Upgrade of the nuclear resonant scattering beamline, BL09XU in SPring-8

An Upgrade of the nuclear resonant scattering beamline, BL09XU in SPring-8 has been conducted. A liquid nitrogen cooled high-heat load monochromator was installed and a 2nd experimental hutch was constructed. The instruments installed in the hutch allow for a variety of sample conditions. Newly developed high-resolution monochromators with better stability including the back scattering geometry monochromator have opened up the easy access to more isotopes and more precise measurements.     

Synthesis of thermally stable aromatic poly(spiroorthocarbonate)s having a Cardo or bent structure

Novel poly(spiroorthocarbonate)s [poly(SOC)]s having a Cardo or bent structure were synthesized by polycondensation of several bis‐catechols having fluorene (BCFL), spirobisindane (BCSPI), or spirobischromane (BCSPC) in the structure with 2,2,6,6‐tetrachlorobenzo[1,2‐d:4,5‐d’]bis[1,3]dioxole (4ClBD). Synthesis of poly(SOC)s was confirmed by NMR and IR spectrometry. The poly(SOC)s obtained from BCFL or BCSPC were soluble in common organic solvents. The glass transition temperature of the poly(SOC)s was not detected by differential scanning calorimetry (DSC) in the range of 50–300 °C. The 10 wt % decomposition temperature of the poly(SOC)s was found to be above 400 °C. These results indicated the high thermal stability of the poly(SOC)s. Soluble poly(SOC)s could be possessed to form a film on a glass plate by the spin coat method. The obtained polymer films were 0.2 μm in thickness with 95% light transmission in the optical wavelength range. These results suggested that the Cardo or bent structure may block the packing of the main‐chain of the structure, which improves the solubility of the polymers, increases transparency, and enhances the thermal stability of SOCs. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 1409‐1416     

Selective nucleophilic additions to poly(methacrylate)s containing isothiocyanate moieties in the side chains and their application in cross‐linking

Reactivity of isothiocynate moieties in the side chain of polymethacrylate with amine, alcohol, or thiol was investigated, and the reactions were applied to preparation of networked polymers. Isothiocyanate of polymer side chain rapidly reacted with amines without a catalyst, to give the corresponding thioureas. However, it did not react with alcohols or thiols under the same conditions. Using 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) as a catalyst, addition of alcohols or thiols to the isothiocyanate proceeded smoothly. Addition of amines, alcohols, and thiols to isothiocyanates moiety contained in the side chain of polymethacrylate also proceeded readily with or without the catalyst, respectively, to effectively give the corresponding side chain modified polymers. Occurrence of these additions was confirmed by ¹H NMR and IR measurements. Glass transition temperatures and thermal decomposition temperatures of the obtained polymers were investigated by differential scanning calorimetry and thermogravimetric analysis. Networked polymers were easily prepared by addition of 1,6‐hexamethylenediamine or hexamethylene glycol to the polymethacrylate having isothiocyanato groups. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1832–1842     

X-ray structure analysis of trans-1,4-polybutadiene

The crystal structure of trans-1,4-polybutadiene has been reported by Natta et al. to be pseudo-hexagonal below its solid-phase transition temperature. In the present X-ray structure analysis, it is revealed that the crystal belongs to the monoclinic system with the space group P2¹/a. The unit cell, with the lattice constants a = 8.63 Å, b = 9.11 Å, c = 4.83 Å, and β = 114°, includes four molecular segments.     

Snthetic Studies on Carotane and Dolastane Type Terpenes: A New Entry to the Total Synthesis of (±)-Daucene Via Intramolecular [2 + 2] Photocycloaddition

An efficient synthesis of new hydroazulene derivatives, 13 and 14, potential intermediates for the syntheses of the the title terpenes, via intramolecular [2 + 2] photocycloaddition is described in the context of the total synthesis of (±)-daucene.     

