C1 Oxidation/C2 Reduction Isomerization of Unprotected Aldoses Induced by Light/Ketone

Unprotected aldoses in water undergo an isomerization reaction via a radical pathway when irradiated with light in the presence of water‐soluble benzophenone. Whereas its anomeric carbon (C1) is oxidized to a carboxy group, the hydroxy group on the C2 carbon is replaced by hydrogen. The generated 2‐deoxy lactones are readily reduced to the corresponding 2‐deoxy aldoses, which are often contained in bioactive compounds.     

Multilayer lattice gas model in the quasichemical approximation

The multilayer lattice gas model is dealt with in the quasichemical approximation. A restriction on the atomic stacking is also introduced in the system so that an atom can occupy only a lattice site whose underlying nearest neighbor lattice sites are all occupied by atoms. The critical condensation of atoms is investigated as the substrate potential is varied. The theory is also applied to the surface roughening of the crystalline bulk.     

Specular reflection of helium and hydrogen molecular beams from the (111) plane of silver

The Debye—Waller (DW) factor in the specular reflection intensity of He and H₂ molecular beams from the Ag (111) plane has been studied experimentally and theoretically. A new expression for the DW factor corrected for a stationary part of the gas—surface interaction potential is derived kinematically and semi-classically by the use of a Morse potential. An analysis of the experimental data through the above DW factor yields a surface Debye temperature of 251 ± 20 K, which is unusually high, and potential depths of 1.5 ± 1.0 meV for He and 6.4 ± 2.9 meV for H₂, which seem slightly too small. These results are discussed on the basis of the nature of gas-surface interactions and in comparison with the results deduced from the conventional DW factor corrected for a constant attractive potential depth.     

Chain orientation and intrinsic anisotropy in birefringence-free polymer blends

We found 10 miscible pairs of dissimilar polymers that rendered birefringence-free polymer blends. Each pair consists of a positive birefringence polymer and a negative one. Zero birefringence in the blend is attained as the result of compensation of positive and negative contributions to the overall birefringence. This concept was confirmed by characterizing the chain orientation of individual chains in the blend using polarized Fourier-transform infrared spectroscopy and by estimating theoretically the intrinsic optical anisotropy of the chain molecules.     

Current state for the development of metallopharmaceutics and anti-diabetic metal complexes

This tutorial review introduces the current state of metallopharmaceutics development by focusing on the topics of anti-diabetic vanadium and zinc complexes. Over thousands of years, people have produced many types of inorganic compounds, and the modern concept of chemotherapy was achieved by Ehrlich, who used an arsenic-containing compound to treat syphilis. Since then, many metallopharmaceutics have been developed worldwide. This review will be helpful to researchers who are interested in the current states of not only metallopharmaceutics but also anti-diabetic metal complexes.     

Intramolecular Benzyne–Phenolate [4+2] Cycloadditions

An intramolecular benzyne–phenolate [4+2] cycloaddition is reported. Benzyne precursors, having vicinal halogen-sulfonate functionalities, linked with a phenol(ate) by various tether groups undergo efficient intramolecular [4+2] cycloaddition by treatment with either Ph₃MgLi or nBuLi for halogen–metal exchange to form various benzobarrelenes.     

Detection of three-base deletion by exciplex formation with perylene derivatives

Here, we synthesized fluorescent DNA probes labeled with two perylene derivatives for the detection of a three-base deletion mutant. One such probe discriminated the three-base deletion mutant from the wild-type sequence by exciplex emission, and the deletion mutant was identifiable even by the naked eye.     

Analysis of Coherent Heteroclustering of Different Dyes by Use of Threoninol Nucleotides for Comparison with the Molecular Exciton Theory

To test the molecular exciton theory for heterodimeric chromophores, various heterodimers and clusters, in which two different dyes were stacked alternately, were prepared by hybridizing two oligodeoxyribonucleotides (ODNs), each of which tethered a different dye on D ‐threoninol at the center of the strand. NMR analyses revealed that two different dyes from each strand were stacked antiparallel to each other in the duplex, and were located adjacent to the 5′‐side of a natural nucleobase. The spectroscopic behavior of these heterodimers was systematically examined as a function of the difference in the wavelength of the dye absorption maxima (Δλ_max). We found that the absorption spectrum of the heterodimer was significantly different from that of the simple sum of each monomeric dye in the single strand. When azobenzene and Methyl Red, which have λ_max at 336 and 480 nm, respectively, in the single strand (Δλ_max=144 nm), were assembled on ODNs, the band derived from azobenzene exhibited a small hyperchromism, whereas the band from Methyl Red showed hypochromism and both bands shifted to a longer wavelength (bathochromism). These hyper‐ and hypochromisms were further enhanced in a heterodimer derived from 4′‐methylthioazobenzene and Methyl Red, which had a much smaller Δλ_max (82 nm; λ_max=398 and 480 nm in the single‐strand, respectively). With a combination of 4′‐dimethylamino‐2‐nitroazobenzene and Methyl Red, which had an even smaller Δλ_max (33 nm), a single sharp absorption band that was apparently different from the sum of the single‐stranded spectra was observed. These changes in the intensity of the absorption band could be explained by the molecular exciton theory, which has been mainly applied to the spectral behavior of H‐ and/or J‐aggregates composed of homo dyes. However, the bathochromic band shifts observed at shorter wavelengths did not agree with the hypsochromism predicted by the theory. Thus, these data experimentally verify the molecular exciton theory of heterodimerization. This coherent coupling among the heterodimers could also partly explain the bathochromicity and hypochromicity that were observed when the dyes were intercalated into the duplex.     

N‐Methyl‐N‐[(Z)‐2‐phenyl­propenyl]­thio­benz­amide

The crystal structure of the title thio­benz­amide, C₁₇H₁₇NS, was determined to investigate the relationship between the photoreactivity in solid state and the structure. The geometry was confirmed to be the Z isomer.