Single-crystal X-ray Diffraction Research Articles

Chiral 3D Perovskite Formation Induced by Chiral Templates.

Chiral 3D perovskites pose challenges compared to lower-dimensional variants due to limited chiral organic cation options. Here, we present a universal and controlled method for synthesizing chiral 3D lead halide perovskites using organic amines or alcohols as chiral templates. Introducing these templates to PbCl2 in N,N-dimethylformamide (DMF) under acidic conditions induces the crystallization of R/S [DMA]PbCl3 (DMA = dimethylamine). The resulting structure aligns with the templates used, stemming from the helical Pb2Cl95- chain as verified by single-crystal X-ray diffraction. Furthermore, the chiral perovskite exhibits absorption and circular dichroism (CD) signals in the high-energy band, enabling the circularly polarized light (CPL) detection in the UV spectrum. A CPL detector constructed by this chiral perovskite demonstrates excellent performance, boasting an anisotropy factor for photocurrent (gIph) of 0.296. Our work not only introduces a novel and controllable method for crafting chiral perovskites but also opens new avenues for circularly polarized light detection.

Prenylated Acetophenone Derivatives from the Leaves of Acronychia pedunculata and Their Anti-proliferative Activities.

Four new prenylated acetophenone derivatives, including one acetophenone dimer [acronyrone D (1)] and three acetophenone monomers [acronyrones E-G (2-4)], along with seven known analogues (5-11) were obtained from the leaves of Acronychia pedunculata. Their structures and absolute configurations were established by analysis of HRMS and NMR data, single crystal X-ray diffraction studies and quantum chemical calculations. In addition, the isolates were tested for their anti-proliferative acivity against HCT-116, RKO and SW480 cancer cell lines. Remarkably, compound 5 exhibited significant anti-proliferative effects on the three cell lines, with IC50 values ranging from 0.24 to 5.3 μM.

Synthesis, structural phase transition and weak itinerant magnetism in NixNbSe2

The article presents the synthesis, structural and magnetic properties of NixNbSe2 (x = 0, 0.05, 0.1, 0.15, 0.2, 0.25). The intercalation limit of Ni in NbSe2 is found to be 25 mol%, above which NiSe appears as a binary impurity phase. Single crystal X-ray diffraction studies show that all the compounds crystallize in the hexagonal P63/mmc space group. However, there is a distinct phase transition beyond x = 0.20 with Ni intercalation in NixNbSe2. The NixNbSe2 compounds crystallized in the parent 2H phase with x value between 0 ≤ x ≤ 0.2. Subsequently, the phase transforms into the 2H(I) phase with an order superstructure of 2 ao × 2 ao × 1 co for 0.20 ≤ x ≤ 0.25 in NixNbSe2. The superstructure formation is attributed to the occupation of Ni at the alternate octahedral voids present in the van der Waals gap of the NbSe2. The XPS results and theoretical analysis clearly show that the intercalation of Ni results in a more metallic character in NixNbSe2. Magnetic measurements on NixNbSe2 (x = 0.05, 0.1, 0.2, 0.25) shows very small magnetic moment at low temperature for all the compounds. Theoretical calculation on Ni0.25NbSe2 shows that the Ni-3d electrons are delocalized and are very weakly spin-polarized, which may be the reason for the experimentally observed weak magnetism in these compounds.

Pyrazine-bridged polymetallic copper-iridium clusters.

Single crystals of the mol-ecular compound, {Cu20Ir6Cl8(C21H24N2)6(C4H4N2)3]·3.18CH3OH or [({Cu10Ir3}Cl4(IMes)3(pyrazine))2(pyrazine)]·3.18CH3OH [where IMes is 1,3-bis-(2,4,6-trimethylphen-yl)imidazol-2-yl-idene], with a unique heterometallic cluster have been prepared and the structure revealed using single-crystal X-ray diffraction. The mol-ecule is centrosymmetric with two {Cu10Ir3} cores bridged by a pyrazine ligand. The polymetallic cluster contains three stabilizing N-heterocyclic carbenes, four Cl ligands, and a non-bridging pyrazine ligand. Notably, the Cu-Ir core is arranged in an unusual shape containing 13 vertices, 22 faces, and 32 sides. The atoms within the trideca-metallic cluster are arranged in four planes, with 2, 4, 4, 3 metals in each plane. Ir atoms are present in alternate planes with an Ir atom featuring in the peripheral bimetallic plane, and two Ir atoms featuring on opposite sides of the non-adjacent tetra-metallic plane. The crystal contains two disordered methanol solvent mol-ecules with an additional region of non-modelled electron density corrected for using the SQUEEZE routine in PLATON [Spek (2015 ▸). Acta Cryst. C71, 9-18]. The given chemical formula and other crystal data do not take into account the unmodelled methanol solvent mol-ecule(s).

