Displaying publications 1 - 20 of 51 in total

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  1. Loh ZH, Kwong HC, Lam KW, Teh SS, Ee GCL, Quah CK, et al.
    J Enzyme Inhib Med Chem, 2021 Dec;36(1):627-639.
    PMID: 33557647 DOI: 10.1080/14756366.2021.1882452
    A new series of 3-O-substituted xanthone derivatives were synthesised and evaluated for their anti-cholinergic activities against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). The results indicated that the xanthone derivatives possessed good AChE inhibitory activity with eleven of them (5, 8, 11, 17, 19, 21-23, 26-28) exhibited significant effects with the IC50 values ranged 0.88 to 1.28 µM. The AChE enzyme kinetic study of 3-(4-phenylbutoxy)-9H-xanthen-9-one (23) and ethyl 2-((9-oxo-9H-xanthen-3-yl)oxy)acetate (28) showed a mixed inhibition mechanism. Molecular docking study showed that 23 binds to the active site of AChE and interacts via extensive π-π stacking with the indole and phenol side chains of Trp86 and Tyr337, besides the hydrogen bonding with the hydration site and π-π interaction with the phenol side chain of Y72. This study revealed that 3-O-alkoxyl substituted xanthone derivatives are potential lead structures, especially 23 and 28 which can be further developed into potent AChE inhibitors.
  2. Yasmin S, Rabi S, Chakraborty A, Kwong HC, Tiekink ERT, Roy TG
    Acta Crystallogr E Crystallogr Commun, 2021 Dec 01;77(Pt 12):1316-1322.
    PMID: 34925906 DOI: 10.1107/S2056989021012184
    The title CuII macrocyclic complex salt tetra-hydrate, [Cu(C22H46N6O2)](C2H3O2)2·4H2O, sees the metal atom located on a centre of inversion and coordinated within a 4 + 2 (N4O2) tetra-gonally distorted coordination geometry; the N atoms are derived from the macrocycle and the O atoms from weakly associated [3.2048 (15) Å] acetate anions. Further stability to the three-ion aggregate is provided by intra-molecular amine-N-H⋯O(carboxyl-ate) hydrogen bonds. Hydrogen bonding is also prominent in the mol-ecular packing with amide-N-H⋯O(amide) inter-actions, leading to eight-membered {⋯HNCO}2 synthons, amide-N-H⋯O(water), water-O-H⋯O(carboxyl-ate) and water-O-H⋯O(water) hydrogen bonds featuring within the three-dimensional architecture. The calculated Hirshfeld surfaces for the individual components of the asymmetric unit differentiate the water mol-ecules owing to their distinctive supra-molecular association. For each of the anion and cation, H⋯H contacts predominate (50.7 and 65.2%, respectively) followed by H⋯O/O⋯H contacts (44.5 and 29.9%, respectively).
  3. Tan MY, Kwong HC, Crouse KA, Ravoof TBSA, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2021 Aug 01;77(Pt 8):788-794.
    PMID: 34422302 DOI: 10.1107/S2056989021006666
    The title thio-urea derivative, C17H19N3OS, adopts a U-shaped conformation with the dihedral angle between the terminal aromatic rings being 73.64 (5)°. The major twist in the mol-ecule occurs about the ethane bond with the Ci-Ce-Ce-Cb torsion angle being -78.12 (18)°; i = imine, e = ethane and b = benzene. The configuration about the imine bond is E, the N-bound H atoms lie on opposite sides of the mol-ecule and an intra-molecular amine-N-H⋯N(imine) hydrogen bond is evident. In the mol-ecular packing, hydroxyl-O-H⋯S(thione) and amine-N-H⋯O hydrogen bonding feature within a linear, supra-molecular chain. The chains are connected into a layer in the ab plane by a combination of methyl-ene-C-H⋯S(thione), methyl-ene-C-H⋯O(hydrox-yl), methyl-C-H⋯π(phen-yl) and phenyl-C-H⋯π(hy-droxy-benzene) inter-actions. The layers stack without directional inter-actions between them. The analysis of the calculated Hirshfeld surface highlights the presence of weak methyl-C-H⋯O(hydrox-yl) and H⋯H inter-actions in the inter-layer region. Computational chemistry indicates that dispersion energy is the major contributor to the overall stabilization of the mol-ecular packing.
