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Biomedical subjects

Anwar Usman

Publications and source records attributed to Anwar Usman.

At least 37 records · Page 2Linked to original sources
PubMed2002

Di-mu-sulfido-bis[diaqua(18-crown-6)barium(II)]-saccharin (1/2).

The molecule of the title compound [systematic name: di-mu-sulfido-bis[diaqua(1,4,7,10,13,16-hexaoxacyclooctadecane-kappa(6)O)barium(II)] bis[1,2-benzisothiazol-3(2H)-one 1,1-dioxide]], [Ba(2)S(2)(C(12)H(24)O(6))(2)(H(2)O)(4)](C(7)H(5)NO(3)S)(2), lies on an inversion centre. The Ba(II) atom encapsulated by the 18-crown-6 ring is coordinated by the six O atoms of the crown, two water O atoms and two bridging S atoms. The four-membered ring composed of the Ba(II) atoms and the bridging S atoms makes a dihedral angle of 67.1 (1) degrees with the crown-ether ring. The aromatic ring system of the saccharin moiety is essentially planar. The packing is built up from layers of the molecules and is stabilized by three intermolecular O-H.O hydrogen bonds.

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PubMed2002

The ternary complex 4-(2-pyridyl)pyridinium-3,5-dinitrobenzoate-3,5-dinitrobenzoic acid (1/1/1).

In the title ternary complex, C(10)H(9)N(2)(+).C(7)H(3)N(2)O(6)(-).C(7)H(4)N(2)O(6), the pyridinium cation adopts the role of the donor in an intermolecular N-H.O hydrogen-bonding interaction with the carboxylate group of the 3,5-dinitrobenzoate anion. The molecules of the ternary complex form molecular ribbons perpendicular to the b direction, which are stabilized by one N-H.O, one O-H.O and five C-H.O intermolecular hydrogen bonds. The ribbons are further interconnected by three intermolecular C-H.O hydrogen bonds into a three-dimensional network.

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PubMed2002

Bis[1-(pyridin-2-yl)ethanone-kappa N 4-phenylthiosemicarbazonato-kappa 2N4,S]manganese(II).

One half of the molecule of the title complex, [Mn(C(14)H(13)N(4)S)(2)], is related to the other half by a twofold axis passing through the Mn atom. This high-spin Mn atom is six-coordinated, in an octahedral geometry, by the azomethine N, the pyridyl N and the thiolate S atom of two planar 1-(pyridin-2-yl)ethanone N(4)-phenylthiosemicarbazone ligands. In the crystal, the molecules are interconnected by N-H.S and C-H.N interactions, forming a three-dimensional network.

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PubMed2002

11-Methyl-12a-phenyl-9a,12a-dihydrophenanthro[9',10:5,6][1,4]dioxino[2,3-d]thiazole.

In the title compound, C(24)H(17)NO(2)S, the dioxine and thiazoline rings are distorted from planarity towards a half-chair and an envelope conformation, respectively. The configurations of the dioxine ring, the thiazoline ring and the attached phenyl ring are conditioned by the sp(3) state of the two bridgehead C atoms. The phenanthrene system is nearly coplanar with the dioxine ring, while the attached phenyl ring is orthogonal to the thiazoline ring.

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PubMed2002

11-Methyl-12a-phenyl-9a,12a-dihydrophenanthro[9',10':5,6][1,4]dioxino[2,3-d]oxazole and 9a-(10-hydroxyphenanthren-9-yl)-11,12a-diphenyl-9a,12a-dihydrophenanthro[9',10':5,6][1,4]dioxino[2,3-d]oxazole.

In the title compounds, C(24)H(17)NO(3), (I), and C(43)H(27)NO(5), (II), the dioxine ring is not planar and tends toward a boat conformation. The oxazoline ring adopts a twisted conformation in molecule (I) but is essentially planar in molecule (II). The configuration of the dioxine-oxazoline system is determined by the sp(3) state of the two shared atoms. The phenanthrene moiety is nearly coplanar with the dioxine ring, while the phenyl ring is perpendicular to the attached oxazole ring. The triclinic unit cell of (II) contains two crystallographically independent molecules related by a pseudo-inversion centre.

