Oligo-nuclear silver thiocyanate complexes with monodentate tertiary phosphine ligands, including novel 'cubane' and 'step' tetramer forms of AgSCN : PR3 (1:1)4.

Adducts of a number of tertiary pnicogen ligands ER(3) (triphenyl-phosphine and -arsine (PPh(3),AsPh(3)), diphenyl,2-pyridylphosphine (PPh(2)py), tris(4-fluorophenyl)phosphine (P(C(6)H(4)-4F)(3)), tris(2-tolyl)phosphine (P(o-tol)(3)), tris(cyclohexyl)phosphine (PCy(3))), with silver(I) thiocyanate, AgSCN are structurally and spectroscopically characterized. The 1:3 AgSCN : ER(3) complexes structurally defined (for PPh(3),AsPh(3) (diversely solvated)) take the form [(R(3)E)(3)AgX], the thiocyanate X = NCS being N-bound, thus [(Ph(3)E)Ag(NCS)]. A 1:2 complex with PPh(2)py, takes the binuclear form [(pyPh(2)P)(2)Ag()Ag(PPh(2)py)(2)] with an eight-membered cyclic core.

Synthesis and conformation of fluorinated β-peptidic compounds.

Experimental and theoretical data indicate that, for α-fluoroamides, the F-C-C(O)-N(H) moiety adopts an antiperiplanar conformation. In addition, a gauche conformation is favoured between the vicinal C-F and C-N(CO) bonds in N-β-fluoroethylamides. This study details the synthesis of a series of fluorinated β-peptides (1-8) designed to use these stereoelectronic effects to control the conformation of β-peptide bonds.

Aspidospermatan-aspidospermatan and eburnane-sarpagine bisindole alkaloids from Leuconotis.

Leucofoline and leuconoline, representing the first members of the aspidospermatan-aspidospermatan and eburnane-sarpagine subclasses of the bisindole alkaloids, respectively, were isolated from the Malayan Leuconotis griffithii. The structures of these bisindole alkaloids were established using NMR and MS analysis, and in the case of leuconoline, confirmed by X-ray diffraction analysis. Both alkaloids showed weak cytotoxicity towards human KB cells.

Syntheses, structures and spectroscopy of uni- and bi-dentate nitrogen base complexes of silver(I) trifluoromethanesulfonate.

In extension of recent synthetic and crystallographic studies of adducts of silver(I) oxyanion salts with uni- and bi-dentate nitrogen-donor ligands, AgX : L (1 : n), a parallel series of complexes formed with silver(I) trifluoromethanesulfonate ('tfs', 'triflate') has been similarly defined, showing rather more divergence from tendencies established with the previous ClO(4), NO(3), F(3)CCO(2) core arrays than might be expected from basicity arguments. Thus, while silver triflate crystallised from neat base forms 1 : 2 mononuclear adducts with 2,4,6-trimethylpyridine and quinoline which comprise essentially linear two-coordinate [LAgL](+) cations, perturbed by approaches of the anions, 1 : 2 adducts obtained similarly from pyridine and 2-methylpyridine are [L(2)Ag(mu-tfs)(2)AgL(2)] dimers, with central four- and eight-membered rings arising from mu-OSO(2)CF(3) and extended mu-(O,O'SOCF(3)) anion bridging modes, respectively. With piperidine, a single-stranded polymer reminiscent of the arrays [(pip)(2)AgX](infinity/infinity), X = Cl, NCS, is formed, the triflate bridging through two of its oxygen atoms, rather than via a single atom bridge.

N'-[1-(5-Bromo-2-hydroxy-phen-yl)ethyl-idene]-3,4,5-trihydroxy-benzohydrazide dimethyl sulfoxide solvate trihydrate.

The benzohydrazide mol-ecule in the title compound, C(15)H(13)BrN(2)O(5)·C(2)H(6)OS·3H(2)O, is almost planar with an r.m.s.

Bis(pyridine-κN){N,N-[1,1'-(pyridine-2,6-di-yl)diethyl-idyne]benzene-sulfono-hydrazonato-κO,N,N',N'',O'}nickel(II).

In the crystal structure of the title compound, [Ni(C(21)H(19)N(5)O(4)S(2))(C(5)H(5)N)(2)], the metal center is seven-coordinate, with an approximate penta-gonal-bipyramidal configuration. The Ni atom is chelated by a dianionic penta-dentate Schiff base via the pyridine N atom, the two azomethine N atoms and the two sulfonyl O atoms. The latter coordinate to Ni at different distances, viz.

Crystal structure and magnetism of a well isolated 2D-quantum Heisenberg antiferromagnet, (Quinolinium)(2)CuBr(4).2H(2)O, and its anhydrous form.

