Presence Of Electron Donor Research Articles

Synthesis, characterization, anxiolytic and anticonvulsant activity, DFT, molecular docking, DMPK studies of chalcone derived from maleic anhydride

Anxiety typically doesn't cause convulsions, but intense stress can reduce the threshold for convulsive bouts in predisposed individuals. Chalcones are known to act directly on the central nervous system (CNS) and the presence of electron donor and acceptor groups attached to the aromatic rings in various positions can alter the properties of the molecule. Thus, this work investigated the anxiolytic and anticonvulsant potential of the new chalcone derivative (E)-6-(4-((E)-3-(3-nitrophenyl)acryloyl)phenyl)-5-oxohex-2-enoic acid (CAMEL). 1H and 13C NMR and ATR-FTIR analyses helped to determine the molecular structure of this chalcone. The energy gap analysis and the higher hardness values than the softness values confirm the stability of CAMEL, with CGDRs indicating that it is more electrophilic in nature. In relation to its potential anxiolytic effect, the tested dose of 40 mg kg-1 of the derivative showed behavior like Diazepam, with activity via GABAA. In addition, the derivative also exhibited a possible anticonvulsant effect at the dose of 20 mg kg-1, being like Diazepam, showing involvement in stages 2 and 3 of GABAA receptors in this process. Given the anxiolytic and anticonvulsant activity shown in vivo and in silico tests, CAMEL is a promising candidate for the treatment of diseases that affect the CNS.

Reduced sulfur compound formation from a leachate-saturated zone under changing temperature conditions

In the leachate-saturation zone of landfills, sulfate reduction is influenced by temperature and electron donors. This study assessed sulfate reduction behaviors under varied electron donor conditions by establishing multiple temperature variation scenarios based on stable temperature fields within the leachate-saturation zone. The results showed that temperature variations altered the microbial community structure and significantly influenced the sulfate reduction process. A more pronounced effect was observed with a temperature difference of 30 °C compared to one of 10 °C. In addition, sulfate reduction was influenced by the presence of electron donors and acceptors. In the middle and low-temperature regions (35 °C and 25 °C), sulfate reduction reaction of acidic organic matter was more significant, while alcohol and saccharide organic substances were more effective in promoting sulfate reduction at high-temperature regions (55 °C). Notably, a 30 °C temperature difference within the leachate-saturation zone significantly altered the microbial community structure, which influenced the sulfate reduction behavior. In particular, Firmicutes and Synergistota played essential roles in mediating the variance in sulfate reduction efficiency with a 30 °C decrease and 30 °C increase, respectively. The results also revealed that temperature changes within landfills were influenced by leachate migration, therefore, controlling leachate recharge can help prevent secondary risks associated with sulfate reduction processes.

Theoretical Study of Khellin Derivatives as Corrosion Inhibitors Based on Density Functional Theory (DFT)

Theoretical studies of Khellin in the presence of electron donor and electron with-drawing groups as a corrosion inhibitor are investigated using the B3LYP/6-31G (d, p) theory level with Gaussian software. This research focuses on the correlation between corrosion inhibition efficiency (EI%) and quantum chemical parameters such as EHOMO (Highest Occupied Molecular Orbital Energy), ELUMO (Lowest Unoccupied Molecular Orbital Energy), energy gap (∆E), dipole moment (µ), absolute hardness (η), absolute softness (σ), the absolute electronegativity (χ), the fractions of electrons transferred from the inhibitor molecule to the metallic atom (∆N), the electrophilicity index (ω), total energy (ET) and theoretical corrosion inhibition efficiency (EI %). The generated results show that the electron-donating groups increase the corrosion inhibition efficiency of Khellin in the sequence -NH2> -SH> -H> -NCH2> -NO2. The highest corrosion inhibition efficiency obtained about 98.40% proves that NH2-Khellin is the best corrosion inhibitor of iron.