  4. Tan MY, Kwong HC, Crouse KA, Ravoof TBSA, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2021 Aug 01;77(Pt 8):839-846.
    PMID: 34422312 DOI: 10.1107/S2056989021007398
    The title zinc bis-(thio-semicarbazone) complex, [Zn(C22H17N4O2S)2], comprises two N,S-donor anions, leading to a distorted tetra-hedral N2S2 donor set. The resultant five-membered chelate rings are nearly planar and form a dihedral angle of 73.28 (3)°. The configurations about the endocyclic- and exocyclic-imine bonds are Z and E, respectively, and that about the ethyl-ene bond is E. The major differences in the conformations of the ligands are seen in the dihedral angles between the chelate ring and nitro-benzene rings [40.48 (6) cf. 13.18 (4)°] and the N-bound phenyl and nitro-benzene ring [43.23 (8) and 22.64 (4)°]. In the crystal, a linear supra-molecular chain along the b-axis direction features amine-N-H⋯O(nitro) hydrogen bonding. The chains assemble along the 21-screw axis through a combination of phenyl-C-H⋯O(nitro) and π(chelate ring)-π(phen-yl) contacts. The double chains are linked into a three-dimensional architecture through phenyl-C-H⋯O(nitro) and nitro-O⋯π(phen-yl) inter-actions.
  5. Yusof ENM, Kwong HC, Karunakaran T, Ravoof TBSA, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2021 Mar 01;77(Pt 3):286-293.
    PMID: 33953953 DOI: 10.1107/S2056989021001870
    The title diorganotin Schiff base derivative, [Sn(C4H9)2(C15H13N3O2S)], features a penta-coordinated tin centre defined by the N,O,S-donor atoms of the di-anionic Schiff base ligand and two methyl-ene-C atoms of the n-butyl substituents. The resultant C2NOS donor set defines a geometry inter-mediate between trigonal-bipyramidal and square-pyramidal. In the crystal, amine-N-H⋯O(meth-oxy) hydrogen bonding is found in a helical, supra-molecular chain propagating along the b-axis direction. The chains are assembled into a layer parallel to (01) with methyl-ene-C-H⋯π(phen-yl) inter-actions prominent; layers stack without directional inter-actions between them. The analysis of the calculated Hirshfeld surface showed the presence of weak methyl-ene-C-H⋯π(phen-yl) inter-actions and short H⋯H contacts in the inter-layer region. Consistent with the nature of the identified contacts, the stabilization of the crystal is dominated by the dispersion energy term.
  6. Paulus G, Kwong HC, Crouse KA, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2020 Aug 01;76(Pt 8):1245-1250.
    PMID: 32844007 DOI: 10.1107/S2056989020008762
    The complete mol-ecule of the title hydrazine carbodi-thio-ate derivative, C32H30N4O2S4, is generated by a crystallographic twofold axis that bis-ects the di-sulfide bond. The mol-ecule is twisted about this bond with the C-S-S-C torsion angle of 90.70 (8)° indicating an orthogonal relationship between the symmetry-related halves of the mol-ecule. The conformation about the imine bond [1.282 (2) Å] is E and there is limited delocalization of π-electron density over the CN2C residue as there is a twist about the N-N bond [C-N-N-C torsion angle = -166.57 (15)°]. An intra-molecular hydroxyl-O-H⋯N(imine) hydrogen bond closes an S(6) loop. In the crystal, methyl-ene-C-H⋯π(tol-yl) contacts assemble mol-ecules into a supra-molecular layer propagating in the ab plane: the layers stack without directional inter-actions between them. The analysis of the calculated Hirshfeld surfaces confirm the importance of H⋯H contacts, which contribute 46.7% of all contacts followed by H⋯C/C⋯H contacts [25.5%] reflecting, in part, the C-H⋯π(tol-yl) contacts. The calculation of the inter-action energies confirm the importance of the dispersion term and the influence of the stabilizing H⋯H contacts in the inter-layer region.
