Synthesis, structure and Hirshfeld surface analysis of 2-oxo-2-chromen-4-yl penta-noate.

In the title compound, CHO, the dihedral angle between the coumarin ring system (r.m.s deviation = 0.

2-Oxo-2-chromen-4-yl 3,3-di-methyl-butano-ate.

In the crystal of the title compound, CHO, the mol-ecules are connected through C-H⋯O hydrogen bonds, generating [100] chains, which are crosslinked by weak π-π stacking inter-actions.

Preformulation study for the selection of a suitable polymer for the development of ellagic acid-based solid dispersion using hot-melt extrusion.

Ellagic acid is one of the most studied polyphenolic compounds due to its numerous promising therapeutic properties. However, this therapeutic potential remains difficult to exploit owing to its low solubility and low permeability, resulting in low oral bioavailability. In order to allow an effective therapeutic application of EA, it is therefore necessary to develop strategies that sufficiently enhance its solubility, dissolution rate and bioavailability.

The Metabolomic study of Calotropis procera Ait. from Burkina Faso, based on chemical functional groups profiling using FTIR.

Background C. procera is an important wild medicinal plant used in different area of Burkina Faso for the neuropsychiatric disorders treatment. It was reported to possess many pharmacological properties because of its phytochemical diversity.

Crystal structure of 2-oxo-2-chromen-7-yl 4-fluoro-benzoate.

In the title compound, CHFO, (I), the benzene ring is oriented at an acute angle of 59.03 (15)° relative to the coumarin plane (r.m.

2-Oxo-2-chromen-7-yl 4--butyl-benzoate.

In the title compound, CHO, the benzoate ring is oriented at an acute angle of 33.10 (12)° with respect to the planar (r.m.

Crystal structure of 2-oxo-2-chromen-3-yl 4-chloro-benzoate and Hirshfeld surface analysis.

In the title compound, CHClO the dihedral angle between the coumarin ring system [maximum deviation = 0.023 (1) Å] and the benzene ring is 73.95 (8)°.

Fluorescence Quenching of Two Coumarin-3-carboxylic Acids by Trivalent Lanthanide Ions.

The effects of various trivalent lanthanide ions (acetates of Ce, Er, Eu, Nd) on the electronic absorption and fluorescence spectra of un-substituted coumarin-3-carboxylic acid (CCA) and 7-N,N-diethylamino-coumarin-3-carboxylic acid (DECCA) have been investigated in dimethylsulfoxide (DMSO) at room temperature. Depending on the lanthanide ion nature and concentration, significant spectral changes of absorption bands occurred for both coumarin derivatives. These spectral changes were attributed to the formation of ground-state complexes between the coumarin carboxylate derivatives and lanthanide ions.

Crystal structure of 2-oxo-2-chromen-3-yl propano-ate.

In the title compound, CHO, the dihedral angle between the coumarin ring system [maximum deviation = 0.033 (8) Å] and the propionate side chain is 78.48 (8)°.

2-Oxo-2H-chromen-4-yl propionate.

In the title compound, C12H10O4, the atoms of the 2-oxo-2H-chromene ring system and the non-H atoms of the 4-substituent all lie on a crystallographic mirror plane. The mol-ecular structure exhibits an intra-molecular C-H⋯O hydrogen bond, which generates an S(6) ring. In the crystal, mol-ecules form R 3 (2)(12) trimeric units via C-H⋯O inter-actions which propagate into layers parallel to the ac plane.

2-Oxo-2H-chromen-4-yl 4-methyl-benzoate.

The asymmetric unit of the title compound, C17H12O4, consists of two independent mol-ecules. The chromen-2-one ring and the 4-methyl-benzoate side chain are inclined to one another at a dihedral angle of 64.79 (10)° in one mol-ecule and 88.

2-Oxo-2H-chromen-4-yl 4-meth-oxy-benzoate.

In the title mol-ecule, C17H12O5, the chromen-2-one ring and the 4-meth-oxy-benzoate side chain are inclined to one another at a dihedral angle of 69.82 (9)°. The crystal structure features parallel sheets of centrosymmetric R2(2)(6) dimers joined by a C(7) chain, resulting in centrosymetric tetra-mers of hydrogen-bonded mol-ecules with graph-set motif R4(4)(40).

2-Oxo-2H-chromen-4-yl 4-tert-butyl-benzoate.

In the title mol-ecule, C(20)H(18)O(4), the three methyl groups of the tert-butyl substituent show rotational disorder. Each methyl group is split over three positions, with refined site-occupation factors of 0.711 (4), 0.

4-[(Hy-droxy)(4-methyl-phen-yl)methyl-idene]isochroman-1,3-dione.

In the title compound, C(17)H(12)O(4), the six-membered heterocyclic ring adopts a distorted screw-boat conformation. The mol-ecular structure exhibits an S(6) ring motif, owing to an intra-molecular O-H⋯O hydrogen bond. In the crystal, weak C-H⋯O contacts generate an infinite chain along the c axis.

4-[(4-Chloro-phen-yl)(hy-droxy)methyl-idene]isochromane-1,3-dione.

In the title compound, C(16)H(9)ClO(4), the six-membered heterocyclic ring adopts a screw-boat conformation. The benzene rings are oriented to each other at a dihedral angle of 59.26 (9)°.

2-Oxochromen-4-yl 4-(dimethyl-amino)-benzoate.

In the title mol-ecule, C(18)H(15)NO(4), the benzoate ring is oriented at a dihedral angle of 43.43 (6)° with respect to the planar [maximum deviation = 0.038 (2) Å] chromene ring.

Revisiting the photophysical properties and excited singlet-state dipole moments of several coumarin derivatives.

The solvent effects on the electronic absorption and fluorescence emission spectra of several coumarins derivatives, containing amino, N,N-dimethyl-amino, N,N-diethyl-amino, hydroxyl, methyl, carboxyl, or halogen substituents at the positions 7, 4, or 3, were investigated in eight solvents with various polarities. The first excited singlet-state dipole moments of these coumarins were determined by various solvatochromic methods, using the theoretical ground-state dipole moments which were calculated by the AM1 method. The first excited singlet-state dipole moment values were obtained by the Bakhshiev, Kawski-Chamma-Viallet, Lippert-Mataga, and Reichardt-Dimroth equations, and were compared to the ground-state dipole moments.