Induced Fitting and Polarization of a Bromine Molecule in an Electrophilic Inorganic Molecular Cavity and Its Bromination Reactivity

Dodecavanadate, [V₁₂O₃₂]^4? (V12), possesses a 4.4 Å cavity entrance, and the cavity shows unique electrophilicity. Owing to the high polarizability, Br₂ was inserted into V12, inducing the inversion of one of the VO₅ square pyramids to form [V₁₂O₃₂(Br₂)]^4? (V12(Br2)). The inserted Br₂ molecule was polarized and showed a peak at 185 cm^?1 in the IR spectrum. The reaction of V12(Br2) and toluene yielded bromination of toluene at the ring, showing the electrophilicity of the inserted Br₂ molecule. Compound V12(Br2) also reacted with propane, n‐butane, and n‐pentane to give brominated alkanes. Bromination with V12(Br2) showed high selectivity for 3‐bromopentane (64 %) among the monobromopentane products and preferred threo isomer among 2‐,3‐dibromobutane and 2,3‐dibromopenane. The unique inorganic cavity traps Br₂ leading the polarization of the diatomic molecule. Owing to its new reaction field, the trapped Br₂ shows selective functionalization of alkanes.     

Full fitting analysis of the relative intermediate form factor measured by neutron spin echo

This paper describes the dynamics of a water-in-oil microemulsion from the dilute to the dense droplet region. Using the relative intermediate form factor method for neutron spin echo data analyses [M. Nagao, H. Seto, Phys. Rev. E 78 (2008) 011507], the shape and structure fluctuations of a droplet microemulsion are successfully decoupled. In the previous paper, we used the first cumulant analysis of the shape fluctuation model, while the full fitting form of the same model is applied in this paper. The final results of the fittings using the first cumulant approximation and the full form of the model are almost identical, and therefore, the validity of the method is strengthened. The estimated bending modulus of the surfactant membrane, κ, is basically the same, within the experimental errors, in the previous and present results. The κ is not affected much by an increase of the droplet concentration. A clear dynamic slowing down of the water droplets is highlighted at the length scale corresponding to the inter-droplet distance from the structure fluctuation analysis.     

Inhibitors of plasmin that extend into both the S and S' binding sites: cooperative interactions between S1 and S2

A new procedure for the synthesis of cyclohexanone-based inhibitors of serine proteases is reported. In this procedure the reactive ketone functionality is carried through the synthesis in masked form as a TBDMS-protected alcohol. Deprotection followed by oxidation of the alcohol generates the final form of the inhibitor. Two new inhibitors, which interact with the S1-S3 and S2' subsites of plasmin, are synthesized using this procedure. Inhibitors 1 and 2 have IC50 values against plasmin of 20 and 24 microM, respectively. The inhibition studies show that cooperative binding of inhibitors in the S1 and S2 subsites of plasmin is important for determining inhibitor selectivity.     

Isoapoptolidin: structure and activity of the ring-expanded isomer of apoptolidin

[formula: see text] Apoptolidin (1) is a novel oncolytic lead that induces apoptosis in transformed cell lines with exceptional selectivity. We report the isolation and characterization of a ring-expanded macrolide isomer of apoptolidin: isoapoptolidin (2). The solution conformation of isoapoptolidin is described. The rate of isomerization was measured under biologically relevant conditions and found to approach equilibrium within the time frame of most cell-based assays. Isoapoptolidin's ability to inhibit mitochondrial F0F1-ATPase is over 10-fold less than that of apoptolidin.     

197Au Mössbauer study of Au/Ni artificial multilayers

¹⁹⁷Au Mössbauer measurements have been performed at 16 K on the Au/Ni artificial multilayers having three different thickness of the layers those are 10Å Au/10Å Ni, 30Å Au/30Å Ni and 53Å Au/53Å Ni on a 250Å pure Au buffer layer. Mössbauer spectra obtained can be decomposed into mainly two components. One is an unperturbed component having an identical isomer shift value to the bulk Au metal. The other is the component perturbed strongly by the Ni layer indicating a broad contribution at positive velocity side and its intensity depends on the thickness of the Au layer. The spectrum from 10Å Au/10Å Ni multilayer is an entirely perturbed one and its area ratio to the component rising from pure Au buffer layer indicates the large Debye-Waller-factor suggesting the supermodulus effect in this multilayer.