  7. Yeo CI, Tan SL, Kwong HC, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2020 Aug 01;76(Pt 8):1284-1290.
    PMID: 32844015 DOI: 10.1107/S2056989020009469
    The title phosphanegold(I) thiol-ate, C26H22AuFNOPS or [Au(C8H7FNOS)(C18H15P)], has the AuI centre coordinated by phosphane-P [2.2494 (8) Å] and thiol-ate-S [2.3007 (8) Å] atoms to define a close to linear geometry [P-Au-S = 176.10 (3)°]. The thiol-ate ligand is orientated so that the meth-oxy-O atom is directed towards the Au atom, forming an Au⋯O close contact of 2.986 (2) Å. In the crystal, a variety of inter-molecular contacts are discerned with fluoro-benzene-C-H⋯O(meth-oxy) and phenyl-C-H⋯F inter-actions leading to dimeric aggregates. These are assembled into a three-dimensional architecture by phenyl-C-H⋯S(thiol-ate) and phenyl-C-H⋯π(fluorobenzene, phen-yl) inter-actions. Accordingly, the analysis of the calculated Hirshfeld surface shows 30.8% of all contacts are of the type C⋯H/H⋯C but this is less than the H⋯H contacts, at 44.9%. Other significant contributions to the surface come from H⋯F/F⋯H [8.1%], H⋯S/S⋯H [6.9%] and H⋯O/O⋯H [3.2%] contacts. Two major stabilization energies have contributions from the phenyl-C-H⋯π(fluoro-benzene) and fluoro-benzene-C-H⋯C(imine) inter-actions (-37.2 kcal mol-1), and from the fluoro-benzene-C-H⋯F and phenyl-C-H⋯O inter-actions (-34.9 kcal mol-1), the latter leading to the dimeric aggregate.
  8. Khairuanuar NL, Crouse KA, Kwong HC, Tan SL, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2020 Jul 01;76(Pt 7):990-997.
    PMID: 32695439 DOI: 10.1107/S2056989020007070
    The title hydrazine carbodi-thio-ate chloro-form hemisolvate, 2C15H14N2O2S2·CHCl3, comprises two independent hydrazine carbodi-thio-ate mol-ecules, A and B, and a chloro-form mol-ecule; the latter is statistically disordered about its mol-ecular threefold axis. The common features of the organic mol-ecules include an almost planar, central CN2S2 chromophore [r.m.s. deviation = 0.0203 Å (A) and 0.0080 Å (B)], an E configuration about the imine bond and an intra-molecular hydroxyl-O-H⋯N(imine) hydrogen bond. The major conformational difference between the mol-ecules is seen in the relative dispositions of the phenyl rings as indicated by the values of the dihedral angles between the central plane and phenyl ring of 71.21 (6)° (A) and 54.73 (7)° (B). Finally, a difference is seen in the disposition of the outer hydroxyl-H atoms, having opposite relative orientations. In the calculated gas-phase structure, the entire mol-ecule is planar with the exception of the perpendicular phenyl ring. In the mol-ecular packing, the A and B mol-ecules assemble into a two-mol-ecule aggregate via N-H⋯S hydrogen bonds and eight-membered {⋯HNCS}2 synthons. The dimeric assemblies are connected into supra-molecular chains via hydroxyl-O-H⋯O(hydrox-yl) hydrogen bonds and these are linked into a double-chain through hy-droxy-O-H⋯π(phen-yl) inter-actions. The double-chains are connected into a three-dimensional architecture through phenyl-C-H⋯O(hydrox-yl) and phenyl-C-H⋯π(phen-yl) inter-actions. The overall assembly defines columns along the a-axis direction in which reside the chloro-form mol-ecules, which are stabilized by chloro-form-methine-C-H⋯S(thione) and phenyl-C-H⋯Cl contacts. The analysis of the calculated Hirshfeld surfaces, non-covalent inter-action plots and inter-action energies confirm the importance of the above-mentioned inter-actions, but also of cooperative, non-standard inter-actions such as π(benzene)⋯π(hydrogen-bond-mediated-ring) contacts.