Reaction of quinoline with HBr and CuBr(2) generates a mixture of two compounds, (quinolinium)(2)CuBr(4).2H(2)O (1) and (quinolinium)(2)CuBr(4) (2) for which single-crystal X-ray structures have been solved. Compound 1 crystallizes in the monoclinic space group C2/c as layers of tetrabromocuprate ions which are separated by intervening layers of quinolinium ions.

Leucophyllidine, a cytotoxic bisindole alkaloid constituted from the union of an eburnan and a new vinylquinoline alkaloid.

A cytotoxic bisindole alkaloid possessing an unprecedented structure constituted from the union of an eburnan half and a novel vinylquinoline alkaloid has been isolated from Leuconotis griffithii. The structure was established by analysis of the spectroscopic data and confirmed by X-ray diffraction analysis. A possible biogenetic pathway to the novel quinolinic coupling partner is presented from an Aspidosperma precursor.

3,4,5-Trihydr-oxy-N'-[(1-methyl-1H-indol-2-yl)methyl-idene]benzohydrazide.

The structure of the title compound, C(17)H(15)N(3)O(4), displays inter-molecular O-H⋯N and O-H⋯O hydrogen bonding between adjacent mol-ecules. Intra-molecular O-H⋯O hydrogen bonds also occur. The molecule is essentially planar with a deviation of 0.

N'-(2,4-Dimethoxy-benzyl-idene)-3,4,5-trihydroxy-benzohydrazide ethanol solvate.

The title compound, C(16)H(16)N(2)O(6)·C(2)H(5)OH, was synthesized from 3,4,5-trihydroxy-benzoyl-hydrazide and 2,4-dimethoxy-benzaldehyde in ethanol. The compound is not planar, with the two aromatic planes of the two aromatic rings twisted by 15.6 (1)°.

catena-Poly[[triphenyl-tin(IV)]-μ-2-[(3,5-di-tert-butyl-4-hydroxy-benz-yl)sulfan-yl]acetato-κO:O'].

The title compound, [Sn(C(6)H(5))(3)(C(17)H(25)O(3)S)](n), comprises two symmetry-independent five-coordinated triphenyl-tin mol-ecules which are linked by carboxyl-ate bridges into a polymeric chain. The Sn(IV) atom is in a distorted trans-C(3)SnO(2) trigonal-bipyramidal geometry. The presence of two bulky tert-butyl groups on the benzene ring prevents any hydrogen-bonding inter-actions involving the hydroxyl substituents.

2-(Benzo[d]thia-zol-2-ylsulfon-yl)-1-(4-bromo-phen-yl)ethanone.

In the title mol-ecule, C(15)H(10)BrNO(3)S(2), the dihedral angle between the benzothia-zole ring system and the benzene ring is 67.57 (12)°. The crystal structure is stabilized by weak inter-molecular C-H⋯O inter-actions.

3,4,5-Trihydr-oxy-N'-(1H-indol-2-ylmethyl-idene)benzohydrazide-1H-indole-2-carbaldehyde azine-methanol (2/1/2).

The title compound, 2C(16)H(13)N(3)O(4)·C(18)H(14)N(4)·2CH(4)O, was crystallized from the reaction between 3,4,5-trihydroxy-benzoyl-hydrazine and indole-2-carbaldehyde in a mixture of ethanol and methanol. The compound is a stoichiometric 2:1 cocrystal of the methanol-solvated reaction product, 3,4,5-trihydr-oxy-N'-(1H-indol-2-ylmethyl-idene)benzohydrazide and 1H-indole-2-carbaldehyde azine that arose unexpectedly during the synthesis. The former mol-ecules are linked by O-H⋯O hydrogen bonds and also by π-π stacking inter-actions between benzoyl-hydrazide rings into a two-dimensional network.

A second monoclinic polymorph of 2-(diformyl-methyl-idene)-3,3-dimethyl-2,3-dihydro-1H-indole.

The crystal structure of the title compound, C(13)H(13)NO(2), is a polymorph of the structure first reported by Helliwell et al. [Acta Cryst. (2006), E62, o737-o738].

(E)-3-(6-Nitro-benzo[d][1,3]dioxol-5-yl)-1-(2,4,6-trimethoxy-phen-yl)prop-2-en-1-one.

In the mol-ecule of the title compound, C(19)H(17)NO(8), the benzodioxole unit is oriented at a dihedral angle of 61.45 (6)° with respect to the meth-oxy-substituted phenyl ring. The nitro group is not co-planar to the benzene ring to which it is attached, making a dihedral angle of 31.

2-(1,3-Benzothia-zol-2-ylsulfan-yl)-1-phenyl-ethanone.

