Crystal structure of 4,4'-dimeth-oxy-2,2'-bi-pyridine

In the title compound, C12H12N2O2, the dihedral angle between the planes of the two pyridine rings is 5.8 (1)°. Neighbouring mol-ecules are linked via C(Me)-H⋯N inter-actions, generating a two-dimensional sheet structure; C-H⋯π inter-actions further link the mol-ecules into a three-dimensional network. An overlapped arrangement of parallel pyridine rings in neighbouring mol-ecules [centroid-to-centroid distance = 3.6655 (15) Å] is observed in the crystal structure.

Crystal structure of 2-(4-tert-butyl-phen-yl)-3-hydroxy-4H-chromen-4-one

Yellow-green fluorescent crystals of the title compound, C19H18O3, were obtained by the reaction of hy-droxy-aceto-phenone and 4-tert-butyl-benzaldehyde with hydrogen peroxide as oxidant. The plane of the benzene ring is slightly twisted to the mean plane of the 4H-chromene-4-one moiety (r.m.s. deviation = 0.0191 Å) by 10.53 (8)°. In the crystal, mol-ecules are linked by pairs of O-H⋯O hydrogen bonds, forming inversion dimers with an R 2 (2)(10) ring motif. The dimers are linked via C-H⋯π inter-actions, forming sheets parallel to (10-1).

Preparation of polypseudorotaxanes composed of cyclodextrin and polymers in microspheres

We prepared polypseudorotaxanes (PPRXs) composed of cyclodextrin (CyD) and polyethylene glycol (PEG) inside microspheres (MSs) by an emulsifying process using polypropylene glycol (PPG) that shows temperature-dependent hydrophilicity changes; PPG is hydrophobic at high temperatures but hydrophilic at low temperatures. An aqueous solution of CyD and PEG was dispersed as droplets in PPG at 60°C then cooled to 0°C to allow water of droplets to transfer into PPG. On removal of water in the droplets, CyD and PEG were left behind as a CyD/PEG PPRX inside the solid-state MSs. Examination of α-, β-, and γ-CyD revealed that α-CyD was suitable for the formation of PPRX containing PEG in this MS preparation procedure. Interestingly, a new PPRX composed of α-CyD and PPG was formed in the α-CyD MSs when they were prepared in the absence of PEG from the aqueous solution of α-CyD. This MS fabrication procedure can control the size and shape of PPRX particles, and will contribute to the production of new types of CyD inclusion complexes.

Aroma of Turmeric: Dependence on the Combination of Groups of Several Odor Constituents

Turmeric is a popular material that plays an important role in the flavor and fragrance industries. Although many compounds have been reported as components of turmeric, its aroma profile has not been clarified. Recently we have developed a new approach for evaluating the complex odors of materials based on recent research on the mechanism of odor recognition. Here we report the characteristic aroma properties of turmeric obtained through the investigation of its aroma profile. The hexane extract of turmeric had a turmeric-like odor, whereas the steam distillate of turmeric had a pungent, non-turmeric-like odor. We carried out bulb-to-bulb distillations of the extract and the steam distillate. For the hexane extract, two fractions with completely different odors were obtained. One was a high boiling point fraction (group A) with a turmeric-like odor, which consisted of ar-turmerone and β-turmerone as the main components, and the other was a low boiling point fraction (group B), which consisted of α-curcumene and β-sesquiphellandrene. In contrast, the bulb-to-bulb distillation of the steam distillate gave a fraction (group C) with a very different odor from groups A and B. Group C was composed of several kinds of alcohols that were not present in groups A and B. These results indicate that the group C fraction causes the different, pungent odor of the turmeric oil obtained by steam distillation. The variation in the aroma of turmeric depended on the combination of these three groups of odor constituents.

Dinuclear nickel(ii) complexes with 2,5-diamino-1,4-benzoquinonediimine ligands as precatalysts for the polymerization of styrene: electronic and steric substituent effects

Substituent effects of the electron-donating ability and bulkiness of R in [{Ni(acac)}₂(μ-RAp)] (RApH₂: azophenines) on properties and catalytic activity are reported.