Conductive materials and applied potential to augment methanogenesis for biogas upgradation: Acidogenic synergy, CO2 dynamics and sustainability analysis

Methane (CH4) and carbon dioxide (CO2) make up the majority of the raw biogas produced by anaerobic digestion (AD). Increasing the process intensity by concurrently consuming CO2 in the presence of electron donors will enhance the gross calorific value of the biogas. The use of conductive materials (CM) and an electro-methanogenic (EM) process was evaluated to study carbon conversion efficiency to CH4 with simultaneous biogas upgradation. Five reactors (R1-control; R2-Granular Activated Carbon (GAC); R3- Nano Zero Valent Iron (NZVI); R4- Closed Circuit (CC); R5-Applied Potential (AP)) were operated using glucose as a source of carbon (30 g/L) to relatively examine the sustainable effect of CM and EM on methanogenesis. Higher biogas yield with higher CH4 production and accumulation of acetic acid was observed more in the NZVI system followed by AP, CC, GAC, and Control operation. NZVI supplemented significantly added to biogas upgradation (7.6 L) with a concurrent CO2 decrease (87%) as compared to the GAC (3.868 L, 43%) and EM (AP, 4.89 L, 52%; CC, 4.73 L, 49%) but its sacrificial and oxidation nature offsets its translation potential. The electron flux generated in AP and CC reactors had a strong regulatory effect that increased CO2 conversion and utilization towards CH4 compared to other circumstances. The genus-level metagenomic analysis showed a predominance of Clostridium, Ruminococcus, and Acetobacter species in all the reactors except the control. The life cycle assessment (LCA) analysis depicted that the system variation studied showed relatively low CO2 emission in the test condition with NZVI showing the least emission followed by AP and CC. This work offers a method for improving overall CH4 production while overcoming the constraints in methanogenesis, using the influence of in situ carbon flux making the process sustainable.

Синтез новых S-производных 4-амино-1,3,5-триазин-2-тиона и их исследование методами ЯМР 1Н, 13С и хромато-масс-спектрометрии

4-Amino-1,3,5-triazine-2-thione 1 interacts with allyl bromide, 2-methyl-3-chloro-1-propene, 2,3-dibromopropene-1, prenyl bromide in DMFA/K2CO3 and with cinnamyl chloride, butenyl bromide in DMFA/NaOH to form 4-allylsulfanyl- 2, 4-(2-methylpropene-2-yl)sulfanyl- 3, 4-(2-bromopropene-2-yl)sulfanyl- 4, 4-(2-methylbutene-2-yl)sulfanyl- 5, 4-cinnamylsulfanyl- 6 and 4-(butene-1-yl)sulfanyl-1,3,5-triazine-2-amines 7, respectively. The structure of compounds 2–7 was studied by 1H NMR, as well as of compounds 5 and 7, in their case including 13C NMR; allyl sulfide 2, prenyl sulfide 5 and butenyl sulfide 7 were also studied using chromatography mass spectrometry. In the 1H NMR spectra of compounds 2–7, the weakest field signal in the range of 8.22–8.30 p.p.m. is the signal of the aromatic proton of the triazine cycle, manifested as a singlet. The signals of protons of the S-CH2 group are observed in a strong field – at 3.10–4.19 p.p.m. – depending on the presence of electron donor or electron acceptor groups in the alkenyl fragment. The protons of the =CH2 group are present only in the structure of sulfides 2–4 and 7; they form two signals in the 1H NMR spectra: one signal at 4.85–5.58 p.p.m., the second at 5.03–6.10 p.p.m. In the 13C NMR spectra of prenyl sulfide 5 and butenyl sulfide 7, the carbon atoms of the S-alkenyl groups resonate in the region of strong fields. In the region of weak fields, the signals of aromatic carbon atoms of the 1,3,5-triazine cycle are observed: 182.32–157.95 p.p.m. In the mass spectra of compounds 2, 5 and 7, the characteristic peaks are [M 15]+ and [M-33]+ peaks, the formation of which is associated with the fragmentation of molecular ions undergoing cleavage of the methyl radical and the •SH radical, respectively. The haloalkyl derivative of the heterocyclic series – 2-chloro-1-(2,2,4-trimethyl-4-phenyl-3,4-dihydroquinoline-1(2H)-yl) ethanoate – in reaction with compound 1 has led to the introduction of a new pharmacophore fragment into the simm-triazine molecule, which contributes to the expansion of the spectrum of potential biological activity of its derivatives.

