Silver to Gold Metallic Luster Changes in Stimuli-Responsive Diacetylene Derivatives Uniquely Arranged within Crystals.

Eye-catching metallic luster materials, especially those whose colors can be controlled by external stimuli, have many potential applications. Here, we present a silver luster material that changes color to gold upon UV irradiation. Diacetylene (DA) derivatives with stilbenes introduced via linkers at both ends ( ( = 1-6)) exhibited significantly different metallic luster and color change behaviors depending on the linker carbon number ().

Formation of charge-transfer complexes in ionic crystals composed of 1,3-bis(dicyanomethylidene)indan anion and viologens bearing alkyl chains.

The relationship between charge-transfer (CT) properties and the molecular arrangement formed from π-electronic ion pairs remains unclear because of the limited variety of π-electron anions. This study addressed this issue by synthesising a series of ion pair assemblies composed of viologen dications with diverse alkyl chains as π-electron cations and 1,3-bis(dicyanomethilidene)indan anion (CMI) as a stable π-electron anion. We obtained seven ionic crystals and identified their assembled structures using single-crystal X-ray analysis.

Hybridization of Wide-Angle X-ray and Neutron Diffraction Techniques in the Crystal Structure Analyses of Synthetic Polymers.

The development in the crystal structure analysis of synthetic polymers using the hybridized combination of wide-angle X-ray and neutron diffraction (WAXD and WAND, respectively) techniques has been reviewed with many case studies performed by the authors. At first, the technical development was reviewed, in which the usage of high-energy synchrotron X-ray source was emphasized for increasing the total number of the observable diffraction peaks, and several examples were introduced. Secondly, the usage of the WAND method was introduced, in which the successful extraction of hydrogen atomic positions was described.

Crystal Structures and Optical Properties of Cyanine Dyes Depending on Various Counter Anions.

In this study, cyanine cations with various counter anions were prepared as examples of ionic materials constructed using charged π-conjugated systems. A series of ion pairs was obtained by anion exchange reactions using iodide salts of carbocyanine dyes. The optical properties were measured by UV/vis absorption and fluorescence spectroscopy; measurements performed in CHCl (less-polar solvent) were altered by the influence of the counter anions.

Optical property control of π-electronic systems bearing Lewis pairs by ion coordination.

π-Electronic systems bearing Lewis pairs were synthesized and their optical responses to added ions were investigated. The tuning of the optical properties was demonstrated by the addition of various ion pairs, and these behaviours were elucidated by theoretical calculations.

Characterization of all second-order nonlinear-optical coefficients of organic N-benzyl-2-methyl-4-nitroaniline crystal.

Full elements of second-order nonlinear optical (NLO) tensor can be completely characterized for an organic NLO crystal for the first time. As-grown bulk N-benzyl-2-methyl-4-nitroaniline (BNA) crystal was processed to expose (100) and (010) crystal orientations with fine optical surfaces by using precision lathe and diamond blade. Then, every five nonvanishing second-order NLO coefficient of BNA can be determined quantitatively using the precisely processed crystals based on 1st-kind Maker fringe measurements.

Concerted Photoluminescence of Electrochemically Self-Assembled CuSCN/Stilbazolium Dye Hybrid Thin Films.

Hybrid thin films of crystalline CuSCN and 4-(,-dimethylamino)-4'-('-methyl)stilbazolium (DAS) in three distinctively different nanostructures were obtained by electrochemical self-assembly from a single pot containing all the chemical ingredients. Their optical properties for UV-vis-NIR absorption, photoluminescence (PL), and PL excitation spectra were examined between 77 and 298 K, in comparison with solution and solid powder of DAS tosylate (DAST). Unlike all other dyes we tested before, PL of DAS was not quenched but rather enhanced when hybridized with CuSCN.

Photoconductive Properties of Dibenzotetrathiafulvalene-Tetracyanoquinodimethane (DBTTF-TCNQ) Nanorods Prepared by the Reprecipitation Method.

Charge-transfer complex crystals have been extensively studied because of their metallic conductivity, photoconductivity, ambipolar charge transport, and high career mobility. Numerous studies of their applications for organic electric devices such as organic field effect transistors and solar cells have reported. However, bulky single crystals of charge-transfer complexes are difficult to handle, specifically to be made into a form of a thin film.

Topochemical polymerization of unsymmetrical aryldiacetylene supramolecules with nitrophenyl substituents utilizing C-H∙∙∙π interactions.

Diacetylenes are versatile building blocks, in which many functional groups can be incorporated for the construction of new materials with desirable properties. In this study, 6-(p or m-nitrophenyl)-3,5-hexadiyne-1-ol (4a or 4b) containing nitrophenyl groups (host) and 2-hydroxyethyl groups (guest) in different diacetylene terminals were designed to establish an ordered supramolecular assembly that is complied with the strict requirements for the topochemical polymerization of diacetylenes. Crystal film and bulk crystals of compound 4b were obtained successfully by cast film and re-precipitation methods.

Synthesis and nanostructures of several tetrathiafulvalene derivatives having the side chains composed of chiral and hydrogen-bonding groups and their charge-transfer complexes.

Tetrathiafulvalene (TTF) derivatives TTF-Bor, TTF-2UM and TTF-4UM having chiral urethane groups were prepared. Among them, TTF-2UM, TTF-4UM and their charge-transfer (CT) complexes with F4TCNQ organized the nanowires. The intermolecular hydrogen bonding of the chiral urethane groups and π-stacking of TTF moieties or the formation of CT complexes resulted in a long one-dimensional nanowires.

Quick and selective synthesis of Li6[α-P2W18O62]·28H2O soluble in various organic solvents.