Crystal structure of fac-tri-chlorido-[tris-(pyridin-2-yl-N)amine]-chromium(III)

In the neutral complex mol-ecule of the title compound, fac-[CrCl3(tpa)] [tpa is tris-(pyridin-2-yl)amine; C15H12N4], the Cr(III) ion is bonded to three N atoms that are constrained to a facial arrangement by the tpa ligand and by three chloride ligands, leading to a distorted octa-hedral coordination sphere. The average Cr-N and Cr-Cl bond lengths are 2.086 (5) and 2.296 (4) Å, respectively. The complex mol-ecule is located on a mirror plane. In the crystal, a combination of C-H⋯N and C-H⋯Cl hydrogen-bonding inter-actions connect the mol-ecules into a three-dimensional network.

An ortho-rhom-bic polymorph of N (1),N (4)-diphenyl-3,6-bis-(phenyl-imino)-cyclo-hexa-1,4-diene-1,4-di-amine

A new ortho­rhom­bic polymorph of the title compound, C₃₀H₂₄N₄, with a density of 1.315 Mg m⁻³, has been obtained. The mol­ecule is centrosymmetric with the centroid of the cyclo­hexa-1,4-diene ring located on an inversion center. The two unique benzene rings are almost perpendicular to each other [dihedral angle = 86.70 (6)°] and are oriented at dihedral angles of 30.79 (5) and 68.07 (5)° with respect to the central cyclo­hexa­diene ring. In the crystal, π–π stacking is observed between the central cyclo­hexa-1,4-diene-1,4-di­amine unit and a phenyl ring of a neighboring mol­ecule [centroid–centroid distance = 3.7043 (7) Å]. The crystal structure of the triclinic polymorph [Ohno et al. (2014 ▶). Acta Cryst. E70, o303–o304] showed chains running along the b-axis direction through weak C—H⋯π inter­actions.

N (1),N (4)-Diphenyl-3,6-bis-(phenyl-imino)-cyclo-hexa-1,4-diene-1,4-di-amine

In the title compound, C30H24N4, the central benzo-quinonedi-imine moiety is approximately planar, with a maximum deviation of 0.044 (14) Å. The four terminal phenyl rings are twisted by 44.95 (11), 54.90 (10), 44.98 (10) and 50.68 (11)° with respect to the mean plane the benzo-quinonedi-imine unit. In the crystal, mol-ecules are linked by weak C-H⋯π inter-actions into supra-molecular chains running along the b-axis direction.

Aroma profile of star anise and the structure-odor relationship of anethole

Star anise is an important fragrance material that has a characteristic anise-like odor. Although the main component of star anise is (E)-anethole, which accounts for over 90% of the constituents, the odor of (E)-anethole is different from that of the material itself. Here, we examined the aroma profile of star anise. GC-MS analysis of star anise extracts showed that it contains many compounds with structures similar to (E)-anethole. Our results indicate that (E)-anethole is the key compound in the odor of star anise, but structurally similar compounds play an important role in creating its odor. We examined the structure-odor relationship of (E)-anethole, focusing on the methoxy and 1-propenyl substituents. Altering the 1-propenyl group changed the odors of all the anethole derivatives. Replacing the methoxy group with a hydrogen atom created compounds with similar fatty odors. This shows that the methoxy group is important for the characteristic odor of anethole. We synthesized anethole derivatives where the methoxy group was replaced with a methyl group. In both methoxy- and methyl-substituted anethole derivatives, altering the 1-propenyl group changed the odors of the derivatives. Therefore, the methoxy and methyl benzene moieties are important structural features for the odor of star anise. The structural characteristics of anethole are closely related to its odor expression.

