桝 飛雄真

Chiral bis(imidazolidine)-derived NCN-rhodium complexes ([PhBidine-RhX2] and [tBu-PhBidine-RhX2]) were prepared by a CH insertion method, and the structures were unequivocally determined by X-ray crystallographic analysis. The [tBu-PhBidine-Rh(OAc)(2)] complex smoothly catalyzed an asymmetric Mannich reaction of malononitrile with N-Boc imines to give products in up to 94% ee, which are useful for the synthesis of chiral -amino acids.

Piezoluminescence and liquid crystallinity of anthracene-based bispyridinium salts were investigated in stimulus-responsive luminescent organic crystals and luminescent ionic liquid crystals. The salts possess an anthracene moiety as a, fluorophore their center, and the pyridiniums attached to the anthracene moiety are substituted with trialkoxybenzyl groups. Single crystals of the salts bearing two trimethoxybenzyl groups were obtained as solvates. Ethyl acetate, acetone, and dioxane solvates of the chlorides have almost the same crystal structures with one-dimensional Channels. Grinding of the solvated crystals caused the extrusion of the included solvent molecules, which resulted in the red shifts of their fluorescence in the solid state. The dimethyl sulfoxide solvate of the hexafluorophosphate also showed piezoluminescene by grinding. Tris(octyloxy)benzyl and tris(dodecyloxy)benzyl derivatives exhibited rectangular columnar liquid crystals upon being heated for their bromide and tetrafluoroborate salts and upon being cooled for their hexafluorophosphate salts. Of these pyridinium hexafluorophosphates showed characteristic, solvent-dependent fluorescence.

A C-amide-substituted O-silylated oxime, (E)-(tert-butyldimethylsiloxyimino)acetic acid N,N-dimethylamide (8b), on treatment with 2.2 equiv of BF3 center dot OEt2, in situ generated boracyclic nitrone-type intermediate BF3 center dot 14, which underwent cycloaddition with alkenes to give 3,5-cis-isoxazolidines as the Major products. The mechanism was strongly supported by isolation of the reaction intermediate 14 that was characterized by X-ray diffraction and its further reaction. This cycloaddition was successfully applied to the synthesis of syn-HPA-12 known as an inhibitor of CERT that mediates the transport of ceramide.

Anthracene derivatives possessing a carbamate group and an ester group at their 9- and 10-positions, respectively, were prepared to furnish pairwise packing of anthracene fluorophores in their crystal structures. They were nonluminescent in ethanol solution and showed AIE (aggregation-induced emission) in aqueous ethanol solution and in solid state. Crystal structure analysis of them showed that the H-bonding networks involved in their crystal structures could be classified into four patterns, H-bonding between the carbamate and the ester carbonyl (motif A), H-bonding between the carbamate and the ester oxygen atom (motif B), H-bonded cyclic dimer of carbamate moieties (motif C), and H-bonded chain among carbamate moieties (motif D). Compounds with pairwisely packed anthracene fluorophores showed dimer emission with the longer fluorescence wavelength than others without the pair formation. Fluorescence maximum wavelengths and lifetimes become longer proportional to the degree of overlapping of two facing anthracene pi-planes.

A macrocyclic compound has been designed and synthesized containing six para-phenylene groups and six alternate N-butyl and N-4-methoxybenzyl substituted amides. The three N-4-methoxybenzyl groups could be removed by N-dealkylation under acidic conditions to give the corresponding secondary amides, which underwent a switch in their conformation from cis to trans. Single crystal X-ray crystallographic analysis revealed that the macrocyclic compound containing six alternate N-butyl and N-4-methoxybenzyl substituted tertiary amide groups existed as the "folded" structure, whereas the macrocyclic compound with six alternate tertiary and secondary amide groups existed as the "unfolded" structure. Furthermore, these changes in the conformation of the hexaamide displayed reversible switching between the "folded" and "unfolded" states. (C) 2014 Elsevier B.V. All rights reserved.

