Investigation of nitro-nitrito photoisomerization: crystal structures of trans-{2,2'-[ethane-1,2-diylbis(nitrilo-methyl-idyne)]diphenolato}(pyridine/4-methyl-pyridine)-nitro-cobalt(III).

The reaction cavities of the nitro groups in the title compounds, trans-{2,2'-[ethane-1,2-diylbis(nitrilo-methyl-idyne)]diphenolato-κ4 O,N,N',O'}(nitro-κN)(pyridine-κN)cobalt(III), [Co(C16H14N2O2)(NO2)(C5H5N)], (I), and trans-{2,2'-[ethane-1,2-diylbis(nitrilo-methyl-idyne)]diphenolato-κ4 O,N,N',O'}(4-methyl-pyridine-κN)(nitro-κN)cobalt(III), [Co(C16H14N2O2)(NO2)(C6H7N)], (II), have been investigated to reveal that the inter-molecular CMe-H⋯O(nitro) contacts in (II) are unfeasible for the nitro-nitrito photochemical linkage isomerization process. In (I), there are two independent complexes showing similar conformations, and the central five-membered chelate ring of the tetra-dentate salen ligand adopts the same absolute configuration. This is the result of pseudo-spontaneous resolution, since the configuration of the five-membered chelate ring may frequently be reversed in solution. In the crystals of (I) and (II), the mol-ecules are linked into three-dimensional networks by C-H⋯O hydrogen bonds.

Investigation of nitro-nitrito photoisomerization: crystal structure of trans-chlorido-nitro-(1,4,8,11-tetra-aza-cyclo-tetra-decane-κ4 N,N',N'',N''')cobalt(III) chloride.

The reaction cavity of the nitro group in the crystal of the title compound, [CoCl(NO2)(C10H24N4)]Cl, (I), was investigated to confirm that it offers sufficient free space for linkage isomerization to occur in accordance with the observed photochemical reactivity. The complex cation has crystallographic 2/m symmetry and the nitro and chloro ligands at the trans positions are statistically disordered. The complete cyclam ligand is generated by symmetry from a quarter of the mol-ecule. In the crystal of (I), the complex cations and Cl- ions are linked into a three-dimensional network by N-H⋯Cl(counter-ion) hydrogen bonds.

Investigation of nitro-nitrito photoisomerization: crystal structures of trans-bis-(acetyl-acetonato-O,O')(pyridine/4-methyl-pyridine/3-hy-droxy-pridine)nitro-cobalt(III).

The reaction cavities of the nitro groups in the title compounds, trans-bis-(acetyl-acetonato-κ2 O,O')(nitro)(pyridine-κN)cobalt(III), [Co(C5H7O2)2(NO2)(C5H5N)], (I), trans-bis-(acetyl-acetonato-κ2 O,O')(4-methyl-pyridine-κN)(nitro)cobalt(III), [Co(C5H7O2)2(NO2)(C6H7N)], (II), and trans-bis-(acetyl-acetonato-κ2 O,O')(3-hy-droxy-pyridine-κN)(nitro)cobalt(III) monohydrate, [Co(C5H7O2)2(NO2)(C5H5NO)]·H2O, (III), have been investigated to reveal that bifurcated inter-molecular C(py)-H⋯O,O contacts in (III) are unfeasible for the nitro-nitrito photochemical linkage isomerization process. In each structure, the pyridine ring and the Co atom lie on a crystallographic mirror plane; in (I) and (II) the nitro group lies in the same plane, whereas in (III), which crystallizes as a monohydrate, the nitro group is disordered over three orientations in a 0.672 (16):0.164 (8):0.164 (8) ratio; the water mol-ecule of crystallization is statistically disordered over two sites adjacent to the mirror plane. In the crystals of (I) and (II), the mol-ecules are linked into [100] chains by C-H⋯O hydrogen bonds, whereas the extended structure of (III) features (010) layers linked by O-H⋯O and C-H⋯O hydrogen bonds. Compounds (I) and (II) were refined as inversion twins.

Investigation of solid-state photochemical nitro-nitrito linkage isomerization: crystal structures of trans-bis-(ethyl-enedi-amine)(iso-thio-cyanato)-nitritocobalt(III) salts: thio-cyanate, chloride monohydrate, and perchlorate-thio-cyanate-(0.75/0.25).

The reaction cavities of the nitro groups in the crystals of the title compounds, trans-[Co(NO2)(NCS)(C2H8N2)2]·X, X = SCN- (I), Cl-·H2O (II), and (ClO4 -)0.75(SCN-)0.25 (III), have been investigated, revealing that the geometry of the inter-molecular N-H⋯O hydrogen bonds in (I) is unsuitable for nitro-nitrito photo-isomerization. The common main building block of these crystal structures is a centrosymmetric pair of complex cations connected by pairwise N-H⋯O(nitro) hydrogen bonds forming an R 2 2(4) ring, which is a narrow diamond shape in (I) but is approximately square in (II) and (III). The structure of (I) was reported earlier [Börtin (1976 ▸). Acta Chem. Scand. A, 30, 503-506] but is described here with an improved disorder model for the thio-cyanate anions and to higher precision.

