Tetra(n-butyl)ammonium salt of a ferrimagnetic complex based on mixed-valent dinuclear ruthenium pivalate and octacyanidotungstate(V)

International audienceA tetra (n-butyl)ammonium (n-Bu4N+) salt of Ru2–W complex consisting of dinuclear ruthenium (II,III) pivalate, ([RuIIRuIII(piv)4]+) (Hpiv = pivalic acid), and octacyanidotungstate(V), [n-Bu4N][{RuIIRuIII(piv)4}2(H2O){WV(CN)8}] (1), was synthesized and characterized by elemental analysis, infrared spectra, and temperature dependence of magnetic susceptibilities (2–300 K). The crystal structure of 1 revealed a zigzag one-dimensional chain molecule along the c axis with alternating arrangement of [RuIIRuIII(piv)4]+ and [WV(CN)8]3−, where another [RuIIRuIII(piv)4]+ unit is dangled from the [WV(CN)8]3− moiety. The magnetic susceptibilities and zero-field-cooled and field-cooled magnetization data showed that the present complex is ferrimagnetic with a Tc value of 5.5 K. The field dependence of magnetization exhibited a hysteresis with a coercive field of 150 Oe at 2 K

Magnetic material based on mixed-valent dinuclear pivalate and cyanidometalate

Mixed-metal complex consisting of ruthenium(II,III) pivalate, ([Ru₂(piv)₄]⁺) (Hpiv = pivalic acid), tetraethylammonium and octacyanidotungstate(V) ions, (Et₄N)[{Ru₂(piv)₄}₂W(CN)₈]·4H₂O, was synthesized and characterized by elemental analysis, infrared and UV-vis spectra and temperature dependence of magnetic susceptibilities (2-300 K). The magnetic susceptibilities, zero-field-cooled and field-cooled magnetizations, and AC susceptibility data showed that the present complex is ferrimagnetic with T_{c} value of 80 K. The field dependence of magnetization exhibited a hysteresis with a coercive field of 17000 Oe at 5 K

Synthesis, Crystal Structures, Electronic Spectra, and Magnetic Properties of Thiolato-Bridged Trinuclear Cobalt(II) Complexes with N, N, S-Tridentate Thiolate Ligands

New trinuclear CoII complexes, [{Co(apaet)2}2Co]X2 (apaet– = 2-[(3-aminopropyl)amino]ethanethiolato; X = SCN (1), ClO4 (2), NO3 (3), Cl (4), Br (5), I (6)) and [{Co(apampt)2}2Co]X2 (apampt– = 1-[(3-aminopropyl)amino]-2-methylpropane-2-thiolato; X = NO3(7), ClO4 (8), Cl (9), Br (10), I (11)), and mononuclear CoIII complexes, [Co(apaet)2]X (X = ClO4 (12), NO3 (13)), were synthesized. Single-crystal X-ray crystallography of 1 and 7 confirmed that the trinuclear complexes have a linear arrangement of octahedral CoIIS2N4-tetrahedral CoIIS4-octahedral CoIIS2N4 chromophores where two thiolate ligands are coordinated to each terminal Co atom in a mer coordination mode and the two thiolato S atoms are further bound to the central Co atom, which is consistent with the electronic spectra and antiferromagnetic propertie

KAgoshima Galactic Object survey with Nobeyama 45-metre telescope by Mapping in Ammonia lines (KAGONMA): Discovery of parsec-scale CO depletion in the Canis Major star-forming region