Amide-bridged ladder poly(p-phenylene) was synthesized in two steps, through the polycondensation of aromatic diamines and dicarboxylic acid derivatives followed by palladium-catalyzed intramolecular direct arylation. The pi-stacked assembly of the polymer in solution was investigated along with the single crystal X-ray structure analysis of a model oligomer.

The speciation of zirconium complexes in ammonium zirconium carbonate (AZC) solutions should be further studied in order to develop high-performance AZC complexes for use in elaborate industrial materials. Thus, the speciation and the structure of various zirconium species in ammonium zirconium carbonate solutions were investigated over a wide range of total carbonate and ammonium concentrations. By employing extended X-ray absorption fine structure analysis, and Raman and C-13 NMR spectroscopy, it was found that four carbonate ions coordinate bidentately to the zirconium ion. In addition, the exact concentration ranges of carbonate and ammonium in AZC necessary to generate the monomeric zirconium carbonate complex [Zr(CO3)(4)](4-) were determined.

A series of binary mixtures composed of glymes (triglyme, G3; tetraglyme, G4; pentaglyme, G5) and alkali-metal bis(trifluoromethanesulfonyl)amide salts (M[TFSA]; M = Li, Na, and K) were prepared, and the correlation between the composition and solvate stability was systematically investigated. Their phase diagrams and Raman spectra suggested complexation of the glymes with M[TFSA] in 1:1 and/or 2:1 molar ratio(s). From isothermal stability measurements, it was found that the formation of structurally stable complexes in the solid state did not necessarily ensure their thermal stability in the liquid state, especially in the case of 2:1 complexes, where uncoordinating or highly exchangeable glyme ligands existed in the molten complexes. The phase-state-dependent Raman spectra also supported the presence of free glymes in certain liquid complexes. The effect of the electric field induced by the alkali-metal cations on the oxidative stability of certain glyme complexes was examined by linear sweep voltammetry and quantum chemical calculations. Although the actual oxidative stability of complexes did not necessarily reflect the calculated HOMO energy levels of the glymes, the strong electric field induced by the smaller M+ cations and proper coordination structures impart high stability to the glyme complexes. The results of thermogravimetry of complexes with different M+ cations revealed that a balance of competitive interactions of the M+ ions with the glymes and [TFSA](-) anions predominates the thermal stability.

The diastereoselective cyclization of 2,5-dibromo-4-hexylaminobenzoic acid was achieved by the microwave-assisted condensation using SiCl4. Moreover, the triple-stranded helical structure of bis(phenylethynyl)benzene units embedded in the cyclic tri(benzamide) scaffold was obtained by a Sonogashira-Hagihara coupling reaction. Two optically active enantiomers that do not racemize even at the elevated temperature were separated by chiral HPLC. The chiral helical topology was revealed by the spectroscopic data and theoretical calculation.

We have characterized a novel aluminum-based homometallic double complex salt, incorporating discrete octa-coordinated cationic [Al(G3)(2)](3+) and hexa-coordinated anionic [Al(TfO)(4)(OH)(2)](3-) complexes (G3 = triglyme, TfO = trifluoromethanesulfonate). X-ray crystallography, Raman spectra, and DFT calculations demonstrate extraordinary weak Al3+ coordination in [Al(G3)(2)](3+).

A 3,3'-bis(aminoimino)BINOL ligand was newly designed and synthesized for the formation of a trinuclear Zn complex upon reaction with Zn(0Ac)2. Using the harmony of the tri-zinc atoms, 1 mol% Zn3(0Ac)4-3,3'-bis(aminoimino)binaphthoxide catalyzed asymmetric iodolactonization in up to 99.9% ee.

An (S,S)-diphenyldiamine-derived bis(imidazolidine)-pyridine (PyBidine)-NiCl2 complex catalyzed the nitro-Mannich reaction of isatin-derived N-Boc ketimines to construct a chiral quaternary aminocarbon center at the C3 position of oxindoles in yields of up to 99% with 95% ee.