Crystal structures of (S)-(+)-5-(3-bromo/chloro-4-isopropoxyphen-yl)-5-methyl-imidazolidine-2,4-dione.

In (S)-(+)-5-(3-bromo-4-isopropoxyphen-yl)-5-methyl-imidazolidine-2,4-dione, C13H15BrN2O3, (I), the hydantoin groups are connected via inter-molecular N-H⋯O hydrogen bonds, forming a terraced sheet structure. In the chloro analogue, (S)-(+)-5-(3-chloro-4-isopropoxyphen-yl)-5-methyl-imidazolidine-2,4-dione, C13H15ClN2O3, (II), the inter-molecular N-H⋯O hydrogen-bonding network forms a flat sheet. Comparison of the crystal structures reveals that (II) is more loosely packed than (I).

Crystal structure of 5,5'-di-bromo-3,3'-di-tert-butyl-6,6'-di-methyl-biphenyl-2,2'-diol.

The whole mol-ecule of the title compound, C22H28Br2O2, is generated by twofold rotation symmetry. The dihedral angle of the biphenyl moiety is 85.05 (11)°. The hy-droxy groups show intra-molecular O-H⋯π inter-actions without any other hydrogen-bond acceptors. In the crystal, there are no other significant inter-molecular inter-actions present.

Synthesis of okicamelliaside, a glucoside of ellagic acid with potent anti-degranulation activity.

Okicamelliaside, a glucoside of ellagic acid with potent anti-degranulation activity, was synthesized from ellagic acid. The regioselectivity, solubility, and high reactivity of the intermediates throughout the synthesis were obtained by the complementary use of triisopropylsilyl (TIPS) and methoxyethoxymethyl (MEM) protective groups on the aglycone skeleton.

(-)-Benzyl 2,3-dide-oxy-ß-d-erythro-hex-2-eno-pyran-oside.

In the title compound, C13H16O4, the six-membered ring of the sugar moiety shows a half-chair conformation. In the crystal, mol-ecules are connected via O-H⋯O hydrogen bonds, forming columns around twofold screw axes along the b-axis direction. There is a disorder of the benz-yloxy group, which has two possible orientations with the phenyl group lying on a common plane [site-occupancy factors = 0.589 (9) and 0.411 (9)].

Three derivatives of 4-fluoro-5-sulfonylisoquinoline.

In 4-fluoroisoquinoline-5-sulfonyl chloride, C(9)H(5)ClFNO(2)S, (I), one of the two sulfonyl O atoms lies approximately on the isoquinoline plane as a result of minimizing the steric repulsion between the chlorosulfonyl group and the neighbouring F atom. In (S)-(-)-4-fluoro-N-(1-hydroxypropan-2-yl)isoquinoline-5-sulfonamide, C(12)H(13)FN(2)O(3)S, (II), there are two crystallographically independent molecules (Z' = 2). The molecular conformations of these two molecules differ in that the amine group of one forms an intramolecular bifurcated hydrogen bond with the F and OH groups, whilst the other forms only a single intramolecular N-H···F hydrogen bond. The N-H···F hydrogen bonds correspond to weak coupling between the N(H) and (19)F nuclei, observed in the (1)H NMR solution-state spectra. In (S)-(-)-4-[(4-fluoroisoquinolin-5-yl)sulfonyl]-3-methyl-1,4-diazepan-1-ium chloride, C(15)H(19)FN(3)O(2)S(+)·Cl(-), (III), the isoquinoline plane is slightly deformed, suggestive of a steric effect induced by the bulky substituent on the sulfonyl group.

A new NF-κB inhibitor based on the amino-epoxyquinol core of DHMEQ.

The amino-epoxyquinols 6a and 6b were synthesized as soluble derivatives of an NF-κB inhibitor DHMEQ (1). In spite of the opposite configuration from 1, 6b rather than 6a affected the deactivation of NF-κB, based on NO secretion and MALDI-TOF MS analysis. It was indicated that 6b inhibited the activation by different manner from that of 1.

Swertisin dihydrate.

The title compound, 6-C-glucopyranosyl-7-O-methylapigenin dihydrate, C(22)H(22)O(10).2H(2)O, is a natural C-glucosylflavone. The flavone skeleton is almost planar, the dihedral angle between the pyran moiety and the 4-hydroxyphenyl ring being 9.8 (3) degrees. The basal plane of the pyranosyl ring of the glucose moiety is almost perpendicular to the benzopyran ring system. The flavone skeletons are stacked along the a axis, forming layers parallel to (001). Between these hydrophobic layers, the glucose groups and water molecules of crystallization are connected via O-H...O hydrogen bonds, forming hydrophilic layers.

Ammonium 4-methoxycinnamate.

In the title compound, NH(4)(+).C(10)H(9)O(3)(-), bimolecular layers of the anions are formed between layers of the cations. There are N-H.O hydrogen bonds between the ammonium ion and the carboxylate groups of the anions. In the crystal structure, the C=C moiety of the cinnamate ion makes an angle of 117.1 (2) degrees with that of the nearest neighbour, indicating that a pedal rotation is required before beta-type [2+2]-photodimerization can take place, which is the predominant mode of the photochemistry of this compound.

