Giant spin pumping at the ferromagnet (permalloy) – organic semiconductor (perylene diimide) interface

Pure spin current based devices have attracted great interest in recent days. Spin current injection into non-magnetic materials is essential for the design and development of such pure spin current based devices. In this context, organic semiconductors (OSCs) can be potential non-magnetic materials over widely explored heavy metals. This is due to the relatively low spin–orbit coupling of OSCs, which is essential to host the spin current with a large spin diffusion length and long spin-relaxation time. This research work demonstrates the harvesting of spin currents at the perylene diimide (PDI)/permalloy (Py) based OSC interface. The observed high linewidth broadening of 2.18 mT from the ferromagnetic resonance spectra indicates the presence of giant spin pumping from Py to PDI. The resultant spin-mixing conductance, 1.54 × 10¹⁸ m⁻² quantifies the amount of spin current injected from Py to PDI, which is in a similar range to ferromagnet/heavy metals.

The spin injection from permalloy into an adjacent perylene diimide (PDI) layer is demonstrated via ferromagnetic resonance associated linewidth broadening. The spin mixing conductance is found to be 1.54×10¹⁸ m⁻² in a similar range to FM/heavy metal.     

The morphologies and fluorescence quantum yields of perylene diimide dye-doped PS and PHVB microspheres

Aggregation and continuous π-stacking have been the major obstacles hindering the fluorescence (FL) quantum yield (Φ_F) of perylene diimide (PDI) derivatives in the condensed phase. To prepare polymer microspheres with nearly unity Φ_F, in this work a POSS functionalized PDI derivative, POSS–PDI–POSS (PPP), was applied as the red fluorophore of poly(3-hydroxylbutyrate-co-3-hydroxyvalerate) (PHBV) and polystyrene (PS) microspheres. The electrosprayed PPP/PHBV and PPP/PS microspheres have unique hollow structures. Moreover, they show bright red FL under a fluorescence microscope. A photophysical study of the microspheres indicates a significant role of the polymer matrix in disrupting the aggregation state and the Φ_F of the embedded PPP fluorophore. Both the PPP/PHBV and the PPP/PS microspheres show higher Φ_F than most PDI materials in the condensed phase. The PPP/PHBV microspheres show Φ_F of 28%, whereas the PPP/PS microspheres give nearly unity Φ_F.

A POSS functionalized perylene diimide (PDI) derivative, PPP, is applied to polymer microspheres as a red fluorophore. Hollow PPP/polystyrene microspheres show a fluorescence quantum yield (Φ_F) of nearly unity.     

Functionalization and metathesis polymerization induced self-assembly of an alternating copolymer into giant vesicles

A facile fabrication of spherical vesicles and micelles by acyclic diene metathesis (ADMET) polymerization and alternative metathesis polymerization (ALTMET) was investigated. We utilize fluorine (FL) and perylene diimide-based (PDI) α,ω-dienes and α,ω-diacrylates to provide a series of homopolymers and alternating copolymers. When using α,ω-dienes as model monomers, TEM measurement indicates that the aromatic FL and PDI building block induced polymers to generate medium-sized (30–50 nm and 90–120 nm, respectively) micelles and vesicles. It was amazing that alternating copolymers derived from PDI α,ω-dienes and FL α,ω-diacrylates spontaneously form giant vesicles with sizes in the range of 0.7 μm to 2.5 μm. The controlled self-assembly of the organic polymer mediated by ADMET and ALTMET techniques avoided extremely annoying post treatment. Therefore, this work establishes a new, versatile synthetic strategy to create nanoparticles having tunable morphologies with potential application as molecular payload delivery vehicles.

Fluorine (FL) and perylene diimide-based (PDI) α,ω-dienes and α,ω-diacrylates were used to synthesise a series of homopolymers and alternating copolymers and provide spherical vesicles and micelles by metathesis polymerization.     

Progress in the synthesis of imide-based N-type polymer semiconductor materials

Based on the development situation and challenge of organic photovoltaics (OPVs) and organic field-effect transistors (OFETs), it is necessary to develop N-type polymer building blocks with specific structures and performance. After decades of development, some excellent polymer receptor building blocks have been developed to construct N-type organic semiconductors, which have been applied in OFETs and OPVs. In this paper, four kinds of imide (bisthiophene imide BTI, bisthiazolimide BTz, naphthalimide NDI, and perylene imide PDI)-based N-type polymer semiconductor materials are introduced, and their applications in OFETs and OPVs are analyzed, too. The molecular structure design and the performance of corresponding materials are summarized to provide further guidance and reference for the design and development of high performance N-type polymer semiconductors.

