The structure of the hydrated calcium(II) ion in aqueous solution has been studied by means extended X-ray absorption fine spectroscopy (EXAFS), large-angle scattering (LAXS), and molecular dynamics (MD) methods. EXAFS data displayed a broad asymmetric distribution Ca−O bond distances with centroid at 2.46(2) Å. LAXS studies on four calcium halide solutions (1.5−2 mol dm-3) gave mean distance 2.46(1) This is consistent hydration number 8 determined from correlations between coordination...

The structure of the hydrated gallium(III), indium(III), and chromium(III) ions has been determined in aqueous perchlorate nitrate solutions by means large-angle X-ray scattering (LAXS) extended absorption fine (EXAFS) techniques. EXAFS studies have performed over a wide concentration range, 0.005-1.0 mol.dm(-)(3) (2.6 for chromium(III)), while LAXS are restricted to concentrated solutions, ca. 1.5 mol.dm(-)(3). All three metal were found coordinate six water molecules, each which hydrogen...

Lanthanide-like: X-ray diffraction and density functional theory studies show that [An(H2O)9]3+ ions of the actinides U3+–Cf3+ in crystals their triflate salts have same structure electrostatic bonding as lanthanide counterparts La3+–Eu3+. Moreover, nine-coordinate geometry is essentially preserved solution for lighter elements (see picture). In recent years there has been considerable progress understanding chemistry low-valent synthesis techniques compounds. A significant number new...

Stable nine-coordination: X-ray diffraction reveals highly symmetrical [M(H2O)9]3+ entities for the actinides americium and curium in single crystals of their triflate salts (see picture, yellow M, red O). Comparison absorption spectra solution confirm that these transplutonium ions are large enough to remain ninefold coordinated also aqueous solution. Supporting information this article is available on WWW under http://www.wiley-vch.de/contents/jc_2002/2007/z603947_s.pdf or from author....

Trivalent lanthanide-like metal ions coordinate nine water oxygen atoms, which form a tricapped trigonal prism in large number of crystalline hydrates. Water deficiency, randomly distributed over the capping positions, was found for smallest isomorphous nonahydrated trifluoromethanesulfonates, [M(H2O)n](CF3SO3)3, M = Sc(III), Lu(III), Yb(III), Tm(III) or Er(III). The hydration n increases (n 8.0(1), 8.4(1), 8.7(1), 8.8(1) and 8.96(5), respectively) with increasing ionic size. Deuterium (2H)...

The structure of the solvated lanthanum(III) ion has been determined in aqueous, dimethyl sulfoxide, and N,N'-dimethylpropyleneurea solution by means EXAFS large-angle X-ray scattering (LAXS) techniques. close agreement between spectra solid nonaaqualanthanum(III) trifluoromethanesulfonate an aqueous perchlorate shows that hydrated most probably same as solid, i.e., nine water molecules coordinated a tricapped trigonal prismatic configuration. data analysis from LAXS measurements resulted...

Time-resolved laser fluorescence spectroscopy (TRLFS) is used to study the hydration of Cm3+ ion in acidified (0.1 M perchloric acid) H2O and D2O from 20 200 degrees C. Strong temperature dependency found for several spectroscopic quantities associated with 6D'(7/2) --> 8S'(7/2) photoemission spectra, similar relative changes both solvents. The emission band shifts lower energy increasing temperature, which attributed an equilibrium between hydrated ions different numbers water molecules...

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 2.09(1) angstroms for solvated in dimethyl sulfoxide solution, consistent six-coordination. Raman and infrared absorption have been recorded, also the deuterated compound, analysed by means normal coordinate methods, together sulfoxide. The effects on vibrational weak intermolecular...

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

The performances of three different Raman spectrometers were compared and evaluated as a suitable tool for the analysis range uranium compounds with view to application in nuclear forensics. These included ore concentrates chemical composition dioxide form powder sintered fuel pellet. are termed 'portable' or 'hand-held' from Ahura Scientific (785 nm), 'Senterra' Bruker (532 785 'T64000′ HORIBA Jobin Yvon (488.0, 514.5, 647.1 752.5 nm). Figures merit such sensitivity, signal-to-noise ratio...

The yttrium(III) ion is found by means of extended X-ray absorption fine-structure spectroscopy (EXAFS) and large angle scattering (LAXS) to be hydrated eight water molecules in aqueous solution. EXAFS data show a slightly asymmetric distribution the Y−O bond distances with centroid at 2.368(5) Å. width implies positional disorder about 0.1 Å on top thermally induced variation distances. solutions solid compound [Y(OH2)8]Cl3·(15-crown-5), which oxygen atoms form distorted bicapped trigonal...

