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  1. Two closely related 2-(benzo-furan-2-yl)-2-oxoethyl benzoates: structural differences and C-H⋯O hydrogen-bonded supra-molecular assemblies
    Then LY, Chidan Kumar CS, Kwong HC, Win YF, Mah SH, Quah CK, et al.
    Acta Crystallogr E Crystallogr Commun, 2017 Jul 01;73(Pt 7):1087-1091.
    PMID: 28775889 DOI: 10.1107/S2056989017009422
    The compounds 2-(1-benzo-furan-2-yl)-2-oxoethyl 2-nitro-benzoate, C17H11NO6 (I), and 2-(1-benzo-furan-2-yl)-2-oxoethyl 2-amino-benzoate, C17H13NO4 (II), were synthesized under mild conditions. Their mol-ecular structures were characterized by both spectroscopic and single-crystal X-ray diffraction analysis. The mol-ecular conformations of both title compounds are generally similar. However, different ortho-substituted moieties at the phenyl ring of the two compounds cause deviations in the torsion angles between the carbonyl group and the attached phenyl ring. In compound (I), the ortho-nitro-phenyl ring is twisted away from the adjacent carbonyl group whereas in compound (II), the ortho-amino-phenyl ring is almost co-planar with the carbonyl group. In the crystal of compound (I), two C-H⋯O hydrogen bonds link the mol-ecules into chains propagating along the c-axis direction and the chains are inter-digitated, forming sheets parallel to [20-1]. Conversely, pairs of N-H⋯O hydrogen bonds in compound (II) link inversion-related mol-ecules into dimers, which are further extended by C-H⋯O hydrogen bonds into dimer chains. These chains are inter-connected by π-π inter-actions involving the furan rings, forming sheets parallel to the ac plane.
  2. Fulltext Three closely related (2E,2'E)-3,3'-(1,4-phenyl-ene)bis-[1-(meth-oxy-phen-yl)prop-2-en-1-ones]: supra-molecular assemblies in one dimension mediated by hydrogen bonding and C-H⋯π inter-actions
    Sim A, Chidan Kumar CS, Kwong HC, Then LY, Win YF, Quah CK, et al.
    Acta Crystallogr E Crystallogr Commun, 2017 Jun 01;73(Pt 6):896-900.
    PMID: 28638654 DOI: 10.1107/S2056989017007460
    In the title compounds, (2E,2'E)-3,3'-(1,4-phenyl-ene)bis-[1-(2-meth-oxy-phen-yl)prop-2-en-1-one], C26H22O4 (I), (2E,2'E)-3,3'-(1,4-phenyl-ene)bis-[1-(3-meth-oxy-phen-yl)prop-2-en-1-one], C26H22O4 (II) and (2E,2'E)-3,3'-(1,4-phenyl-ene)bis-[1-(3,4-di-meth-oxy-phen-yl)prop-2-en-1-one], C28H26O6 (III), the asymmetric unit consists of a half-mol-ecule, completed by crystallographic inversion symmetry. The dihedral angles between the central and terminal benzene rings are 56.98 (8), 7.74 (7) and 7.73 (7)° for (I), (II) and (III), respectively. In the crystal of (I), mol-ecules are linked by pairs of C-H⋯π inter-actions into chains running parallel to [101]. The packing for (II) and (III), features inversion dimers linked by pairs of C-H⋯O hydrogen bonds, forming R2(2)(16) and R2(2)(14) ring motifs, respectively, as parts of [201] and [101] chains, respectively.
  3. Fulltext Crystal structure and Hirshfeld surface analysis of (2E,2'E)-3,3'-(1,4-phenyl-ene)bis-[1-(2,4-di-fluoro-phen-yl)prop-2-en-1-one]
    Kwong HC, Sim A, Chidan Kumar CS, Then LY, Win YF, Quah CK, et al.
    Acta Crystallogr E Crystallogr Commun, 2017 Dec 01;73(Pt 12):1812-1816.
    PMID: 29250392 DOI: 10.1107/S205698901701564X
    The asymmetric unit of the title compound, C24H14F4O2, comprises of one and a half mol-ecules; the half-mol-ecule is completed by crystallographic inversion symmetry. In the crystal, mol-ecules are linked into a three-dimensional network by C-H⋯F and C-H⋯O hydrogen bonds. Some of the C-H⋯F links are unusually short (< 2.20 Å). Hirshfeld surface analyses (dnorm surfaces and two-dimensional fingerprint plots) for the title compound are presented and discussed.
