Low resistance Cu[3]Ge compounds formation by the lowtemperature treatment of Cu/Ge system in atomic hydrogen

The research deals with the regularities for Cu[3]Ge compound formation under the low temperature treatment of a double-layer Cu/Ge system deposited on i-GaAs substrate in atomic hydrogen flow. The treatment of a Cu/Ge/i-GaAs system with layer thicknesses, respectively, of 122 and 78 nm, in atomic hydrogen with a flow rate of 10{15} at.·сm{-2} s{-1} for a duration of 2.5{-10} min at room temperature, leads to an interdiffusion of Cu and Ge and formation of a polycrystalline film containing stoichiometric phase Cu[3]Ge. The film consists of vertically oriented grains of dimensions 100-150 nm and has a minimum specific resistance of 4.5 [mu omega] сm. Variation in the treatment duration of Cu/Ge/i-GaAs samples in atomic hydrogen affects Cu and Ge distribution profiles, the phase composition of films formed, and the specific resistance of the latter. As observed, Cu3Ge compound synthesis at room temperature demonstrates the stimulative effects characteristic of atomic hydrogen treatment for both Cu and Ge diffusion and for the chemical reaction of Cu[3]Ge compound generation. Activation of these processes can be conditioned by the energy released during recombination of hydrogen atoms adsorbed on the surface of a Cu/Ge/i-GaAs sample

Crystal structures of binuclear Bi(III) chloride and bromide complexes with some cations — Alkylated pyridine derivatives

© 2017, Pleiades Publishing, Ltd. By a reaction of [BiX 6 ] 3– with salts of various N-alkylated pyridine derivatives in 2M HX (X = Cl, Br), (N-BzPy) 4 [Bi 2 X 10 ] complexes (X = Cl (1), Br (2), (4-MePyH) 4 [Bi 2 Cl 10 ] (3)) are obtained and structurally characterized

Heterogeneous bromination of alkenes using Bi(III) polybromide complexes as {Br<inf>2</inf>} source

© 2016 The Royal Society of Chemistry.A new polybromide Bi(iii) complex (PyH)3{[Bi2Br9](Br2)} was synthesized and characterized by XRD and other methods. This compound is able to act as a selective bromination agent towards various types of substituted alkenes

Polymeric hybrid iodoplumbates and iodobismuthates containing mono- and bisalkylated derivatives of 1,2-bis(4-pyridyl)ethylene: Structural and optical features

© 2017 Elsevier B.V.Reactions of PbI2 with N-alkylated derivatives of 1,2-bis(4-pyridyl)ethylene (bpen) MeBpenI and Me2BpenI2 result in 1D-polymeric complexes [{Pb(MeBpen)I3}] (1) and (Me2bpen)[{PbI3}]2 (2). For both compounds, band gap values were determinated experimentally; 1 demonstrates weak red luminescence. Binuclear hybrid iodobismuthate [Bi2(MeBpen)2I8] (3) was obtained by the similar scheme using BiI3 instead of PbI2

Use of the macrocyclic ligand cucurbit[6]uril for isolation of tetranuclear lanthanide aquahydroxo-carboxylate complexes from aqueous solutions

The tetranuclear lanthanide complexes {[Ln4(μ3-OH) 4(μ2-OH)2(C5NH 4COO)2 (H2O)4-(C36H 36N24O12)2][Ln(H2O) 8]1.5[Ln(H2O)6(NO3) 2]0.5} (NO3)9•nH2O (Ln = Ho, Gd, or Er) were prepared by heating (130 °C) aqueous solutions of lanthanide nitrates, cucurbit[6]uril (C36H36N 24O12), and 4-cyanopyridine. The tetradentate coordination of the macrocyclic cucurbit[6]uril ligands through the portals leads to the formation of sandwich compounds, in which the tetranuclear hydroxo complex is located between two macrocyclic molecules. The polynuclear complexes are additionally stabilized by the chelating effect of the isonicotinate ligands generated by hydrolysis of 4-cyanopyridine. In the complexes, the aromatic moiety of the isonicotinate ion is encapsulated into the hydrophobic inner cavity of cucurbit[6]uril. In the absence of cucurbit[6]uril, the reaction with 4-cyanopyridine produces only the polymeric complexes [Nd(C5NH 4COO)3(H2O)2] and [Ln(C 5NH4COO)2(H2O)4]NO 3 (Ln = Pr, Sm, or Gd), whose structures were established by X-ray diffraction. In water and aqueous solutions of nonionic and cationic surfactants, irreversible changes of the tetranuclear fragment of the complex (Ln = Gd) were observed after storage for two days, whereas the anionic surfactant stabilizes the complexes. © 2006 Springer Science+Business Media, Inc

Supramolecular assemblies of triblock copolymers with hexanuclear molybdenum clusters for sensing antibiotics in aqueous solutions via energy transfer

The work introduces the supramolecular assembly of triblock copolymers, namely (PEO)13(PPO)30(PEO)13 (L64), (PPO) 14(PEO)24(PPO)14 (17R4), (PPO) 8(PEO)22(PPO)8 (10R5) and (PEO) 21(PPO)67(PEO)21 (P123) with novel cluster complexes [K(diglyme)(CH3CN)]2[Mo6I 14] (1) and [K2(diglyme)(CH3CN) 5][Mo6I14] (2) as a route to increase their water solubility. Dynamic light scattering and photophysical measurements reveal the decisive influence of the arrangement of PEO and PPO blocks and of their length on both colloidal and photophysical properties of these solutions. ES-MS data reveal [Mo6I14]2- clusters as the predominant form in aqueous solutions of L64 and P123. The steady state and time resolved luminescence data indicate concentration dependent sensitizing of the Mo-centered luminescence through the energy transfer from difloxacin to [Mo 6I14]2- mediated by the ion-pairing. The impact of both arrangement and length of PEO and PPO blocks in the luminescent response of [Mo6I14]2- to difloxacin is discussed. The aqueous solutions of L64 at pH 4 provide the optimal conditions for the sensing of difloxacin through the cluster luminescence. This journal is © the Partner Organisations 2014

Easy-plane to easy-axis anisotropy switching in a Co(ii) single-ion magnet triggered by the diamagnetic lattice

Single ion magnets SIMs with large magnetic anisotropy are promising candidates for realization of single molecule based magnetic memory and qubits. Creation of materials with magnetically uncoupled spatially separated SIMs requires dilution in a diamagnetic matrix. Herein, we report that progressive dilution of paramagnetic Co II by diamagnetic Zn II in the SIM [CoxZn 1 amp; 8722;x piv 2 2 NH2 Py 2], x 1 0 beyond a threshold of 50 reveals an abrupt structural change, where the distorted tetrahedral Zn coordination structure is superimposed on the remaining Co ions, which were initially in a distorted octahedral environment. Dilution induced structure modification switches the magnetic anisotropy from easy plane D 36.7 cm amp; 8722;1 to easy axis type D amp; 8722;23.9 cm amp; 8722;1 , accompanied by a fivefold increase of the magnetic relaxation time at 2 K. Changes of the static and dynamic magnetic properties are monitored by electron paramagnetic resonance spectroscopy and AC susceptibility measurements. Complementary quantum chemical ab initio calculations quantify the influence of structural changes on the electronic structure and the magnetic anisotropy. Thus, magnetic dilution hits two goals at once, the creation of isolated magnetic centres and an improvement of their SIM propertie