 ISC. DFT computations indicated ferromagnetic interactions between the radical and chromophore (J=0.07–0.13 eV). Reversible formation of the radical anion of the NDI moiety by photoreduction of the radical-NDI dyads in the presence of sacrificial electron donor triethanolamine (TEOA) is achieved. This work is useful for design of new triplet photosensitizers based on the REISC effect.
Tuning the optoelectronic properties of core-substituted naphthalene diimides by the selective conversion of imides to monothioimides
Etheridge,Fernando,Golen,Rheingold,Sauve
, p. 46534 - 46539 (2015)
Selective sulfur substitution of the distal carbonyls of a core-substituted naphthalene diimide was obtained when a combination of core and imide substituents were used. The substituents appear to inhibit thionation of the proximal carbonyl by steric hindrance. Each thionation caused a 50 nm bathochromic shift of the visible absorption band and an anodic shift of the reduction potentials. The dithionated compound has a λmax in the near-IR at 733 nm and an optical gap of 1.59 eV, which is unusually low for this type of molecule. Thionation of carbonyls offers a useful avenue for tuning optoelectronic properties of NDI-based materials.
Influences of the number of 2-ethylhexylamine chain substituents on electron transport characteristics of core-substituted naphthalene diimide analogues
Birajdar, Shailesh S.,Naqvi, Samya,More, Kerba S.,Puyad, Avinash L.,Kumar, Rachana,Bhosale, Sidhanath V.,Bhosale, Sheshanath V.
, p. 1590 - 1600 (2021)
We designed and synthesized a series of naphthalenediimide (NDI) derivatives through core-substitution (coded as cNDI) with various number of 2-ethyl-hexylamine (EHA) chains at different positions. The molecular structure of cNDI derivatives such as cNDI-1EHA, cNDI-2EHA, cNDI-3EHA and cNDI-4EHA bearing one, two, three and four 2-ethyl-hexylamine chains, respectively, was confirmed by different spectroscopic techniques such as FTIR, 1H-NMR, 13C-NMR spectroscopy and mass spectrometry. Interestingly, the incorporation of different numbers of 2-ethyl-hexylamine on electron-deficient cNDI yields diverse photophysical and electrochemical properties. The change in the number of alkyl chains on the NDI core significantly influences the redox properties and the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels. The changes in the morphology of the spin-coated films before and after annealing are reorganized differently depending on the number of 2-ethyl-hexylamine topology proved by scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. The electron mobility of cNDIs was examined by following the standard protocol of the space-charge limiting current (SCLC) method. The NDI derivatives bearing various number of 2-ethyl-hexylamine chains at the NDI core after thermal treatment at 170 °C exhibited very good electron mobility of the order of 10-6 to 10-4 cm2 V-1 s-1. The observed electron mobility trends depend not only on the number of 2-ethyl-hexylamine substituents but also on the changes in thin-film morphology.
Cooperative Supramolecular Block Copolymerization for the Synthesis of Functional Axial Organic Heterostructures
Agasti, Sarit S.,Behera, Tejmani,Capelli, Riccardo,Chowdhury, Arindam,Empereur-Mot, Charly,George, Subi J.,Mahato, Jaladhar,Pavan, Giovanni M.,Sarkar, Aritra,Sasmal, Ranjan
, p. 11528 - 11539 (2020)
Supramolecular block copolymerzation with optically or electronically complementary monomers provides an attractive bottom-up approach for the non-covalent synthesis of nascent axial organic heterostructures, which promises to deliver useful applications in energy conversion, optoelectronics, and catalysis. However, the synthesis of supramolecular block copolymers (BCPs) constitutes a significant challenge due to the exchange dynamics of non-covalently bound monomers and hence requires fine microstructure control. Furthermore, temporal stability of the segmented microstructure is a prerequisite to explore the applications of functional supramolecular BCPs. Herein, we report the cooperative supramolecular block copolymerization of fluorescent monomers in solution under thermodynamic control for the synthesis of axial organic heterostructures with light-harvesting properties. The fluorescent nature of the core-substituted naphthalene diimide (cNDI) monomers enables a detailed spectroscopic probing during the supramolecular block copolymerization process to unravel a nucleation-growth mechanism, similar to that of chain copolymerization for covalent block copolymers. Structured illumination microscopy (SIM) imaging of BCP chains characterizes the segmented microstructure and also allows size distribution analysis to reveal the narrow polydispersity (polydispersity index (PDI) ≈ 1.1) for the individual block segments. Spectrally resolved fluorescence microscopy on single block copolymerized organic heterostructures shows energy migration and light-harvesting across the interfaces of linearly connected segments. Molecular dynamics and metadynamics simulations provide useful mechanistic insights into the free energy of interaction between the monomers as well as into monomer exchange mechanisms and dynamics, which have a crucial impact on determining the copolymer microstructure. Our comprehensive spectroscopic, microscopic, and computational analyses provide an unambiguous structural, dynamic, and functional characterization of the supramolecular BCPs. The strategy presented here is expected to pave the way for the synthesis of multi-component organic heterostructures for various functions.
