A new heterobinuclear Gd(III)-Cu(II) complex [GdCu] = GdCu(OTf)_{3}(bdmap)_{2}(H_{2}O). THF (OTf=SO_{3}CF_{3}) has been prepared by reaction of 1,3-bis(dimethylamino)-2-propanol (bdmapH) with Cu(OCH_{3})_{2} and lanthanide triflate salt Gd(OTf)_{3} in a 2:1:1 ratio in THF. Its structure has been determined by single-crystal X-ray diffraction. [GdCu] crystallizes on an orthorhombic lattice, space group P2_{1}2_{1}2_{1} with Z=4 and a=11.023(3) Å, b=17.555(15) Å, c=20.212(7) Å, V=3911(4) Å^{3}. For 2194 independent reflections with I > 1σ(I), full-matrix least squares refinement with anisotropic thermal parameters for Gd, Cu, S, and O converged to unweighted and weighted R factors of 0.074 and 0.085, respectively. Gd is coordinated by six O and two N. Cu is coordinated by two O and two N. Gd and Cu are bridged by two alkoxo O atoms with separation of 3.311(4) Å. The magnetic susceptibilities were measured over the temperature range 1.7-20 K at the field range 0.01-0.5 T. The data of [GdCu] at 0.05 T have been analyzed with the use of a Heisenberg spin Hamiltonian Ĥ=-2JŜ_{Gd}·Ŝ_{Cu} giving g=2.046(2), J=-0.039(3) cm^{-1}. This shows that Gd-Cu spins are coupled very weakly in the antiferromagnetic manner, though the distance between Gd(III) and Cu(II) ions is rather short.
The classical limit of the effective antiferromagnetic Heisenberg Hamiltonian has been investigated on the series of free clusters (molecules) of C_{N} (N = 32, 44, 50, 58, 60,, 70 and 84). The valley structures of the frustrated ground states were determined. Moreover, the probability distributions of the spin correlation functions were calculated.
We investigated the growing sodium clusters, induced by the laser light resonant with a sodium dimer transition. We observed the intensity of light scattered by clusters. The clusters were produced in the stainless steel cell containing sodium vapor and helium. We obtained data on cluster mean size and dynamics from fitting the theoretical formulas to the experimental data. The model of clusters' evolution basing on the thermodynamics of the vapor-liquid transition was applied.
We report the observation of the size evolution of the laser light formed clusters. A cell containing sodium vapor and the buffer gas (He) under high pressure was used in the experiment. Changes of the radius and of the density of transient clusters were observed via the time evolution of the intensity of right-angle scattered light. The rate of the cluster radius growth was found to vary from 0.012 to 0.1 μm/s.
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