  9. Dallasta Pedroso S, Caracelli I, Zukerman-Schpector J, Soto-Monsalve M, De Almeida Santos RH, Correia CRD, et al.
    Acta Crystallogr E Crystallogr Commun, 2020 Jul 01;76(Pt 7):1080-1086.
    PMID: 32695456 DOI: 10.1107/S2056989020007914
    The title compound, C23H24N2O9, is a tetra-substituted pyrrolidine derivative with a twisted conformation, with the twist evident in the C-C bond bearing the adjacent acet-yloxy substituents. These are flanked on one side by a C-bound 4-meth-oxy-phen-yl group and on the other by a methyl-ene group. The almost sp 2-N atom [sum of angles = 357°] bears a 4-nitro-benzyl-oxycarbonyl substituent. In the crystal, ring-methyl-ene-C-H⋯O(acet-yloxy-carbon-yl) and methyl-ene-C-H⋯O(carbon-yl) inter-actions lead to supra-molecular layers lying parallel to (01); the layers stack without directional inter-actions between them. The analysis of the calculated Hirshfeld surfaces indicates the combined importance of H⋯H (42.3%), H⋯O/O⋯H (37.3%) and H⋯C/C⋯H (14.9%) surface contacts. Further, the inter-action energies, largely dominated by the dispersive term, point to the stabilizing influence of H⋯H and O⋯O contacts in the inter-layer region.
  10. Caracelli I, Zukerman-Schpector J, Kwong HC, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2020 Jul 01;76(Pt 7):1051-1056.
    PMID: 32695451 DOI: 10.1107/S2056989020007380
    The title compound, C20H20N4O3, is constructed about a tri-substituted 1,2,3-triazole ring, with the substituent at one C atom flanked by the C and N atoms being a substituted amide group, and with the adjacent C and N atoms bearing phenyl and benzyl groups, respectively; the dihedral angle between the pendant phenyl rings is 81.17 (12)°, indicative of an almost orthogonal disposition. In the crystal, pairwise amide-N-H⋯O(carbon-yl) hydrogen bonds lead to a centrosymmetric dimer incorporating methyl-ene-C-H⋯π(benzene) inter-actions. The dimers are linked into a supra-molecular layer in the ab plane via methyl-ene-C-H⋯N(azo) and benzene-C-H⋯O(amide) inter-actions; the layers stack along the c-axis direction without directional inter-actions between them. The above-mentioned inter-molecular contacts are apparent in the analysis of the calculated Hirshfeld surface, which also provides evidence for short inter-layer H⋯C contacts with a significant dispersion energy contribution.
  11. Dallasta Pedroso S, Caracelli I, Zukerman-Schpector J, Soto-Monsalve M, De Almeida Santos RH, Correia CRD, et al.
    Acta Crystallogr E Crystallogr Commun, 2020 Jun 01;76(Pt 6):967-972.