Hybrid CdSe/ZnS Quantum Dot-Gold Nanoparticle Composites Assembled by Click Chemistry: Toward Affordable and Efficient Redox Photocatalysts Working with Visible Light.

A new modular, easy-to-synthesize photocatalyst was prepared by assembling colloidal CdSe/ZnS quantum dots (QD) and gold nanoparticles (AuNP) via their ligands thanks to copper-catalyzed azide to alkyne cycloaddition (CuAAC) click chemistry. The resulting composite (QD-AuNP) photocatalyst was tested with a benchmark photoredox system previously reported by our group, for which QD alone acted as a photocatalyst but with a modest quantum yield (QY = 0.06%) and turnover number (TON = 350 in 3 h) due to poor charge separation. After optimization, the QD-AuNP composites exhibited much improved photocatalytic performances: up to five times higher TON (2600 in 3 h) and up to 24 times faster reaction in the first 10 min of visible irradiation. Such an improvement is attributed to an efficient electron transfer from QD to AuNP in the photoexcited QD-AuNP composites, which ensures a much better charge separation than that in QD alone. This was confirmed by studying both (i) the quenching of the QD photoluminescence during the synthesis of the QD-AuNP composites and (ii) the blue shift of the AuNP plasmon absorption band due to the accumulation of up to 7400 electrons per AuNP in QD-AuNP composites under visible light irradiation in the presence of electron donors.

(Invited) Single Atom Catalysts in Functionalized Carbon Nitride for Efficient Solar CO2 Reduction

Single atom catalysts (SACs) have demonstrated unique properties in a variety of chemical transformations. Using graphitic carbon nitride (C3N4) as a photoactive support, we have prepared different cobalt SACs for use in solar CO2 reduction. Functionalization of C3N4 was carried out to produce well-defined N4 binding sites for cobalt ions. Spectroscopic techniques and computational tools were employed to confirm the structures of the SACs. In these photosynthetic assemblies, C3N4 absorbs visible light and, in the presence of electron donor, transfers electrons to the cobalt sites for CO2-reduction catalysis.

Phenalenone derivatives: The voyage from photosensitizers to push-pull fluorescent molecules

Phenalenone and several phenalenone derivatives have the remarkable capacity to produce singlet oxygen (1O2), via photosensitization, with singlet oxygen quantum yield values close to unity in most solvents. Considerable efforts have been made to obtain phenalenones that red-shifted their absorption but maintaining the high capacity of generation of singlet oxygen.The presence of electron donors on specific positions of the aromatic ring promotes important changes. Herein, with the presence of a dimethylamino substituent in position 3 or 6, we were able to modulate singlet oxygen generation capacity and fluorescence. Both, 3DMAPNF and 6DMAPNF show red-shifted absorption (compared with phenalenone) associated with ππ* transitions. Solvent effect in absorption and emission properties were observed for 6DMAPNF, while that for 3DMAPNF no fluorescence response was observed. Both, show a decrease in singlet oxygen quantum yield with polarity of solvent, always with 3DMAPNF singlet oxygen quantum yield values greater than for 6DMAPN. No singlet oxygen generation was observed for both compounds in H2O.

Cation recognition controlled by protonation or chemical reduction: a computational study.