Phenylenediurea dibenzoic acid derivatives 1, 2, 3, and 5 and an amide derivative 4 were synthesized, and their molecular structures were elucidated to be an S-shape by single crystal X-ray analysis. Crystals of 1 were obtained as a DMF solvate, while those of 2 and 3 were not. Sheet and ladder structures were created in the crystal packing of 1 and 3, and 2, respectively. Unlike the para-substituted diureas 1-3 which possessed meso-conformation, the meta-substituted diurea 5 exhibited helical-conformation in its crystal structure. The way of crystal packing of 4 is analogous to that of the corresponding dicarboxylic acid derivative 2. A water cluster of a chair-shaped hexagonal array of water molecules was created in the crystal structure of 4. Diureas 1 and 2 gave cocrystals with melamine recrystallized from DMF/ethyl acetate and DMF/H2O, respectively. Unusual zigzag tapes of a H-bonding network of melamine were created in both cocrystals. The zigzag tapes were connected with S-shaped diureas by H-bonding to furnish an interpenetrated fishnet-type crystal structure.

The structure of a nickel complex of imidazoline-aminophenol (IAP) prepared from IAP with Ni(OAc)(2) was elucidated as cis-bis(imidazolineaminophenoxide) [Ni(IAP)(2)]. The [Ni(IAP)(2)] complex smoothly promoted catalytic asymmetric 1,4-addition of 3-indolyl-3-oxindole to nitroethylene to provide chiral mixed 3,3-bisindoles with high enantioselectivities. Mechanistic studies using ESI-MS analyses suggest that one IAP ligand dissociated from [Ni(IAP)(2)] to generate the Ni-enolate of 3-indolyl-3-oxindole. From the optically active 3,3-mixed indole adduct, biologically important 3-indolyl-3-pyrrolidinoindoline was successfully synthesized in a three-step reaction sequence.

Three different types of coordination polymers, one-dimensional (1D) straight chain, 1D-columnar structure, and two-dimensional (2D) layer structure, have been prepared by the complexation of Ag(I) ions with bis(pyridyl) ligands linked by an aromatic sulfonamides and structurally characterized by single-crystal X-ray diffraction and thermogravimetric analysis. Structural analyses showed that the complexation of the 3-pyridyl ligand with AgOTf and the complexation of the 4-pyridyl ligand with AgBF4 in CHCl3/CH3CN resulted in the formation of 1D straight-chain polymers. In the complexation of the 3-pyridyl ligand with AgBF4 in CHCl3/CH3CN, the resulting continuous ID columnar coordination polymers were formed containing a racemic mixture of left- and right-handed helices. Furthermore, the 2D-layer structure was constructed by the complexation of a 4-pyridyl ligand with AgSbF6 in CHCl3/MeOH.

The oxidation of 9-p-tolylcarbazole by iron(III) perchlorate in acetonitrile produces oligo(9,9'-di-p-tolyl-3,3'-bicarbazyl), partially doped with perchlorate. To the chloroform solution of the oligomers, we added metals to produce hybrid solutions. The hybrid films, prepared by applying the solutions onto a glass plate, exhibited good transparencies (90% or above in the visible region) and electrical conductivities of 4.1 x 10(-3) S cm(-1).

Novel cyclic aromatic amide oligomers containing highly fluorescent 9,10-diphenylanthracene units were prepared by condensation of a monomer with amino and ester functional groups using lithium bis(trimethylsilyl) amide. The cyclic trimer (C3A, 40%) and tetramer (C4A, 8%) were isolated using preparative gel permeation chromatography. Some of the aromatic proton signals derived from anthracene were observed in the upfield region (6.96-6.87 ppm) in the H-1 nuclear magnetic resonance spectrum of C3A. X-ray crystallographic analysis indicated that three anthracene moieties are inclined with respect to the cyclic skeleton and partly overlap each other. The fluorescence peak maximum of C3A (438 nm) showed a small red-shift compared with that of an acyclic model compound (425 nm). Reduction of the amide carbonyl group in C3A gave the cyclic trimer HC3A, which has a tertiary amine unit. The fluorescence peak maximum of HC3A (489 nm) was largely red-shifted from that of C3A and exhibited strong solvent dependence. A linear correlation was observed between the Stokes shift (Delta nu), ranging from 2981 to 6646 cm(-1), and the Reichardt's solvent polarity parameter [ ET(30)].