  4. Fulltext Steric repulsion and supra-molecular assemblies via a two-dimensional plate by C-H⋯O hydrogen bonds in two closely related 2-(benzo-furan-2-yl)-2-oxoethyl benzoates
    Then LY, Chidan Kumar CS, Kwong HC, Win YF, Mah SH, Quah CK, et al.
    Acta Crystallogr E Crystallogr Commun, 2017 Jul 01;73(Pt 8):1227-1231.
    PMID: 28932442 DOI: 10.1107/S2056989017010556
    2-(Benzo-furan-2-yl)-2-oxoethyl 2-chloro-benzoate, C17H11ClO4 (I), and 2-(benzo-furan-2-yl)-2-oxoethyl 2-meth-oxy-benzoate, C18H14O5 (II), were synthesized under mild conditions. Their chemical and mol-ecular structures were analyzed by spectroscopic and single-crystal X-ray diffraction studies, respectively. These compounds possess different ortho-substituted functional groups on their phenyl rings, thus experiencing extra steric repulsion force within their mol-ecules as the substituent changes from 2-chloro (I) to 2-meth-oxy (II). The crystal packing of compound (I) depends on weak inter-molecular hydrogen bonds and π-π inter-actions. Mol-ecules are related by inversion into centrosymmetric dimers via C-H⋯O hydrogen bonds, and further strengthened by π-π inter-actions between furan rings. Conversely, mol-ecules in compound (II) are linked into alternating dimeric chains propagating along the [101] direction, which develop into a two-dimensional plate through extensive inter-molecular hydrogen bonds. These plates are further stabilized by π-π and C-H⋯π inter-actions.
  5. Fulltext The crystal structure of zwitterionic 2-{[(4-imin-iumyl-3-methyl-1,4-di-hydro-pyridin-1-yl)meth-yl]carbamo-yl}benzoate hemihydrate
    Chidan Kumar CS, Sim AJ, Ng WZ, Chia TS, Loh WS, Kwong HC, et al.
    Acta Crystallogr E Crystallogr Commun, 2017 Jul 01;73(Pt 7):927-931.
    PMID: 28775853 DOI: 10.1107/S2056989017007836
    The asymmetric unit of the title compound, C15H15N3O3·0.5H2O, comprises two 2-{[(4-iminiumyl-3-methyl-1,4-di-hydro-pyridin-1-yl)meth-yl]carbamo-yl}benzoate zwitterions (A and B) and a water mol-ecule. The dihedral angles between the pyridine and phenyl rings in the zwitterions are 53.69 (10) and 73.56 (11)° in A and B, respectively. In the crystal, mol-ecules are linked by N-H⋯O, O-H⋯O, C-H⋯O and C-H⋯π(ring) hydrogen bonds into a three-dimensional network. The crystal structure also features π-π inter-actions involving the centroids of the pyridine and phenyl rings [centroid-centroid distances = 3.5618 (12) Å in A and 3.8182 (14) Å in B].
  6. Fulltext Synthesis, spectroscopic and Hirshfeld surface analysis and fluorescence studies of (2E,2'E)-3,3'-(1,4-phenyl-ene)bis-[1-(4-hy-droxy-phen-yl)prop-2-en-1-one] N,N-di-methyl-formamide disolvate
    Kwong HC, Sim AJ, Chidan Kumar CS, Quah CK, Chantrapromma S, Naveen S, et al.
    Acta Crystallogr E Crystallogr Commun, 2018 Jun 01;74(Pt 6):835-839.
    PMID: 29951241 DOI: 10.1107/S2056989018007429
    In the bis-chalcone mol-ecule of the title compound, C24H18O4·2C3H7NO, the central benzene and terminal hy-droxy-phenyl rings form a dihedral angle of 14.28 (11)° and the central C=C double bond adopts a trans configuration. In the crystal, the bis-chalcone and solvate mol-ecules are inter-connected via O-H⋯O hydrogen bonds, which were investigated by Hirshfeld surface analysis. Solid-state fluorescence was measured at λex = 4400 Å. The emission wavelength appeared at 5510 Å, which corresponds to yellow light and the solid-state fluorescence quantum yield (Ff) is 0.18.