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PubMed2002

(Dibenzyl sulfoxide-kappa O)bis(1,3-diphenylpropane-1,3-dionato-kappa(2)O,O')dioxouranium(VI).

In the title compound, [UO(2)(C(15)H(11)O(2))(2)(C(14)H(14)OS)], the U(VI) atom is coordinated by seven O atoms in a distorted pentagonal-bipyramidal geometry. Both diphenylpropane-1,3-dionate systems are nearly planar. The sulfoxide moiety is in a distorted tetrahedral geometry, while its two aromatic rings are nearly orthogonal to one another. The crystal packing is stabilized by two bifurcated hydrogen-bonding interactions involving both uranyl O atoms.

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PubMed2002

1-Acetyl-3'-(4-bromophenyl)-3'-chlorospiro[3H-indole-3,2'-oxetan]-2(1H)-one.

In the title compound, C(18)H(13)BrClNO(3), the heterocyclic ring of the indole is distorted from planarity towards an envelope conformation. The orientations of the indole, oxetane, chloro and bromophenyl substituents are conditioned by the sp(3) states of the spiro-junction and the Cl-attached C atoms.

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PubMed2002

1-Acetyl-3-[1-(4-methoxyphenyl)-2-oxopropylidene]-1H-indol-2(3H)-one: a twinned crystal.

The crystal of the title compound, C(20)H(17)NO(4), which was used for collecting intensity data was twinned. Each of the two crystallographically independent molecules in the asymmetric unit has a planar indole moiety perpendicular to a planar oxopropyl moiety. The distribution of the bonds at the central C atom joining the oxopropyl, phenyl and indole substituents is also planar. The packing is stabilized by intermolecular C-H* * *O interactions, as well as by dipole-dipole and van der Waals interactions.

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PubMed2002

Bis[hydrogen 1,1'-bis(diphenylphosphinato)ferrocenium] octachlorodiantimony(III).

In the title compound, [Fe(C(34)H(29)O(2)P(2))](2)[Sb(2)Cl(8)], the discrete centrosymmetric [Sb(2)Cl(8)]2- anions are formed from two edge-shared square pyramids of Cl atoms about each Sb atom. Within the cation, the two diphenylphosphinate groups share one H atom and the ferrocene cyclopentadienyl rings are in a staggered conformation, with the average value of the twist angle being 46 degrees. In the crystal, each [Sb(2)Cl(8)]2- anion is involved in eight C-H* * *Cl interactions with four surrounding cations and these interactions interconnect the ions to form molecular columns along the a direction.

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PubMed2002

Bis[1,1'-bis(diphenylphosphino)ferrocenium] hexadecachlorotetraantimony(III) ethanol solvate.

In the title compound, [Fe(C(17)H(14)P)(2)](2)[Sb(4)Cl(16)] x C(2)H(6)O, the Fe atoms lie on inversion centres and the pairs of cyclopentadienyl rings are consequently in a fully staggered conformation. The centrosymmetric anionic clusters formed by [Sb(4)Cl(16)](4-) are surrounded by the cations and are held together by weak C-H...Cl interactions. These formations stack along the a axis to form columns, and the columns are interconnected by another weak C-H...Cl interaction along the b axis.

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PubMed2002

Piperazine-1,4-diium--2,4-dinitrophenolate--water (1/2/2).

In the title 1/2/2 adduct, C(4)H(12)N(2)(2+) x 2C(6)H(3)N(2)O(5)(-) x 2H(2)O, the dication lies on a crystallographic inversion centre and the asymmetric unit also has one anion and one water molecule in general positions. The 2,4-dinitrophenolate anions and the water molecules are linked by two O-H...O and two C-H...O hydrogen bonds to form molecular ribbons, which extend along the b direction. The piperazine dication acts as a donor for bifurcated N-H...O hydrogen bonds with the phenolate O atom and with the O atom of the o-nitro group. Six symmetry-related molecular ribbons are linked to a piperazine dication by N---H.O and C---H.O hydrogen bonds.

