Anisotropic dipole polarizability of transition metal atoms: Sc(2D), Ti(3F,3P), V(4F,4P,6D), Ni(3F) and ions: Sc2+(2D), Ti2+(3F,3P)

Dipole polarizability tensor components and quadrupole moments of transition-metal atoms Sc, Ti, V, Ni, and Cu and ions Sc2+ and Ti2+ are computed using finite field complete active space self-consistent field and multireference configuration interaction ab initio methods. Perpendicular components of the dipole polarizability tensor are calculated from equations involving only parallel components of the polarizability tensor and its average value. Mean polarizability and polarizability anisotropy decrease in the Sc-Ni series. Relativistic effects are accounted for with the Douglas-Kroll Hamiltonian. The consequences of the anisotropic properties of these atoms to their interactions with spherically symmetric rare gases are also discussed.     

Exchange interactions in copper(II) complexes with tridentate Schiff bases: EPR and magnetic studies

The influence of the nature of ligands upon the magnetic and EPR properties was investigated for the series of polynuclear Cu(II) complexes with tridentate Schiff bases. A similar tendency of changes in the |J| and D parameters was found for binuclear Cu(II) complexes with ligands derived from condensation of 3-amino-1-propanol with 2-hydroxyaldehydes and acetylacetone as well as for Cu(II) complexes with condensation products of o-aminophenol and β-diketones. The Cu(II) complex with Schiff base of 1-amino-2-propanol and acetylacetone exhibits ferromagnetic behaviour suggesting tetrameric structure.     

Trajectories joining critical points of nonlinear parabolic and hyperbolic partial differential equations

Consider the following nonlinear Dirichlet boundary value problems:

$\text{D}{}_{\mathrm{t}}\text{u(t,x)=Lu(t,x)+f(u(t,x)),}\text{t?0,x∈Ω}\text{u(t,x)=0,}\text{t?0,x∈?Ω}$

(1.1)

$\text{D}{}_{\mathrm{t}}\text{D}{}_{\mathrm{t}}\text{u(t,x)=Lu(t,x)+}\text{α}\text{L(D}{}_{\mathrm{t}}\text{u(t,x))+f(u(t,x)),}\text{α}\text{>0,t?0,x∈Ω}\text{u(t,x)=0,}\text{t?0,x∈?Ω}$

(1.2)

$\text{Lu(x)+f(u(x)),}\text{x∈Ω}\text{u(x)=0,}\text{x∈?Ω}$

. (1.3) In all of these equations, f: R → R is a locally Lipschitzian asymptotically linear function with positive asymptotic slope, f(0) = 0, and L is a self-adjoint, negativedefinite and strongly elliptic second-order differential operator on a smooth domain Ω in Rⁿ. The solutions of (1.1) and (1.2) generate semiflows which are not pointdissipative and whose equilibria are determined by solutions of (1.3). In this paper, using an extension (due to the present author) of Conley's Morse index theory to noncompact spaces, we prove not only the existence of positive solutions of (1.3) (a result shown earlier by Peitgen and Schmitt using different methods), but also show the existence of (nonconstant) heteroclinic orbits of (1.1) and (1.2) joining two sets of equilibria.     

Studies of physico-chemical properties of mixed adsorbent in the zeolite/SiO2 system

The paper presents physico-chemical properties of mixed adsorbents in the clinoptylolite (mordenite)/SiO₂ system containing 30, 50, 80 mass% zeolite. Adsorption capacity towards polar (water, butanol) and non-polar (n-octane) substances as well as total surface heterogeneity (energetic and geometrical) were determined. Desorption energy distribution functions as well as fractal dimensions were also determined and compared with the low-temperature nitrogen adsorption data. Irregular shapes of the curves q=f(E _d) as well as large values of volumetric fractal dimensions (D _f~2.6) revealed heterogeneous properties of the zeolite/SiO2 system surfaces. Addition of zeolite increases total heterogeneity of the material.     

Spectrochemical Properties of Noncubical Transition Metal Complexes in Solution. XII. Angular Overlap Studies of Salicylideneethylenediamine Cu(II) Complex in Various Solvents

As a part of our general interest in the UV-Vis spectroscopy of multidentate mixed-donor ligands, the (salicylideneethylenediamine)Cu(II) complex has been prepared and characterized by elemental analyses, solubility in common solvents, molar conductivities, and ultraviolet (UV), and visible (Vis) spectroscopy. The combined results of spectrophotometric measurements and EPR spectra, as well as known the X-ray structure for solids, were used to determine the structure of the investigated complex in solutions. The spectra of [Cu(salen)] (H₂salen = salicylideneethylenediamine), were measured in various solvents at room temperature, resolved by Gaussian analysis, and angular overlap model (AOM) treated in C _2v symmetry. Because of overparametrization problems, the bis(salicylaldehyde)Cu(II) complex has been characterized and AOM treated. The results of this have been used for AOM studies of [Cu(salen)]. The effect of the solvents upon the - and -bonding ligand abilities is discussed.     

Functionalized di- and tetrathia-crowns and their use to quantitatively separate and recover gold(III), palladium(II), silver(I) and mercury(II) Ions

Two new dithia-crowns containing a hydroxy group and 1,4,7,10-tetrathia-18-crown-6 containing an allyl-oxymethyl substituent were prepared in good yields. Two of these crowns were covalently attached to silica gel. The silica gel-bound thia-crowns were used to separate gold( III ), palladium( II ), silver( I ) and mercury( II ) ions from an aqueous 0.1 M nitric acid solution which also contained 1.0 M ferric chloride.