  7. Fulltext Crystal structure and Hirshfeld surface analysis of a pyridiniminium bromide salt: 1-[2-([1,1'-biphen-yl]-4-yl)-2-oxoeth-yl]-3-methyl-1,4-di-hydro-pyridin-4-iminium bromide
    Sheshadri SN, Kwong HC, Chidan Kumar CS, Quah CK, Siddaraju BP, Veeraiah MK, et al.
    Acta Crystallogr E Crystallogr Commun, 2018 May 01;74(Pt 5):752-756.
    PMID: 29850106 DOI: 10.1107/S2056989018006217
    In the cation of the title salt, C20H19N2O+·Br-, the phenyl rings are inclined to one another by 38.38 (8)°, whereas the central phenyl ring and the pyridiniminium ring are almost perpendicular with a dihedral angle of 87.37 (9)°. The N+=C cationic double bond was verified by the shortened bond length of 1.337 (2) Å. In the crystal, the Br- anion is linked to the cation by an N-H⋯Br hydrogen bond. C-H⋯O hydrogen bonds link adjacent pyridiniminium cations into inversion dimers with an R22(18) graph-set motif. These dimers are stacked in a phen-yl-phenyl T-shaped geometry through C-H⋯π inter-actions. A Hirshfeld surface analysis was conducted to verify the contributions of the different inter-molecular inter-actions.
  8. Fulltext 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
    Sanjeeva Murthy TN, Naveen S, Chidan Kumar CS, Veeraiah MK, Quah CK, Siddaraju BP, et al.
    Acta Crystallogr E Crystallogr Commun, 2018 Aug 01;74(Pt 8):1134-1137.
    PMID: 30116578 DOI: 10.1107/S2056989018010216
    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.
  9. Fulltext Crystal structure and Hirshfeld surface analysis of (2E)-3-(3-chloro-phen-yl)-1-(3,4-di-meth-oxy-phen-yl)prop-2-en-1-one
    Sheshadri SN, Atioğlu Z, Akkurt M, Chidan Kumar CS, Quah CK, Siddaraju BP, et al.
    Acta Crystallogr E Crystallogr Commun, 2018 Jul 01;74(Pt 7):935-938.
    PMID: 30002889 DOI: 10.1107/S205698901800837X
    In title compound, C17H15ClO3, the dihedral angle between the benzene and chloro-phenyl rings is 18.46 (7)°. In the crystal, mol-ecules are linked by C-H⋯O hydrogen contacts, enclosing an R22(14) ring motif, and by a further C-H⋯O hydrogen contact, forming a two-dimensional supra-molecular structure extending along the direction parallel to the ac plane. 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 36.2% of the surface.
  10. Green synthesis of selenium based N-heterocyclic carbene compounds; structural, in-vitro anticancer and molecular docking studies
    Hayat K, Tariq U, Wong QA, Quah CK, Majid ASA, Nazari V M, et al.
    Comput Biol Chem, 2021 Oct;94:107567.
    PMID: 34500323 DOI: 10.1016/j.compbiolchem.2021.107567
    Benzimidazolium salts (3-6) were synthesized as stable N-Heterocyclic Carbene (NHC) precursors and their selenium-NHC compounds/Selenones (7-10) were prepared using water as a solvent. Characterization of each of the synthesized compounds was carried out by various analytical and spectroscopic (FT-IR, 1H-, 13C NMR) methods. X-ray crystallographic analyses of single crystals obtained for salts 3 and 5 were carried out. Synthesized salts and their Se-NHCs were tested in-vitro for their anticancer potential against Cervical Cancer Cell line from Henrietta Lacks (HeLa), Breast cancer cell line (MDA-MB-231), Adenocarcinoma cell line (A549) and human normal endothelial cell line (EA.hy926). MTT assay was used for analysis and compared with standard drug 5-flourouracil. Benzimidazolium salts (3-6) and their selenium counter parts (7-10) were found potent anticancer agents. Salt 3-5 were found to be potent anticancer against HeLa with IC50 values 0.072, 0.017 and 0.241 μM, respectively, which are less than standard drug (4.9 μM). The Se-NHCs (7-10) had also shown significant anticancer potential against HeLa with IC50 values less than standard drug. Salts 3, 4 against EA.hy926, compounds 3,5,6, and 10 against MDA-MB-321, and compounds 4, 10 against A-549 cell line were found more potent anticancer agents with IC50 values less than standard drug. Molecular docking for (7-10) showed their good anti-angiogenic potential having low binding energy and significant inhibition constant values with VEGFA (vascular endothelial growth factor), EGF (human epidermal growth factor), COX1 (cyclooxygenase-1) and HIF (hypoxia inducible factor).
