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Research has been conducted on the diastereoselective 1,4-addition of organocuprates to 3-O-, 4-O, or 6-O-crotonyl derivatives of methyl alpha-D-hexopyranosides. The results of this addition are described.

Pedal-like conformational changes and dimerization of trans-cinnamamide in cocrystals with phthalic acid were observed by in situ x-ray.

A novel ammonium ionophore, which exhibits superior NH(sub 4)(super +) selectivity compared with that of the natural antibiotic nonactin, was successfully designed and synthesized based on a 19-membered crown compound (TD19C6) having three decalino subunits in the macrocyclic system. This bulky decalino subunit is effective for (1) increasing the structural rigidity of the cyclic compound, (2) introducing the 'block-wall effect', which prevents forming a complex with a large ion, and (3) increasing the lipophilicity of the ionophore molecule. In the ammonium ionophore design, the first factor contributes to increasing the NH(sub 4)(super +) selectivity relative to smaller ions such as Li(super +), Na(super +), or even the closest size, K(super +), and the second factor increases the NH(sub 4)(super +) selectivity over larger ions such as Rb(super +) and Cs(super +). The X-ray structural analysis proved that TD19C6 forms a size-fit complex with NH(sub 4)(super +) in its crown ring cavity. As an application of this ionophore, an ion sensor (ion-selective electrode) was prepared, which exhibited NH(sub 4)(super +) to K(super +) and Na(super +) selectivity of 10 and 3000 times, respectively. This electrode showed a better performance compared to the electrode based on nonactin, which is the only ammonium ionophore presently used in practical applications.

Research has been conducted on the Wieland-Miescher ketone enantiomers. Results from yeast strains screening are discussed.

An X-ray study for photoinert 2,4,6-triisopropyl-4'-(methoxycarbonyl)-benzophenone was conducted to identify the possible origin of its remarkable photostability. Results of the study indicated that the distances between the carbonyl oxygen and the o-i-Pr methine hydrogens are within the critical limits for hydrogen abstraction to occur but a narrow reaction cavity or the compact crystal packing around both of the o-i-Pr groups interfering with the photocyclization.

(VO-(Xsalton)), with a C=C double bond in the five-membered chelate ring moiety, was formed from the dehydrogenation of Schiff base-oxovanadium(IV) complexes upon heating at 210 degrees Centigrade for three to 15 hours in the solid state in the air. X-ray structure analyses showed the structure of (VO(3-EtOsal-meso-stien)) to adopt a distorted square pyramid with the oxo atom at the apical position, while the vanadium atom of (VO(3-EtOsalton)) takes on a distorted octahedron conformation.

The preparation and characterization of new tetradentate Schiff base-oxovanadium(IV) complexes (VO-(3-Xsal-(R,R)-2,4-ptn)) containing the H2(3-Xsal-(R,R)-2,4-ptn) N,N'-di-3-Xsalicylidene-(R,R)-2,4-pentanediamine where X = EtO,MeO,H were performed. Consequently, the conversion of the 3-ethoxy substituted complex from an orange polymeric crystal to a green monomeric crystal was achieved after heating for 10 mins. at 170 degrees Celsius. Likewise, its conversion to orange upon suspension in water-acetonitrile solution was carried out.

An experiment of photoirradiation to single, powdered crystals consisting of a chiral host and guest results in the first in situ observation of intramolecular rotation and cyclization of N-methyl-N-{(E)-methylmethacryloyl} anilide.

The selective photocoupling reaction occurring in crystalline adduct of tetracyanobenzene (TCNB) with benzyl cyanide was described. The crystal structural conformation suggested that TCNB and BzCN were interacting through weak charge-transfer (CT) forces. The photochemistry between TCBN-BzCN system in the solution was very different from that in the solid state.

The article focuses on a study on the synthesis of okicamelliaside, a glucoside of ellagic acid with potent anti-degranulation activity. It states that in the study, triisopropylsilyl (TIPS) and methoxyethoxymethyl (MEM) protective groups were used on the aglycone skeleton to obtain the regioselectivity, solubility, and high reactivity of the intermediates throughout the synthesis of okicamelliaside.

In 4-fluoroisoquinoline-5-sulfonyl chloride, C9H5ClFNO2S, (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, C12H13FN2O3S, (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 19F nuclei, observed in the 1H NMR solution-state spectra. In ( S)-(−)-4-[(4-fluoroisoquinolin-5-yl)sulfonyl]-3-methyl-1,4-diazepan-1-ium chloride, C15H19FN3O2S+·Cl−, (III), the isoquinoline plane is slightly deformed, suggestive of a steric effect induced by the bulky substituent on the sulfonyl group. [ABSTRACT FROM AUTHOR]

The title compound, 6-C-glucopyranosyl-7-O-methylapigenin dihydrate, C22H22O10·2H2O, 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)°. 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. [ABSTRACT FROM AUTHOR]

[2+2]Photodimerization of the title compound, C[sub 19]H[sub 20]CINO[sub 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) Å. 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 Kα than with Mo Kg radiation. [ABSTRACT FROM AUTHOR]