Low and High Molecular Mass Dithienopyrrole–Naphthalene Bisimide Donor–Acceptor Compounds: Synthesis, Electrochemical and Spectroelectrochemical Behaviour
Rybakiewicz, Renata,Glowacki, Eric D.,Skorka, Lukasz,Pluczyk, Sandra,Zassowski, Pawel,Apaydin, Dogukan Hazar,Lapkowski, Mieczyslaw,Zagorska, Malgorzata,Pron, Adam
, p. 2839 - 2851 (2017)
Two low molecular weight electroactive donor–acceptor–donor (DAD)-type molecules are reported, namely naphthalene bisimide (NBI) symmetrically core-functionalized with dithienopyrrole (NBI-(DTP)2) and an asymmetric core-functionalized naphthalene bisimide with dithienopyrrole (DTP) substituent on one side and 2-ethylhexylamine on the other side (NBI-DTP-NHEtHex). Both compounds are characterized by low optical bandgaps (1.52 and 1.65 eV, respectively). NBI-(DTP)2undergoes oxidative electropolymerization giving the electroactive polymer of ambipolar character. Its two-step reversible reduction and oxidation is corroborated by complementary EPR and UV/Vis–NIR spectroelectrochemical investigations. The polymer turned out to be electrochemically active not only in aprotic solvents but also in aqueous electrolytes, showing a distinct photocathodic current attributed to proton reduction. Additionally, poly(NBI-(DTP)2) was successfully tested as a photodiode material.
BODIPY-based donor-acceptor π-conjugated alternating copolymers
Popere, Bhooshan C.,Della Pelle, Andrea M.,Thayumanavan
, p. 4767 - 4776 (2011)
Four novel π-conjugated copolymers incorporating 4,4-difluoro-4-borata- 3a-azonia-4a-aza-s-indacene (BODIPY) core as the "donor" and quinoxaline (Qx), 2,1,3-benzothiadiazole (BzT), N,N′-di(2′-ethyl) hexyl-3,4,7,8-naphthalenetetracarboxylic diimide (NDI), and N,N′- di(2′-ethyl)hexyl-3,4,9,10-perylene tetracarboxylic diimide (PDI) as acceptors were designed and synthesized via Sonogashira polymerization. The polymers were characterized by 1H NMR spectroscopy, gel permeation chromatography (GPC), UV-vis absorption spectroscopy, and cyclic voltammetry. Density functional theory (DFT) calculations were performed on polymer repeat units, and the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energy levels were estimated from the optimized geometry using B3LYP functional and 6-311g(d,p) basis set. Copolymers with Qx and BzT possessed HOMO and LUMO energy levels comparable to those of BODIPY homopolymer, while PDI stabilized both HOMO and LUMO levels. Semiconductor behavior of these polymers was estimated in organic thin-film transistors (OTFT). While the homopolymer, Qx, and BzT-based copolymers showed only p-type semiconductor behavior, copolymers with PDI and NDI showed only n-type behavior.
N-Type Water/Alcohol-Soluble Naphthalene Diimide-Based Conjugated Polymers for High-Performance Polymer Solar Cells
Wu, Zhihong,Sun, Chen,Dong, Sheng,Jiang, Xiao-Fang,Wu, Siping,Wu, Hongbin,Yip, Hin-Lap,Huang, Fei,Cao, Yong
, p. 2004 - 2013 (2016)
With the demonstration of small-area, single-junction polymer solar cells (PSCs) with power conversion efficiencies (PCEs) over the 10% performance milestone, the manufacturing of high-performance large-area PSC modules is becoming the most critical issue for commercial applications. However, materials and processes that are optimized for fabricating small-area devices may not be applicable for the production of high-performance large-area PSC modules. One of the challenges is to develop new conductive interfacial materials that can be easily processed with a wide range of thicknesses without significantly affecting the performance of the PSCs. Toward this goal, we report two novel naphthalene diimide-based, self-doped, n-type water/alcohol-soluble conjugated polymers (WSCPs) that can be processed with a broad thickness range of 5 to 100 nm as efficient electron transporting layers (ETLs) for high-performance PSCs. Space charge limited current and electron spin resonance spectroscopy studies confirm that the presence of amine or ammonium bromide groups on the side chains of the WSCP can n-dope PC71BM at the bulk heterojunction (BHJ)/ETL interface, which improves the electron extraction properties at the cathode. In addition, both amino functional groups can induce self-doping to the WSCPs, although by different doping mechanisms, which leads to highly conductive ETLs with reduced ohmic loss for electron transport and extraction. Ultimately, PSCs based on the self-doped WSCP ETLs exhibit significantly improved device performance, yielding PCEs as high as 9.7% and 10.11% for PTB7-Th/PC71BM and PffBT4T-2OD/PC71BM systems, respectively. More importantly, with PffBT4T-2OD/PC71BM BHJ as an active layer, a prominent PCE of over 8% was achieved even when a thick ETL of 100 nm was used. To the best of our knowledge, this is the highest efficiency demonstrated for PSCs with a thick interlayer and light-harvesting layer, which are important criteria for eventually making organic photovoltaic modules based on roll-to-roll coating processes.