  11. Fulltext Crystal structure and Hirshfeld surface analysis of (E)-3-(2-chloro-phen-yl)-1-(2,5-di-chloro-thio-phen-3-yl)prop-2-en-1-one
    Murthy TNS, Atioğlu Z, Akkurt M, Veeraiah MK, Quah CK, Chidan Kumar CS, et al.
    Acta Crystallogr E Crystallogr Commun, 2019 Feb 01;75(Pt 2):124-128.
    PMID: 30800435 DOI: 10.1107/S2056989018018066
    The mol-ecular structure of the title compound, C13H7Cl3OS, consists of a 2,5- di-chloro-thio-phene ring and a 2-chloro-phenyl ring linked via a prop-2-en-1-one spacer. The dihedral angle between the 2,5-di-chloro-thio-phene and 2-chloro-phenyl rings is 9.69 (12)°. 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 two intra-molecular C-H⋯Cl contacts and one intra-molecular C-H⋯O contact, forming S(5)S(5)S(6) ring motifs. In the crystal, the mol-ecules are linked along the a-axis direction through van der Waals forces and along the b axis by face-to-face π-stacking between the thio-phene rings and between the benzene rings of neighbouring mol-ecules, forming corrugated sheets lying parallel to the bc plane. 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 (28.6%), followed by C⋯H/H⋯C (11.9%), C⋯C (11.1%), H⋯H (11.0%), Cl⋯Cl (8.1%), O⋯H/H⋯O (8.0%) and S⋯H/H⋯S (6.6%).
  12. Fulltext 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
    Murthy TNS, Atioğlu Z, Akkurt M, Chidan Kumar CS, Veeraiah MK, Quah CK, et al.
    Acta Crystallogr E Crystallogr Commun, 2018 Sep 01;74(Pt 9):1201-1205.
    PMID: 30225099 DOI: 10.1107/S2056989018010976
    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%).
  13. Fulltext 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
    Sheshadri SN, Atioğlu Z, Akkurt M, Veeraiah MK, Quah CK, Chidan Kumar CS, et al.
    Acta Crystallogr E Crystallogr Commun, 2018 Aug 01;74(Pt 8):1063-1066.
    PMID: 30116562 DOI: 10.1107/S2056989018009416
    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.
  14. Fulltext Design, Synthesis and Docking Studies of Flavokawain B Type Chalcones and Their Cytotoxic Effects on MCF-7 and MDA-MB-231 Cell Lines
    Abu Bakar A, Akhtar MN, Mohd Ali N, Yeap SK, Quah CK, Loh WS, et al.
    Molecules, 2018 Mar 08;23(3).