Representative molecular structures of four N-type polymer semiconductors materials (a: N2000; b: PPDI-DTT, c: TBDI-DT and d: PDTzTIT) based on NDI, PDI, BTI and BTzI, respectively.     

Influence of non-covalent interactions in dictating the polarity and mobility of charge carriers in a series of crystalline NDIs: a computational case study

Polycyclic aromatic compounds and their derivatives have emerged as potential molecular entities for air-stable n-type organic semiconductors. In particular, naphthalene diimide (NDI)-derived compounds stand out as one of the most promising classes of molecules that have been studied extensively. There have been a lot of debatable experimental reports on the OFET performance characteristics of some of these materials, which have not yet been resolved completely. Hence, the critical intrinsic aspect of the molecular materials during charge transport in a bulk crystalline state would be essential to categorise the potential candidates. As a case study, in this comprehensive computational approach, we investigated the structural and supramolecular organization in single crystals and the role of those aspects in the bulk carrier transport of a group of selected end-substituted NDI derivatives. A subtle alteration of the end group was observed to result in the modulation of the polarity of charge transport and the charge carrier mobility in the single crystalline state. The disparity is addressed by considering the electronic coupling of the transport states, symmetry of the frontier molecular orbitals and various non-covalent intermolecular interactions. We expect that the present study would benefit towards the rational designing of air-stable n-type organic molecular semiconductors for efficient electronic devices.

Bulk carrier transport properties of a group of selected N-substituted naphthalene diimide derivatives are investigated.     

Effects of mPEG-DSPE/corannulene or perylene nanoparticles on the ovary and oocyte

Corannulene (Cor) is a polycyclic aromatic hydrocarbon (PHA) whose molecular structure is three dimensional with a unique bowl-like structure and surface charge. Perylene (Per) is similar to corannulene, with 20π electrons in its fragrance system, but it is a planar structure. Although scientists in various fields have been extensively investigating corannulene, the toxicological evaluation on organisms and its possible mechanisms remain unclear. Our objective is to investigate the toxic effects of corannulene and perylene on ovaries and oocytes. First, corannulene and perylene were wrapped with 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethyleneglycol)] (mPEG-DSPE) to form mPEG-DSPE/corannulene nanoparticles (mP-D/CoNps) and mPEG-DSPE/perylene nanoparticles (mP-D/PeNps), which enhanced their water solubility and biocompatibility. Then, the toxic effects of mP-D/CoNps or mP-D/PeNps on the quality of mouse oocytes and their possible mechanisms were studied in vivo. Our results indicated that mP-D/CoNps or mP-D/PeNps affected the first polar body extrusion of oocytes, increased the number of primordial follicles in the ovary, altered mitochondrial membrane potentials, induced oxidative stress and led to autophagy and apoptosis.

Corannulene (Cor) is a polycyclic aromatic hydrocarbon (PHA) whose molecular structure is three dimensional with a unique bowl-like structure and surface charge.     

Real roles of perylene diimides for improving photocatalytic activity

Three novel visible-light-driven composite photocatalysts: five-membered O-heterocyclic annulated perylene diimide doped TiO₂ (PDI-1/TiO₂), 1-phenol-N,N′-dicyclohexyl perylene-3,4,9,10-tetracarboxylic diimide doped TiO₂ (PDI-2/TiO₂), and N,N′-dicyclohexyl perylene diimide doped TiO₂ (PDI-3/TiO₂), were synthesized using a hydrothermal synthesis method. The effects of introducing PDIs with different structures into TiO₂ were evaluated by assaying the photodegradation rate of Methylene Blue (MB). The photoactivities of the PDI-1/TiO₂ and PDI-2/TiO₂ catalysts were better than that of PDI-3/TiO₂. This is because the large surface area of PDI-1 nanorods and PDI-2 nanobelts extended the 1D charge carrier channel, which facilitated electron transfer to the TiO₂ surface and improved the photocatalytic activity of the composites. The PDI-1/TiO₂ composite showed the highest photoactivity, and the activity remained at 86.4% after four reuse cycles. The extended π–π stacking of self-assembled PDI-1 and the strong interactions between self-assembled PDI-1 and TiO₂ played significant roles in accelerating charge transfer and decreasing recombination of photogenerated electron–hole pairs. The steric hindrance of the phenoxy substituent at the bay position of PDI-2 prevented the PDI-2 nucleus from contacting TiO₂ and weakened the interaction between PDI-2 and TiO₂, which further resulted in the low photoactivity of PDI-2/TiO₂. This work provides a practical way to improve the performances of traditional organic and inorganic composite photocatalysts.