To control biochemical processes, non-covalent interactions involving cations are activated by protons or electrons. In the present study, the bonding situation between: (i) carboxylic acid or (ii) ferrocene-functionalized crown ether derivatives and cations (Li+, Na+ or K+) has been elucidated and, mainly, tuned by the substitution of hydrogen atoms by electron donor (-NH2) or acceptor (-NO2) groups. The deprotonation of the carboxyl groups improves the interaction with the cations through more favorable electrostatic O⋯cation interactions. Reducing the ferrocene structures favors cationic recognition supported by a less unfavorable iron⋯cation binding. The receptors preferably interact with smaller cations because of more attractive electrostatic and orbital (σ or π) O⋯cation interactions. The presence of electron donor or acceptor groups in the carboxylic acid-functionalized crown ethers promotes less attractive interactions with the cations, mainly due to the less favorable electrostatic O⋯Na+ interactions. The -H → -NH2 substitution in the ferrocene framework favors the cationic recognition. It is based on the strengthening of the electrostatic and σ O⋯Na+ and H2N⋯Na+ bonds. The (i) absence of repulsive electrostatic iron⋯cation interactions, or (ii) the presence of oxygen atoms with large electron density, ensures carboxylic acid-functionalized crown ethers have more favorable interactions with cations than ferrocene compounds. Therefore, this work has demonstrated how cation recognition can be improved by structural changes in carboxylic acid- or ferrocene-functionalized crown ethers and has shown that the carboxylic acid molecules appear to be better candidates for cation recognition than ferrocene derivatives.

Assembling CdSe Quantum Dots into Polymeric Micelles Formed by a Polyethylenimine-Based Amphiphilic Polymer to Enhance Efficiency and Selectivity of CO2-to-CO Photoreduction in Water.

Colloidal quantum dots (QDs) as photocatalysts enable catalysis of CO2-to-CO conversion in the presence of electron donors. The surface and/or interfacial chemical environment of the QDs is essential for the activity and selectivity of the CO2 photoreduction. Various strategies, including exposing active metal sites or anchoring functional organic ligands, have been applied to tune the QDs' surface chemical environment and thus to improve both activity and selectivity of CO2 photoreduction, which occurs at surface of the QDs. However, the efficient and selective photocatalytic CO2 reduction with QD photocatalysts in water is still a challenging task due to low CO2 solubility and robust competing reaction of proton reduction in water. Different from state-of-the-art QDs' surface manipulation, we proposed to ameliorate the interfacial chemical environment of CdSe QDs via assembling the QDs into functional polymeric micelles in water. Herein, CdSe@PEI-LA assemblies were constructed by loading CdSe QDs into polymeric micelles formed by PEI-LA, a polyethylenimine (PEI)-based functional amphiphilic polymer. Due to self-assembly and high CO2 adsorption capacity of PEI-LA in water, the photocatalytic CO2-to-CO conversion efficiency and selectivity of the CdSe@PEI-LA assemblies in water were dramatically improved to 28.0 mmol g-1 and 87.5%, respectively. These two values increased 57 times and 1.5 times, respectively, compared with those of the pristine CdSe QDs. Mechanism studies revealed that CdSe QDs locate in polymeric micelles of high CO2 local concentration and the photoinduced electron transfer from the conduction band of CdSe QDs to Cd-CO2* species is thermodynamically and kinetically improved in the presence of PEI-LA. The CdSe@PEI-LA system represents a successful example of using a functionalized amphiphilic polymer to ameliorate interfacial microenvironments of nanocrystal photocatalysts and realizing efficient and selective CO2 photoreduction in water.

Bioremediation of perfluorochemicals: current state and the way forward.

