Coordination chemistry effects of the space-demanding solvent molecule ,'-dimethylpropyleneurea.

Crystallographic investigations of eight homoleptic ,'-dimethylpropyleneurea (dmpu) coordinated metal ions in the solid state, [Mg(dmpu)]I (1), [Ca(dmpu)]I (2), [Ca(dmpu)](ClO) (3), [Ca(dmpu)](CFSO) (4), [Sr(dmpu)](CFSO) (5), [Ba(dmpu)](CFSO) (6), [Sc(dmpu)]I (7), and [Pr(dmpu)]I(I) (8), and the complex [CoBr(dmpu)] (9) as well as the structures of the dmpu coordinated calcium, strontium, barium, scandium(III) and cobalt(II) ions and the cobalt(II) bromide complex in dmpu solution as determined by EXAFS are reported. The methyl groups in the dmpu molecule are close to the oxygen donor atom, causing steric restrictions, and making dmpu space-demanding at coordination to metal ions. The large volume required by the dmpu ligand at coordination contributes to crowdedness around the metal ion with often lower coordination numbers than for oxygen donor ligands without such steric restrictions.

Visualising the ionome in resistant and susceptible plant-pathogen interactions.

At the morphological and anatomical levels, the ionome, or the elemental composition of an organism, is an understudied area of plant biology. In particular, the ionomic responses of plant-pathogen interactions are scarcely described, and there are no studies on immune reactions. In this study we explored two X-ray fluorescence (XRF)-based ionome visualisation methods (benchtop- and synchrotron-based micro-XRF [µXRF]), as well as the quantitative inductively coupled plasma optical emission spectroscopy (ICP-OES) method, to investigate the changes that occur in the ionome of compatible and incompatible plant-pathogen interactions.

Unraveling the Ground State and Excited State Structures and Dynamics of Hydrated Ce Ions by Experiment and Theory.

The 4f-5d transition of Ce provides favorable optical spectroscopic properties such as high sensitivity and quantum yield, making it a most important dopant for lanthanide-activated phosphors. A key for the design of these materials with fine-tuned color emission is a fundamental understanding of the Ce ground state and excited state structures and the dynamics of energy transfer. Such data is also crucial for deriving coordination chemistry information on Ce ions in different chemical environments directly from their optical spectra.

Eu(iii) and Cm(iii) tetracarbonates - in the quest for the limiting species in solution.

The structural and spectroscopic properties of the compounds [C(NH)][Gd:M(CO)(HO)]·0.75HO (1) and [C(NH)][Y:M(CO)]·2HO (2) (M = Eu, Cm) were determined. The crystals contain differently hydrated tetracarbonate complexes, [M(CO)(HO)] and [M(CO)], which were used as structural and spectroscopic models of Eu(iii) and Cm(iii) tetracarbonate species in aqueous solutions.

First structural characterization of Pa(iv) in aqueous solution and quantum chemical investigations of the tetravalent actinides up to Bk(IV): the evidence of a curium break.

More than a century after its discovery the structure of the Pa(4+) ion in acidic aqueous solution has been investigated for the first time experimentally and by quantum chemistry. The combined results of EXAFS data and quantum chemically optimized structures suggest that the Pa(4+) aqua ion has an average of nine water molecules in its first hydration sphere at a mean Pa-O distance of 2.43 Å.

Structure and spectroscopy of hydrated neptunyl(VI) nitrate complexes.

Complexation between hexavalent neptunium and nitrate was studied in aqueous nitric acid solution using optical absorption, vibrational and X-ray absorption spectroscopies. Distributions of aqueous [NpO2](2+), [NpO2(NO3)](+) and [NpO2(NO3)2] species were obtained as a function of nitric acid concentration between 0 and 14 M. The crystal structure of [NpO2(NO3)2(H2O)2]·H2O was determined.

Complexation of europium(III) by bis(dialkyltriazinyl)bipyridines in 1-octanol.

The present work focuses on highly selective ligands for An(III)/Ln(III) separation: bis(triazinyl)bipyridines (BTBPs). By combining time-resolved laser-induced fluorescence spectroscopy, nanoelectrospray ionization mass spectrometry, vibronic sideband spectroscopy, and X-ray diffraction, we obtain a detailed picture of the structure and stoichiometry of the first coordination sphere of Eu(III)-BTBP complexes in an octanolic solution. The main focus is on the 1:2 complexes because extraction studies revealed that those are the species extracted into the organic phase.

Complexation of Cm(III) with fluoride in aqueous solution in the temperature range from 20 to 90 °C. A joint TRLFS and quantum chemical study.

The formation of hydrated CmF2+ and CmF2+ species in aqueous solutions are studied in the temperature range of 20−90 °C at different fluoride concentrations and at constant ionic strength as well as at constant fluoride concentration and different ionic strengths by means of time-resolved laser fluorescence spectroscopy (TRLFS). The molar fractions of the Cm3+ aqua ion, CmF2+, and CmF2+ species are determined by peak deconvolution of the emission spectra. An increase of the mono- and difluoro complexes is observed with increasing fluoride concentration and/or increasing temperature.