In the mol-ecule of the title compound, C(15)H(11)NOS(2), the 1,3-benzothia-zole ring is oriented at a dihedral angle of 6.61 (6)° with respect to the phenyl ring. In the crystal structure, inter-molecular C-H⋯O inter-actions link the mol-ecules in a herring-bone arrangement along the b axis and π-π contacts between the thia-zole and phenyl rings [centroid-centroid distance = 3.

2-(1,3-Benzoxazol-2-ylsulfan-yl)-1-phenyl-ethanone.

In the title compound, C(15)H(11)NO(2)S, a new thio-benzoxazole derivative, the dihedral angle between the benzoxazole ring and the phenyl ring is 9.91 (9)°. An inter-esting feature of the crystal structure is the short C⋯S [3.

Bis[4-(dimethyl-amino)pyridinium] tetra-bromidobis(4-methyl-phen-yl)stannate(IV).

In the title compound, (C(7)H(11)N(2))(2)[SnBr(4)(C(7)H(7))(2)], the tetra-bromidobis(4-methyl-phen-yl)stannate(IV) anion possesses a centre of inversion located at the Sn(IV) atom. In the crystal structure, two inversion-related cations are linked to the anion via weak N-H⋯Br hydrogen bonds.

Bis[4-(dimethyl-amino)pyridinium] tetra-bromidobis(4-chloro-phen-yl)stannate(IV)-4-bromo-chloro-benzene (1/1).

In the title compound, (C(7)H(11)N(2))(2)[SnBr(4)(C(6)H(4)Cl)(2)]·C(6)H(4)BrCl, the Sn(IV) atom in the tetra-bromidobis(4-chloro-phen-yl)stannate(IV) anion lies on a centre of inversion. The distances between the 4-(dimethyl-amino)pyridinium N atom and the Br atoms of the anion are 3.450 (2) and 3.

N-[1-(2-Hydroxy-phen-yl)ethyl-idene]-N-(1H-indol-3-ylmethyl-ene)carbonic dihydrazide.

In the crystal structure of the title compound {alternative name: 1-[1-(2-hydroxy-phen-yl)ethyl-ideneamino]-3-(1H-indol-3-ylmethyl-eneamino)urea}, C(18)H(17)N(5)O(2), the planar indole component is twisted at an angle of 63.7 (10)° with respect to the rest of the mol-ecule. This compound is one of a series being studied for biological activity.

2-Hydr-oxy-5-nitro-benzaldehyde thio-semicarbazone.

The mol-ecule of the title compound, C(8)H(8)N(4)O(3)S, is planar. Adjacent mol-ecules are linked through O-H⋯S, N-H⋯S and N-H⋯O hydrogen bonds into a three-dimensional network.

N'-(5-Bromo-2-hydroxy-benzyl-idene)-3,4,5-trihydroxy-benzohydrazide dihydrate.

The title compound, C(14)H(11)BrN(2)O(5)·2H(2)O, crystallizes as hydrogen-bonded sheets. The 2-hydr-oxy group on the benzyl-idene group forms an intra-molecular hydrogen bond to the N atom of the C=N double bond. The amino N atom is a hydrogen-bond donor to a water mol-ecule.

N'-(2-Hydr-oxy-5-nitro-benzyl-idene)benzene-sulfonohydrazide.

The mol-ecule of the title compound, C(13)H(11)N(3)O(5)S, shows a phenyl group and an almost planar intra-molecularly hydrogen-bonded N'-(2-hydr-oxy-5-phenyl-ebenzyl-idene)hydrazino group disposed about the S atom. Adjacent mol-ecules are linked by N-H⋯O(nitro) hydrogen bonds, producing a linear chain that runs along the b axis of the unit cell.

Bis{μ-2-(1H-indol-3-yl)-N'-[1-(5-methyl-2-oxidophen-yl)ethyl-idene]-aceto-hydraz-idato}bis-[aqua-zinc(II)] dimethyl sulfoxide tetra-solvate.

The dinuclear title compound, [Zn(2)(C(19)H(17)N(3)O(2))(2)(H(2)O)(2)]·4C(2)H(6)OS, lies about a center of inversion. The deprotonated monoanion O,N,O-chelates the Zn atom; the hydr-oxy O atom also engages in bonding to the symmetry-related Zn atom so that one N and three O atoms form a square around the metal. The coordination geometry is square-pyramidal, with the apical site occupied by a water mol-ecule.

Bis{2-bromo-4-chloro-6-[2-(phenyl-sulfon-yl)hydrazonometh-yl]phenolato-κN,O}copper(II).

The Cu atom in the title compound, [Cu(C(13)H(9)BrClN(2)O(3)S)(2)], is chelated by two deprotonated Schiff base ligands in a square-planar coordination geometry; the Cu atom lies on a center of inversion. The -NH- group of one anion forms an intra-molecular hydrogen bond to the phenolate atom of the symmetry-related ion.