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PubMed2002

Dichlorobis(trimethylenethiourea-kappaS)antimony(III) chloride.

In the title compound, [SbCl(2)(C(4)H(8)N(2)S)(2)]Cl, the coordination around the Sb atom can be described as distorted pseudo-octahedral. Both rings of the trimethylenethiourea ligands [alternatively 3,4,5,6-tetrahydropyrimidine-2(1H)-thione] adopt an envelope conformation. The molecules are connected into dimers in the ab plane by two intermolecular hydrogen bonds. The dimers are arranged into infinite one-dimensional chains along the a axis as a result of the Cl(-) ions forming intermolecular hydrogen bonds with three NH groups.

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PubMed2002

Bis(ethylenediamine)copper(II) bis(O,O'-diethyl dithiophosphate).

In the structure of the title compound, [Cu(II)(en)(2)][(EtO)(2)P(S)S](2) (en is ethylenediamine) or [Cu(C(2)H(8)N(2))(2)](C(4)H(10)O(2)PS(2))(2), the Cu atom lies on a center of inversion and is coordinated in a slightly distorted square coordination geometry by four N atoms from two ethylenediamine molecules. The diethyl dithiophosphate moieties, (EtO)(2)P(S)S(-), act as counter-anions.

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PubMed2002

Syn- and anticlinal isomers of 2a'-acetoxy-1,7'-diacetyl-7',7a'-dihydro-2-oxospiro[1H-indole-3(2H),2'(2a'H)-oxeto[3,2-b]indole].

In the syn- and anticlinal isomers of the title compound, C(22)H(18)N(2)O(6), the indole moiety is not completely planar, with the pyrrolidine ring being distorted very slightly towards a conformation intermediate between half-chair and envelope. The molecular and packing structures in the crystals of these isomers are stabilized by C-H...O interactions.

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PubMed2002

New crown-shaped polyoxovanadium(V) cluster cation with a mu(6)-sulfato anion and zwitterionic mu-(beta-alanine): crystal structure of [V(6)O(12)(OH)(3)(O(2)CCH(2)CH(2)NH(3))(3)(SO(4))][Na][SO(4)].13H(2)O.

Treatment of vanadium(V) oxide with an ethanol-concentrated sulfuric acid mixture, followed by the addition of an equimolar amount of beta-alanine and sodium hydroxide, and finally raising the pH to 3.9 with sodium carbonate solution, under continuous heating in a water bath and in the presence of air, leads to the polyionic sodium cyclo-[mu(6)-(sulfato-O,O',O'')tris[mu-(beta-alanine-O,O')-mu-oxo]tris(mu-hydroxo-mu-oxo)hexa[oxovanadium(V)]] sulfate tridecahydrate which crystallizes in the monoclinic P2(1)/n space group [a = 9.5192(4), b = 20.1185(9), c = 22.6174(9) A, beta = 97.011(1) degrees; Z = 4]. The crown-shaped polyoxovanadium(V) cluster cation, with carboxylate-bridging amino acid ligands, has an Anderson structure with two unique capping sulfato ligands. Its structural analysis, together with IR, UV-vis, and preliminary data on its solution properties, is presented.

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PubMed2001

4-[3-(3,4-dimethoxyphenyl)prop-2-enoyl]phenyl methacrylate and 4-[3-(2-bromophenyl)prop-2-enoyl]phenyl methacrylate.

Chalcones (alpha,beta-unsaturated ketones) are effective antitumour agents. It has been proved that having halogen or methoxy groups substituted in various positions of the phenyl ring enhances the activity of chalcones many times. The title compounds, C21H20O5 and C19H15BrO3, respectively, were chosen for crystallographic study in order to determine their structures and conformations. In both compounds, the keto group is in the s-cis conformation and is almost planar. There are weak intramolecular interactions in both structures.

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