    PMID: 29518053 DOI: 10.3390/molecules23030616
    Flavokawain B (1) is a natural chalcone extracted from the roots of Piper methysticum, and has been proven to be a potential cytotoxic compound. Using the partial structure of flavokawain B (FKB), about 23 analogs have been synthesized. Among them, compounds 8, 13 and 23 were found in new FKB derivatives. All compounds were evaluated for their cytotoxic properties against two breast cancer cell lines, MCF-7 and MDA-MB-231, thus establishing the structure-activity relationship. The FKB derivatives 16 (IC50 = 6.50 ± 0.40 and 4.12 ± 0.20 μg/mL), 15 (IC50 = 5.50 ± 0.35 and 6.50 ± 1.40 μg/mL) and 13 (IC50 = 7.12 ± 0.80 and 4.04 ± 0.30 μg/mL) exhibited potential cytotoxic effects on the MCF-7 and MDA-MB-231 cell lines. However, the methoxy group substituted in position three and four in compound 2 (IC50 = 8.90 ± 0.60 and 6.80 ± 0.35 μg/mL) and 22 (IC50 = 8.80 ± 0.35 and 14.16 ± 1.10 μg/mL) exhibited good cytotoxicity. The lead compound FKB (1) showed potential cytotoxicity (IC50 = 7.70 ± 0.30 and 5.90 ± 0.30 μg/mL) against two proposed breast cancer cell lines. It is evident that the FKB skeleton is unique for anticancer agents, additionally, the presence of halogens (Cl and F) in position 2 and 3 also improved the cytotoxicity in FKB series. These findings could help to improve the future drug discovery process to treat breast cancer. A molecular dynamics study of active compounds revealed stable interactions within the active site of Janus kinase. The structures of all compounds were determined by ¹H-NMR, EI-MS, IR and UV and X-ray crystallographic spectroscopy techniques.
  15. Fulltext Design, synthesis and cytotoxic effects of curcuminoids on HeLa, K562, MCF-7 and MDA-MB-231 cancer cell lines
    Zamrus SNH, Akhtar MN, Yeap SK, Quah CK, Loh WS, Alitheen NB, et al.
    Chem Cent J, 2018 Mar 19;12(1):31.
    PMID: 29556774 DOI: 10.1186/s13065-018-0398-1
    BACKGROUND: Curcumin is one of the leading compound extracted from the dry powder of Curcuma longa (Zingiberaceae family), which possess several pharmacological properties. However, in vivo administration exhibited limited applications in cancer therapies.

    RESULTS: Twenty-four curcumin derivatives have synthesized, which comprises cyclohexanone 1-10, acetone 11-17 and cyclopentanone 18-24 series. All the curcuminoids were synthesized by the acid or base catalyzed Claisen Schmidt condenstion reactions, in which β-diketone moiety of curcumin was modified with mono-ketone. These curcuminoids 1-24 were screened against HeLa, K562, MCF-7 (an estrogen-dependent) and MDA-MB-231 (an estrogen-independent) cancer cell lines. Among them, acetone series 11-17 were found to be more selective and potential cytotoxic agents. The compound 14 was exhibited (IC50 = 3.02 ± 1.20 and 1.52 ± 0.60 µg/mL) against MCF-7 and MDA-MB-231 breast cancer cell lines. Among the cyclohexanone series, the compound 4 exhibited (IC50 = 11.04 ± 2.80, 6.50 ± 01.80, 8.70 ± 3.10 and 2.30 ± 1.60 µg/mL) potential cytotoxicity against four proposed cancer cell lines, respectively. All the curcucminoids were characterized with the detailed1H NMR, IR, UV-Vis, and mass spectroscopic techniques. The structure of compound 4 was confirmed by using the single X-ray crystallography. Additionally, we are going to report the first time spectral data of (2E,6E)-2,6-bis(2-methoxybenzylidene)cyclohexanone (1). Structure-activity relationships revealed that the mono-carbonyl with 2,5-dimethoxy substituted curcuminoids could be an essential for the future drugs against cancer diseases.

    CONCLUSIONS: Curcuminoids with diferuloyl(4-hydroxy-3-methoxycinnamoyl) moiety with mono carbonyl exhibiting potential cytotoxic properties. The compound 14 was exhibited (IC50 = 3.02 ± 1.20 and 1.52 ± 0.60 µg/mL) against MCF-7 and MDA-MB-231 breast cancer cell lines.

  16. Fulltext Synthesis and crystal structures of N-substituted pyrazolines
    Loh WS, Quah CK, Chia TS, Fun HK, Sapnakumari M, Narayana B, et al.
    Molecules, 2013 Feb 20;18(2):2386-96.