Air-exposed di(2-ethylhexyl) dithiophosphate (Phoslex DT-8 (R)) has been previously shown to be ableto selectively extract scandium ions from waste water produced during zirconium refining. In the absence of exposure to air, Phoslex DT-8 (R) is not effective for scandium ion extraction, therefore, a compound produced by air-oxidation was suspected to be responsible for the selective extraction of the metal. In the present study, we employed P-31 NMR spectroscopy and mass spectrometry in order to identify this active species. We revealed that a sulfur atom of Phoslex DT-8 (R) was substituted for an oxygen atom on oxidation yielding O,O-bis(2-ethylhexyl) hydrogen thiophosphate (BOHTP). This compound was subsequently synthesized in high purity, and was confirmed to possess similar extraction capabilities for scandium as the oxidized Phoslex DT-8 (R).

Perchlorate-doped 3-methoxythiophene oligomer was chemically synthesized, and its solutions were applied to produce films characterized by their gold-like luster which showed no degradation in the ambient atmosphere for at least one year. The oligomer is characterized by its good solvent-soluble, good film-forming, and moderate electrical conducting properties. More importantly, wide-angle and grazing incidence X-ray diffraction measurements revealed that the gold-like films have a compact periodic layered structure with a lamellar interlayer spacing of 1.10 nm and an intralayer spacing of 0.34 nm, though the oligomer involves no long alkyl chains. It was proposed that the strong gold-like luster could be related to the highly regular and compact nature of the lamellae in the oligomer films.

The synthesis and structural investigation of aromatic-aliphatic oligoamide foldamers reveals a zig-zag tape conformation with local conformational variability that precludes long range order.

We have performed single crystal X-ray diffraction analyses of two 1-alkyl-3-methylimidazolium hexafluorophosphate ([C(n)mim]PF6) salts, [C(1)mim]PF6, and [C(3)mim]PF6. The thermo-dynamically metastable crystalline phase (beta phase) of the former was obtained by crystallization from the melt in a capillary for the crystallographic analysis. Both the cation and the anion in the beta phase of [C(1)mim]PF6 show higher point group symmetry than those in the stable alpha phase. This result is shown to be consistent with the fact that the melting point of the beta polymorph (314 K) is significantly lower than that of the alpha polymorph (364 K). The crystal structure of [C(3)mim]PF6 seems to be typical of that characteristic of the crystals of imidazolium-based room temperature ionic liquids. The cation conformation is the one in between those characteristic of the crystal structures of [C(2)mim]PF6 and [C(4)mim]PF6. When taken together, all crystallographic data for the [C(n)mim]PF6 series (n = 1-4) demonstrate the influence of the alkyl chain length dependence on structural packing in these salts. The free volume fractions for these structures are calculated and compared to the lattice energy simply based on formula unit volume. It is shown that the difference in the alkyl chain length of the imidazolium cations does not monotonically change with the lattice energy of the crystal structure, and the latter also depends on the packing efficiency of the constituent ions in the structure.

We synthesized porphyrinylamide 4b and its N-methylated derivative 5b. Direct N-methylation of porphyrinylamides 4 proved unsuccessful, so 5b was obtained via N-methylation of 5-aminoporphyrin 10 with potassium hexamethyldisilazide. The secondary amide 4b exists in trans-amide form, while N-methylated amide 5b exists in the cis-amide form, both in solution and in the crystal. Thus, N-methylation of the amide bond of 4b resulted in trans to cis conformational alteration. (C) 2013 Elsevier Ltd. All rights reserved.

Dynamic atroposelective resolution of chiral salts derived from oily racemic nicotinamides and enantiopure dibenzoyltartaric acid (DBTA) was achieved by crystallization. The absolute structures of the axial chiral nicotinamides were determined by X-ray structural analysis. The chirality could be controlled by the selection of enantiopure DBTA as a chiral auxiliary. The axial chirality generated by dynamic salt formation was retained for a long period after dissolving the chiral salt in solution even after removal of the chiral acid. The rate of racemization of nicotinamides could be controlled based on the temperature and solvent properties, and that of the salts was prolonged compared to free nicotinamides, as the molecular structure of the pyridinium ion in the salts was different from that of acid-free nicotinamides. © 2013 by the authors.