Perfluorochemicals are widely found in the environment due to their versatile uses and persistent nature. Perfluorochemicals have also been detected in human and animals due to direct or indirect exposures, giving rise to health concerns. This review aims to examine the bioremediation of perfluorochemicals with plants, bacteria and fungi, including their efficiency and limitations. It also aims to propose the future prospects of bioremediation of perfluorochemicals. This review retrieved peer-reviewed journal articles published between 2010 and 2021 from journal databases consisting of Web of Science, Scopus and ScienceDirect. This review shows that multiple Pseudomonas species could degrade perfluorochemicals particularly perfluoroalkyl acids under aerobic condition. Acidimicrobium sp. degraded perfluoroalkyl acids anaerobically in the presence of electron donors. A mixed Pseudomonas culture was more effective than pure cultures. Multiple plants were found to bioconcentrate perfluorochemicals and many demonstrated the ability to hyperaccumulate perfluoroalkyl acids, particularly Festuca rubra, Salix nigra and Betula nigra. Fungal species, particularly Pseudeurotium sp. and Geomyces sp., have the potential to degrade perfluorooctanoic acid or perfluorooctane sulphonic acid. Perfluorochemicals bioremediation could be advanced with identification of more candidate species for bioremediation, optimization of bioremediation conditions, mixed culturing, experiments with environmental media and studies on the biochemical pathways of biotransformation. This review provides comprehensive insight into the efficiency of different bacterial, plant and fungal species in perfluorochemicals bioremediation under different conditions, their limitations and improvement.

Molecular photonics of dienones based on cycloalkanones and their derivatives

Spectroscopic, luminescent, and spectral kinetic properties of cycloalkanone-based dienones and their diethylamino, methylthio, methoxy, and dimethoxy derivatives were studied. The presence of electron-donating substituents results in a red shift of the absorption and fluorescence spectral maxima. A laser pulse causes dienones to undergo intersystem crossing to the underlying triplet state with a lifetime of 0.2–40 μs as well as results in the formation of stable photoproducts capable of photoinduced conversion to the initial dienones. It also gives rise to intermediate products resulting from redox photoreactions of 2,4-bis(4-diethylaminobenzylidene)cyclobutanone in methanol in the presence of electron donor (ascorbic acid) and acceptor (para-nitroacetophenone) compounds.

Electron Transfer-Mediated Photodegradation of Phototoxic Antipsychotic Drug Quetiapine.

Quetiapine (QTP) (1), a psychotropic agent belonging to a chemical class, dibenzothiazepine derivatives, is photosensitive and photolabile. Its photochemistry was studied in the presence of an electron donor N,N-dimethylaniline (DMA) and an electron acceptor 1,4-dicyanobenzene (DCB) under anaerobic conditions. This resulted in photoinduced electron transfer-mediated transformation of drug QTP. Irradiation of Quetiapine (QTP, 1) in the presence of electron donor N,N-dimethylaniline (DMA) under anaerobic conditions in a photochemical reactor afforded one major photoproduct 2 when irradiation of QTP (1) was carried out in the presence of electron acceptor 1,4-dicyanobenzene (DCB) under similar conditions; it afforded 3 as a major photoproduct. These photoproducts were isolated and characterized on the basis of their spectral (IR, UV, 1H NMR, 13C NMR, and mass spectra) studies. The photophysical properties of Quetiapine were also determined in several solvents to investigate the relevance of the molecular structure in their photophysics and consequently in their photochemistry.

Push–pull effect to improve the electronic and optical properties of [7] circulene

AbstractIn the present research, an electron donor‐acceptor (push‐pull) compound based on [7] circulene was studied using density functional theory (DFT) methods. The electron donor and acceptor units were attached to [7] circulene to improve optical properties. It was demonstrated that the band gap of [7]circulene molecule was lowered in electron donor and acceptor groups' presence, also the CN‐CIR7‐NHLi and CF3‐CIR7‐NHLi molecules have the lowest values of the band gap. It was observed that the optical properties of [7]circulene molecule was improved in the presence of electron donor and acceptor units. Between these units, the ‐CN and ‐CF3 as electron acceptors and ‐NHLi substituents as electron donor groups have higher enhancements on optical properties of circulene which is corresponding to the results obtained for energy gap values. The electric dipole moment (𝜇D) and the charge transfer, the electronic properties, polarizability (α), and first hyperpolarizability (β) values of the investigated molecules have been also computed. The results of this research may be useful in designing new materials applicable as improved photosensitizer and photodynamic therapy. All calculations and analyses are carried out by using DFT and dependent time DFT (TD‐DFT) with the B3LYP/6–311G (d,p) model in the Gaussian 09 software packages.

