Synthesis, molecular structure, FT-IR, Raman, XRD and theoretical investigations of (2E)-1-(5-chlorothiophen-2-yl)-3-(naphthalen-2-yl)prop-2-en-1-one

Crystal structure and Hirshfeld surface analysis of a bromo-chalcone: (E)-1-(3-bromo-phen-yl)-3-(2,6-di-chloro-phen-yl)prop-2-en-1-one

In the title chalcone derivative, C15H9BrCl2O, the aryl rings are inclined to each by 14.49 (17)°, and the configuration about the C=C bond is E. There is a short intra-molecular C-H⋯Cl contact present resulting in the formation of an S(6) ring motif. In the crystal, the shortest inter-molecular contacts are Cl⋯O contacts [3.173 (3) Å] that link the mol-ecules to form a 21 helix propagating along the b-axis direction. The helices stack up the short crystallographic a axis, and are linked by offset π-π inter-actions [inter-centroid distance = 3.983 (1) Å], forming layers lying parallel to the ab plane. A qu-anti-fication of the inter-molecular contacts in the crystal were estimated using Hirshfeld surface analysis and two-dimensional fingerprint plots.

Crystal structure and Hirshfeld surface analysis of (2E)-3-(2,4-di-chloro-phen-yl)-1-(2,5-di-chloro-thio-phen-3-yl)prop-2-en-1-one

The mol-ecular structure of the title compound, C13H6Cl4OS, consists of a 2,5-di-chloro-thio-phene ring and a 2,4-di-chloro-phenyl ring linked via a prop-2-en-1-one spacer. The dihedral angle between the 2,5-di-chloro-thio-phene ring and the 2,4-di-chloro-phenyl ring is 12.24 (15)°. The mol-ecule has an E configuration about the C=C bond and the carbonyl group is syn with respect to the C=C bond. The mol-ecular conformation is stabilized by intra-molecular C-H⋯Cl contacts, producing S(6) and S(5) ring motifs. In the crystal, the mol-ecules are linked along the a-axis direction through face-to-face π-stacking between the thio-phene rings and the benzene rings of the mol-ecules in zigzag sheets lying parallel to the bc plane along the c axis. The inter-molecular inter-actions in the crystal packing were further analysed using Hirshfield surface analysis, which indicates that the most significant contacts are Cl⋯H/ H⋯Cl (20.8%), followed by Cl⋯Cl (18.7%), C⋯C (11.9%), Cl⋯S/S⋯Cl (10.9%), H⋯H (10.1%), C⋯H/H⋯C (9.3%) and O⋯H/H⋯O (7.6%).

Crystal structure and Hirshfeld surface analysis of (2E)-3-(3-bromo-4-fluoro-phen-yl)-1-(3,4-di-meth-oxy-phen-yl)prop-2-en-1-one

In the mol-ecule of the title compound, C17H14BrFO3, the aromatic rings are tilted with respect to the enone bridge by 13.63 (14) and 4.27 (15)°, and form a dihedral angle 17.91 (17)°. In the crystal, centrosymmetrically related mol-ecules are linked by pairs of C-H⋯O hydrogen bonds into dimeric units, forming rings of R22(14) graph-set motif. The dimers are further connected by weak C-H⋯O hydrogen inter-actions, forming layers parallel to (10). Hirshfeld surface analysis shows that van der Waals inter-actions constitute the major contribution to the inter-molecular inter-actions, with H⋯H contacts accounting for 29.7% of the surface.

Crystal structure and Hirshfeld surface analysis of (E)-3-(2-chloro-4-fluoro-phen-yl)-1-(2,5-di-chloro-thio-phen-3-yl)prop-2-en-1-one

In the title chalcone-thio-phene derivative, C13H6Cl3FOS, the aromatic rings are inclined to one another by 12.9 (2)°, and the thio-phene ring is affected by π-conjugation. In the crystal, mol-ecules are linked by C-H⋯F hydrogen bonds, forming an R22(8) ring motif. A Hirshfeld surface analysis was conducted to verify the contribution of the different inter-molecular inter-actions. The shape-index surface clearly shows that the two sides of the mol-ecules are involved in the same contacts with neighbouring mol-ecules and the curvedness plots show flat surface patches characteristic of planar stacking.

Synthesis and detailed spectroscopic characterization of various hydroxy-functionalized fluorescent chalcones: A combined experimental and theoretical study

Four different bright yellow to orange hydroxy-substituted chalcones (i.e., 2',4-di-hydroxy (1), 2',3',4-trihydroxy (2), 2',3',4'-trihydroxy (3), and 2'-hydroxy-4-methoxy (4) chalcones) were synthesized and characterized by LC-MS, FT-IR, FT-Raman, and fluorescence spectroscopy and thermogravimetric analysis. UV-visible absorption spectroscopy was also used. The experimental (theoretical) bandgaps of 1, 2, 3, and 4 are 2.89 (2.90), 2.93 (2.95), 3.04 (3.09), and 3.01 (2.91) eV, respectively. The hydroxy-substituted chalcones exhibited strong dual emissions as a consequence of the locally excited states followed by internal charge transfer processes. The molecular structures, lowest energy transitions, vibrational frequencies, and spectroscopic information were calculated using density functional theory and time-dependent density functional theory methods at the B3LYP/6-31G(d,p) theoretical level. The experimental and theoretical data were compared and the relationship between them was briefly discussed.

(2E)-1-(5-Chlorothiophen-2-yl)-3-{4-[(E)-2-phenylethenyl]phenyl}prop-2-en-1-one: Synthesis, XRD, FT-IR, Raman and DFT studies

A novel (2E)-1-(5-chlorothiophen-2-yl)-3-{4-[(E)-2-phenylethenyl]phenyl}prop-2-en-1-one [C21H15ClOS] compound has been synthesized and its structure has been characterized by FT-IR, Raman and single-crystal X-ray diffraction techniques. The conformational isomers, optimized geometric parameters, normal mode frequencies and corresponding vibrational assignments of the compound have been examined by means of HF, MP2, BP86, BLYP, BMK, B3LYP, B3PW91, B3P86 and M06-2X functionals. Reliable vibrational assignments and molecular orbitals have been investigated by the potential energy distribution and natural bonding orbital analyses, respectively. The compound crystallizes in the triclinic space group P-1 with the cis-trans-trans form. There is a good agreement between the experimentally determined structural parameters and vibrational frequencies of the compound and those predicted theoretically using the density functional theory with the BLYP and BP86 functionals.