Three novel visible-light-driven composite photocatalysts were synthesized by hydrothermal method. The effects of introducing PDIs with different structures into TiO₂ were evaluated by assaying the photodegradation rate of methylene blue.     

Factor analysis of the influence of environmental conditions on VOC emissions from medium density fibreboard and the correlation of the factors with fitting parameters

Volatile organic compounds (VOCs) emitting from building materials are one of the main sources of indoor pollution. Environmental factors have obvious effects on VOC emissions from building materials. However, no unified conclusions have been achieved on the influence of relative humidity (RH) and air change rate (ACR), and there is little research on the correlations of RH and ACR with parameters in VOCs emission fitting models. Therefore, factor analysis was applied in this paper to study the influence of RH and ACR on VOCs emissions. Medium density fibreboard pannels with the coating of oil-based paint were applied at four ACR (0.5 h⁻¹, 1.0 h⁻¹, 2.0 h⁻¹, 3.0 h⁻¹) and four RH (20%, 30%, 50%, 70%) conditions in 60 L environmental chambers. Tenax TA tubes were used to collect VOCs and thermal desorption-gas chromatography mass spectrometry was applied to determine the concentrations. The results show that RH influences the initial stage of VOCs emission and has a positive correlation with the emission concentrations. In the later emission stage, RH has no obvious influence on VOCs emissions, while the concentrations of VOCs are inversely proportional to ACR. The parameters in the single exponential model a₁ and b₁ have power-law or polynomial relationships with ACR and RH. ACR has negative correlations with a₁ and positive correlations with b₁, resulting in a negative influence on VOCs emissions, while RH has a complex influence on VOCs emissions. This study elucidated how RH and ACR impact VOCs emissions from oil-based paint coating medium density fibreboard and further influence human health exposure risks, which can then be used to improve indoor air quality.

RH has positive effects on the initial VOC emissions and ACR has negative effects on VOC emissions. a₁ has a power relationship with ACR and a polynomial relationship with RH and b₁ has a polynomial relationship with both ACR and RH.     

Solid-state AIEnh-circularly polarised luminescence of chiral perylene diimide fluorophores

Solid-state organic fluorescent materials are important for the development of electroluminescent sensing devices. Herein, we report that N,N′-bis((R)-1-phenylethyl)perylene-3,4,9,10-tetracarboxylic diimide [(R,R)-BPP] and its antipode [(S,S)-BPP], which contain extended π-electrons through planar perylenes, emit solid-state aggregation-induced-enhanced (AIEnh) circularly polarised luminescence (CPL) in inorganic (KBr) pellets and organic-polymer-film (PMMA- and myo-IPU-film) states; this CPL is difficult to observe in solution. These chiral perylene fluorophores emit AIEnh-CPL with high dissymmetry factors (g_CPL) (up to 2.4 × 10⁻³) and high quantum yields (Φ_F, up to 0.43) in the three solid matrices.

Chiral N,N′-bis(1-phenylethyl)perylene-3,4,9,10-tetracarboxylic acid diimide (BPP) exhibits solid-state aggregation-induced enhanced circularly polarized luminescence (AIEnh-CPL) in KBr, PMMA, and myo-IPU matrices..     

Enhanced Li+ charge storage in naphthalene diimide/vanadium pentoxide intercalates

N,N′-Bis(4-aminophenyl)-1,4,5,8-naphthalene diimide (NDI-ph) was intercalated into lamellar vanadium pentoxide (V₂O₅) in different amounts to prepare hybrid intercalates. The presence of the imide supports the material’s ability to form lithium salts with the structural stabilization of the oxide matrix. This effect is remarkable in charge/discharge cycles in terms of Li⁺ uptake and discharge by the lamellar intercalates, as we could double the ion uptake capacity (1.27 Li⁺ per V₂O₅ unit vs. 0.66 for pure V₂O₅), enhance the chemical reversibility and double the specific charge capacity (188 mA h g⁻¹vs. 98 mA h g⁻¹ for pure V₂O₅) with very small amounts of this imide. This is the first paper dealing with naphthalene diimide intercalates in vanadium pentoxide xerogel for Li⁺ storage.

