Preparation of α- and β-D-glucoseptanose pentaacetates.

The α- and β-D-glucoseptanose pentaacetates have been prepared by treatment of ethyl 1-thio-β-D-glucoseptanoside tetraacetate with mercury(II) acetate in acetic acid. The solid state structure of the β-isomer has been determined by X-ray diffraction.

(3R,4S,5S,8S,10R,13R)-3-Hy-droxy-kaura-9(11),16-dien-18-oic acid.

The title compound, C(20)H(28)O(3), was isolated during our investigation into the chemical composition and pharmacological activity of Centipeda cunninghamii (DC.) A. Braun & Asch.

Isolation of a sultone as an unusual acetolysis product.

Acetolysis of methyl 5,6-di-O-acetyl-2,3-O-isopropylidene-β-L-gulofuranoside has yielded a sultone, 4-(1,2,5,6-tetra-O-acetyl-β-L-gulofuranos-3-yl)-6-methyl-1,2-oxathiin 2,2-dioxide (2) whose structure was determined by X-ray diffraction. (1)H and (13)C NMR spectral properties of 2 are presented together with a rationale for its formation. Preparation and properties of the related α-d-mannofuranos-3-yl compound 4 are described.

Fluxionality in a paramagnetic seven-coordinate iron(II) complex: a variable-temperature, two-dimensional NMR and DFT study.

The preparation and detailed characterizations of the high-spin seven-coordinate complexes [M(kappa(7)N-L)](ClO(4))(2) (M = Mn(II), Fe(II); L = N,N,N',N'-tetrakis(2-pyridylmethyl)-2,6-bis(aminomethyl)pyridine) are described. The X-ray crystal structures reveal seven-coordinate metal complex ions. Consideration of continuous shape measures reveals that the coordination environments about the metal ions are better described as having (C(s)) face-capped trigonal prismatic symmetry than (C(2)) pentagonal bipyramidal symmetry.

2,3-Dichloro-benzene-1,4-diol.

The achiral title compound, C(6)H(4)Cl(2)O(2), crystallizes with O-H⋯O hydrogen bonding linking mol-ecules into layers. Between layers there are chains of Cl⋯Cl⋯Cl inter-actions with alternating distances of 3.274 (2) and 3.

2,8-Dimethyl-tricyclo-[5.3.1.1]dodecane-syn-2,syn-8-diol-propanoic acid (1/1).

The racemic title compound, C(14)H(24)O(2)·C(3)H(6)O(2), crystallizes in the monoclinic space group P2(1)/c as a 1:1 diol/carboxylic acid cocrystal, A-B. The lattice incorporates infinite chains of the alcohol-carboxylic acid-alcohol supra-molecular synthon, (⋯O-H⋯O=C(R)-O-H⋯O-H⋯), in which the hydrogen-bonded mol-ecules (A-B-A)(n) surround a pseudo-threefold screw axis. The carboxylic acid group functions like an extended alcohol hydr-oxy group.

(1R*,2R*,4S*,5R*,6R*,8S*)-4,8-Dimethyl-2,6-diphenyl-bicyclo-[3.3.1]nonane-2,6-diol.

The racemic title compound, C(23)H(28)O(2), crystallizes in the space group C2/c as a layered structure in which a centrosymmetric three hydrogen bond sequence links four molecules. Both hydroxy groups are involved in this arrangement, but they differ in that one participates in two hydrogen bonds while the other takes part in only one. Between layers, the aromatic rings take part in edge-face interactions [shortest C-H⋯C distances 3.

1,4-Dichloro-naphthalene-2,3-diol.

The achiral planar (maximum deviation 0.014 Å) title compound, C(10)H(6)Cl(2)O(2), crystallizes in the chiral space group P2(1)2(1)2(1) in an arrangement incorporating conventional O-H⋯O hydrogen bonding leading to a supra-molecular chain.

7α,15α-Dibromo-8,16-diphenyl-6,7,14,15-tetra-hydro-6α,14α-epithio-cyclo-octa-[1,2-b:5,6-b']diquinoline deuterochloro-form solvate.

In the racemic title compound, C(34)H(22)Br(2)N(2)S·CDCl(3), pairs of diquinoline host mol-ecules form centrosymmetric brick-like dimers utilizing three different aryl edge-to-face inter-actions (EF(1-3)). The dimeric (EF)(6) (i.e.

Chiral and achiral phosphine derivatives of alkylidyne tricobalt carbonyl clusters as catalyst precursors for (asymmetric) inter- and intramolecular Pauson-Khand reactions.

Phosphine derivatives of alkylidyne tricobalt carbonyl clusters have been tested as catalysts/catalyst precursors in intermolecular and (asymmetric) intramolecular Pauson-Khand reactions. A number of new phosphine derivatives of the tricobalt alkylidyne clusters [Co3(micro3-CR)(CO)9] (R = H, CO2Et) were prepared and characterised. The clusters [Co3(micro3-CR)(CO)9-x(PR'3)x] (PR'3 = achiral or chiral monodentate phosphine, x = 1-3) and [Co3(micro3-CR)(CO)7)(P-P)] (P-P = chiral diphosphine; 1,1'- and 1,2-structural isomers) were assayed as catalysts for intermolecular and (asymmetric) intramolecular Pauson-Khand reactions.