Impact of Skin on the Movement of Nitrates in a Fractured Porous Media: Numerical Investigations

The objective of this study is to analyse the movement of nitrates and dissolved oxygen under the effect of denitrification in a fracture–matrix (F–M) system with skin formation. An implicit finite difference scheme is developed to model the coupled nonlinear partial differential equations. A varying grid is considered at the fracture–skin interface to handle the mass transfer from the fracture to the skin. Bacterial growth is taken into account in the fracture. The growth is affected by the presence of electron donor and electron acceptor. Sensitivity analysis is performed for various fluid flow velocities, skin diffusion coefficients, facture dispersion coefficients, skin porosities (S-P), fracture apertures and rock–matrix (R–M) porosities. Outcomes of this study indicate that the occurrence of skin enriches the transport of nitrates as compared to the absence of skin when denitrification process exists in the system. The low fluid velocity (0.5 m/day) reduces the transport of nitrates to a distance of 5 m, whereas a high fluid velocity (5.0 m/day) triggers up to a distance of 30 m from the fracture inlet. The higher skin diffusion coefficient enhances the migration of nitrates and dissolved oxygen compared to the lower skin diffusion coefficients. The fracture aperture variation from 100 to 500 μm increases the movement of nitrates and dissolved oxygen in fracture from 4 to 10 m, respectively. The variation of S-P from 25 to 75% also follows the same trend. Variation in R–M porosity has an insignificant effect on the movement of nitrates and dissolved oxygen.

Dye-Sensitized Hydrogen Production by Porphyrin/Rh-Doped-Titania-Nanosheet Complex

Abstract Rh-doped titania nanosheet (Rh-TNS, Ti1.78Rh0.02□0.20O40.22− (□: vacant)) was synthesized. The adsorption behavior of Zn(II)TMPyP4+ (Zinc(II) 5,10,15,20-tetrakis(1-methylpyridinium-4-yl)porphyrin) on Rh-TNS was examined. According to the absorption and fluorescence measurements, the efficient fluorescence quenching of Zn(II)TMPyP4+ was observed on Rh-TNS, indicating the electron injection from excited Zn(II)TMPyP4+ to Rh-TNS. By irradiating monochromatic 450 nm light to Rh-TNS/Zn(II)TMPyP4+ complex under the presence of electron donor (ascorbic acid) in water, hydrogen production was observed. The quantum yield for hydrogen production was 5.0% under the optimized condition. The action spectra for hydrogen production well coincided with the absorption spectra of Zn(II)TMPyP4+. These results indicate that a dye-sensitized hydrogen production system where Rh-TNS was used as a host material, an electron acceptor and a catalyst, was established.

Influence of Electron Acceptors and Donors on the Dye-Photosensitized Decomposition of 2-Mercaptobenzothiazole

It has been shown that the quantum yield of the dye-photosensitized decomposition of 2-mercaptobenzothiazole (MBT) in aqueous solutions increases in the case of irradiation of dyes in the presence of electron acceptors. In the presence of electron donors, the quantum yields of the photosensitized decomposition reaction of MBT either remains unchanged or decreases. The donor thiocyanate and iodide ions were the exception; in this case, this was due to the formation of radical anions in the subsequent reactions of iodine and thiocyanate radicals with their anions, respectively. A mechanism has been suggested for the photosensitization of 2-mercaptobenzothiazole decomposition by dyes in the presence of electron acceptors and donors.

Surface Modification of Liposomes Using IR700 Enables Efficient Controlled Contents Release Triggered by Near-IR Light.

