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In the title compound, C20H18O4, the dihedral angle between the 2H-chromen-2-one ring system and the phenyl ring is 89.12 (5)°. In the crystal, the molecules are connected through C—H...O hydrogen bonds to generate [010] double chains that are reinforced by weak aromatic π–π stacking interactions. The unit-cell packing can be described as a tilted herringbone motif. The H...H, H...O/O...H, H...C/C...H and C...C contacts contribute 46.7, 24.2, 16.7 and 7.6%, respectively, to its Hirshfeld surface.

In the title compound, C20H18O4, the dihedral angle between the 2H-chromen-2-one ring system and the phenyl ring is 89.12(5)°. In the crystal, the molecules are connected through C--H...O hydrogen bonds to generate [010] double chains that are reinforced by weak aromatic p-p stacking interactions. The unit-cell packing can be described as a tilted herringbone motif. The H...H, H...O/O...H, H...C/C...H and C...C contacts contribute 46.7, 24.2, 16.7 and 7.6%, respectively, to its Hirshfeld surface. [ABSTRACT FROM AUTHOR]

In the title compound, C17H18ClNO5, which was synthesized by reacting 4-chloro-3-formylcoumarin, acetic acid and tert-butyl isocyanide, the acetamido side chain is convoluted with ring-to-side chain C—C—C—C, C—C—C—N and C—C—N—C torsion angles of −123.30 (14), −135.73 (12) and 176.10 (12)°, respectively. In the crystal, N—H...O and weak C—H...O hydrogen bonds are present, which together with π–π coumarin-ring interactions [ring centroid separations = 3.4582 (8) and 3.6421 (9) Å], give rise to a layered structure lying parallel to (001).

The asymmetric unit of the title compound, C13H14O3, contains two independent molecules, A and B, that are interconnected through an offset π–π interaction [inter-centroid separation = 3.6087 (4) Å]. The fused benzene and pyran-2-one rings in each molecule are essentially coplanar, having dihedral angles of 1.22 (12) and 1.57 (12)° for molecules A and B, respectively. Similarly, the coumarin ring system and the 7-propoxy substituent are close to being coplanar [C—C—O—C torsion angles = 2.9 (2) and 1.4 (2)° for molecules A and B, respectively]. In the crystal, the molecules are connected by C—H...O hydrogen bonds, forming supramolecular tapes along [100] that are linked into a three-dimensional network by C—H...π interactions, as well as by the aforementioned π–π interactions.

• Unique crystal packing with 3D-π-stacking interaction. • Coumarin based novel chemo-sensor for detection of aqueous Co2+, Ni2+ and Cu2+ ions through naked eyes and fluorimetrically. • Interaction with calf-thymus DNA. A new coumarin derivative, 4-amino-3-nitroso-2 H -chromen-2-one (B) was synthesized through a very easy procedure and charecterized by 1H- and 13C- NMR, FTIR, HRMS and single crystal XRD analysis. Its photo-physical characteristics along with its transition metal ion-sensing capability were cultivated. Unique crystal packing with 3D-π-stacking interaction was observed. DFT calculation gave more insight into the electronic properties of B and was found to be in very good agreement with the X-ray data. The studies of solvatochromism of B in various solvents of different polarities as well as its pH dependency have been provided. The compound was employed as a simple fluorimetric as well as colorimetric chemosensor for the investigation of Ni2+, Co2+ and Cu2+ ions. The Job's plot experiments disclosed 2:1, 3:1 and 1:1 stoichiometric bindings between B and the corresponding analyte ions Ni2+, Co2+ and Cu2+, respectively. The detection limits and the binding constant values of B for the Ni2+, Co2+ and Cu2+ions have also been provided. In addition, several experiments employing this chemosensor with calf-thymus DNA (CT-DNA) unveiled itself as a groove binder. A coumarin derivative B with unique crystal packing having 3D-π-stacking interaction, senses aqueous Co2+, Ni2+ and Cu2+ ions, and interacts with CT-DNA through groove binding. DFT calculation gave more insight into the electronic properties of B. The photo-physical studies like solvatochromism of B in various solvents with different polarities, pH dependency of B gave interesting observations. [Display omitted] [ABSTRACT FROM AUTHOR]