Herein we report the synthesis of α-Dawson type POM, Li6[α-P2W18O62]·28H2O, directly from the use of Li2WO4 as the tungstate source. The salt obtained was soluble not only in water but also in a range of polar and non-polar organic solvents, such as benzene.

Radical-initiator-Induced solid-state polymerization of butadiyne nanocrystals in water and their dispersion stabilization.

Butadiyne nanocrystals in water are usually polymerized by UV or gamma-ray irradiation to give polydiacetylene (PDA) nanocrystals. In this study, we confirmed that solid-state polymerization of 1,6-di(N-carbazolyl)-2,4-hexadiyne (DCHD) and 5,7-dodecadiyn-1,12-diyl bis[N-(butoxycarbonyl-methyl)carbamate] (4BCMU) could be stimulated by water-soluble radical initiators. The radical initiators used were potassium peroxodisulfate, three kinds of azo-type compounds and a redox initiator.

Study of molecular arrangement of organized molecular films of charge-transfer complexes containing 1,3-dithiole-2-thione-4,5-dithiolate by in-plane and out-of-plane X-ray diffractions.

We investigated the molecular arrangement and surface morphology of organized molecular films of alkylammonium-M bis(1,3-dithiole-2-thione-4,5-dithiolate) ((dmit)(2), M = Ni, Au, and Pd) charge-transfer complexes using the surface pressure-area (pi-A) isotherm, polarized visible spectroscopy, in-plane and out-of-plane X-ray diffractions (XRD), and atomic force microscopy (AFM). Since Langmuir-Blodgett films of alkylammonium-M(dmit)(2) generally exhibit superconductivity, it may be possible to develop novel electronic molecular devices on the subnanometer scale. In the bulk state, several alkylammonium-M(dmit)(2) molecules could not form a highly ordered layered structure along the c-axis and a subcell structure of the alkyl chain in the ab-plane; however, almost all molecules formed a layered structure in the film multilayers.

Unusual photopolymerization behavior of amino Acid-derived polydiacetylene supramolecules.

UV-irradiation of aqueous suspensions of amino acid-derived amphiphilic diacetylene supramolecules promotes a process that involves initial formation of species that absorb at 640 nm followed by the generation of polymers that have longer wavelength (686 nm) absorbance. The initially formed intermediate polydiacetylenes display substantial colorimetric reversibility while the long wavelength absorbing polymers show irreversible thermochromism during heating and cooling cycles. The long wavelength absorbing polydiacetylenes, formed from amino acid-derived amphiphilic diacetylene supramolecules, are suggested to have more planer backbone structures that allow more efficient overlap of the conjugated p-orbitals.

Missense mutation with/without nonsense mutation of the p53 gene is associated with large cell morphology in human malignant lymphoma.

Mutations in p53 gene exons 5-9 were studied in 44 non-Hodgkin's lymphomas (NHL) consisting of 35 B-NHL and 9 T-NHL. Missense mutations were found in two diffuse large B-cell lymphomas (DLBL) and one peripheral T-cell lymphoma (unspecified). Double transversion missense and nonsense mutations were detected in one DLBL and one adult T-cell leukemia/lymphoma.

Combined molecular and supramolecular bottom-up nanoengineering for enhanced nonlinear optical response: experiments, modeling, and approaching the fundamental limit.

The authors study the combination of two independent strategies that enhance the hyperpolarizability of ionic organic chromophores. The first molecular-level strategy is the extension of the conjugation path in the active chromophore. The second supramolecular-level strategy is the bottom-up nanoengineering of an inclusion complex of the chromophore in an amylose helix by self-assembly.

Synthesis and characterization of monodispersed polymer/polydiacetylene nanocrystal composite particles.

Monodispersed polymer/polydiacetylenecomposite particles were synthesized by soap-free seeded emulsion polymerization of styrene andmethyl methacrylate; the products were characterized by XRD, SEM, TEM, UV-visible spectroscopy, and single particle scattering spectroscopy. In the synthesis process, polydiacetylene nanocrystals were found to act as inhibitor, and consequently a relatively low concentration was necessary. Different monomers lead to the differences in reaction condition and particle morphology; the PMMA composite particles were simpler in preparation than polystyrene particles, but the latter havebetter spherical morphology.

Monodispersed quinacridone nanocrystals prepared by a high-temperature and high-pressure liquid crystallization method.

Monodispersed quinacridone nanocrystals were fabricated by a high-temperature and high-pressure liquid crystallization method, which proved to be an advanced technique for fabricating nanocrystals of pigment compound. The aqueous dispersion liquid of quinacridone nanocrystals was very stable. The nanocrystats had a spherical shape with an average size of 60 nm when water was used as the high-temperature and high-pressure liquid at 260 degrees C and cooling solvent.

Alpha-fetoprotein-producing esophageal carcinoma: a case report.

We report herein a rare case of esophageal carcinoma producing alpha-fetoprotein (AFP). A 69-year-old man presenting elevated AFP was admitted in order to investigate its origin, which several liver examinations done before admission had not revealed. At admission, his serum AFP was 76.

Single-crystal-to-single-crystal transformation of diolefin derivatives in nanocrystals.

Topochemical [2 + 2] cycloaddition polymerization of methyl p-phenylenediacrylate and 2,5-distyrylpyridine in nanocrystals, prepared by the reprecipitation method, were investigated in comparison with those in bulk crystals. The bulk single crystals, larger than 1 mum in size, broke into microcrystals with variety of size and shape in the course of polymerization. Interestingly, however, these nanocrystals show single-crystal-to-single-crystal transformation.