Stimuli-responsive liposomes are promising drug carriers for cancer treatment because they enable controlled drug release and the maintenance of desired drug concentrations in tumor tissue. In particular, near-IR (NIR) light is a useful stimulus for triggering drug release from liposomes based on its advantages such as deep tissue penetration and safety. Previously, we found that a silicon phthalocyanine derivative, IR700, conjugated to antibodies, can induce the rupture of the cell membrane following irradiation by NIR light. Based on this finding, we constructed IR700-modified liposomes (IR700 liposomes) and evaluated their drug release properties triggered by NIR light. IR700 liposomes released substantial amounts of encapsulated calcein following irradiation by NIR light. Drug release was substantially suppressed by the addition of sodium azide, suggesting that liposomal membrane permeabilization was mediated by singlet oxygen generated from IR700. Moreover, calcein release from IR700 liposomes triggered by NIR light was promoted under conditions of deoxygenation and the presence of electron donors. Thus, membrane disruption should be induced by the physical change of IR700 from highly hydrophilic to hydrophobic as we previously described, although singlet oxygen can cause a certain level of membrane disruption under normoxia. We also observed that doxorubicin-encapsulated IR700 liposomes exhibited significant cytotoxic effects against CT-26 murine colon carcinoma cells following NIR light exposure. These results indicate that IR700 liposomes can efficiently release anti-cancer drugs following NIR light irradiation even under hypoxic conditions and, therefore, they would be useful for cancer treatment.

Multifunctional naphthalene diimide-based coordination polymers: Photochromism and solventchromism

Naphthalene diimides (NDIs), a class of organic dyes with high photochemical activity and high redox activity, have attracted considerable interest attributing to their photoinduced electron transfer to form stable radical anions upon irradiation in the presence of electron donors. In this study, a naphthalenediimide-based ligand and different aromatic carboxylic acids self-assembled in the presence of zinc ions, forming three novel coordination polymers, [Zn2 (DPMNI) (TPDC)2] (1), [Zn (DPMNI) (BPC)] (2), Zn (DPMNI) (HBTC) (3) (DPMNI = N,N′-bis(4-pyridylmethyl)-1,4,5,8-naphthalene diimide, H2TPDC = thiophene-2,5-dicarboxylic acid, H2BPC = 4,4′-biphenyldicarboxylic acid, H3BTC = 1,3,5-benzenetricarboxylic acid). These coordination polymers characterized by single-crystal X-ray diffraction, elemental analyses, IR spectroscopy, powder X-ray diffraction, and theromgravimetric analysis. Because of the presence of electron-deficient NDI moieties, they exhibit reversible photochromic properties. Furthermore, due to the different π–π interactions between the NDI moieties and aromatic carboxylic acid, compounds 1–3 exhibit different photosensitive properties. Moreover, the solvatochromic behaviour of compound 1 was also investigated.

Photochromic and photocontrolled luminescence properties of two metal-organic frameworks constructed from a naphthalene diimide derivative

Naphthalene diimides (NDIs), a class of organic dyes with high photochemical activity and strong luminescent characteristics, have attracted considerable interest because of their photoinduced electron transfer to form stable radical anions in the presence of electron donors upon irradiation. In this paper, two novel metal–organic frameworks constructed from NDIs chromophoric and aromatic dicarboxylic acids, [Zn2(DPMNI)(NCA)2·0.5DMF] (1), [Zn(DPMNI)(PTA)·DMF] (2), (H2NCA = 1,4-naphthalenedicarboxylic acid, H2PTA = p-phthalic acid, DPMNI = N,N′-bis(4-pyridylmethyl)-1,4,5,8-naphthalene diimide, DMF = N,N′-dimethylformamide), have been synthesized and characterized systematically. Because of the presence of electron-deficient NDI moieties, they exhibit reversible naked photochromic properties upon irradiation and photocontrolled luminescence due to the generation of NDI radicals. The carboxylate groups as electron donors play a key role in the photoinduced electron-transfer process, and the lone pair–π interaction is a preferred pathway to support photoinduced electron transfer from our work. This study has not only convincingly corroborated the relationship between the photoresponsive rate and non-covalent interactions, but also provided a feasible idea to design novel luminescence switching materials.