Some chalcones derived from thiophene-3-carbaldehyde: synthesis and crystal structures

Abstract

The synthesis, spectroscopic data and crystal and molecular structures of four 3-(3-phenylprop-1-ene-3-one-1-yl)thiophene derivatives, namely 1-(4-hydroxyphenyl)-3-(thiophen-3-yl)prop-1-en-3-one, C13H10O2S, (1), 1-(4-methoxyphenyl)-3-(thiophen-3-yl)prop-1-en-3-one, C14H12O2S, (2), 1-(4-ethoxyphenyl)-3-(thiophen-3-yl)prop-1-en-3-one, C15H14O2S, (3), and 1-(4-bromophenyl)-3-(thiophen-3-yl)prop-1-en-3-one, C13H9BrOS, (4), are described. The four chalcones have been synthesized by reaction of thiophene-3-carbaldehyde with an acetophenone derivative in an absolute ethanol solution containing potassium hydroxide, and differ in the substituent at the para position of the phenyl ring: –OH for 1, –OCH3 for 2, –OCH2CH3 for 3 and –Br for 4. The thiophene ring in 4 was found to be disordered over two orientations with occupancies 0.702 (4) and 0.298 (4). The configuration about the C=C bond is E. The thiophene and phenyl rings are inclined by 4.73 (12) for 1, 12.36 (11) for 2, 17.44 (11) for 3 and 46.1 (6) and 48.6 (6)° for 4, indicating that the –OH derivative is almost planar and the –Br derivative deviates the most from planarity. However, the substituent has no real influence on the bond distances in the α,β-unsaturated carbonyl moiety. The molecular packing of 1 features chain formation in the a-axis direction by O—H...O contacts. In the case of 2 and 3, the packing is characterized by dimer formation through C—H...O interactions. In addition, C—H...π(thiophene) interactions in 2 and C—H...S(thiophene) interactions in 3 contribute to the three-dimensional architecture. The presence of C—H...π(thiophene) contacts in the crystal of 4 results in chain formation in the c-axis direction. The Hirshfeld surface analysis shows that for all four derivatives, the highest contribution to surface contacts arises from contacts in which H atoms are involved.

DFT Prediction of Factors Affecting the Structural Characteristics, the Transition Temperature and the Electronic Density of Some New Conjugated Polymers

“…The interval between round one and round two: C–C: varies from 1.36 Å to 1.50 Å, C–O: 1.25 Å, C–H: 1.09 Å. The obtained results are completely consistent with the structural determination [ 47 ] for which C–C = 1.33 Å, C–O =1.23 Å. The second round: C–C = 1.36–1.42 Å, C–S = 1.72 Å, C–H: 1.09 Å, C–H: 1.09 Å.…”

“…The obtained results are completely consistent with the structural determination for which C–C = 1.33 Å, C–O =1.23 Å. The second round: C–C= 1.36–1.42 Å, C–S = 1.72 Å, C–H: 1.09 Å, C–H: 1.09 Å [ 47 ]. When increasing the thickness (h) of the atomic layer from h = 6 Å to h = 9, 12 and 15 Å, the transition temperature range of poly(C 13 H 8 OS–H) shows a negligible change value from 504 K < T < 558 K to 504 K < T < 564 K and E g increases from E g = 1.646 eV to E g = 1.675 eV.…”

“…The absorption spectrum showed that the bandgap and optical properties are closely related to the shape of the thiophene molecule [ 45 , 46 ]. Most recently, our research group empirically studied C 13 H 8 OS–X monomers (X = H, Br, OH, OCH 3 and OC 2 H 5 ) that were synthesized from thiophene-3-carbaldehyde [ 47 ]. Their structures were confirmed by FTIR, 1 H-NMR, and 13 C-NMR spectroscopy.…”

“…We showed that the chemical polymerization of monomers C 13 H 8 OS–FeCl 3 in chloroform had been performed, as recently reported [ 48 , 49 , 50 , 51 ]. The obtained results show that the bonding lengths between atoms 1 and 2 are: C–C with Br (1.33 Å), OH (1.33 Å), OCH 3 (1.33 Å), and OC 2 H 5 (1.32 Å); as well as C–O with Br (1.22 Å), OH (1.23 Å), OCH 3 (1.23 Å), and OC 2 H 5 (1.22 Å) [ 47 ]. However, the effect of doping structure on the structural shape, the transition temperature and the electronic structure of the monomer C 13 H 8 OS–X (X are: H, Br, OH, OCH 3 , OC 2 H 5 ) is still unknown.…”

Synthesis, crystal structure and Hirshfeld surface analysis of diethyl 2,6-dimethyl-4-(thiophen-3-yl)-1,4-dihydropyridine-3,5-dicarboxylate

“…As a continuation of our research on the chemical and physical properties of novel polythiophenes (Nguyen et al, 2016; Vu et al, 2016), some new thiophene monomers have ISSN 2056-9890 been prepared (Vu et al, 2017(Vu et al, , 2018(Vu et al, , 2019Nguyen et al, 2017). In this study, the synthesis and crystal structure of diethyl 2,6dimethyl-4-(thiophen-3-yl)-1,4-dihydropyridine-3,5-dicarboxylate are presented together with a Hirshfeld surface analysis and non-covalent interaction plots.…”