We characterized cromolyn sodium (CS) hydrates and evaluated their molecular states in low-dose formulations using Na-multiquantum magic-angle spinning (MQMAS) nuclear magnetic resonance (NMR) analysis. Two CS hydrates, low-water-content hydrated form and high-water-content hydrated form containing 2-3 and 5-6 hydrates, respectively, were prepared by humidification. Single-crystal X-ray diffraction and powder X-ray diffraction analysis revealed that these CS hydrates contained sodium channel structures and that water molecules were adsorbed on the sodium nucleus. C-13-cross-polarization/MAS NMR spectra of these hydrates revealed similar results, confirming that the water molecules were adsorbed not on the cromolyn skeletons but mainly on the sodium nucleus. In contrast, Na-23-MQMAS NMR analysis allowed us to clearly distinguish these hydrates without discernible effects from quadrupolar interaction. Thus, MQMAS NMR analysis is a valuable tool for evaluating salt drugs and their formulations. (c) 2013 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 102:2738-2747, 2013

Crystal structures of U-shaped aromatic ureadicarboxylic acid possessing two carboxy moieties at meta-positions of phenyl rings were investigated. It afforded cocrystals with dipyridyl derivatives. In addition to the U-shaped conformation obtained by recrystallization from methanol, another three types of U-shaped conformations were found in the crystal structure of the cocrystals. The direction of H-bonding was fixed based on the relative geometry of two carboxy moieties in the resulting conformations. Depending on these conformations, triple helices with one-dimensional water channels, infinite cross-belt, and step-like structures were generated via H-bonding between the carboxy and the pyridyl moieties. Methanol solvate was obtained for the cocrystal with 1,4-di(pyridine-4-yl)benzene which showed different U-shaped conformation of urea dicarboxylic acid from that involved in the cocrystal free of methanol.

Optically active materials could be generated by simple solidification of achiral materials without an external chiral source. When achiral cis-3,4-diphenylsuccinimides were solidified in the presence of a catalytic amount of DBU by evaporating the solvent with stirring, optically active trans-3,4-diphenylsuccinimides were obtained quantitatively with high enantiomeric excesses. © 2013 The Royal Society of Chemistry.

N,N'-Bis(2,3,7,8,12,13,17,18-octaethylporphyrin-5-yl)urea (3) exhibits cis-trans conformational switching depending on the solvent properties, and can adopt the cofacial porphyrin dimer structure under certain conditions. The conformational preference can be switched by electrochemical stimulus. © The Royal Society of Chemistry.

A detailed study of the Ni-catalyzed [4+3+2] cycloaddition reaction between ethyl cyclopropylideneacetate and dienynes has been conducted, resulting in the development of a new method for the synthesis of compounds containing nine-membered rings. We studied the reactivity of various dienynes, together with their substituent and conformational effects. The mechanism of the reaction was probed by examining the stoichiometric reactions of the Ni complexes and dienynes.

Eight cocrystals were formed from three adamantane-based bisphenols with structurally analogous skeletons and three bispyridines. Various 1D chains were constructed through intermolecular OH/N hydrogen bonds. Two crystals containing nonsubstituted bisphenols showed the formation of 1D zigzag chains, which were generated from two bisphenols and two bispyridines in one pitch of the 1D chain. Three crystals including chlorine-substituted bisphenols indicated the generation of 1D zigzag chains, and the pitches of these chains were longer than that of 1D chains composed of nonsubstituted bisphenols. Three crystals containing bromine-substituted bisphenols exhibited different shapes of 1D chains from other crystals, which were consisted of one bisphenol and one bispyridine in one pitch. These 1D chains assembled via intermolecular CH/O and/or CH/π interactions. The halogen substituents on the adamantane-based bisphenols influence on not only the shapes of 1D chains, but also 2D and 3D structures mainly due to steric hindrances. © 2013 American Chemical Society.