SrNp(PO4)2: an original ordered modification of cheralite.

The new compound SrNp(PO(4))(2) (orthorhombic Cmca) has been synthesized by a solid-state reaction and its crystal structure solved ab initio and refined by Rietveld analysis. Though chemically and structurally related to the cheralite CaTh(PO(4))(2), SrNp(PO(4))(2) shows alternate layers of SrO(10) and NpO(8) polyhedra instead of a disordered array of 9-fold polyhedra. Raman and IR spectroscopic measurements also account for ordered cations.

Ambidentate coordination in hydrogen bonded dimethyl sulfoxide, (CH3)2SO...H3O+, and in dichlorobis(dimethyl sulfoxide) palladium(II) and platinum(II) solid solvates, by vibrational and sulfur K-edge X-ray absorption spectroscopy.

The strongly hydrogen bonded species (CH3)2SO...

An EXAFS spectroscopic, large-angle X-ray scattering, and crystallographic study of hexahydrated, dimethyl sulfoxide and pyridine 1-oxide hexasolvated mercury(II) ions.

The structure of the solvated mercury(II) ion in water and dimethyl sulfoxide has been studied by means of large-angle X-ray scattering (LAXS) and extended X-ray absorption fine structure (EXAFS) techniques. The distribution of the Hg-O distances is unusually wide and asymmetric in both solvents. In aqueous solution, hexahydrated [Hg(OH(2))(6)](2+) ions in a distorted octahedral configuration, with the centroid of the Hg-O distance at 2.

The hydration of the scandium(III) ion in aqueous solution and crystalline hydrates studied by XAFS spectroscopy, large-angle X-ray scattering and crystallography.

The structures of the hydrated scandium(III) ion and of the hydrated dimeric hydrolysis complex, [Sc2(mu-OH)2]4+, in acidic aqueous solutions have been characterized by X-ray absorption fine structure (XAFS) and large-angle X-ray scattering (LAXS) methods. Comparisons with crystalline reference compounds containing hydrated scandium(III) ions in well characterized six-, seven- and eight-coordinated polyhedra have been used to evaluate the coordination numbers and configurations in aqueous solution. In strongly acidic aqueous solution the structure of the hydrated scandium(III) ion is found to be similar to that of the eight-coordinated scandium(III) ion with distorted bicapped trigonal prismatic coordinating geometry in the crystalline [Sc(H2O)(8.

Hydration of Cm3+ in aqueous solution from 20 to 200 degrees C. A time-resolved laser fluorescence spectroscopy study.

Time-resolved laser fluorescence spectroscopy (TRLFS) is used to study the hydration of the Cm3+ ion in acidified (0.1 M perchloric acid) H2O and D2O from 20 to 200 degrees C. Strong temperature dependency is found for several of the spectroscopic quantities associated with the 6D'(7/2) --> 8S'(7/2) photoemission spectra, with similar relative changes in both solvents.

Large ground-state and excited-state crystal field splitting of 8-fold-coordinate Cm3+ in [Y(H2O)8]Cl3.15-crown-5.

The optical spectra of Cm(3+) incorporated into the crystalline host structure of [Y(H(2)O)(8)]Cl(3).15-crown-5 (1) is investigated by using laser spectroscopic methods at temperatures between 20 and 293 K. The coordination geometry of the [Y(H(2)O)(8)](3+) entity in 1 is a distorted bicapped trigonal prism with approximately C(2) point symmetry, as confirmed by single-crystal X-ray diffraction at 200 K.

Highly hydrated cations: deficiency, mobility, and coordination of water in crystalline nonahydrated scandium(III), yttrium(III), and lanthanoid(III) trifluoromethanesulfonates.

Trivalent lanthanide-like metal ions coordinate nine water oxygen atoms, which form a tricapped trigonal prism in a large number of crystalline hydrates. Water deficiency, randomly distributed over the capping positions, was found for the smallest metal ions in the isomorphous nonahydrated trifluoromethanesulfonates, [M(H2O)n](CF3SO3)3, in which M = Sc(III), Lu(III), Yb(III), Tm(III) or Er(III). The hydration number n increases (n = 8.

Vibrational spectroscopic force field studies of dimethyl sulfoxide and hexakis(dimethyl sulfoxide)scandium(III) iodide, and crystal and solution structure of the hexakis(dimethyl sulfoxide)scandium(III) ion.

Hexakis(dimethyl sulfoxide)scandium(III) iodide, [Sc(OS(CH(3))(2))(6)]I(3) contains centrosymmetric hexasolvated scandium(III) ions with an Sc-O bond distance of 2.069(3) angstroms. EXAFS spectra yield a mean Sc-O bond distance of 2.

The Structure of the Hydrated Gallium(III), Indium(III), and Chromium(III) Ions in Aqueous Solution. A Large Angle X-ray Scattering and EXAFS Study.

The structure of the hydrated gallium(III), indium(III), and chromium(III) ions has been determined in aqueous perchlorate and nitrate solutions by means of the large-angle X-ray scattering (LAXS) and extended X-ray absorption fine structure (EXAFS) techniques. The EXAFS studies have been performed over a wide concentration range, 0.005-1.