Experimental and theoretical investigation of five mosapride forms

Mosapride (Mosa) is an active pharmaceutical ingredient commonly used for the treatment of gastroesophageal reflux disease. The purpose of this study is to investigate the possibility of discovering novel solid forms of Mosa that may arise during the process of drug product development, and subsequently analyze their structure. Five forms are obtained here: one is Mosa monohydrate, which has been reported before, and four are new forms (Mosa anhydrate, Mosa methanol hydrate (1:1:1), Mosa ethanol hydrate (1:1:1), and Mosa DMSO solvate (1:1)). The phase composition of the forms was analyzed by powder X-ray diffraction, thermal analysis, and FTIR analysis. The crystal structures of all five forms were successfully solved using single-crystal X-ray diffraction. To investigate the characteristics of five forms, a combination of X-ray crystallography, 13C solid-state nuclear magnetic resonance, molecular electrostatic potential surface, and Hirshfeld surface analysis methods were employed. It's demonstrated that the conformation of Mosa was changed due to the introduction of solvates. The water molecules play vital roles in the formation of Mosa solvates. The presence of water during the preparation process can result in different forms. Furthermore, DVS data demonstrate that the stability of Mosa solvates was significantly impacted by relative humidity.

Rare earth mixed sandwich complexes with tetraalkylphospholide and cyclooctatetraenide ligands

A series of rare earth (mono)phospholide mixed sandwich complexes of the general form [M(PC4R4)(COT)(THF)n] (M = Sc, Y, La, Lu; R = Me, Et; COT = cyclooctatetraenide, {C8H8}2–; n = 0 to 2) have been isolated by the treatment of iodide precursors, [M(COT)(I)(THF)n], (1M, M = Sc, Y, Lu, n = 2; M = La, n = 3) with potassium phospholide salts, [K(PC4R4)]n (R = Me, Et). The solid-state molecular structures and speciation of these sandwich complexes depends upon both the ionic radius of the rare earth metal, along with small steric and solubility differences which arise between the two per-alkylated phospholide ligands. The smaller {PC4Me4} ligand gave monomeric Lewis-base free [M(C8H8)(PC4Me4)] (2M, M = Sc, Lu) with smaller rare earths Sc(III) and Lu(III), but moving to larger ions Y(III) and La(III), the products were poorly soluble and could only be isolated as THF-adducts, [Y(C8H8)(PC4Me4)(THF)] (3) and [La(C8H8)(PC4Me4)(THF)2] (4). The slightly increased steric demands of {PC4Et4} gave monomeric Lewis-base free complexes for Sc(III), Lu(III), and Y(III) in [M(C8H8)(PC4Et4)] (5M, M = Sc, Y, Lu), whereas for La(III) a dimeric complex was isolated, [La(C8H8)(µ-PC4Et4)]2 (6). We also report the synthesis and molecular structures of 1Sc and 1Lu, as well as [LuI3(THF)3] (7) for the first time. All complexes were characterised by single crystal X-ray diffraction, multi-nuclear NMR, UV-Vis-NIR and ATR-IR spectroscopies in addition to elemental analysis.

Synthesis and molecular structure exploration of novel piperidin-4-one imine derivatives combined with DFT and X-ray: A new class of antioxidant and anti-inflammatory agents

