The reflection of very cold neutrons from diamond powder nanoparticles

We study possibility of efficient reflection of very cold neutrons (VCN) from powders of nanoparticles. In particular, we measured the scattering of VCN at a powder of diamond nanoparticles as a function of powder sample thickness, neutron velocity and scattering angle. We observed extremely intense scattering of VCN even off thin powder samples. This agrees qualitatively with the model of independent nanoparticles at rest. We show that this intense scattering would allow us to use nanoparticle powders very efficiently as the very first reflectors for neutrons with energies within a complete VCN range up to $10^{-4}$ eV

Synthesis and Characterization of the New Cluster Complex {Mo<inf>3</inf>S<inf>4</inf>} with the Hemilabile Phosphine-Selenoether Ligand

Abstract: The reaction of [Mo3S4(Tu)8(H2O)]Cl4·4H2O (Tu is thiourea) with (PhCH2CH2)2-PCH2CH2SeC5H11) (PSe) followed by purification on a chromatographic column packed with silica gel using a saturated solution of KPF6 in acetone as an eluent results in the formation of [Mo3S4Cl3(PSe)3]PF6 (I) in a yield of 44%. Compound I is characterized by X-ray diffraction analysis, 1H, 31P{1H}, and 77Se NMR spectroscopy, IR spectroscopy, UV-Vis spectroscopy, cyclic voltammetry, and electrospray ionization mass spectrometry. Several species differed in the coordination mode of three PSe ligands, which can bind to molybdenum via one (phosphorus) or two (phosphorus and selenium) donor atoms, are formed in a solution of compound I at room temperature. This behavior is not observed for the compounds similar in structure with PS ligands of an analogous type. Complex I demonstrates a higher catalytic activity than its analogue with the PS ligand in the reduction of nitrobenzene to aniline under the action of diphenylsilane