    PMID: 23429377 DOI: 10.3390/molecules18022386
    Four pyrazole compounds, 3-(4-fluorophenyl)-5-phenyl-4,5-dihydro-1H-pyrazole-1-carbaldehyde (1), 5-(4-bromophenyl)-3-(4-fluorophenyl)-4,5-dihydro-1H-pyrazole-1-carbaldehyde (2), 1-[5-(4-chlorophenyl)-3-(4-fluorophenyl)-4,5-dihydro-1H-pyrazol-1-yl]ethanone (3) and 1-[3-(4-fluorophenyl)-5-phenyl-4,5-dihydro-1H-pyrazol-1-yl]propan-1-one (4), have been prepared by condensing chalcones with hydrazine hydrate in the presence of aliphatic acids, namely formic acid, acetic acid and propionic acid. The structures were characterized by X-ray single crystal structure determination. The dihedral angles formed between the pyrazole and the fluoro-substituted rings are 4.64(7)° in 1, 5.3(4)° in 2 and 4.89(6)° in 3. In 4, the corresponding angles for molecules A and molecules B are 10.53(10)° and 9.78(10)°, respectively.
  17. Fulltext 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
    Bindya S, Chidan Kumar CS, Naveen S, Siddaraju BP, Quah CK, Raihan MA
    Acta Crystallogr E Crystallogr Commun, 2019 Feb 01;75(Pt 2):264-267.
    PMID: 30800464 DOI: 10.1107/S205698901900104X
    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.
  18. Fulltext 6-(Hex-5-en-yloxy)naphthalene-2-carb-oxy-lic acid
    Rahman ML, Srinivasa HT, Mohd Yusoff M, Kwong HC, Quah CK
    Acta Crystallogr Sect E Struct Rep Online, 2014 Jun 1;70(Pt 6):o696-7.
    PMID: 24940271 DOI: 10.1107/S1600536814010642
    The asymmetric unit of the title compound, C17H18O3, comprises three independent mol-ecules with similar geometries. In each mol-ecule, the carbonyl group is twisted away from the napthalene ring system, making dihedral angles of 1.0 (2), 1.05 (19)° and 1.5 (2)°. The butene group in all three mol-ecules are disordered over two sets of sites, with a refined occupancy ratio of 0.664 (6):0.336 (6). In the crystal, mol-ecules are oriented with respect to their carbonyl groups, forming head-to-head dimers via O-H⋯O hydrogen bonds. Adjacent dimers are further inter-connected by C-H⋯O hydrogen bonds into chains along the a-axis direction. The crystal structure is further stabilized by weak C-H⋯π inter-actions.
  19. 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
    Chidan Kumar CS, Fun HK, Parlak C, Rhyman L, Ramasami P, Tursun M, et al.
    Spectrochim Acta A Mol Biomol Spectrosc, 2014 Nov 11;132:174-82.
    PMID: 24858359 DOI: 10.1016/j.saa.2014.04.155
    A novel (2E)-1-(5-chlorothiophen-2-yl)-3-(naphthalen-2-yl)prop-2-en-1-one [C17H11ClOS] compound has been synthesized and its structure has been characterized by FT-IR, Raman and single-crystal X-ray diffraction techniques. The isomers, optimized geometrical parameters, normal mode frequencies and corresponding vibrational assignments of the compound have been examined by means of the density functional theory method, employing, the Becke-3-Lee-Yang-Parr functional and the 6-311+G(3df,p) basis set. 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 monoclinic space group P2₁/c with the unit cell parameters a=5.7827(8)Å, b=14.590(2)Å, c=16.138(2)Å and β=89.987 (°). The CC bond of the central enone group adopts an E configuration. There is a good agreement between the theoretically predicted structural parameters and vibrational frequencies and those obtained experimentally.
  20. Fulltext 6-Cyanona-phthalen-2-yl 4-hexyl-benzo-ate
    Rahman ML, Srinivasa HT, Mashitah MY, Kwong HC, Quah CK
    Acta Crystallogr Sect E Struct Rep Online, 2014 May 1;70(Pt 5):o620.
    PMID: 24860410 DOI: 10.1107/S160053681400909X
    In the title compound, C24H23NO2, a whole mol-ecule is disordered over two sets of sites with occupancies in a ratio of 0.692 (6):0.308 (6). In the major disorder component, the naphthalene ring system forms a dihedral angle of 68.6 (5)° with the benzene ring. The corresponding angle in the minor component is 81.6 (10)°. In the crystal, mol-ecules are linked into chains propagating along the b-axis direction via weak C-H⋯O hydrogen bonds. The crystal packing is further consolidated by weak C-H⋯π inter-actions.
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