Two new anthracen- and pyrene-based coumarin derivatives, 3-(4-(anthracen-10-yl)phenyl)coumarin ( 4 ) and 3-(4-(pyrene-1-yl)phenyl)coumarin ( 5 ), were synthesized and characterized by FT-IR, 1 H NMR, element analysis and single crystal X-ray crystallography. The UV–vis absorption and photoluminescence spectra of these coumarin derivatives were investigated. The results show that compound 4 and 5 exhibit blue and blue-green emissions, respectively, under ultraviolet light excitation. Compared with the compound 4 , the emission peak of compound 5 was bathochromically shifted by about 80 nm due to the more planar structure and larger π-conjugation. [ABSTRACT FROM AUTHOR]

In this paper a new cyclometalated iridium(III) coumarin complex, Ir(III)bis(3-(2-benzothiazolyl)coumarinato N,C)(acetylacetonate) (Ir(L)(acac)), was synthesized and characterized. X-ray crystallography demonstrated that the iridium(III) ion is hexacoordinated by two C atoms and two N atoms from 3-(2-benzothiazolyl)coumarinato ligands and two O atoms from acac ligand, displaying distorted octahedral coordination geometry. The Ir(L)(acac) complex has good thermal stability with less than 2 % weight-reduction occurring at 300 °C, and exhibits strong reddish orange emission. The results shown that Ir(L)(acac) is useful for fabrication organic light-emitting diodes. [ABSTRACT FROM AUTHOR]

Abstract: A series of new Cu(II) complexes with the hydroxy derivatives of benzo[b]furan and coumarin have been electrochemically synthesized. The geometry of the metal–ligand interaction has been described using the single crystal X-ray diffraction method and X-ray absorption spectroscopy. Two ligands are bonded to the metal cation via the acetyl and deprotonated hydroxyl O atoms. The centrosymmetric coordination polyhedron of Cu(II) exhibits a square-planar geometry (CuO4), with both ligands coordinating in the chelating mode. [Copyright &y& Elsevier]

Abstract: A new coumarin derivative, 3-(4-(anthracen-10-yl)phenyl)-benzo[5,6]coumarin, was synthesized and characterized by FT-IR, 1H NMR, element analysis and single crystal X-ray crystallography. The dihedral angle of benzo[5,6]coumarin ring and phenyl group is 36.15°, and the dihedral angle of phenyl group and anthracene skeleton is 89.37°. The UV–vis absorption and photoluminescence of the compound were discussed. The result shown that the compound exhibits high fluorescence quantum yield (Φ F ), large Stokes shift and green emission (508nm). The molecular structure of the compound was optimized using density functional theory (DFT) at B3LYP/6-31G(d) level, and the HOMO and LUMO levels of the compound were deduced. [Copyright &y& Elsevier]

Abstract: The structure of 7-(N,N′-diethylamino)-coumarin-3-carboxylic acid (DCCA) was verified by single crystal X-ray crystallography. The UV–vis absorption and fluorescence of DCCA were discussed. The compound exhibits strong blue emission under ultraviolet light excitation. The molecular structure of DCCA was optimized using density function theory (DFT) at B3LYP/6-31G level, showing that the optimized geometers parameters are in good agreement with experiment data. In addition, the HOMO and LUMO levels of DCCA were deduced. [Copyright &y& Elsevier]

