Facile sulfur‐assisted carbonylation of diaminoresorcinol with carbon monoxide

4,6‐Diaminoresorcinol, which is a raw material of ZYLON (PBO fiber), has an instability in air atmosphere. Therefore, very stable benzo[1,2‐d:5,4‐d']bis‐2(3H)‐oxazolone recognized a useful equivalent of 4,6‐diaminoresorcinol during the stages of production, storage, and transportation. By combining the sulfur‐assisted carbonylation of 4,6‐diaminoresorcinol dihydrochloride with carbon monoxide and triethylamine under 0.1 MPa at 20°C for 4 h in DMF with the oxidation of resulting hydrogen sulfide salt with molecular oxygen for 2 h, benzo‐[1,2‐d:5,4‐d']bis‐2(3H)‐oxazolone was obtained in a quantitative yield. Also, carbonylation of 2,5‐diaminohydroquinone dihydrochloride and 2,5‐diamino‐1,4‐benzenedithiol dihydrochloride was smoothly performed to give benzo[1,2‐d:4,5‐d']bis‐2(3H)‐oxazolone and benzo[1,2‐d:4,5‐d']bis‐2(3H)‐ thiazolone, respectively, in good to excellent yields under similar reaction conditions. Furthermore, 2,6‐dimercaptobenzo[1,2‐d:5,4‐d']bisoxazole, which is another equivalent of 4,6‐diaminoresorcinol, was obtained in excellent yield by the thiocarbonylation of 4,6‐diaminoresorcinol dihydro‐chloride with carbon disulfide in the presence of 1‐methylpyrrolidine at 20°C for 24 h in DMF. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 23:111–116, 2012; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.20746     

Creation of polarized ultracold neutrons and observation of Ramsey resonance for electric dipole moment measurement

Polarized UCNs have been created by selecting only one spin state passing through a magnetized Fe foil. Typical degree of polarization was about 90 %. The polarization relaxation time in the prototype Ramsey cell was $T_1 =1100^{+800}_{-400}(Nd,Pr)-(Tb,Dy,Gd)-(Fe,Co,Al,Cu)-B magnets were heat treated in two different ways and investigated in the temperature range 4.2 to 400 K. After optimal heat treatment intrinsic coercive field _i H _c?= 1640 and 5040 kA/m for room temperature and 10 K was obtained and the temperature coefficient of remanence α?=??0.01 for temperature range 80 to 375 K was found. On basis of magnetic measurements and ⁵⁷Fe Mössbauer spectroscopy, the possible reasons for the increase of _i H _c during multi-step heat treatment are discussed.     

Different Modes of Anion Response Cause Circulatory Phase Transfer of a Coordination Cage with Controlled Directionality

Controlled directional transport of molecules is essential to complex natural systems, from cellular transport up to organismal circulatory systems. In contrast to these natural systems, synthetic systems that enable transport of molecules between several spatial locations on the macroscopic scale, when external stimuli are applied, remain to be explored. Now, the transfer of a supramolecular cage is reported with controlled directionality between three phases, based on a cage that responds reversibly in two distinct ways to different anions. Notably, circulatory phase transfer of the cage was demonstrated based on a system where the three layers of solvent are arranged within a circular track. The direction of circulation between solvent phases depended upon the order of addition of anions.     

Magnetic moments of proton drip-line nuclei13O and9C

The magnetic moments of the proton drip-line nuclei¹³O(I = 3/2^–,T _1/2 = 8.6 ms) and 9C(I = 3/2^–,T _1/2 = 126 ms) have been determined for the first time through the combined techniques of polarized radioactive nuclear beams and-NMR detection. The observed magnetic moments are ¦(¹³O)¦ = 1.3891 ±0.0003 _N and ¦(⁹C)¦ = 1.3914 ±0.0005 _N. Spin expectation values are deduced to be 0.76 and 1.44 for¹³O and⁹C, respectively. While the of¹³O is consistent with the systematics from isospinT= 1/2 mirror pairs, the of⁹C is unusually large, even far larger than the single particle value, = 1.     

Hyperfine Interactions of 12B in CaB6

The hyperfine interactions of short-lived β-emitter ¹²B implanted into a CaB₆ crystal have been studied by means of the β-NMR technique. An electric quadrupole splitting has been observed at room temperature from which an electric field gradient of q=−(1.34±0.05)×10²¹ V/m² was determined. From the present result, it was found that the ¹²B nuclei are mainly implanted in the substitutional boron site. This revised version was published online in September 2006 with corrections to the Cover Date.     

Spin-lattice relaxation of 25Al and 28P in Pt

The spin-lattice relaxation times T ₁ for short-lived β emitters ²⁵Al(I?=?5/2, T _1/2?= 7.2 s) and ²⁸P(I?=?3, T _1/2?= 270 ms) in Pt were measured by means of the β-NMR technique. As a result, T ₁[²⁵Al in Pt] = (1.1 $^{+\ 0.7}_{-\ 0.3})$ s and T ₁[²⁸P in Pt] >0.5 s were obtained at temperatures of 17 and 20 K, respectively. The Knight shifts were estimated from the Korringa relation, which were evaluated by comparing to the first principle calculations.     

Amorphous structures of iron obtained by quenching of the liquid state

The frozen-in structure of liquid iron was relaxed under periodic boundary conditions, where the potential of Pak and Doyama was used. The pair distribution functions of the final quenched structures resemble that of the amorphous structure, but depend on the details of the initial atomic arrangement.     

The T = 1, isospin triplet states in A = 30 nuclei

The level structure of ³⁰S was studied using the ${}^{28}\text{Si}\text{(τ,}\text{n}\text{p}\text{)}\text{reaction at}\text{E}{}_{\mathrm{\tau }}\text{= 9.5}\text{MeV}\text{,}\text{and}\text{J}{}^{\mathrm{\pi }}$ values were determined for some proton-emitting states by the neutron-proton angular correlation measurements. The Coulomb displacement energy of the isospin triplet state of A = 30 nuclei was analyzed using first-order perturbation theory. Large deviations from perturbation theory were found for the ground state, the 2⁺₁ state, the 3^?₁ state and the second excited 0⁺ state. These results might be explained by the effect of the pairing correlation of the two valence protons in ³⁰S under the assumption of charge symmetry for the nucleon-nucleon interaction.     

Construction of a protein-detection system using a loop peptide library with a fluorescence label

Construction of a novel protein-detection system was carried out using a designed peptide library with fluorescent labels based on loop structures. As a basic model study, detection of alpha-amylase using fluorescent-labeled peptides derived from an active loop of tendamistat was examined. The detection methods for proteins with immobilized peptides as well as peptides in solution have been successfully established. Based on these results, a loop peptide library that has various turn sequences grafted on a stable loop structure has been constructed. Various proteins with recognition patterns corresponding, for instance, to "protein fingerprints" could be detected using an immobilized peptide library. The present results suggest that the system can be applied to the development of a peptide microarray that behaves as a protein chip.