    PMID: 32523774 DOI: 10.1107/S205698902000701X
    The title compound, C13H19NO8, is based on a tetra-substituted pyrrolidine ring, which has a twisted conformation about the central C-C bond; the Cm-Ca-Ca-Cme torsion angle is 38.26 (15)° [m = methyl-carboxyl-ate, a = acet-yloxy and me = methyl-ene]. While the N-bound ethyl-carboxyl-ate group occupies an equatorial position, the remaining substituents occupy axial positions. In the crystal, supra-molecular double-layers are formed by weak methyl- and methyl-ene-C-H⋯O(carbon-yl) inter-actions involving all four carbonyl-O atoms. The two-dimensional arrays stack along the c axis without directional inter-actions between them. The Hirshfeld surface is dominated by H⋯H (55.7%) and H⋯C/C⋯H (37.0%) contacts; H⋯H contacts are noted in the inter-double-layer region. The inter-action energy calculations point to the importance of the dispersion energy term in the stabilization of the crystal.
  12. Setifi Z, Kwong HC, Tiekink ERT, Maris T, Setifi F
    Acta Crystallogr E Crystallogr Commun, 2020 Jun 01;76(Pt 6):835-840.
    PMID: 32523750 DOI: 10.1107/S2056989020006271
    The CoII atom in the title complex, [Co(SO4)(C12H8N2)(H2O)3] (or C12H14CoN2O7S), is octa-hedrally coordinated within a cis-N2O4 donor set defined by the chelating N-donors of the 1,10-phenanthroline ligand, sulfate-O and three aqua-O atoms, the latter occupying an octa-hedral face. In the crystal, supra-molecular layers lying parallel to (110) are sustained by aqua-O-H⋯O(sulfate) hydrogen bonding. The layers stack along the c-axis direction with the closest directional inter-action between them being a weak phenanthroline-C-H⋯O(sulfate) contact. There are four significant types of contact contributing to the calculated Hirshfeld surface: at 44.5%, the major contribution comes from O-H⋯O contacts followed by H⋯H (28.6%), H⋯C/C⋯H (19.5%) and C⋯C (5.7%) contacts. The dominance of the electrostatic potential force in the mol-ecular packing is also evident in the calculated energy frameworks. The title complex is isostructural with its manganese, zinc and cadmium containing analogues and isomeric with its mer-tri-aqua analogue.
  13. Rusli AF, Kwong HC, Crouse KA, Jotani MM, Tiekink ERT
    Acta Crystallogr E Crystallogr Commun, 2020 Feb 01;76(Pt 2):208-213.
    PMID: 32071748 DOI: 10.1107/S2056989020000328
    The title hydrazine carbodi-thio-ate, C13H18N2OS2, is constructed about a central and almost planar C2N2S2 chromophore (r.m.s. deviation = 0.0263 Å); the terminal meth-oxy-benzene group is close to coplanar with this plane [dihedral angle = 3.92 (11)°]. The n-butyl group has an extended all-trans conformation [torsion angles S-Cm-Cm-Cm = -173.2 (3)° and Cm-Cm-Cm-Cme = 180.0 (4)°; m = methyl-ene and me = meth-yl]. The most prominent feature of the mol-ecular packing is the formation of centrosymmetric eight-membered {⋯HNCS}2 synthons, as a result of thio-amide-N-H⋯S(thio-amide) hydrogen bonds; these are linked via meth-oxy-C-H⋯π(meth-oxy-benzene) inter-actions to form a linear supra-molecular chain propagating along the a-axis direction. An analysis of the calculated Hirshfeld surfaces and two-dimensional fingerprint plots point to the significance of H⋯H (58.4%), S⋯H/H⋯S (17.1%), C⋯H/H⋯C (8.2%) and O⋯H/H⋯O (4.9%) contacts in the packing. The energies of the most significant inter-actions, i.e. the N-H⋯S and C-H⋯π inter-actions have their most significant contributions from electrostatic and dispersive components, respectively. The energies of two other identified close contacts at close to van der Waals distances, i.e. a thione-sulfur and meth-oxy-benzene-hydrogen contact (occurring within the chains along the a axis) and between methyl-ene-H atoms (occurring between chains to consolidate the three-dimensional architecture), are largely dispersive in nature.