5bα,6,7,13bα,14,15-Hexahydro-acridino[4,3-c]acridine.

The racemic title compound, C(24)H(20)N(2), gives spontaneous resolution with the formation of conglomerate crystals in the space group P2(1)2(1)2(1) when crystallized from ethyl acetate. The twisted mol-ecules pack in parallel regions (ab plane) which then form a herringbone pattern along c.

5,7,9,10-Tetra-hydro-5β,10β-methano-3aα,8aα-methyl-propenocyclo-octa-[1,2-c:5,6-c']dipyrazole-3,8(2H,4H)-dione monohydrate.

The racemic title compound, C(15)H(16)N(4)O(2)·H(2)O, crystallizes as a hydrogen-bonded layer structure incorporating the solvent water mol-ecules. Within the layers, there are three distinct hydrogen-bonding motifs which can be classified as R(2) (2)(8), R(4) (2)(8) and R(4) (4)(12).

8-Methyl-5-methyl-ene-2-oxotricyclo[5.3.1.1]dodecan-endo-8-ol.

The title compound, C(14)H(20)O(2), crystallizes with homochiral chains of mol-ecules hydrogen bonded together along the b axis. Adjacent chains in the ab plane contain mol-ecules of the same chirality, leading to a chiral segregation of the mol-ecules into layers.

Tetra-phenyl-phospho-nium hydrogen oxalate.

In the title compound, C(24)H(20)P(+)·C(2)HO(4) (-), two symmetry-independent ion pairs are present. The cations aggregate into puckered sheets via zigzag infinite chains of sixfold phenyl embraces and parallel fourfold phenyl embraces, while the anions form hydrogen-bonded chains between the sheets of cations. In the two independent oxalate anions, the angles between the normals to the two least-squares carboxyl-ate COO planes are unusually large, viz.

cis-[PtBr2{PPh2(4-catechol)}2]: synthesis, crystal structure, and computational modelling of its binding to nanocrystalline TiO2.

The complex cis-[PtBr(2){PPh(2)(4-catechol)}(2)]1 has been synthesized by cleavage of the four methyl groups from cis-[PtCl(2){PPh(2)(4-veratrole)}(2)] using BBr(3), followed by work-up in the presence of excess bromide. An X-ray crystal structure of 1.(ethanol)(2) confirms that the two catechol rings are adjacent to each other and approximately parallel, and therefore well structured to act as double bidentate ligands for adjacent metal atoms on the surface of a nanocrystal.

A paradigm shift in the construction of heterobimetallic complexes: synthesis of group 2 & 4 metal-calix[6]arene complexes.

Deprotonation of calix[6]arenes with barium in methanol followed by the addition of [Ti(OPr(i))(4)] or [Zr(OBu(n))(4)] is effective in the formation of novel dimeric 2:1 barium-titanium(IV)/zirconium(IV) calix[6]arene complexes. In these complexes a central Ti(IV)/Zr(IV) coordinated in the exo-position connects the two calix[6]arenes in the 1,3-alternate conformation, each with an endo-barium sharing common phenolate groups with the titanium/zirconium centre and participating in cation-pi interactions. A homometallic barium calix[6]arene dimer was also prepared wherein the calix[6]arenes are in the 1,3-alternate conformation with each coordinating one endo- and one exo-barium centre.

Pi-halogen dimer interactions and the inclusion chemistry of a new tetrahalo aryl host.

The preparation of 1,4,8,11-tetrabromo-5b[small alpha],6,12b[small alpha],13-tetrahydropentaleno[1,2-b:4,5-b[prime or minute]]diquinoline is described. This is a further member of the tetrahalo aryl host family, and forms crystalline lattice inclusion compounds with many guests. The X-ray structures of the allyl cyanide, 1,2,3-trichloropropane, chlorobenzene, toluene, benzene-water, methyl chloroform and carbon tetrachloride inclusion compounds are described, and compared with that of the solvent-free apohost.

Selective 1,3-complexation of p-(t)Bu-calix[4]arene by [TiCp(2)Me(2)].

Reaction of p-(t)Bu-calix[4]arene with dimethyl titanocene results in high yield selective 1,3-dimetallation of the calixarene in the cone conformation by selective cleavage of one methyl group.

Tetraphenylarsonium iodide, a new determination.

The reported crystal structures of Ph(4)P(+).I(-) and Ph(4)As(+).I(-) have been re-examined.

2:1 Ba/Ti(IV) heterobimetallic complex based on two calix[6]arenes.

Reaction of p-Bu(t)-calix[6]arene with barium metal in methanol then [Ti(OPr(i))4] affords a heterobimetallic complex with a central Ti(IV) attached to two calix[6]arenes in the 1,3-alternate conformation, each with an endo-barium sharing common phenolate groups with the titanium centre.