The effect of dietary vitamin E level on selenium status in rats

The effect of varying levels of dietary vitamin E on selenium status was determined using 40 Wistar rats with similar initial body weight. The rats were equally divided into four groups and fed the following dietary treatments (mg vitamin E/kg DM): 18 (control; C-diet), 0 (0E-diet), 9 (0.5E-diet) and 36 (2E-diet) for either 4-week (Phase 1) or 8-week (Phase 2) period. At the end of experiment, animals were slaughtered to measure vitamin E and selenium levels in the brain, liver, spleen, kidney, muscles and blood tissues. Dietary vitamin E levels did not affect feed and water intake and body weight. But whole-blood selenium concentration in rats fed 0E-diet was higher than in rats fed 2E-diet after 4 weeks. Selenium level in muscle, spleen and brain was also higher (p < 0.05) in rats fed the 0E-diet than in rats fed C-diet after 4 weeks of feeding. On the other hand, selenium level in the muscle was lower (p < 0.05) in rats fed 0.5E-diet than in those fed 0E-diet after 4 weeks of feeding, but not after 8 weeks of feeding. Increasing dietary vitamin E level directly influenced selenium content of the spleen and brain after 8 weeks of feeding 2E-diet. Moreover, the twofold increase in vitamin E intake resulted in a tendency to reduce whole-blood selenium level and total selenium in the liver and kidney after 4 and 8 weeks. The results showed that the increasing dietary vitamin E level resulted in a tendency to reduce Se contents in some vital organs of the body such as the liver and kidney, suggesting their close compensatory interrelationship. Therefore, dietary vitamin E level directly influenced selenium metabolism in the animal body.

Preferential behavior on donating atoms of an ambidentate ligand 2-methylisothiazol-3(2H)-one in its metal complexes

Five metal complexes of 2-methylisothiazol-3(2H)-one (MIO), [Co(III)(NH3)5(MIO)](3+), [Ru(II)(NH3)5(MIO)](2+), [Ru(III)(NH3)5(MIO)](3+), [Pt(II)Cl3(MIO)](-), and trans-[U(VI)O2(NO3)2(MIO)2], were synthesized, and their structures were determined by single-crystal X-ray crystallography. MIO is an ambidentate ligand and coordinates to metal centers through its oxygen atom in the cobalt(III), ruthenium(III), and uranium(VI) complexes and through its sulfur atom in the ruthenium(II) and platinum(III) complexes. This result suggests that MIO shows preferential behavior on its donating atoms. We also studied the electron-donor abilities of the oxygen and sulfur atoms of MIO. Various physical measurements on the conjugate acid of MIO and the MIO complexes allowed us to determine an acid dissociation constant (pKa) and donor number (DN) for the oxygen atom of MIO and Lever's electrochemical parameter (EL) and a relative covalency parameter (kL) for the sulfur atom.

cis-Dichloridobis(ethyl methyl sulfide-κS)oxidovanadium(IV)

The mononuclear title complex, [VCl2O(C3H8S)2], features a V(IV)=O double bond [1.5845 (15) Å] in an overall trigonal-bipyramidal coordination environment defined by two Cl(-) and the S atoms of two (CH3CH2)(CH3)S ligands. In the crystal, pairs of mol-ecules form centrosymmetric dimers via C-H⋯O hydrogen bonds between the methyl C-H group and the oxidovanadium O atom of a neighbouring mol-ecule.

Di-μ-acetato-κ4O:O′-μ-oxido-κ2O:O′-bis[cis-(2,2′-bipyridine-κ2N,N′)-trans-(pyridine-κN)ruthenium(III)] bis(hexafluoridophosphate)

The hemerythrin-type dinuclear title complex, [Ru₂(CH₃COO)₂O(C₁₀H₈N₂)₂(C₅H₅N)₂](PF₆)₂, consists of two Ru^III ions with a six-coordinate octa­hedral geometry, bridged by an oxide and two acetate ligands, with a bidentate 2,2′-bipyridine ligand and a pyridine ligand bonding at terminal positions. The Ru—Ru distance and Ru—O—Ru angle are 3.2838 (3) Å and 121.79 (7)°, respectively, and the average Ru—N(pyridine) bond length is 2.164 (8) Å. Several C—H⋯F, C—H⋯O and C—H⋯N inter­actions generate a three-dimensional network in the crystal structure. π–π stacking inter­actions [centroid–centroid distance = 3.6389 (3) Å] between inversion-related 2,2′-bipyridine rings are also observed.