The title compound afforded four different types of crystals as pseudopolymorphs upon crystallization from a variety of different solvents. Single-crystal X-ray analysis revealed that the nonsolvated crystals exclusively formed a zigzag chain motif through hydrogen-bonding interactions (H-bonds). In contrast, the solvent-containing crystals formed a helical chain motif through H-bonds to give rise to channel-shaped network structures. The inner spaces of the channels were occupied by solvent molecules from the crystallization solvent. These solvent-containing crystals could be converted to the nonsolvated crystals by removal of the solvent molecules by drying under reduced pressure at 45 C. They also showed mutual polymorphic transitions via a solvent-exchange process. © 2012 American Chemical Society.

The facile synthesis of an organic electric conducting nanowire is described. The simple oxidation of 9-methylcarbazole by iron(III) perchlorate in a methanol/acetonitrile mixture under atmospheric pressure and temperature produces abundant nanowires without using a template. The nanowire consists of 9,9'-dimethyl-3,3'-dicarbazyl and has a rectangular nanowire shape with an average diameter of 397 +/- 50 nm and length of 17 +/- 5 mu m. The results of the elemental analysis, H-1 NMR, FT-IR, XPS, and ESR measurements revealed that the chemical composition of the nanowire is (dicarbazyl)(0.12)(dicarbazylium center dot ClO4-)(0.88)center dot H2O. This result, combined with the UV-vis-NIR measurement, demonstrates that 9,9'-dimethyl-3,3'-dicarbazyl stacks in a mixed valence state. The nanowire is electroactive and has an electric conductivity of 3.0 X 10(-5) S cm(-1).

Vinylogy is a widely accepted principle involving the transfer of electronic chemical character through a double bond, and many reactions have been developed by applying this concept. In contrast, phenylogy, which involves the connection of two substituents through a benzene ring, is rarely recognized as a related idea. In this article, we present synthesis and physical properties, including their structure and reactivity of phenylogous amides. This amide mimetic unit is relatively stable and easily prepared by the Hartwig-Buchwald amination reaction. The effect of the resonance was examined by means of crystallography, reactivity and UV-vis spectroscopy. (C) 2012 Elsevier Ltd. All rights reserved.

The quantum molecular sieving effects of pore-structure-controlled single-walled carbon nanotubes (SWCNTs) for H-2 and D-2 were evaluated at 20, 40, and 77 K. The adsorption amounts of D-2 were larger than those of H-2. The lower the adsorption temperature, the greater the difference between the D-2 and H-2 adsorption amounts. Bundled SWCNTs with interstitial pores of diameter 0.6 nm gave the greatest adsorption difference between D-2 and H-2 per unit pore volume. Diffusion-dominated behavior was observed in the low-pressure region at 20 and 40 K as a result of lower mobility. Bundled SWCNTs with only interstitial pores provided a significant quantum molecular sieving as a result of strongly interacting potential wells.

We report an enantioselective synthesis of the polyhydroxylated pyrrolidine alkaloid (+)-DMDP. The key steps in the synthesis were guanidinium ylide mediated asymmetric aziridination, stereospecific ring opening of trans-3-vinylaziridine-2-carboxylate with an oxygen nucleophile, iodine-mediated 5-endo-trig amino cyclization, and Prevost displacement. In addition, a potential common intermediate for the polyhydroxylated pyrrolizidine alkaloids (+)-hyacinthacine A(1) and (+)-1-epi-australine was synthesized from a diastereoisomeric cis-aziridine coformed in the asymmetric aziridination using the same strategy. A rationale for the diastereoselectivity observed for the iodine-mediated amino cyclization reactions is proposed on the basis of the heats of formation of the products.

Single crystal X-ray structures of cocrystals, 1.2 and 1.3, derived from U-shaped ureadicarboxylic acid (1) with 2-aminopyrimidine (2) and melamine (3), respectively, were examined. Cocrystals were obtained as a 1:1 mixture of 1 and the corresponding base. Two molecules of 1 and two molecules of the base were combined together via intermolecular H-bonding creating a supramolecularly assembled cyclic heterotetramer motif of rhombus shape. In the case of cocrystal 1.3, the cyclic heterotetramers were connected via H-bonding by utilizing a remaining amino group of melamine resulting in the formation of a tape of cyclic heterotetramer. (C) 2012 Elsevier Ltd. All rights reserved.