Photochromism of the inclusion crystals of a new hydroperoxybiindenylidene.

Inclusion crystals of 3,1'-bis-(4-fluorophenyl)-1'-hydroperoxy-3'-hydroxy-1',3'-dihydro-3H-[2,2']biindenyliden-1-one showed photochromic and photomagnetic properties in the solid state.

Rac- and meso-3,3'-Bis(3,5-dimethylphenyl)-3H,3'H-2,2'-biindenylidene-1,1'(2H,2'H)-dione.

In the rac isomer of the title compound, C(34)H(28)O(2), the two C-Ph(dimethylphenyl) bond axes make an angle of 58.7 (1) degrees. There is no short contact between the two 3,5-dimethylphenyl rings, although the dihedral angle between them is 4.93 (7) degrees. The meso isomer has a center of symmetry at the middle of the C=C bond, and the two C-Ph(dimethylphenyl) bond axes are antiparallel to one another.

Single-crystal-to-single-crystal photodimerization of 4-chlorocinnamoyl-O,O'-dimethyldopamine.

[2+2]Photodimerization of the title compound, C(19)H(20)ClNO(3), has been observed in situ by single-crystal X-ray diffraction. Pairs of monomers related by centers of symmetry have parallel C=C bonds at a C.C distance of 4.155 (17) A. Irradiation of a single crystal with a mercury lamp achieves 100% conversion to the dimer. Redetermination of the structure during the course of the reaction revealed a linear correlation between the percent conversion to the dimer and the decrease in the cell Volume. The displacement parameters for the pure dimer structure are substantially smaller than those for the pure monomer structure. The dimerization reaction is also induced by irradiation with X-rays, the induction being stronger with Cu Kalpha than with Mo Kalpha radiation.

Four copper(II) complexes with potentially tetradentate tripodal ligands.

The four title Cu(II) compounds are chloro[(2-furylmethyl)bis(2-pyridylmethyl)amine-N,N',N"]copper(II) perchlorate, [CuCl(C(17)H(17)N(3)O)]ClO(4), (I), chloro{2-[bis(2-pyridylmethyl)amino]ethanolato-N,N',N",O}copper(II) hemi[tetrachlorocopper(II)], [CuCl(C(14)H(17)N(3)O)][CuCl(4)](1/2), (II), chloro[(2-morpholinoethyl)bis(2-pyridylmethyl)amine-N,N',N",N"']copper(II) perchlorate, [CuCl(C(18)H(24)N(4)O)]ClO(4), (III), and chloro[(2-piperidinylethyl)bis(2-pyridylmethyl)amine-N,N',N",N"']copper(II) hexafluorophosphate, [CuCl(C(19)H(26)N(4))]PF(6), (IV). They have tripodal potentially tetradentate ligands. In (I), the O atom of the furan moiety weakly coordinates to the Cu atom at a distance of 2.750 (3) A.

micro-Acetato-O:O'-bis{[bis(salicylidene)ethylenediaminato]manganese(III)} perchlorate.

In the title complex, [Mn(2)(C(16)H(14)N(2)O(2))(2)(C(2)H(3)O(2))]ClO(4), two [Mn(salen)] moieties [salen is bis(salicylidene)ethylenediamine] are connected through a micro-acetate bridge in a syn-anti fashion. The Mn.Mn distance is 5.365 (1) A.

micro-Chloro-bis{[benzylbis(2-pyridylmethyl)amine-kappa(3)N]chlorocopper(II)} perchlorate hemihydrate.

In the title dinuclear Cu(II) compound, [Cu(2)Cl(3)(C(19)H(19)N(3))(3)]ClO(4).0.5H(2)O, the coordination geometry around the Cu atoms is square pyramidal, with the bridging Cl atom at the apical positions. The Cu-Cl-Cu angle is 136.9 (1) degrees and the Cu.Cu distance is 4.961 (1) A.

Redetermination of bis{[(2-hydroxyphenylmethyl)bis(2-pyridylmethyl)aminato]copper(II)} diperchlorate.

The structure of the title compound, [Cu(2)(C(19)H(18)N(3)O)(2)](ClO(4))(2), was reported with insufficient accuracy because of a twinning problem by Adams, Bailey, Campbell, Fenton & He [J. Chem. Soc. Dalton Trans. (1996), pp. 2233-2237]. The dinuclear phenolate-bridged Cu(II) complex has an inversion centre.

(-)-(3S)-4-(2-{[4,4-Dimethoxy-6-(benzyloxymethyl)perhydropyran-2-yl]methyl}-1,3-dithian-2-yl)-4-methyl-3-(1,1,2,2-tetramethyl-1-silapropoxy)pentan-1-ol.

The absolute configuration was determined for the title compound, (-)-C(32)H(56)O(6)S(2)Si, (I), which was prepared in a synthetic study on the natural products bryostatins. Two independent molecules show similar conformations, except for the orientation of the methoxy groups.