Inflammation is one of the pertinent responses of the body, depending mainly on the process and factors involved in combating the oxidative species produced either by any infection or failure of the antioxidant pathways. In search of new compounds to exhibit antioxidant and anti-inflammatory activity here, we have successfully reported the synthesis of three novel compounds of Piperidin-4-one skeleton by adopting simple and convenient methods. Compound 1, (3, 3-dimethyl-2, 6-bis(3,4,5-trimethoxyphenyl) piperidin-4-one) was synthesized by one-pot Mannich condensation reaction having good yield (88 %). Furthermore in the next step highly functionalized imine derivatives, Compound 2 (3,3-dimethyl-2,6-bis (3,4,5-trimethoxyphenyl) piperidine-4-one) hydrazine carbothioamide) and Compound 3 (3,3-dimethyl-2,6-bis(3,4,5-trimethoxyphenyl) piperidin-4-one oxime) were prepared by the condensation reaction with thiosemicarbazide and hydroxylamine hydrochloride with compound 1, respectively. The structure of the compounds has been deduced by the combined use of modern spectroscopic and single crystal x-ray diffraction (XRD) techniques. in-silico ADMET studies predict pharmacokinetic properties and showed that compounds are non toxic on vital organs. The optimized geometry and reactivity parameters of compounds were further calculated based on the B3LYP/6-31G (d, p) density functional theory (DFT). The negative values of chemical potential follow the trend as 2 (−0.2101) >3 (−0.2198) >1(-0.2233) signifies that all compounds are reactive in nature as evident from in-vitro antioxidant and anti-inflammatory response were determined by using the DDPH assay and protein denaturation methods respectively. Compounds possess good radical scavenging activity having IC 50 values 30.392 μM (2), 37.802 (1) μM, and 72.285 (3) μM, and anti-inflammatory response in same manner indicating that 2 (71.3 %) is more active than compound 1 (43.5 %) and 3 (39.3 %) marking them as a potential antioxidant and anti-inflammatory agents.

Insights into Co (II)-based hybrid materials for photocatalytic and antioxidant applications

Metal-organic materials are widely used as scaffolds to create porous materials for various applications. However, research on solid compositions from hybrid materials (HB) is limited. This study examines two hybrid components using spectroscopic techniques and single crystal X-ray diffraction. The crystal structure analysis reveals a monoclinic system for compounds Co(HCO2)2·2H2O (I) and (C6H10N2)2[CoCl4]Cl2 (II) in the P21/c space group. Compound I features cobalt octahedra with coordinated formate ions and water molecules, while compound II contains organic cations, anions, and free chlorides with interconnected structural motifs. UV light at 400 nm induces high photocatalytic activity in both complexes, leading to significant degradation rates within 80 minutes. Trapping experiments identify activated species as h+ and •O2−. Antioxidant activity assessments highlight their antioxidative potentials.

Tale of Two Polymorphs: Investigating the Structural Differences and Dynamic Relationship between Nirmatrelvir Solid Forms (Paxlovid).

Two anhydrous polymorphs of the novel antiviral medicine nirmatrelvir were discovered during the development of Paxlovid, Pfizer's oral Covid-19 treatment. A comprehensive experimental and computational approach was necessary to distinguish the two closely related polymorphs, herein identified as Forms 1 and 4. This approach paired experimental methods, including powder X-ray diffraction and single-crystal X-ray diffraction, solid-state experimental methods, thermal analysis, solid-state nuclear magnetic resonance and Raman spectroscopy with computational investigations comprising crystal structure prediction, Gibbs free energy calculations, and molecular dynamics simulations of the polymorphic transition. Forms 1 and 4 were ultimately determined to be enantiotropically related polymorphs with Form 1 being the stable form above the transition temperature of ∼17 °C and designated as the nominated form for drug development. The work described in this paper shows the importance of using highly specialized orthogonal approaches to elucidate the subtle differences in structure and properties of similar solid-state forms. This synergistic approach allowed for unprecedented speed in bringing Paxlovid to patients in record time amidst the pandemic.

The novel cocrystals of acacetin with 4,4′-bipyridine and 2,2′-bipyridine: Crystal structures analysis, stability and dissolution evaluation

To our best knowledge, acacetin has great potential for market development and clinical application due to its various pharmacological effects including antioxidant, anti-inflammatory, anti-cancer, neuroprotective, hepatoprotective, cardioprotective and so on. However, low solubility and poor bioavailability overshadow its prospect for new drug development and application. In order to optimize the solubility of acacetin, a scientific and reasonable cocrystal design was launched. In this study, the cocrystal of acacetin-4,4′-bipyridine and acacetin-2,2′-bipyridine were successfully prepared and systematically characterized by single-crystal X-ray diffraction, powder X-ray diffraction, fourier transform infrared spectroscopy, differential scanning calorimetry and thermogravimetric analysis. With the efforts of structural analysis and theoretical calculation, it was found that the two formed cocrystals including acacetin-4,4′-bipyridine and acacetin-2,2′-bipyridine possessed significant distinctions in terms of the type of space group and crystal system, the lattice arrangement as well as the forces and hydrogen bonds connections involved in the generation of cocrystals. By the evaluation of stability and dissolution, the results indicated that two cocrystals could keep stable under high temperature, high humidity as well as light condition and significant enhancement in the solubility and dissolution rate of acacetin were achieved by the formation of two new cocrystals which might be contributed to the increase of its bioavailability. This study was of significance to not only investigate the differences of two cocrystals in the aspects of space group, lattice arrangement, intermolecular force and thermodynamic stability, but also provided a new approach to optimize the solubility of acacetin.

