Upward temperature shift of the intrinsic phase lag of the magnetization of Bis(phthalocyaninato)terbium by ligand oxidation creating an S = 1/2 spin

An alternating-current (ac) magnetic susceptibility measurement for the [(Pc)(2)Tb(III)](0) complex (Pc = phthalocyaninato) has shown that ligand oxidation of the anionic [(Pc)(2)Tb(III)](-) complex gives rise to a significant upward shift of the temperature range where the magnetization response shows a phase lag behind the time-varying external magnetic field. The peaks of the out-of-phase component of the ac susceptibility of the pi-radical [(Pc)(2)Tb(III)](0) were observed at 50, 43, and 36 K with ac magnetic fields of 10(3), 10(2), and 10 Hz, respectively, which were more than 10 K higher than the corresponding values of the anionic complex with a closed-shell pi-system. The ac susceptibility measurements on the complex with octa(dodecoxy)-substituted Pc ligand, which is readily dilutable in diamagnetic media, proved that the significant rise of the temperatures occurs as an intrinsic single-molecular property of the complex possessing both J = 6 and S = (1)/(2) systems, and is not due to long-range magnetic order or interactions between adjacent unpaired pi-electrons.     

Birefringence control by hydrogen bonding on compatible polymer pair composed of hydrogenated ring‐opening polymer and modified polystyrene

A new polymer blend composed of a hydrogenated ring‐opening polymer (HROP) with an ester group and hydroxyl functionalized polystyrene (HFP) produced the excellent transparent materials which enabled a precise birefringence control in keeping with the other physical properties for optical film use. The blend with a composition from 0.28 to 0.35 for the HFP weight fraction showed an extraordinary wavelength dispersion, transmitting through a zero birefringence point at the critical fraction of 0.45, while each polymer showed an ordinary wavelength dispersion. The observed excellent transparency even above those of the glass transition temperature was attributed to a depressed phase separation that resulted from strong hydrogen bond between the ester and hydroxyl groups. An IR analysis of the film demonstrated a remarkable red‐shift in the carbonyl peak with an increase of the hydroxylated polystyrene content, indicating a strong hydrogen bond between those groups. This new polymer blend provides a useful design to achieve practical demands for film use, both optical and mechanical under the fabrication conditions using the melt extrusion technique. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3132–3143     

Mesogenicity of testosterone and estrone derivatives

Mesogenicity of 3β, 17β-bis(4-n-alkoxybenzoyloxy) androstene homologues (BABA) (carbon No. of alkoxy group, n, = 1-10) were studied by use of D.S.C. and a polarized microscopy. It was found that the n = 4-10 compounds of BABA have one cholesteric mesophase with high thermal stability enantiotropically, and that the n = 1-3 compounds decompose just above the melting point. Mesogenicities of BABA and several testosterone and estrone derivatives were also discussed from the perspective of chemical structure and shape. The presence of an intramolecular long-range dipole coupling in two alkoxybenzoyloxy chromophores is found in BABA from CD spectral studies.     

Combined EPMA and AES depth profiling of a multilayer Ti-Al-O-N coating

In order to compare thin-film electron probe microanalysis (EPMA) and Auger electron spectroscopy (AES) regarding reliability in quantifying chemical compositions of Ti-Al-O-N coatings with depth, a multilayer was prepared on a silicon wafer by using reactive ionized cluster beam deposition technique. Within a total thickness of about 25 nm the composition of the multilayer varied step by step from Ti-Al-O-N at the bottom to Al-O at the top. AES and, as an innovation, EPMA crater edge profiling was applied to measure the composition with depth. For quantification special thin-film EPMA techniques based on Monte Carlo simulations were applied. The chemical binding states of Al and Ti with depth were analysed using a high resolution energy analyser (MAC 3) for the AES investigations working in the direct mode. According to the deposition procedure the concentration profiles of the components varied with depth for both AES and EPMA measurements. AES provided a better depth resolution than EPMA. To get a true calibration of the depth scale an in-situ measurement method like an optical interferometry will be required. Assuming that the relative sensitivity factors are available AES depth profiling delivers concentration profiles with good accuracy. The new EPMA application provided quantitative depth profiles concerning concentration and coverage. For EPMA crater edge profiling the coating needs to be deposited on a foreign substrate because depth distributions of elements being present in both the layer and the substrate cannot be resolved.The combination of AES-depth profiling with EPMA crater edge profiling techniques is a powerful tool to analyse heterostructures quantitatively.     

Gas chromatographic determination of lower fatty acids in gaseous samples via conventional in situ derivatization of the strontium salts catalysed by poly(crow ether)

Poly(crown ether)-catalysed derivatization of lower fatty acids with p-bromophenacyl bromide or pentafluorobenzyl bromide has been used for their determination in gaseous samples by gas chromatography (employing either flame-ionization or electron-capture detection). Stontium hydroxide was employed as a base for the derivatization, taking advantage of the fact that a column packed with strontium hydroxide-coated glass beads is very suitable for preconcentration of the fatty acids from ambient air. In situ derivatization of lower fatty acids, preconcentrated on the glass beads as their strontium salts, proceeded nearly quantitatively in acetonitrile. Traces of lower fatty acids in artificial sample gases could be determined successfully using this conventional derivatization followd by direct injection of the reaction mixture into a gas chromatograph.     

Upper Bound on the Diameter of a Domination Dot-Critical Graph

A vertex of a graph is called critical if its deletion decreases the domination number, and an edge is called dot-critical if its contraction decreases the domination number. A graph is said to be dot-critical if all of its edges are dot-critical. In this paper, we show that if G is a connected dot-critical graph with domination number k??? 3 and diameter d and if G has no critical vertices, then d??? 2k?3.     

Effect of discrete track medium at high areal density

The degradation of SNR caused by the higher uniaxial crystalline anisotropy field (Hk) of medium and small write fields of narrower write width is one of the problems for achieving higher areal density. The SNR dependence on Hk of a medium with different write fields of head using the discrete track medium (DTM) is investigated by using micromagnetics simulation. As a result, the curves of SNR as a function of Hk have peak values. In DTM, the peak values of SNR are almost constant at any Hk of the medium and different write fields. Higher SNR is realized even at low Hk and small write field in DTM.     

Synthesis and evaluation of 2-Nonylaminopyridine derivatives as PPAR ligands

To find novel PPAR ligands, we prepared several 3-{3 or 4-[2-(nonylpyridin-2-ylamino)ethoxy]phenyl}propanoic acid derivatives which were designed based on the structure of our previous PPARgamma ligand 1. In PPAR binding affinity assays, compound 4, which had an ethoxy group at the C-2 position of the propanoic acid of 1, showed selective binding affinity for PPARgamma. Compound 3, with an ethyl group at the C-2 position, was found to be a PPARalpha/gamma dual ligand. Compound 6, the meta isomer of 1, has been shown to be a PPARalpha ligand. The introduction of methyl (7) and ethyl (8) groups to the C-2 position of the propanoic acid of 6 further improved PPARalpha-binding potency. In cell-based transactivation assay, compounds 3 and 4 showed dual-agonist activity toward PPARalpha and PPARgamma. Compound 6 was found to be a triple agonist and compound 8 proved to be a selective PPARalpha agonist. In the human hypodermic preadipocyte differentiation test, it was demonstrated that the maximal activity of compounds 3 and 4 was higher than that of rosiglitazone.