N,N′-Bis(4-aminophenyl)-1,4,5,8-naphthalene diimide (NDI-ph) was intercalated into lamellar vanadium pentoxide (V₂O₅) in different amounts to prepare hybrid intercalates.     

Fluorescent perylene derivative functionalized titanium oxide gel for sensitive and portable ascorbic acid detection

An inorganic titanium oxide (TiO) gel sensor was demonstrated for convenient detection of ascorbic acid (AA). It is composed of TiO (PI–TiO) functionalized with a perylene diimide derivative containing carboxylic groups as a new soft dopant material. A traditional solvothermal reaction is adopted to prepare the PI–TiO composite, which exhibits a different spectrum according to the reaction time. The final gel possesses a strong chelating affinity with AA molecules, in which phenol hydroxyl groups are shown to compete with those already present in PI. We further utilize the functionalized gel to prepare a series of films with a simple and portable AA response. A visual colour variation can be recognized by the naked eye, together with obvious fluorescence changes for selective and sensitive AA detection. Finally, the as-prepared gel film displays good stability and reproducibility for real sample responses with satisfying results.

A fluorescent inorganic titanium oxide gel sensor was prepared from perylene diimide functionalized composite materials, and applied for sensitive and portable ascorbic acid detection.     

Copper oxide integrated perylene diimide self-assembled graphitic pencil for robust non-enzymatic dopamine detection

Exploring a robust, extremely sensitive, cost-effective and reliable assay platform for the precise analysis of dopamine (DA) has become a big challenge predominantly at the clinical level. To participate in this quest, herein, we fabricated a perylene diimide (PDI) self-assembled graphitic surface of the graphitic pencil electrode (GPE) anchored copper oxide (CuO). The self-assembled N-rich PDI led to the fast movement of ions by decreasing the bandgap and improved the electron transport kinetics with more exposed catalytic active sites, thus resulting in the robust electrochemical sensing of DA. The designed sensor exhibited good sensitivity (4 μM⁻¹ cm⁻²), high structural stability, repeatability and excellent reproducibility with an RSD value of 2.9%. Moreover, the developed system showed a wide linear range (5 μM to 500 μM) and reliable selectivity even in the presence of co-existing interferants, such as ascorbic acid and uric acid. The fabricated nanohybrid was eventually employed to analyze DA in spiked physiological fluids and provided satisfactory recoveries. The designed PDI-CuO based interface also showed a very low detection limit of 6 nM (S/N = 3), consequently confirming its suitability for clinical and biological applications.

Exploring a robust, extremely sensitive, cost-effective and reliable assay platform for the precise analysis of dopamine (DA) has become a big challenge predominantly at the clinical level.     

Single-pot tandem oxidative/C–H modification amidation process using ultrasmall PdNP-encapsulated porous organosilica nanotubes

Herein, we studied a single-pot method with a dual catalysis process towards the conversion of primary aromatic alcohols to amides using ultrasmall Pd_NPs of controlled uniform size (1.8 nm) inside hybrid mesoporous organosilica nanotubes (MO-NTs). The catalyst exhibited excellent performance in water under mild conditions and showed high stability. The catalytic activity towards the tandem oxidation of alcohols in the presence of amine salts and H₂O₂ to their corresponding amides without producing byproducts was evaluated, and high yields were obtained for all products. The structure of the organosilica nanotubes containing palladium nanoparticles was investigated using various characterization techniques such as XRD, TEM, BET, solid-state ²⁹Si NMR and solid-state ¹³C CP MAS NMR. Catalyst recycling tests showed that the catalytic power of PdNPs@B-SNTs was preserved after 8 cycles and a slight decrease in catalyst activity was observed.

Herein, we studied a single-pot method with a dual catalysis process towards the conversion of primary aromatic alcohols to amides using ultrasmall Pd_NPs of controlled uniform size (1.8 nm) inside hybrid mesoporous organosilica nanotubes (MO-NTs).     

Progress in perylene diimides for organic solar cell applications

Compared to fullerene materials, non-fullerene acceptor materials have in recent years been more widely used in organic solar cell devices due to their optical properties and due to the ease of carrying out syntheses to tune their electronic energy levels. Non-fullerene acceptors constitute a major focus of research in the development of bulk-heterojunction organic solar cells. Recent developments have yielded increased power conversion efficiency (PCE) levels for non-fullerene acceptor materials, with the PCE levels now shown to exceed 20%. Perylene diimide (PDI), a non-fullerene acceptor material, has been widely studied because of its good transmission capacity and strong electron affinity. This paper summarizes the application of PDI molecules as acceptor materials in organic solar cells in recent years, detailing the strategies and approaches of molecular design and their application effects.