2-{[2,2-Bis(diethyl-amino)-ethan-2-ylium-thio-yl]sulfan-yl}-1,1-bis-(diethyl-amino)-ethyl-ium bis-(perchlorate)

The title salt, C(20)H(42)N(4)S(2) (2+)·2ClO(4) (-), was obtained from the reaction of bis-(diethyl-amino)-carbeniumdithio-carboxyl-ate, (Et(2)N)(2)C(2)S(2), with Fe(ClO(4))(2)·6H(2)O in CH(2)Cl(2). The title compound, in which one of the S atoms of (Et(2)N)(2)C(2)S(2) is bound to a 1,1-bis-(diethyl-amino)-ethane moiety, has two carbenium C atoms, and the charge compensation is provided by two perchlorate anions. The N(2)C-CS(2) bond length is 1.512 (4) Å, corresponding to a C-C single bond, and the dihedral angle between N(2)C- and -CS(2) planes [72.0 (2)°] is smaller than that of (Et(2)N)(2)C(2)S(2) [82.0 (1)°]. The crystal structure features C-H⋯S hydrogen bonds.

Di-μ-chlorido-μ-(dimethyl sulfide)-bis-{dichlorido[(dimethyl selenide-κSe)(dimethyl sulfide-κS)(0.65/0.35)]niobium(III)}(Nb-Nb)

The dinuclear compound, [Nb₂Cl₆(C₂H₆S)_1.7(C₂H₆Se)_1.3], features an Nb^III=Nb^III double bond [2.6878 (5) Å]. The mol­ecule lies on a twofold rotation axis that passes through the middle of this bond as well as through the bridging dimethyl sulfide ligand. The Nb^III ion exists in an octa­hedral coordination environment defined by two terminal and two bridging Cl atoms, and (CH₃)₂Se/(CH₃)₂S ligands. The (bridging) ligand lying on the twofold rotation axis is an ordered (CH₃)₂S ligand, whereas the terminal ones on a general position are a mixture of (CH₃)₂Se and (CH₃)₂S ligands in a 0.647 (2):0.353 (2) ratio (the methyl C atoms are also disordered).

Effect of supplementing Rhodes grass hay (Chloris gayana) with Berchemia discolor or Zizyphus mucronata on the performance of growing goats in Kenya

Twenty growing Small East African goats were used to determine the effects of feeding sun-dried leaves of the browse forages Berchemia discolor and Zizyphus mucronata as supplements to low-quality basal diet, Rhodes grass (Chloris gayana) hay, on voluntary feed intake (VFI), digestibility and growth performance. The grass hay and maize bran were used as a control. The dried leaves were then included at the rates of 15% and 30% of the dry matter intake (DMI). Berchemia discolor had the highest crude protein (CP) content of 195.5 g/kg DM, while Z. mucronata had CP content of 169.5 g/kg DM. The grass hay had the lowest CP content of 50.9 g/kg DM. The browse forages had low fibre content [Neutral detergent fibre (NDF); 257.9-369.5 g/kg DM], while the grass hay had high fibre content (NDF; 713.1 g/kg DM). Goats in the groups supplemented with either of the browse forages had higher total DMI, nitrogen (N) intake and retention and live-weight gains than those in the control diet group. The digestibility of DM and organic matter (OM) was not affected by supplementation, but the CP digestibility increased with supplementation. The use of the browse forages as supplements for goats fed on poor-quality basal diets would enhance the performance of the animals.

Structural and Optical Properties of Highly Efficient 2- μm Thick CdS/CdTe Thin Film Solar Cells

The structural and optical properties of CdS/CdTe(S) interface region of 2-μm thick CdS/CdTe solar cells have been studied in conjunction with photovoltaic performances of the solar cells. The properties are found to be crucially influenced by the annealing temperature and oxygen concentration of the CdCl2 treatment. An increase in VOC and F.F. found in the solar cells with the CdCl2 treatment at < 360°C is interpreted as due to suppression of interdiffusion of sulfur and tellurium at the CdS/CdTe(S) interface. On the other hand, the electromodulated photoluminescence with UV light excitation (UVE-EMPL) study reveals that the increasing VOC due to increasing oxygen concentration to 5% is likely to be caused by an increase in the built-in electric field in n+-CdTe1−xSx just adjacent to the CdS/CdTe(S) interface. As a result of the modification of the process parameters, we have achieved the conversion efficiency of 13.6% (VOC: 0.817V, JSC: 23.0 mA/cm2, F.F.: 0.725) using 2.3-μm thick PV active layer without anti-reflection coating.