Solution state structure and equilibria of lanthanide (fod) complexes revisited: A H, C and F nuclear magnetic resonance study of Eu(fod).

In a qualitative approach, variable temperature H, F and C nuclear magnetic resonance (NMR) were used to characterize the solution state structure and equilibria of the widely used lanthanide solvent reagent Eu(fod) . Despite the fact that the side chain fluorines are far from the coordination site, the F- H NMR spectra turned out to be sensitive reporters of self-coordination and/or adduct formation with other ligands. For example, they predict/explain immediately the otherwise hardly predictable magnitude of the expectable paramagnetic effects.

Dithallium(III)-Containing 30-Tungsto-4-phosphate, [TlNa(HO)(PWO)]: Synthesis, Structural Characterization, and Biological Studies.

Here we report on the synthesis and structural characterization of the dithallium(III)-containing 30-tungsto -4-phosphate [TlNa(HO){PWO}] (1) by a multitude of solid-state and solution techniques. Polyanion 1 comprises two octahedrally coordinated Tl ions sandwiched between two trilacunary {PW} Wells-Dawson fragments and represents only the second structurally characterized, discrete thallium-containing polyoxometalate to date. The two outer positions of the central rhombus are occupied by sodium ions.

Aminopropyl-Silica Hybrid Particles as Supports for Humic Acids Immobilization.

A series of aminopropyl-functionalized silica nanoparticles were prepared through a basic two step sol-gel process in water. Prior to being aminopropyl-functionalized, silica particles with an average diameter of 549 nm were prepared from tetraethyl orthosilicate (TEOS), using a Stöber method. In a second step, aminopropyl-silica particles were prepared by silanization with 3-aminopropyltriethoxysilane (APTES), added drop by drop to the sol-gel mixture.

Solid-State NMR Study of Paramagnetic Bis(alaninato-κ(2)N,O)copper(II) and Bis(1-amino(cyclo)alkane-1-carboxylato-κ(2)N,O)copper(II) Complexes: Reflection of Stereoisomerism and Molecular Mobility in (13)C and (2)H Fast Magic Angle Spinning Spectra.

Solid-state stereochemistry and mobility of paramagnetic copper(II) complexes formed by aliphatic amino acids (l-alanine, d,l-alanine, 1-amino-2-methyl-alanine) and 1-amino(cyclo)alkane-1-carboxylic acids (alkane = propane, butane, pentane, hexane) as bidentate ligands has been studied by (13)C and (2)H solid-state fast magic angle spinning (MAS) NMR spectroscopy. We examined the prospective method to characterize solid-state paramagnetic compounds in a routine way. Both (13)C and (2)H MAS spectra can distinguish d,l and l,l diastereomers of natural and polydeuterated bis([Dn]alaninato)copper(II) (n = 0, 2, 8) complexes with axial and/or equatorial methyl positions (conformations) primarily due to different Fermi-contact (FC) contributions.

Comparative analysis of zaleplon complexation with cyclodextrins and hydrophilic polymers in solution and in solid state.

The aim of this work was to investigate the potential synergistic effect of water-soluble polymers (hypromellose, HPMC and polyvinylpyrrolidone, PVP) on zaleplon (ZAL) complexation with parent β-cyclodextrin (βCD) and its randomly methylated derivative (RAMEB) in solution and in solid state. The addition of HPMC to the complexation medium improved ZAL complexation and solubilization with RAMEB (K(ZAL/RAMEB)=156±5M(-1) and K(ZAL/RAMEB/HPMC)=189±8M(-1); p<0.01), while such effect was not observed for βCD (K(ZAL/βCD)=112±2M(-1) and K(ZAL/βCD/HPMC)=119±8M(-1); p>0.