This paper summarizes the application of PDI molecules in organic solar cells in recent years, detailing the strategies and approaches of molecular design and their application effects.     

Arenium cation or radical cation? An insight into the cyclodehydrogenation reaction of 2-substituted binaphthyls mediated by Lewis acids

Perylene and its derivatives are some of the most interesting chromophores in the field of molecular design. One of the most employed methodologies for their synthesis is the cyclodehydrogenation of binaphthyls mediated by Lewis acids. In this article, we investigated the cyclodehydrogenation reaction of 2-substituted binaphthyls to afford the bay-substituted perylene. By using AlCl₃ as a Lewis acid and high temperatures (the Scholl reaction), two new products bearing NH₂ and N(CH₃)₂ groups at position 2 of the perylene ring were synthesized. Under these conditions, we were also able to obtain terrylene from ternaphthalene in 38% yield after two cyclodehydrogenation reactions in a single step. The attempts to promote the formation of a radical cation (necessary intermediary for the oxidative aromatic coupling mechanism) by using FeCl₃ or a strong oxidant like 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) did not yield the expected products. DFT calculations suggested that the lack of reaction for oxidative aromatic coupling is caused by the difference between the oxidation potentials of the donor/acceptor couple. In the case of the Scholl reaction, the regiochemistry involved in the formation of the σ-complex together with the activation energy of the C–C coupling reaction helped to explain the differences in the reactivity of the different substrates studied.

Cyclodehydrogenation reactions of 2-substituted binaphthyls induced by a Lewis acid. Synthesis and theoretical studies of the reaction mechanisms.     

Immobilized TiO2 nanoparticles on carbon nanotubes: an efficient heterogeneous catalyst for the synthesis of chromeno[b]pyridine derivatives under ultrasonic irradiation

A new protocol for the synthesis of chromeno[b]pyridine derivatives is described via a three-component reaction of 4-aminocoumarin, aromatic aldehydes and malononitrile catalyzed by TiO₂ nanoparticles immobilized on carbon nanotubes (TiO₂-CNTs) as an efficient heterogeneous catalyst under ultrasonic irradiation in water. The sustainable and economic benefits of the protocol are the high yields of products, short reaction time, simple work-up procedure, and use of a non-toxic and reusable catalyst.

A new synthesis of chromeno[b]pyridines is described via reaction of 4-aminocoumarin, aromatic aldehydes and malononitrile catalyzed by TiO₂ nanoparticles immobilized on CNTs as an efficient heterogeneous catalyst under ultrasonic irradiation.     

Mechanistic insight into the non-hydrolytic sol–gel process of tellurite glass films to attain a high transmission

The development of amorphous films with a wide transmission window and high refractive index is of growing significance due to the strong demand of integrating functional nanoparticles for the next-generation hybrid optoelectronic films. High-index TeO₂-based glass films made via the sol–gel process are particularly suitable as their low temperature preparation process promises high compatibility with a large variety of nanoparticles and substrates that suffer from low thermal stability. However, due to the lack of in-depth understanding of the mechanisms of the formation of undesired metallic-Te (highly absorbing species) in the films, the preparation of high-transmission TeO₂-based sol–gel films has been severely hampered. Here, by gaining insight into the mechanistic chemistry of metallic-Te formation at different stages during the non-hydrolytic sol–gel process, we identify the chemical route to prevent the generation of metallic-Te in a TeO₂-based film. The as-prepared TeO₂-based film exhibits a high transmission that is close to the theoretical limit. This opens up a new avenue for advancing the performance of hybrid optoelectronic films via incorporating a large variety of unique nanoparticles.

This work develops a high-transparency amorphous film with a wide transmission window and high refractive index, which can potentially meet the strong demand of integrating functional nanoparticles for the next-generation hybrid optoelectronic films.     