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

The formation of aqueous Cm(III) nitrate complexes is studied in the temperature range from 5 to 200 °C by time resolved laser fluorescence spectroscopy (TRLFS). experiments are performed a custom build high pressure and cell. complex measured at concentrations ranging 0.10 4.61 mol/kg H2O. mono- dinitrate quantified peak deconvolution spectra complexation constants determined as function temperature. conditional equilibrium extrapolated zero ionic strength using specific ion interaction...

More than a century after its discovery the structure of Pa(4+) ion in acidic aqueous solution has been investigated for first time experimentally and by quantum chemistry. The combined results EXAFS data chemically optimized structures suggest that aqua an average nine water molecules hydration sphere at mean Pa-O distance 2.43 Å. available early tetravalent actinide (An) elements from Th(4+) to Bk(4+) show An-O bonds have pronounced electrostatic character, with bond distances following...

The time dependent changes of Lu speciation (used as Am(III) homologue), initially sorbed onto 2-line ferrihydrite at pH 5.9, during tempering (70 degrees C) to stable crystalline transformation products, goethite and hematite, is studied. Microscopies (AFM, SEM), XRD FTIR spectroscopy confirm both with a predominance hematite. investigation another series 8.0 (75 C, [Lu(III)initial] 7 times higher) shows that the cell volume hematite increases, suggesting incorporation in crystal structure....

Theoretical extended X-ray absorption fine structure (EXAFS) spectra have been computed from molecular dynamics (MD) simulation data. Based on MD-generated geometries, EXAFS were generated with the FEFF6 program, commonly used in analysis of experimental spectra. The effects multiple scattering and second-shell neighbors theoretical evaluated for CaCl2(aq) AlCl3(aq), i.e., two solutions very different cation hydration structures. are significantly larger more structured Al3+ solution....

The strongly hydrogen bonded species (CH3)2SO⋯H3O+ formed in concentrated hydrochloric acid displays a new low energy feature its sulfur K-edge X-ray absorption near edge structure (XANES) spectrum. Density Functional Theory-Transition Potential (DFT-TP) calculations reveal that the strong bonding decreases of transition S(1s) → LUMO, which has antibonding σ*(S–O) character, with about 0.8 eV. Normal coordinate force field analyses vibrational spectra show SO stretching constant from 4.72 N...

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

Abstract BaTh(PO 4 ) 2 has been synthesized by a wet chemistry route and the new isotype BaNp(PO solid‐state reaction. Although former subject of several studies since early 1980s, crystal structures both compounds are reported here for first time. Rietveld analysis shows Ba layers alternating with An(PO slabs along axis. those isostructural to RbEu(SO , these phosphates can be seen as modified yavapaiite derivatives increased coordination numbers (XIV) Th/Np (VIII). Raman electron...

Abstract The structure of the solvated mercury(II) ion in water and dimethyl sulfoxide has been studied by means large‐angle X‐ray scattering (LAXS) extended absorption fine (EXAFS) techniques. distribution HgO distances is unusually wide asymmetric both solvents. In aqueous solution, hexahydrated [Hg(OH 2 ) 6 ] 2+ ions a distorted octahedral configuration, with centroid distance at 2.38(1) Å, are surrounded diffuse second hydration sphere Hg⋅⋅⋅O II 4.20(2) Å. sulfoxide, six Hg⋅⋅⋅S...

Lanthanoid-artig: Röntgenbeugung und DFT-Studien ergaben, dass die Ionen [An(H2O)9]3+ der Actinoide U3+–Cf3+ in Kristallen ihrer Triflatsalze dieselbe Struktur elektrostatische Bindung wie ihre Lanthanoid-Gegenstücke La3+–Eu3+ aufweisen. Zudem zeigte sich, Neunfachkoordination Lösung bei den leichteren Elementen weitgehend erhalten ist (siehe Bild).

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

Surface sensitive grazing incidence XAFS measurements of mineral sorbed metal cations are used to characterize the at reactive surface sites. Two different systems studied: (1) Hf(IV) onto (001) basal plane freshly cleaved mica and a oxidized silicon wafer (2) U(VI) (110) α-Al2O3 two concentrations orientations crystal polarization vector incident synchrotron radiation. Similar findings reported for amorphous silica, EXAFS metrical parameters on both show that mononuclear species forms. The...

The FTIR spectra of the complexes lanthanides (Ln = La − Lu, except for radioactive Pm) with 2,6-bis(5,6-dipropyl-1,2,4-triazin-3-yl)pyridine have been measured in both mid- and far-IR ranges. revealed some characteristic bands shifting towards higher wavenumbers increasing lanthanide atomic number. X-ray diffraction results on several (La, Pr, Nd, Sm, Eu, Tm Yb) decreasing Ln–ligand distances same direction. DFT calculations using M062X exchange–correlation functional performed selected...