Redox-induced conformational alteration of N-aryl-N-phenylamides, in which the N-aryl group consists of a hydroquinone-p-quinone system, was examined. The reduced form bearing a dihydroxyphenyl or dimethoxyphenyl group exists mainly in the E-form, whereas the oxidized form bearing a N-benzoquinone moiety takes the Z-form both in the crystal and in solution. This redox-induced conformational alteration is associated with a marked change in optical properties. This system appears to have suitable properties for use in external redox stimulus-responsive functional switching. (c) 2012 Elsevier Ltd. All rights reserved.

An unusual alkaloid with a 2-azaquinone-phenylhydrazone structure, katorazone (1), and other metabolites were isolated from the ethyl acetate extract of Streptomyces sp. IFM 11299. The chemical structure of katorazone (1) was elucidated by 1D and 2D NMR analyses together with HR-ESI mass spectrometry. Katorazone (1) showed a synergistic effect in combination with TRAIL and decreased the viability of human gastric adenocarcinoma (AGS) cells. (C) 2012 Elsevier Ltd. All rights reserved.

N-(2-Phenoxyphenyl)benzenesulfonamide (1) and fluorine-substituted N-(2-phenoxyphenyl)benzene sulfonamides (2-5) were designed to examine the effect of a fluorine group in the polymorphism of aromatic sulfonamides. Single-crystal X-ray analysis revealed that those with a fluorine (2-5) afforded polymorphs or pseudopolymorphs while the sulfonamide without fluorine (1) did not. From the differential scanning calorimetry measurements, stable (2a-5a) and metastable (2b-5b) crystalline forms were identified. The sulfonamide 1 formed a dimer through hydrogen bonds (H-bonds), which were aligned into two-dimensional (2D) layers via pi/pi and CH/pi interactions. In 2b, 3b, and 4a, the sulfonamide constructed a dimer through H-bonds, which formed 2D layers via CH/F interactions. The sulfonamides 4 formed a one-dimensional (1D) straight chain via H-bonds, which were arranged into 2D layers via CH/F, CH/O, and CH/pi interactions in 4b. The sulfonamide 5 either formed a dimer through H-bonds, which formed 2D layers via CH/O and pi/pi interactions in 5a, or formed a 1D straight chain via CH/O and pi/pi interactions, which were arranged into 2D layers via F/F and CH/F interactions in 5b. In the pseudopolymorph 5c, the sulfonamide 5 formed a 1D zigzag chain via CH/F interactions and was assembled into 2D layers via pi/pi interactions.

Crystal structures of three zwitterionic bisimidazolium salts 1-3 in which imidazolium sulfonate moieties were connected with aromatic linkers, p-xylylene, 4,4'-dimethylenebiphenyl, and phenylene, respectively, were examined. The latter two were obtained as hydrates. An S-shaped molecular structure in which the sulfonate moiety was placed on the imidazolium ring was observed for 1. A helical array of hydrated water molecules was obtained for 2 while a linear array of hydrated water molecules was observed for 3. (C) 2012 Elsevier B.V. All rights reserved.

A series of bis(imidazolium) salts with several n-alkylene linkers (carbon numbers: 4-8) incorporating tetrafluoroborate anions were characterized by thermal analysis and single-crystal X-ray analysis. A correlation between macroscopic thermal properties and microscopic crystal structures was investigated. A unique linker-length dependence of the melting points of bis(imidazolium) salts is attributed to variations in the molecular conformation and the packing structure resulting from a balance among cooperative ionic interaction, van der Waals interaction, and pi-pi interaction in the crystalline state. In addition, an even-odd effect of the n-alkylene linker was observed in the crystal structures.