  14. Arafath MA, Kwong HC, Adam F, Mohiuddin M, Sarker MS, Salim M, et al.
    Acta Crystallogr E Crystallogr Commun, 2020 Jan 01;76(Pt 1):91-94.
    PMID: 31921459 DOI: 10.1107/S2056989019016852
    The mol-ecule of the title compound, C28H22N4O9, exhibits crystallographically imposed twofold rotational symmetry, with a dihedral angle of 66.0 (2)° between the planes of the two central benzene rings bounded to the central oxygen atom. The dihedral angle between the planes of the central benzene ring and the terminal phenol ring is 4.9 (2)°. Each half of the mol-ecule exhibits an imine E configuration. An intra-molecular O-H⋯N hydrogen bond is present. In the crystal, the mol-ecules are linked into layers parallel to the ab plane via C-H⋯O hydrogen bonds. The crystal studied was refined as a two-component pseudomerohedral twin.
  15. Arif Tawfeeq N, Kwong HC, Mohamed Tahir MI, Ravoof TBSA
    Acta Crystallogr E Crystallogr Commun, 2019 Nov 01;75(Pt 11):1613-1619.
    PMID: 31709078 DOI: 10.1107/S2056989019013458
    In the title hydrazinecarbodi-thio-ate derivative, C27H26N2O2S2, the asymmetric unit is comprised of four mol-ecules (Z = 8 and Z' = 4). The 4-meth-oxy-phenyl rings are slightly twisted away from their attached olefinic double bonds [torsion angles = 5.9 (4)-19.6 (4)°]. The azomethine double bond has an s-trans configuration relative to one of the C=C bonds and an s-cis configuration relative to the other [C=C-C= N = 147.4 (6)-175.7 (2) and 15.3 (3)-37.4 (7)°, respectively]. The torsion angles between the azomethine C=N double bond and hydrazine-1-carbodi-thio-ate moiety indicate only small deviations from planarity, with torsion angles ranging from 0.9 (3) to 6.9 (3)° and from 174.9 (3) to 179.7 (2)°, respectively. The benzyl ring and the methyl-enesulfanyl moiety are almost perpendicular to each other, as indicated by their torsion angles [range 93.7 (3)-114.6 (2)°]. In the crystal, mol-ecules are linked by C-H⋯O, N-H⋯S and C-H⋯π(ring) hydrogen-bonding inter-actions into a three-dimensional network. Structural details of related benzyl hydrazine-1-carbodi-thio-ate are surveyed and compared with those of the title compound.
  16. Arafath MA, Kwong HC, Adam F
    Acta Crystallogr E Crystallogr Commun, 2019 Oct 01;75(Pt 10):1486-1489.
    PMID: 31636980 DOI: 10.1107/S2056989019012623
    The PtII atom in the title complex, [Pt(C15H18N4O4S)(C2H6OS)], exists within a square-planar NS2O donor set provided by the N, S, O atoms of the di-anionic tridentate thio-semicarbazo ligand and a dimethyl sulfoxide S atom. The two chelate rings are coplanar, subtending a dihedral angle of 1.51 (7)°. The maximum deviation from an ideal square-planar geometry is seen in the five-membered chelate ring with an S-Pt-S bite angle of 96.45 (2)°. In the crystal, mol-ecules are linked via N-H⋯O, C-H⋯O, C-H⋯N and C-H⋯π inter-actions into two-dimensional networks lying parallel to the ab plane. The conformations of related cyclo-hexyl-hydrazine-1-carbo-thio-amide ligands are compared to that of the title compound.
  17. Chantrapromma S, Kwong HC, Prachumrat P, Kobkeatthawin T, Chia TS, Quah CK
    Acta Crystallogr E Crystallogr Commun, 2019 Aug 01;75(Pt 8):1280-1283.