Novel polymeric nitridomanganese(V) and nitridochromium(V) complexes with a Schiff base ligand, [MnN(salpn)] and [CrN(salpn)] (H 2 (salpn): N , N '-disalicylidene-1,3-propanediamine) were prepared by photolysis of azido complexes. X-ray crystal structure analyses show that the complexes have an isostructural polymeric structure (···M≡N···M≡N···) with the N···M distances being 2.528(3) Å for M=Mn, and 2.508(2) Å for M=Cr. [ABSTRACT FROM AUTHOR]

In the crystals of trans-4-methylcinnamamide, C10H11NO (I), trans-4-chlorocinnamarnide, C9H8ClNO (II), trans-3-(2-thienyl)acrylamide, C7H7NOS (III), and trans-cinnamamide, C9H9NO (IV), the shortest intermolecular C···C distances between the C=C double bonds are 3.670 (2), 3.632 (2), 3.762 (3) and 4.120 (2) Å, respectively, for the pair of molecules related by a center of symmetry. The structure analysis was also carried out for trans-2-(p-chlorophenyl)-cis-4-(p-chlorophenyl)-1-trans-3-diamidocyclobutane, C18H16Cl2-N2O2, (V), which is the α-type photodimer of (II). The N-H···O hydrogen-bond networks in (I)-(III) are composed of two-dimensional pleated sheets, and those in (IV) and (V) of one-dimensional fiat ribbons. The single crystals of (I), (II) and (IV) were photoirradiated with a 250 W ultra-high-pressure mercury lamp through a band-pass filter or a long- pass fitter for 2-5 h. The photodimer was produced in each crystal with retention of the single-crystal form. The populations of the dimers were converged to 86.2 (4), 48.4 (6) and 4.5 (2)% in the refinement of the crystals after photoirradiation, (I), (II) and (IV), respectively. Although the intermolecular N-H···O hydrogen-bond network remained in (I') and (II'). the network was partly broken in (IV') in the process of photoreaction. [ABSTRACT FROM AUTHOR]

Studies the crystal structure of 2,4,6-triisopropyl-4-(S)-phenyl-alaninocarbonylbenzophenone methyl ester using the crystal-to-crystal conversion technique. Crystal structure before and after photocyclization; Absolute configuration around the asymmetric carbon atom in the cyclobutenol ring of the product.

Studies the crystal structures of 2,4,6-triisopropylbenzophenone and its derivatives. Barriers for the photocyclization of 4-chloroformyl-2,4,6-triisopropylbenzophenone; Intramolecular movements of isopropyl groups in the triisopropylphenyl plane toward the carbonyl C atom.

In the title compound, C28H32N6O6·2C2H6OS, the host mol­ecules are linked by N—H⋯N hydrogen bonds at both of the terminal amide groups, forming zigzag chains along the [01 ] direction. Two di­methyl sulfoxide mol­ecules are connected to a host mol­ecule by N—H⋯O hydrogen bonds. [ABSTRACT FROM AUTHOR]

Examines the crystal structure of the rac and meso isomer of the organic compound 3,3′-Bis(3,5-dimethyl-phenyl)-3H,3′H-2,2′-biindenylidene-1,1′(2H,2′H)-dione. Dihedral angle between 3,5-dimethyl-phenyl rings; Symmetry elements of the compound; Chemical structure of the compound.

In the title compound, C7H10N+·C7H3N2O6−, the ammonium group of the cation and the carboxyl­ate group of the anion are connected via hydrogen bonds, forming columns along the b axis. [ABSTRACT FROM AUTHOR]

In the title compound, C7H10NO2+·C7H3N2O6−·H2O, the aromatic rings of the cation and anion are stacked alternately along the a axis. The ammonium group of the cation, the carboxyl­ate moiety of the anion and a water mol­ecule of crystallization are connected via N—H⋯O and O—H⋯O hydrogen bonds, forming hydro­philic columns along the c axis. [ABSTRACT FROM AUTHOR]

Isomer (I) of the title compound, C30H24O2, has been obtained as yellow plate-like crystals. The di­hydro­bi­indene skeleton is approximately planar, and there are two phenyl substituents on the same side of the skeleton plane. The mol­ecules are connected via an O—H⋯O hydrogen bond, forming spiral chains along the b axis. [ABSTRACT FROM AUTHOR]

Isomer (II) of the title compound, C30H24O2, has been obtained as pale-orange needle-shaped crystals. The di­hydro­bi­indene skeleton is approximately planar, and there are two phenyl substituents on different sides of the skeleton plane. There is an intramolecular O—H⋯O hydrogen bond. [ABSTRACT FROM AUTHOR]

In the title compound, NH4+.C10H903 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)° with that of the nearest neighbour, indicating that a pedal rotation is required before βtype [2+2]-photo-dimerization can take place, which is the predominant mode of the photochemistry of this compound. [ABSTRACT FROM AUTHOR]