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Single-Component Magnetic Conductors Based on Mo3S7 Trinuclear Clusters with Outer Dithiolate Ligands
2004
A trinuclear cluster complex containing the Mo(3)S(7) central unit coordinated to dithiolate ligands, in particular the organic dmit (1,3-dithia-2-thione-4,5-dithiolate) anion, has been used to prepare a single-component molecular conductor formed by the threefold symmetry magnetic building block Mo(3)S(7)(dmit)(3) (1). The [Mo(3)S(7)(dmit)(3)](2)(-) ([1](2)(-)) diamagnetic anion forms dimers by interaction between the electrophilic cluster axial sulfur atoms and the sulfur atoms of the outer dithiolate ligand. Additional contacts between adjacent dmit ligands result in chain formation. The two-electron oxidation of [1](2)(-) yields to a three-dimensional molecular solid formed by neutral M…
New binary antimonide Hf5Sb3
1999
Abstract Hf5Sb3 can be prepared by arc-melting of hafnium and previously synthesized HfSb2. It crystallizes like the high-temperature modification of Zr5Sb3 in the Y5Bi3 structure type, space group Pnma, Z=4, a=740.75(9) pm, b=871.8(1) pm, c=1073.6(1) pm, V=693.3(1) 106pm3. An antimonide analogous to the low-temperature form of Zr5Sb3 was not obtained during our investigations. In the structure of Hf5Sb3, the Hf atoms form a three-dimensional network with numerous short Hf–Hf contacts, including the Sb atoms in severely distorted two- and three-capped trigonal prismatic voids. Calculations of the electronic structure, performed with the extended Huckel approximation as well as the TB-LMTO-A…
Structure and photoreactivity of stable zwitterionic group 6 metal allenyls
2013
The synthesis and mechanistic study of the unprecedented reactivity of a series of zwitterionic η(1)-metal allenyls are reported.
Nb 4 Te 17 I 4 , a New Pseudo One‐Dimensional Solid‐State Polytelluride
1994
The new ternary compound Nb4Te17I4 has been prepared and structurally characterized. It crystallizes in the monoclinic system, space group C2/c with unit-cell parameters a = 16.199(4), b = 8.128(2), c = 27.355(6) A, β = 110.84(2)°, Z = 4. The structure consists of infinite one-dimensional niobium/tellurium chains running parallel to the crystallographic c direction. The chains are separated by iodine atoms. Short and long metal–metal distances alternate in the sequence of three consecutive short bonds ([d ≈ 3.1 – 3.2 A) and one long (d = 4.268 A) metal–metal separation. Each Nb atom is eight-coordinate. The composition of the chain is ∞11[(Nb5+)2(Nb4+)2(Te22−)4(Te32−)3(I−)4].
Structure and properties of some nitro derivatives of N -methyl- N -phenylnitramine
2000
Abstract Ten mono-, di- and tri-nitro derivatives of N-methyl-N-phenylnitramine were prepared and investigated using spectral and electrooptical methods. Three of them, viz. N-(2, 5-dinitrophenyl)-N-methylnitramine (monoclinic, P21/c, a=8.248(2), b=11.655(2), c=10.404(2) A , β=102.57(2)°), N-(2,3-dinitrophenyl)-N-methylnitramine (monoclinic, P21/c, a=9.224(2), b=7.222(2), c=15.458(4) A , β=101.08(2)°)) and N-(3,5-dinitrophenyl)-N-methylnitramine (monoclinic, P21/n, a=9.814(2), b=12.000(2), c=8.865(2) A , β=114.94(2)°) were examined by the X-ray diffraction method. The nitramino group is nearly planar with the short N(7)–N(8) bond and strongly electron deficient N(8) atom. The nitramino grou…
Synthesis, Structure, and Electrical Properties of Ta 4 FeTe 4
1995
Ta4FeTe4 has been synthesized and its structure determined by single-crystal X-ray methods. It crystallizes in the ortho-rhombic space group Pbam with Z = 4 and a = 10.514(5), b = 18.275(7), and c = 4.815(1) A. Ta4FeTe4 has a chain structure built up by Fe-centered Ta8-square antiprisms sharing common square faces. The resistivity of Ta4FeTe4 has been measured by a two-point method. Ta4FeTe4 shows metallic behavior. The structure of Ta4FeTe4 is discussed in relation to other early transition metal cluster compounds. A rational approach to the synthesis of related compounds is proposed.
Solution stoichiometry determines crystal stoichiometry in halogen-bonded supramolecular complexes
2007
The behavior of the methylisonicotinate (MINC) building block as halogen bonding-acceptor module has been investigated in the solid state. Both the N and the O atoms of MINC interact with the iodine atoms of 1,4-diiodotetrafluorobenzene (DITFB) giving rise to N⋯I and O⋯I interactions. Hierarchy between these interactions allows the control of the composition and thus the structure of the supramolecular complex, according to the composition of the reaction mixture. A structure based on an infinite chain and a trimeric supermolecule have been obtained starting from a 1 ∶ 1 MINC/DITFB stoichiometry or by using a large excess of MINC, respectively. While the former structure shows simultaneous …
Pyrolysis of vegetable oil soaps—Palm, olive, rapeseed and castor oils
2011
Abstract Saponified, palm, olive, rapeseed and castor oils were pyrolysed (at 750 °C for 20 s) by pyrolysis gas chromatography with mass selective and flame ionisation detection (Py-GC/MSD and FID) to clarify their thermochemical behaviours. The liquefiable compounds recovered from palm, olive and rapeseed oils mainly contained linear alkenes (up to C 19 ) and alkanes (up to C 17 ), both similar to those found in gasoline (C 4 –C 10 ) and diesel fuel (C 11 –C 22 ) boiling range fractions of petroleum, whereas in the case of castor oil a significant amount of undesired oxygen-containing products (e.g., ketones and phenols) were formed. The obtained data on reaction mechanisms can also be uti…
Child protection in Europe: development of an international cross-comparison model to inform national policies and practices
2015
We report a five-nations project in comparative child protection to provide recommendations on policy and practice to inform the redevelopment of the Swiss child protection system. The Swiss Federal Government and the Optimus and Oak Foundations commissioned the project—collective title: Association Programme National pour la Protection de l'Enfant. We identify the historical developmental trajectories of child protection systems together with common drivers: the evidential basis for the prevalence and effects of child abuse, the co-joining of social and economic policies and practices to promote early investment in children, the influence of children's rights and comparative international …
Tracing anthropogenic thallium in soil using stable isotope compositions.
2014
Thallium stable isotope data are used in this study, for the first time, to apportion Tl contamination in soils. In the late 1970s, a cement plant near Lengerich, Germany, emitted cement kiln dust (CKD) with high Tl contents, due to cocombustion of Tl-enriched pyrite roasting waste. Locally contaminated soil profiles were obtained down to 1 m depth and the samples are in accord with a binary mixing relationship in a diagram of Tl isotope compositions (expressed as e(205)Tl, the deviation of the (205)Tl/(203)Tl ratio of a sample from the NIST SRM 997 Tl isotope standard in parts per 10(4)) versus 1/[Tl]. The inferred mixing endmembers are the geogenic background, as defined by isotopically l…