In observational studies of infrared dark clouds, the number of detections of CO freeze-out onto dust grains (CO depletion) at pc-scale is extremely limited, and the conditions for its occurrence are, therefore, still unknown. We report a new object where pc-scale CO depletion is expected. As a part of Kagoshima Galactic Object survey with Nobeyama 45-m telescope by Mapping in Ammonia lines (KAGONMA), we have made mapping observations of NH3 inversion transition lines towards the star-forming region associated with the CMa OB1 including IRAS 07077-1026, IRAS 07081-1028, and PGCC G224.28-0.82. By comparing the spatial distributions of the NH3 (1,1) and C18O (J=1-0), an intensity anti-correlation was found in IRAS 07077-1026 and IRAS 07081-1028 on the ~1 pc scale. Furthermore, we obtained a lower abundance of C18O at least in IRAS 07077-1026 than in the other parts of the star-forming region. After examining high density gas dissipation, photodissociation, and CO depletion, we concluded that the intensity anti-correlation in IRAS 07077-1026 is due to CO depletion. On the other hand, in the vicinity of the centre of PGCC G224.28-0.82, the emission line intensities of both the NH3 (1,1) and C18O (J=1-0) were strongly detected, although the gas temperature and density were similar to IRAS 07077-1026. This indicates that there are situations where C18O (J=1-0) cannot trace dense gas on the pc scale and implies that the conditional differences that C18O (J=1-0) can and cannot trace dense gas are unclear.Comment: 19 pages, 15 figures, 4 tables, accepted for Publications of the Astronomical Society of Japan (PASJ). The version 1 is the Author's Original Version. My accepted manuscript will be publicly available on the arXiv one year after publication in the PAS

Geometrical Isomerism in Ru2Au Heterometal Assembly: Cis-Linking of Tetracyanidoaurate to Tetrakis(Μ-Butanoato)Diruthenium

A heterometal assembled complex of tetrakis(μ-butanoato)diruthenium(II,III) and tetracyanidoaurate(III) [RuIIRuIII(n-C3H7COO)4AuIII(CN)4]n was synthesized and characterized by the elemental analysis and infrared spectroscopy. The single-crystal X-ray structure analysis revealed that the complex consists of zigzag chain molecules of alternating arrangement of the Ru2(n-C3H7COO)4+ and Au(CN)4– units with cis-bridging mode of the Au(CN)4– units. The temperature dependence of the magnetic susceptibility data (4.5—300 K) showed that the magnetic interaction between the dinuclear RuIIRuIII units (S= 3/2) is negligibly small with a zero-field splitting parameter D value of 60 cm-1

Discovery of the Pigtail Molecular Cloud in the Galactic Center

This paper reports the discovery of a helical molecular cloud in the central molecular zone (CMZ) of our Galaxy. This "pigtail" molecular cloud appears at (l, b, V_LSR) ~ (-0.7deg, +0.0deg, -70 to -30 km/s), with a spatial size of ~ (20 pc)^2 and a mass of (2-6) 10^5 solar masses. This is the third helical gaseous nebula found in the Galactic center region to date. Line intensity ratios indicate that the pigtail molecular cloud has slightly higher temperature and/or density than the other normal clouds in the CMZ. We also found a high-velocity wing emission near the footpoint of this cloud. We propose a formation model of the pigtail molecular cloud. It might be associated with a magnetic tube that is twisted and coiled because of the interaction between clouds in the innermost x_1 orbit and ones in the outermost x_2 orbit.Comment: 15 pages, 6 figures, accepted for publication in Astrophysical Journa

高等学校数学科「数学Ｉ」における統計指導での変数変換の扱いに関する実践研究

高等学校数学科「数学Ⅰ：データの相関」の指導において、変数変換Y=aX+b の指導のあり方を提案する。変数変換Y=aX+b を用いた平均、分散等を表計算ソフトExcel を用いて求める中で成り立つ性質を生徒に気づかせ、その理由を証明する意欲を引き出す指導を試みた。その結果、変換した変量Yについて、表計算ソフトで統計量を求めることは108 名中49 名、約45% の生徒ができていたことが確認できた。一方、E（Y）=aE（X）+b 、V（Y）=a2 V（X） が成り立っていることに気づく者はいなかった。生徒は直観的には理解しているものの、それを数式を用いて証明するまでには至っていなかったことが確認できた