Abstract: A novel coumarin derivative containing an electron-transporting moiety (benzotriazole), 3-(1H-benzotriazol-1-yl)-4-methyl-benzo[7,8]coumarin (BMBC), was synthesized and characterized by element analysis, 1H NMR, FT-IR and UV–vis absorption spectra, TG-DTA and single crystal X-ray crystallography. Crystallographic data reveal a dihedral angle of 60.4° between the benzocoumarin and benzotriazole rings, which is attributed to the spatial hindrance of a 4-positioned methyl group. The photoluminescent behaviors of BMBC doped in PMMA were discussed. The compound exhibits a strong blue emission under ultraviolet light excitation. The ground-state geometries, the lowest energy transition and the UV–vis spectrum of BMBC have been studied with density functional theory (DFT) and time-dependent density functional theory (TD-DFT) at B3LYP/6-31G(d) level, showing that the calculation outcomes are in good agreement with experimental data. [Copyright &y& Elsevier]

Abstract: A novel coumarin derivative containing an electron-transporting moiety (benzotriazole), 3-(1-benzotriazole)-4-methyl-coumarin (BMC), was synthesized from starting substances, i.e. benzotriazole and 2-hydroxyacetophenone. The compound structure was verified by FT-IR, 1H NMR, element analysis and single crystal X-ray crystallography. Crystallographic data reveal a dihedral angle of 108° between the coumarin and benzotriazole rings, which is attributed to the spatial hindrance of a 4-positioned methyl group. The fluorescence and UV–vis absorption of BMC were discussed. The compound exhibits a strong UV emission peak at 385nm under 360nm excitation. The molecular structure of BMC was optimized using density functional theory (DFT) at B3LYP/6-31G(d) level, showing that the optimized geometric parameters are in good agreement with experimental data. In addition, the HOMO and LUMO levels of BMC were deduced. [Copyright &y& Elsevier]

One diethylamine coumarin derivative with nitro substituted chalcone structure was synthesized via typical condensation reaction between 4-nitro-2-(hydroxyl)acetophenone with 7-(diethylamino)coumarinaldehyde in good yields. The investigation indicated that the compound exhibits quickly obvious UV–vis absorption, color change and fluorescence response to cyanide and copper ions in acetonitrile conditions. The bonding mechanism based on spectra change and in situ 1 H NMR suggested that cyanide is bonded to 4-position of coumarin and 1:2 complexation between compound and copper ion forms. [ABSTRACT FROM AUTHOR]

• New coumarin derivative (4-[(pyridin -3- ylmethyl) amino ]−2 H -chromen-2-one) (L TA) was synthesized and characterized by spectroscopic techniques. • The ligand was characterized by single-crystal X-ray diffraction method and optimized by DFT method. • The chemical reactivity, kinetic and thermodynamic parameters of L TA were calculated. • The interaction of L TA with SARS-CoV-2/Main protease (Mpro) was studied. • The docking simulation showed active L TA molecule with the ability to inhibit SARS-CoV-2. Currently, Covid-19 pandemic infects staggering number of people around the globe and causes a high rate of mortality. In order to fight this disease, a new coumarin derivative ligand (4-[(pyridin -3- ylmethyl) amino ]-2 H -chromen-2-one) (L TA) has been synthesized and characterized by single-crystal X-ray diffraction, NMR, ATR, UV-Visible and cyclic voltammetry. Chemical reactivity, kinetic and thermodynamic studies were investigated using DFT method. The possible binding mode between L TA and Main protease (Mpro) of SARS-CoV-2 and their reactivity were studied using molecular docking simulation. Single crystal X-ray diffraction showed that L TA crystallizes in a monoclinic system with P 2 1 space group. The reactivity descriptors such as nucleophilic index confirm that L TA is more nucleophile, inducing complexation with binding species like biomolecules. The kinetic and thermodynamic parameters showed that the mechanism of crystal formation is moderately exothermic. The binding energy of the SARS-CoV-2/Mpro-L TA complex and the calculated inhibition constant using docking simulation showed that the active L TA molecule has the ability to inhibit SARS-CoV-2. Image, graphical abstract [ABSTRACT FROM AUTHOR]