Synthesis, physicochemical and pharmacological characterizations of a tetra-[methylimidazolium] dihydrogen decavanadate, inhibiting the IGR39 human melanoma cells development

Melanoma is a skin cancer that arises from melanocytes and can spread quickly to the other organs of the body, if not treated early. Generally, melanoma shows an inherent resistance to conventional therapies. In this regard, new potential drugs are being developed as possible treatments for melanoma. In this paper, we report the synthesis of a new decavanadate compound with organic molecules for a potential therapeutic application. The tetra-[methylimidazolium] dihydrogen decavanadate(V) salt (C4H7N2)4[H2V10O28] is characterized by single-crystal X-ray diffraction, by FT-IR, UV–Vis and 51V NMR spectroscopy, as well as by thermal analysis (TGA and DSC). The compound crystallizes in the monoclinic centrosymmetric space group P21/c. Its formula unit consists of one dihydrogen decavanadate anion [H2V10O28]4− and four organic 4-methylimidazolium cations (C4H7N2)+. Important intermolecular interactions are N-H···O and O-H···O hydrogen bonds and π-π stacking interactions between the organic cations, revealed by analysis of the Hirshfeld surface and its two-dimensional fingerprint plots. Interestingly, this compound inhibits the viability of IGR39 cells with IC50 values of 14.65 μM and 4 μM after 24 h and 72 h of treatment, respectively. The analysis of its effect by flow cytometry using an Annexin V-FITC/IP cell labeling, showed that (C4H7N2)4H2V10O28 compound induced IGR39 cell apoptosis and necrosis. Molecular docking studies performed against TNFR1 and GPR40, as putative targets, suggest that the (C4H7N2)4[H2V10O28] compound may act as inhibitor of these proteins, known to be overexpressed in melanoma cells. Therefore, we could consider it as a new potential metallodrug against melanoma.

DNA/BSA Binding and Antimicrobial Properties of Biguanide-Cu(II) Complexes.

The biguanide Cu(II) complexes [Cu(L1-4)2](ClO4)2 were synthesized and spectroscopic/analytical techniques were used to clarify their structures. Single crystals of complex [Cu(L4)2](ClO4)2 was obtained and its definite structure was determined by single crystal X-ray diffraction study. The complexes [Cu(L1-4)2](ClO4)2 were screened for their FSds-DNA interactions by using UV-Vis absorption and fluorescence spectroscopies. The complexes [Cu(L2)2](ClO4)2 and [Cu(L3)2](ClO4)2 were shown to exhibit higher affinity for binding DNA. Examining the EB-DNA interaction, it is believed that the complexes interact with DNA through a groove binding mechanism. The interaction of complexes with BSA were observed through the quenching of the fluorescence emission. Complexes [Cu(L2)2](ClO4)2 and [Cu(L3)2](ClO4)2 show moderate binding affinity to BSA through a static mode. Additionally, the Cu(II) complexes were screened for their antibacterial activities against various bacterial strains. Complexes showed potential antimicrobial activity against Salmonella typhimurium, Bacillus cereus, Salmonella typhimurium and S. aureus.

Synthesis of Zintl Phase Metal Silicide Thermoelectric Materials in Magnesium/Zinc Flux.

Zintl phases have potential applications as thermoelectric materials for power generation and cooling owing to their complex crystal structures and unique electronic properties. We carried out reactions of silicon with barium and strontium in excess Mg/Zn flux to synthesize (Ba/Sr)5+xMg19-xSi12 Zintl phases, investigating the effect of varying Ba/Sr ratio on site mixing and thermoelectric properties. (Ba/Sr)5+xMg19-xSi12 compounds with 0 < x < 3 are charge-balanced Zintl phases which adopt the hexagonal Ho5Ni19P12 structure type (space group P6̅2m). Density of states calculations indicate that these materials are semimetals. Single-crystal X-ray diffraction data and elemental analysis for Ba5Mg19Si12, Ba4.86Sr2.94Mg16.20Si12, Ba3.63Sr4.20Mg16.17Si12, Ba1.93Sr5.99Mg16.08Si12, and Sr7.82Mg16.18Si12 show occupation of barium and strontium cations in Ho sites, while strontium mixes with magnesium on a specific Ni site. Powder XRD data of products show that they are single phase throughout the sample. Thermoelectric measurements indicate that increasing strontium content and mixing on three cation sites decreases thermal conductivity; it is hypothesized that improved overall thermoelectric behavior is likely due to the rattling of the Sr cations in their positions.