The [5 + 2] cycloaddition reaction of 2-vinylaziridines with sulfonyl isocyanates proceeded smoothly under mild conditions, and various cyclic ureas were isolated in high yields. The remarkable solvent effect on the reaction was observed, and the preferential formation of the seven-membered ring occurred when the reaction was carried out in CH2Cl2. The scope and limitation were studied, and the mechanism of this reaction was discussed. This study provides a new and simple method for the synthesis of seven-membered cyclic ureas.

We synthesized three series of imidazolium-based ionic liquids (ILs) containing cycloalkyl groups such as cyclopentyl, cyclohexyl, or cycloheptyl groups incorporating bis(trifluoromethanesulfonyl)amide anions and characterized them with respect to physicochemical properties and molecular reorientational dynamics. A comparison of the physicochemical properties revealed that cycloalkyl-substituted imidazolium ILs have higher densities, viscosities, and glass transition temperatures than the respective n-alkyl-substituted imidazolium ILs. Among three series, the cyclopentyl-substituted IL exhibits exceptionally lower viscosity. Observation of correlation times by C-13 NMR spectroscopy revealed that a remarkably lower viscosity for the cyclopentyl-substituted IL and a considerably higher viscosity for the cyclohexyl- and cycloheptyl-substituted ones are closely related to the respective reorientational motion of the cations. The cause of these distinctions is suggested to be attributed to the difference of activation energy for the conformational interconversion of their substituents.

Chiral properties of bowl-shaped cyclic triamides bearing functional groups with hydrogen-bonding ability were examined. Chiral induction of cyclic triamide 3a was observed by addition of chiral amine in solution, and chiral separation was achieved by simple crystallization to afford chiral capsule-type dimer structure of 4a.

A low-molecular-mass molecule with no long alkyl chain, a mixed-valence 9,9'-dimethyl-3,3'-bicarbazyl, is self-assembled into highly-regular straight micro/nanotubes by the one-step electrooxidation of its precursor, 9-methylcarbazole, in methanol without templates. The driving force of the tube formation is investigated.

In order to examine versatility of ureadicarboxylic acids as U-shaped building blocks for crystal engineering, their crystal structures and cocrystals with pyridine derivatives were investigated. H-bonding networks created by a sequential linking of H-bonded carboxylic acid dimers resulted in the formation of ladder-type networks in the crystals of N,N-diethyl-N,N'-diphenylureadicarboxylic acid (2) and N,N'-diallyl-N,N'-diphenylureadicarboxylic acid (3). A zigzag type H-bonding network with wedging of water molecules into carboxy carboxy H-bonding was observed for N,N'-dibenzyl-N,N'-diphenylureadicarboxylic acid (4). Cocrystals of N,N'-dimethyl-N,N'-diphenylureadicarboxylic acid (1) with 2,S-di(pyridine-4-yl)thiazolo[5,4-d]thiazole (5) and 2 with 4,4'-dipyridyl (6) afforded zigzag-type assembled structures. Two types of channel structures were created in the cocrystals of! and dipyridylurea (7) by inclusion of water molecules together with either methanol or ethanol. The former afforded a straight-type one-dimensional channel, while the latter afforded a fishnet-type two-dimensional channel.

A series of cis-preferential aromatic N-methyl amides was designed and synthesized, and acid-induced conformational alteration of these compounds was investigated by means of NMR measurements in solution and X-ray crystal structure analysis. Compounds with a terminal N-methyl-N-(2-pyridyl) amide unit showed acid-induced conformational change from cis to trans, while those with a terminal N-methyl-2-pyridinecarboxamide unit showed a change of the carbonyl orientation from anti to syn with retention of cis conformation. (C) 2011 Elsevier Ltd. All rights reserved.

Organic crystals containing several types of water channels are generated by clipping water molecules with biszwitterionic imidazolium carboxylates as hydrogen-bonding acceptors. The types of water channels to be generated depend on the size and the shape of the aromatic spacers tethered with two imidazolium carboxylates moieties. Clusters of water tetramers and dimers were obtained from imidazolium carboxylates with phenylene (1) and naphthalene (2) linkers, respectively. The latter showed pseudopolymorphism, affording layers of water hexamers. Imidazolium carboxylate possessing biphenylene linker (3) afforded channels of discrete water tetramers.