Conjugated polymers based on benzodithiophene and arylene imides: Extended absorptions and tunable electrochemical properties
Chen, Jian,Shi, Min-Min,Hu, Xiao-Lian,Wang, Mang,Chen, Hong-Zheng
, p. 2897 - 2902 (2010)
Three novel conjugated polymers have been designed and synthesized via the alternative copolymerization of the electron-donating monomer benzodithiophene (BDT) and three different electron-accepting monomers: perylene diimide (PDI), naphthalene diimide (NDI), and phthalimide (PhI). All obtained copolymers show good solubility in common organic solvents as well as broader absorptions in visible region and narrower optical band gaps compared to homopolymers from BDT units. It is found that the absorptions of the copolymers are red-shifted with increasing the electron-withdrawing ability of the co-monomer. In particular, the absorption edge of P(BDT-NDI) film extends to 760. nm, whereas that of P(BDT-PhI) film is only at 577. nm. Cyclic voltammograms of the three polymers disclose that P(BDT-PDI) and P(BDT-NDI) are typical n-type materials because PDI and NDI are strong electron-accepting groups, while P(BDT-PhI) is a stable p-type material where the weak electron-withdrawing monomer (PhI) is introduced. The results suggest that the absorption range and the electrochemical properties of the conjugated polymers can be tuned by appropriate molecule-tailoring, which will help exploring ideal conducting polymers for potential applications in polymer optoelectronics, especially in polymer solar cells.
Tricomponent Supramolecular Multiblock Copolymers with Tunable Composition via Sequential Seeded Growth
Agasti, Sarit S.,Das, Angshuman,George, Subi J.,Sarkar, Aritra,Sasmal, Ranjan,Venugopal, Akhil
, p. 18209 - 18216 (2021)
Synthesis of supramolecular block co-polymers (BCP) with small monomers and predictive sequence requires elegant molecular design and synthetic strategies. Herein we report the unparalleled synthesis of tri-component supramolecular BCPs with tunable microstructure by a kinetically controlled sequential seeded supramolecular polymerization of fluorescent π-conjugated monomers. Core-substituted naphthalene diimide (cNDI) derivatives with different core substitutions and appended with β-sheet forming peptide side chains provide perfect monomer design with spectral complementarity, pathway complexity and minimal structural mismatch to synthesize and characterize the multi-component BCPs. The distinct fluorescent nature of various cNDI monomers aids the spectroscopic probing of the seeded growth process and the microscopic visualization of resultant supramolecular BCPs using Structured Illumination Microscopy (SIM). Kinetically controlled sequential seeded supramolecular polymerization presented here is reminiscent of the multi-step synthesis of covalent BCPs via living chain polymerization. These findings provide a promising platform for constructing unique functional organic heterostructures for various optoelectronic and catalytic applications.
Broadband visible light-harvesting naphthalenediimide (NDI) triad: Study of the intra-/intermolecular energy/electron transfer and the triplet excited state
Wu, Shuang,Zhong, Fangfang,Zhao, Jianzhang,Guo, Song,Yang, Wenbo,Fyles, Tom
, p. 4787 - 4799 (2015)
A triad based on naphthalenediimides (NDI) was prepared to study the intersystem crossing (ISC), the fluorescence-resonance-energy-transfer (FRET), as well as the photoinduced electron transfer (PET) processes. In the triad, the 2-bromo-6-alkylaminoNDI moiety was used as singlet energy donor and the spin converter, whereas 2,6-dialkylaminoNDI was used as the singlet/triplet energy acceptor. This unique structural protocol and thus alignment of the energy levels ensures the competing ISC and FRET in the triad. The photophysical properties of the triad and the reference compounds were studied with steady-state UV-vis absorption spectra, fluorescence spectra, nanosecond transient absorption spectra, cyclic voltammetry, and DFT/TDDFT calculations. FRET was confirmed with steady-state UV-vis absorption and fluorescence spectroscopy. Intramolecular electron transfer was observed in polar solvents, demonstrated by the quenching of both the fluorescence and triplet state of the energy acceptor. Nanosecond transient absorption spectroscopy shows that the T1 state of the triad is exclusively localized on the 2,6-dialkylaminoNDI moiety in the triad upon selective photoexcitation into the energy donor, which indicates the intramolecular triplet state energy transfer. The intermolecular triplet state energy transfer between the two reference compounds was investigated with nanosecond transient absorption spectroscopy. The photophysical properties were rationalized by TDDFT calculations.