Undobolins A-L, Ophiobolin-Type Sesterterpenoids from Aspergillus undulatus.

Twelve previously undescribed ophiobolin-type sesterterpenoids, undobolins A-L (1-12), were isolated from Aspergillus undulatus, and their structures were elucidated by spectroscopic analysis, ECD calculations, and single-crystal X-ray diffraction experiments. Compound 1 was the second example of 20-nor-ophiobolin reported, while compounds 2-6 were notable for oxygenation of C-2, and compound 6 showed significant inhibitory activity against ConA-induced T lymphocyte proliferation with an IC50 value of 2.3 μM, which suggests a promising new direction in the quest for immunosuppressive agents.

Synthesis, Characterization, and Evaluation of a Hindered Phenol-Linked Benzophenone Hybrid Compound as a Potential Polymer Anti-Aging Agent

Hindered phenol antioxidants and benzophenone UV absorbers are common polymer additives and often used in combination applications to enhance the anti-aging performance of polymer materials. This study primarily aims to incorporate hindered phenol and benzophenone structures into a single molecule to develop a multifunctional polymer additive with good anti-aging performance. Thus, a novel potential polymer anti-aging agent, namely 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid 3-(4-benzoyl-3-hydroxyphenoxy)propyl ester (3C), was synthesized using 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid, 3-bromo-1-propanol, and 2,4-dihydroxybenzophenone as raw materials by two-step procedure. The structure of compound 3C was characterized by nuclear magnetic resonance (NMR), high-resolution mass spectrometry (HRMS), Fourier-transform infrared (FT-IR) spectroscopy, and X-ray single crystal diffraction. Its thermal stability and UV resistance were assessed using thermogravimetric analysis (TGA) and UV absorption spectroscopy (UV). The compound 3C as an additive was incorporated into the preparation of polyolefin elastomer (POE) films. The anti-aging performance of POE films was evaluated by measuring parameters such as oxidation induction time, melt flow index, transmittance, and infrared spectra of the artificially aged POE films. The results indicate that the compound 3C exhibits a promising anti-aging performance in both thermo-oxidative aging and ultraviolet aging tests of POE films and is a potential polymer anti-aging agent.

Electrochemically Active Copper Complexes with Pyridine-Alkoxide Ligands

Pyridine-alkoxide (pyalk) ligands that support transition metals have been studied for their use in electrocatalytic applications. Herein, we used the pyalk proligands diphenyl(pyridin-2-yl)methanol ([H]PhPyalk, L1), 1-(pyren-1-yl)-1-(pyridin-2-yl)ethan-1-ol ([H]PyrPyalk, L2), 1-(pyridine-2-yl)-1-(thiophen-2-yl)ethan-1-ol ([H]ThioPyalk, L3), and 1-(ferrocenyl)-1-(pyridin-2-yl)ethan-1-ol ([H]FePyalk, L4) to synthesize CuII complexes that vary in nuclearity and secondary coordination sphere. Also, the proligand 1-(ferrocenyl)-1-(5-methoxy-pyridin-2-yl)ethan-1-ol ([H]FeOMePyalk, L5) was synthesized with a methoxy substituted pyridine; however, the isolation of a CuII complex ligated by L5 was not possible. Under variable reaction conditions, the pyalk ligands reacted with CuII precursors and formed either mononuclear or dinuclear CuII complexes depending on the amount of ligand added. The resulting complexes were characterized by single crystal X-ray diffraction, elemental analysis, and cyclic voltammetry.

Bridging Titanium Nitrido Complexes Containing A Linear Ti-N-Ti Core with A Two-Coordinate Nitrido Ligand.

