Chemistry of polyfunctional molecules-123. Reactions of BiBr3, SbI3 and AsI3 with LiN(PPh2)2; X-ray structure of a cyclophosphazene salt containing arsenic(I)

BiBr₃ or SbI₃ react at 20°C with LiN(PPh₂)₂ (1) to give elementary Bi or Sb and the P---P coupled phosphazene ligand Ph₂P---N=PPh₂---PPh₂=N---PPh₂ (2). The reaction of AsI₃ with 1 at room temperature formed yellow needles of the eight-membered heterocycle (3), whereas AsI₃ interacted at 80°C with 1 in the molar ratio of 1:3 to give elementary arsenic and 2. Treatment of AsI₃ and 1 at 20°C in a 1:2 stoichiometry yielded the seven-membered, cyclic arsenium(I) salt

Full-size image

I·4THF (5·4THF), which was characterized by elemental analysis, conductivity, mass, IR and NMR spectroscopy and single-crystal X-ray structural analysis.     

Komplexchemie polyfunktioneller Liganden. XLV. Tetracarbonylchrom-, -molybdän- und -wolframkomplexe mit 1,1,1-Tris(diphenylarsinomethyl)ethan

Complex Chemistry of Polyfunctional Ligands. XLV. Tetracarbonylchromium, -molybdenum, and -tungsten Complexes of 1,1,1-Tris(diphenylarsinomethyl)ethan Ultraviolet irradiation of M(CO)₆ (M = Cr, Mo, W) with the potentially tridendate chelating ligand CH₃C[CH₃As(C₆H₅)₂]₃ react in CH₃CN to the complexes cis-M(CO)₄CH₃C[CH₂As-(C₆H₅)₂]₃ in which always one arsenic donor of the ligand is uncoordinated. The vibrational spectra (i.r., f.i.r., and Raman) of the compounds are discussed in detail.     

Chemie polyfunktioneller liganden LXIII. Adamantankäfigverbindungen mit den heteroelementen arsen,stickstoff und silizium

The reaction of 1,1,1-tris(diiodarsinomethyl)ethane, CH₃C(CH₂AsI₂)₃ (I), with i-C₃H₇NH₂, n-C₄H₉NH₂, C₆H₅NH₂, p-CH₃C₆H₄NH₂ and [(CH₃)₃Si]₂NH in the presence of (C₂H₅)₃N as auxiliary base in THF gives the adamantane cage compounds CH₃C(CH₂AsNC₃H₇)₃ (III), CH₃C(CH₂AsNC₄H₉)₃ (IV), CH₃C(CH₂AsNC₆H₅)₃ (V), CH₃C(CH₂AsNC₆H₄CH₃)₃ (VI) and CH₃C[CH₂AsNSi(CH₃)₃]₃ (VII). VII is also obtained in the reaction of I with NaN[Si(CH₃)₃]₂. The by-product (CH₃)₃SiO(CH₂)₄I (VIII) could be isolated in both syntheses of VII. All compounds have been characterized by mass spectrometry and infrared, Raman and ¹H NMR spectroscopy.     

Chemie polyfunktioneller Moleküle. 101 [1]: Synthese eines Diphenylphosphin-substituierten Cyclophosphamide und Röntgenstrukturanalyse seines Oxidations-produkts