    PMID: 31417807 DOI: 10.1107/S2056989019010442
    In the title benzohydrazide derivative, C14H12N2O4, the azomethine C=N double bond has an E configuration. The hydrazide connecting bridge, (C=O)-(NH)-N=(CH), is nearly planar with C-C-N-N and C-N-N=C torsion angles of -177.33 (10) and -174.98 (12)°, respectively. The 4-hy-droxy-phenyl and 3,4-di-hydroxy-phenyl rings are slightly twisted, making a dihedral angle of 9.18 (6)°. In the crystal, mol-ecules are connected by N-H⋯O and O-H⋯O hydrogen bonds into a three-dimensional network, while further consolidated via π-π inter-actions [centroid-centroid distances = 3.6480 (8) and 3.7607 (8) Å]. The conformation is compared to those of related benzyl-idene-4-hy-droxy-benzohydrazide derivatives.
  18. Arafath MA, Kwong HC, Adam F
    Acta Crystallogr E Crystallogr Commun, 2019 Jul 01;75(Pt 7):1065-1068.
    PMID: 31392026 DOI: 10.1107/S2056989019008946
    The asymmetric unit of the title compound, C15H21N3OS, comprises of two crystallographically independent mol-ecules (A and B). Each mol-ecule consists of a cyclo-hexane ring and a 2-hy-droxy-3-methyl-benzyl-idene ring bridged by a hydrazinecarbo-thio-amine unit. Both mol-ecules exhibit an E configuration with respect to the azomethine C=N bond. There is an intra-molecular O-H⋯N hydrogen bond in each mol-ecule forming an S(6) ring motif. The cyclo-hexane ring in each mol-ecule has a chair conformation. The benzene ring is inclined to the mean plane of the cyclo-hexane ring by 47.75 (9)° in mol-ecule A and 66.99 (9)° in mol-ecule B. The mean plane of the cyclo-hexane ring is inclined to the mean plane of the thio-urea moiety [N-C(=S)-N] by 55.69 (9) and 58.50 (8)° in mol-ecules A and B, respectively. In the crystal, the A and B mol-ecules are linked by N-H⋯S hydrogen bonds, forming 'dimers'. The A mol-ecules are further linked by a C-H⋯π inter-action, hence linking the A-B units to form ribbons propagating along the b-axis direction. The conformation of a number of related cyclo-hexa-nehydrazinecarbo-thio-amides are compared to that of the title compound.
  19. Arif Tawfeeq N, Kwong HC, Mohamed Tahir MI, Ravoof TBSA
    Acta Crystallogr E Crystallogr Commun, 2019 Jun 01;75(Pt 6):774-779.
    PMID: 31391964 DOI: 10.1107/S2056989019006480
    In the title bis-chalcone, C17H12Br2O, the olefinic double bonds are almost coplanar with their attached 4-bromo-phenyl rings [torsion angles = -10.2 (4) and -6.2 (4)°], while the carbonyl double bond is in an s-trans conformation with with respect to one of the C=C bonds and an s-cis conformation with respect to the other [C=C-C=O = 160.7 (3) and -15.2 (4)°, respectively]. The dihedral angle between the 4-bromo-phenyl rings is 51.56 (2)°. In the crystal, mol-ecules are linked into a zigzag chain propagating along [001] by weak C-H⋯π inter-actions. The conformations of related bis-chalcones are surveyed and a Hirshfeld surface analysis is used to investigate and qu-antify the inter-molecular contacts.
  20. Arafath MA, Kwong HC, Adam F
    Acta Crystallogr E Crystallogr Commun, 2019 May 01;75(Pt 5):571-575.
    PMID: 31110788 DOI: 10.1107/S2056989019004444
    In the title compound, C10H13N3OS, the azomethine C=N double bond has an E configuration. The phenyl ring and methyl-hydrazine carbo-thio-amide moiety [maximum deviation = 0.008 (2) Å] are twisted slightly with a dihedral angle of 14.88 (10)°. In the crystal, mol-ecules are linked into sheets parallel to the ab plane via N-H⋯S hydrogen bonds and C-H⋯π inter-actions.
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