The synthesis of monodispersed M-CeO2/SiO2 nanoparticles and formation of UV absorption coatings with them

CeO₂/polymer nanoparticles have drawn considerable attention for their excellent UV absorption properties. However, many challenges still exist in the successful incorporation of ceria into the polymer matrix for the easy agglomeration and photocatalytic activity of CeO₂ nanoparticles. Herein, we address these issues by constructing three-layer structured nanoparticles (M-CeO₂@SiO₂) and incorporating them into a polymer matrix through a mini-emulsion polymerization process. During this process, small-sized nano-ceria became uniformly anchored on the surfaces of monodisperse silica particles first, and then the particles were coated with an MPS/SiO₂ shield. The morphology and dispersion of the nanoparticles were investigated using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The performance of the hybrid films was characterized using UV-vis absorption spectroscopy (UV-vis) and water contact angle (WCA) measurements. Results showed that the M-CeO₂@SiO₂ nanoparticles exhibited a three-layer structure with a mean diameter of 360 nm, and they possess good compatibility with acrylic monomers. After the addition of M-CeO₂@SiO₂, hybrid films exhibited enhanced UV absorption capacity as expected, accompanied by an obvious improvement in hydrophobicity (the water contact angle increased from 84.2° to 98.2°). The results showed that the hybrid films containing M-CeO₂@SiO₂ particles possess better global performance as compared with those containing no particles.

Herein, we report the synthesis of monodispersed M-CeO₂/SiO₂ nanoparticles and their use in the construction of a UV absorption coating.     

Visible-light-driven CO2 reduction on dye-sensitized NiO photocathodes decorated with palladium nanoparticles

The thin-layer-stacked dye-sensitized NiO photocathodes decorated with palladium nanoparticles (nPd) can be used for the visible-light-driven selective reduction of CO₂, mostly to CO, at potentials starting as low as 0 V vs. RHE (compared to −0.6 V in the dark for electrocatalysis). The photosensitization of NiO by the organic dye P1, with a surface coverage of 1.5 × 10⁻⁸ mol cm⁻², allows the hybrid material to absorb light in the 400–650 nm range. In addition, it improves the stability and the catalytic activity of the final material decorated with palladium nanoparticles (nPd). The resulting multi-layered-type photocathode operates according to the electron-transfer-cascade mechanism. On the one hand, the photosensitizer P1 plays a central role as it generates excited-state electrons and transfers them to nPd, thus producing the catalytically active hydride material PdH_x. On the other hand, the dispersed nPd, absorb/adsorb hydrogen and accumulate electrons, thus easing the reductive electrocatalysis process by further driving the separation of charges at the photoelectrochemical interface. Surface analysis, morphology, and roughness have been assessed using SEM, EDS, and AFM imaging. Both conventional electrochemical and photoelectrochemical experiments have been performed to confirm the catalytic activity of hybrid photocathodes toward the CO₂ reduction. The recorded cathodic photocurrents have been found to be dependent on the loading of Pd nanoparticles. A sufficient amount of loaded catalyst facilitates the electron transfer cascade, making the amount of dye grafted at the surface of the electrode the limiting parameter in catalysis. The formation of CO as the main reaction product is postulated, though the formation of traces of other small organic molecules (e.g. methanol) cannot be excluded.

(A) Cross-section view of the stack of active layers constituting a hybrid photocathode for CO₂ reduction. (B) Structure of dye P1 sensitizing the NiO semiconductor. (C) Energy-level matching between components of the modified photocathode.     

Realization of multi-configurable logic gate behaviour on fluorescence switching signalling of naphthalene diimide congeners

Organic entities like suitably functionalized naphthalene diimide (NDI) exhibited logical behaviours in response to various external stimuli and can be used to develop digital logic operations. The present findings include utilization of two congeners of NDI i.e., N1 and N2 for the successive turning ON/OFF of fluorescence with inclusion of acid and base. The recognition of the switching phenomenon of the probes N1 and N2 are applied to construct fundamental digital logic gates such as NOT, YES, IMPLICATION, INHIBIT, etc. The inputs to each of the logic gates are defined by the presence or absence of acid and base. Accordingly, the outputs generated from the gates are in the form of fluorescence ON or OFF status denoted by “1” and “0” respectively. Likewise, we have adopted Boolean algebra and its associated De-Morgan''s theorem to build the combined logic gates such as XOR and XNOR gates. The proposed logic gates are validated by the optical behaviour of the congeners N1 and N2 in response to acid as well as base and the experimental results are confirmed by the theoretical predictions. The proposed work can have potential applications in next-generation logic based analytical applications.

The implementation of functional congeners of naphthalene diimide experiencing fluorescence ON/OFF switching signalling in response to external stimuli, is suitably realized to construct multi-configurable molecular logic gates.