Inhaltsübersicht. Diphenylphosphin und rac-Cyclophosphamid (ClCH₂CH₂)₂NP(O)N(H)(CH₂)₃O (1) reagieren in Gegenwart von n-Butyllithium zu einem Zwischenprodukt, das mit Wasser das diphenylphosphinsubstituierte Cyclophosphamid, (Ph₂PCH₂CH₂)₂NP(O)N(H)(CH₂)₃O, (2) bildet. Metallierung von 2 mit n-BuLi am N(3)-Atom und Umsetzung mit D₂O führt zum N(3)-Deuteroderivat 2a. Mit H₂O₂ reagiert 2 zur all-Phosphinoxid Verbindung, [Ph₂P(O)CH₂CH₂]₂NP(O)N(H)(CH₂)₃O, (4), die mit 0,5 Mol Wasser auskristallisiert und von der zur Charakterisierung des H-Bückenbindungssystems eine Röntgenstrukturanalyse angefertigt wurde. Die NMR-Spektren (¹H, ¹³C, ³¹P, ¹⁴N) weisen 2–4 als dynamische Moleküle aus. Chemistry of Polyfunctional Molecules. 101. Synthesis of a Diphenylphosphinesubstituted Cyclophosphamide and the X-ray Diffraction of its Oxidation Product Diphenylphosphine and rac-cyclophosphamide, (ClCH₂CH₂)₂NP(O)N(H)(CH₂)₃O, (1) react in the presence of n-BuLi to an intermediate which hydrolyses to the diphenylphosphine substituted Cyclophosphamide, (Ph₂PCH₃CH₂)₂NP(O)N(H)(CH₂)₃O, (2). Metallation of 2 with n-BuLi at the N(3) atom, followed by treatment with D₂O yields the N(3)-deuterated derivative 2a. With H₂O₂ 2 forms the all-phosphine-oxide compound, [Ph₂P(O)CH₂CH₂]₂NP(O)N(H)(CH₂)₃O, ( 4 ), which crystallizes with 0.5 mole of water. In order to characterize the H-bridge bonding system a X-ray structure analysis of 4 was carried out. The NMR-Spectra (¹H, ¹³C, ³¹P, ¹⁴N) indicate 2–4 as dynamic molecules.     

Magneto-Structural analysis of rotating electrical machines

The vibrations of the stator core of a rotating electrical machine induce acoustic noise. These oscillations of the stator yoke are excited of the force density due to the magnetic field in the air gap. This requires a transient magnetic field analysis coupled with a dynamic mechanical analysis. Coupling these two different physical fields results in a high numerical effort and usually one direction of the interaction is disregarded. This paper presents a method to calculate the vibrations of a stator core under design operating conditions. For this purpose, harmonic electromagnetic excitation forces have been calculated in a linear magnetic field analyses using the finite element method. The resulting forces have been applied to a linear structural dynamic FE model in the frequency domain. The results of the calculations are harmonic velocities specified by amplitude and phase from the structural surface of the stator core. (© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Activation of Visuomotor Systems during Visually Guided Movements: A Functional MRI Study

The dorsal stream is a dominant visuomotor pathway that connects the striate and extrastriate cortices to posterior parietal areas. In turn, the posterior parietal areas send projections to the frontal primary motor and premotor areas. This cortical pathway is hypothesized to be involved in the transformation of a visual input into the appropriate motor output. In this study we used functional magnetic resonance imaging (fMRI) of the entire brain to determine the patterns of activation that occurred while subjects performed a visually guided motor task. In nine human subjects, fMRI data were acquired on a 4-T whole-body MR system equipped with a head gradient coil and a birdcage RF coil using aT^*₂-weighted EPI sequence. Functional activation was determined for three different tasks: (1) a visuomotor task consisting of moving a cursor on a screen with a joystick in relation to various targets, (2) a hand movement task consisting of moving the joystick without visual input, and (3) a eye movement task consisting of moving the eyes alone without visual input. Blood oxygenation level-dependent (BOLD) contrast-based activation maps of each subject were generated using period cross-correlation statistics. Subsequently, each subject's brain was normalized to Talairach coordinates, and the individual maps were compared on a pixel by pixel basis. Significantly activated pixels common to at least four out of six subjects were retained to construct the final functional image. The pattern of activation during visually guided movements was consistent with the flow of information from striate and extrastriate visual areas, to the posterior parietal complex, and then to frontal motor areas. The extensive activation of this network and the reproducibility among subjects is consistent with a role for the dorsal stream in transforming visual information into motor behavior. Also extensively activated were the medial and lateral cerebellar structures, implicating the cortico–ponto–cerebellar pathway in visually guided movements. Thalamic activation, particularly of the pulvinar, suggests that this nucleus is an important subcortical target of the dorsal stream.