A series of titanium m2-nitrido complexes supported by the triamidoamine ligand Xy-N3N (Xy-N3N = {(3,5-Me2C6H3)NCH2CH2}3N3-) is reported. The titanium azido complex [(Xy-N3N)TiN3] (1-N3), prepared by salt metathesis of the chloride complex [(Xy-N3N)TiCl] (1-Cl) with NaN3, reacted with lithium metal or with alkali metal naphthalenides (alkali metal M = Na, K, and Rb) in THF to give the corresponding dinuclear m2-nitrido complexes M[(Xy-N3N)Ti=N-Ti(Xy-N3N)] (2-M; M = Li, Na, K, Rb). Single crystal X-ray diffraction studies of 2-Li, 2-Na, and 2-K revealed alkali metal dependent structures in the solid state. While 2-Li and 2-K contain a m2-nitrido ligand with a linear Ti-N-Ti core, 2-Na includes a m3-nitrido ligand as part of a T-shape Ti2NaN fragment with the sodium cation weekly coordinated to the nitrido nitrogen atom. When the synthesis of the nitrido complexes was carried out in the presence of excess alkali metals, selective decomposition of the nitrido complexes was observed affording some intractable titanium species along with the trialkali metal salts [M3(Xy-N3N)] (3-M) (M = Li, Na, K, and Rb). These salts were also prepared by deprotonation of (Xy-N3N)H3 with the corresponding alkali metal hexamethyldisilazide and characterized by multinuclear NMR spectroscopy as well as single crystal X-ray diffraction.

Carboxylate bridging Cd(II)-based 1D coordination polymer: Structure, fabrication of Schottky device and selective sorption of Bromocresol Green

Phenyl-1,3-diacetate (1,3-PDAt) bridging Cd(II)-based 1D coordination polymer {[Cd(1,3-PDAt)(phen)]⋅(MeOH)⋅(H2O)0.5}n, (CP) where 1,10-phenanthroline (phen) serves as chelating ligand has been structurally confirmed by Single Crystal X-Ray Diffraction measurements along with other spectral data. The thermal treatment releases MeOH at ∼90 °C and the final product ends at CdO. The Tauc’s plot evaluates the band gap, 3.87 eV (calculated value, 3.76 eV) using absorption spectral data which marks the semiconducting nature of the material. This has motivated us to fabricate Schottky Diode device and the measured conductance is 8.87 × 10−6 S/m in the dark. Interestingly, 1D CP shows selective and specific sorption of Bromocresol Green (BG) out of four common dyes (Methylene blue, Methyl orange, Rhodamine B, and Bromocresol Green (BG)). Besides, the sorbed BG in the CP is leached out on treating with water and the CP has been re-used for further sorption studies. Thus, the CP is economically recycled which is the first principle of Sustainable Development Goals.

Design, synthesis and antiviral activity of indole derivatives containing quinoline moiety.

A series of indole derivatives containing quinoline structures were designed and synthesized. The synthesized compounds were characterized by NMR and HRMS. And W14 was performed by single crystal X-ray diffraction experiments. The antiviral activity studies showed that some of the target compounds possessed significant activity against tobacco mosaic virus (TMV). In particular, W20 had significant activity. The results of in vivo anti-TMV activity assay showed that W20 possessed the best curative and protective activities with EC50 values of 84.4 and 65.7 μg/mL, which were better than ningnanmycin (NNM) 205.1 and 162.0 μg/mL, respectively. The results of Microscale thermophoresis (MST) showed that W20 had a strong binding affinity for the tobacco mosaic virus coat protein (TMV-CP) with a dissociation constant (Kd) of 0.00519 μmol/L, which was superior to that of NNM (1. 65320 μmol/L). The molecular docking studies were in accordance with the experimental results. In addition, the determination of malondialdehyde (MDA) content in tobacco leaves showed that W20 improved the disease resistance of tobacco. Overall, this study shows that indole derivatives containing quinoline can be used as new antiviral agents for plant viruses for further research.

Cooperative Binding and Chirogenesis in an Expanded Perylene Bisimide Cyclophane.

The encapsulation of more than one guest molecule into a synthetic cavity is a highly desirable yet a highly challenging task to achieve for neutral supramolecular hosts in organic media. Herein, we report a neutral perylene bisimide cyclophane, which has a tailored chiral cavity with an interchromophoric distance of 11.2 Å, capable of binding two aromatic guests in a π-stacked fashion. Detailed host-guest binding studies with a series of aromatic guests revealed that the encapsulation of the second guest in this cyclophane is notably more favored than the first one. Accordingly, for the encapsulation of the coronene dimer, a cooperativity factor (α) as high as 485 was observed, which is remarkably high for neutral host-guest systems. Furthermore, a successful chirality transfer, from the chiral host to encapsulated coronenes, resulted in a chiral charge-transfer (CT) complex and the rare observation of circularly polarized emission originating from the CT state for a noncovalent donor-acceptor assembly in solution. The involvement of the CT state also afforded an enhancement in the luminescence dissymmetry factor (glum) value due to its relatively large magnetic transition dipole moment. The 1:2 binding pattern and chirality-transfer were unambiguously verified by single-crystal X-ray diffraction analysis of the host-guest superstructures.