Radiation durability of aluminophosphate glass prepared for the stable storage of high-level nuclear wastes

⁵⁷Fe Mössbauer spectra of 30CaO·15Al₂O₃·5Fe₂O₃·25PbO·25P₂O₅ glass consist of two quadrupole doublets due to distorted Fe(III)O₆ and Fe(II)O₆ octahedra. Mössbauer spectra of the aluminophosphate glass irradiated with⁶⁰Co γ-rays (≈5·10⁴Gy) were essentially the same as those of non-irradiated glass. Mössbauer spectra of γ-ray irradiated aluminophosphate glass, containing 10 stable isotopes (Sr, Y, Zr, Nb, Mo, Ba, La, Ce, Pr, and Nd) as the simulated nuclear waste, were also the same as those of non-irradiated glass. These results indicate that the aluminophosphate glass containing iron and lead has high radiation-durability, in addition to high heat resistivity and high water resistivity.     

Vibrational spectra of hydrated rare earth orthophosphates

Weinschenkite-type LnPO₄·2H₂O (Ln is Gd, Tb, Dy, Ho, Y, Er, Tm or Yb) and rhabdophane-type, LnPO₄·H₂O (Ln is La, Ce, Pr, Nd, Sm, Eu, Gd, Tb or Dy) have been investigated by IR absorption spectroscopy (4000–400 cm⁻¹) and Raman scanning spectroscopy (1400–100 cm⁻¹).The IR spectra of weinschenkite-type LnPO₄·2H₂O (Ln is Gd→Yb) are characterized by a band at 750±6 cm⁻¹ and the occurrence of a doublet in the region of the HOH bending vibrations, the low-frequency component exceeding the first high-frequency component in intensity. This rather peculiar pattern has already been observed in other compounds of similar chemical composition and is interpreted as arising from the presence of water molecules coordinated to the same metal cation. The Raman and IR spectra of these compounds have been interpreted in a manner based on the known structure of CaSO₄·2H₂O, which is isostructural with the weinschenkite-type compounds.The Raman and IR spectra of rhabdophane-type LnPO₄·H₂O is analyzed on the basis of the knowledge of the space group of rare earth orthophosphates rhabdophane-type. Its relation with the spectra of rare earth orthophosphates weinschenkite-type is discussed.     

Theoretical analysis of the alternative additions of radicals to multiple bonds

The alternative additions of the hydrogen atom and methyl, aminyl, and methoxyl radicals to the double bond of CH₂=Y (Y = CHR, CR₂, CHCH=CH₂, CHPh, NH, O) compounds are theoretically analyzed using the intersecting parabolas method and DFT. The enthalpies, activation energies, and geometric parameters of the transition state in the reactions R^· + CH₂=Y → RCH₂Y^· and R^· + CH₂=Y → RYC^·H₂ are calculated. The results obtained by the two methods are compared with experimental data. The competing alternative radical additions to the multiple bonds are governed by the enthalpies of the reactions.     

邻羟基苯甲酸希土配合物的合成及晶体结构

本文合成了邻羟基苯甲酸(o-HOC_6H_4CO_2H)与十五种希土的配合物,测定了铈,铽的配合物晶体结构。二者均属单斜晶系,铈配合物空间群为P2_1/n。配位数为9,铽配合物空间群为Cc,配位数为8.两种配合物均呈无限链状聚合结构。     

Hydrogen bonded С–H···Y (Y = O,S, Hal) molecular complexes: A natural bond orbital analysis

Hydrogen bonded C–H···Y complexes formed by H₂O, H₂S molecules, hydrogen halides, and halogen-ions with methane, halogen substituted methane as well as with the C₂H₂ and NCH molecules were studied at the MP2/aug-cc-pVDZ level. The structure of NBOs corresponding to lone pair of acceptor Y, n_Y, and vacant anti-σ-bond C–H of proton donor was analyzed and estimates of second order perturbation energy Е⁽²⁾ characterizing donor–acceptor n_Y → σ_C-H^* charge-transfer interaction were obtained. Computational results for complexes of methane and its halogen substituted derivatives show that for each set of analogous structures, the Е_nY→σ*C-H⁽²⁾ energy tends to grow with an increase in the s-component percentage in the lone pair NBO of acceptor Y. Calculations for different C···Y distances show that the equilibrium geometries of complexes lie in the region where the E⁽²⁾ energy is highest and it changes symbatically with the length of the covalent С–H bond when the R(C···Y) distance is varied. The performed analysis allows us to divide the hydrogen bonded complexes into two groups, depending on the pattern of overlapping for NBOs of the hydrogen bridge.     

Y(NCS)3·4(1/2)H2O和Y(NCS)3·2(1/2)H2O的制备、性质及标准生成焓的测定

本文首次制备了异硫氰酸钇低水合物Y(NCS)₃·4 1/2H₂O和Y(NCS)₃·2 1/2H₂O,采用量热法测定了它们在298.15K时的标准生成焓,进而计算了它们的晶格能以及相应的标准脱水焓。     

Beiträge zur Lanthanoidchemie. III Zur Kenntnis von 2-(Dimethylaminomethyl)ferrocenyl-Verbindungen des Samariums und Yttriums

Contribution to Organolanthanoide Chemistry. III. On 2-(Dimethylaminomethyl)ferrocenyl Compounds of Samarium and Yttrium Earlier results, indicating the ability of the bulky 2-(dimethylaminomethyl)ferrocenyl-group (FcN) to form thermocally stable, heterobimetallic organolanthanide compounds, were proved by the synthesis of organo-rare-earth derivatives (C₅Me₅)₂Sm(FcN) ( II ), (C₅H₅)Sm(FcN)Cl ( III ), respectively (C₅Me₅)Y(FcN)Cl ( IV ) from the corresponding complex cyclopentadienyl rare-earth chlorides (C₅Me₅)₂SmCl · KCl · THF, (C₅H₅)SmCl₂ · THF and (C₅Me₅)YCl₂ · KCl · 1,8 THF and 2-(dimethylaminomethyl)ferrocenyl lithium (FcN)Li ( I ) as organylating agent. The synthesized compounds were proved by elementary analysis, IR, ¹H, ¹³C NMR and UV-VIS spectra as well as by measuring the magnetic moments and by mass spectroscopy.     

Why is N···Be distance of NH3H+···DBeH shorter than that of NH3D+···HBeH? paradoxical geometrical isotope effects for partially isotope‐substituted dihydrogen‐bonded isotopomers

The partial isotope substitution for the change of geometrical parameters, interaction energies, and nuclear magnetic shielding tensors (σ) of dihydrogen‐bonded NH₃X⁺···YBeH (X, Y = H, D, and T) systems is analyzed. Based on the theoretical calculation, the distance between heavy atoms R_N···Be of NH₃H⁺···DBeH is clearly found to be shorter than that in NH₃D⁺···HBeH. Such apparently paradoxical geometrical isotope effect (GIE) on R_N···Be is revealed by the cooperative effect of two kinds of (1) primary covalent‐bonded GIE and (2) secondary dihydrogen‐bonded one. We have demonstrated that (1) the covalent bond lengths become shorter by heavier isotope‐substitution and (2) the dihydrogen‐bonded distance R_X···Y becomes shorter by heavier Y and lighter X isotope‐substitution due to the difference of electronic structure reflected by the nuclear distribution. We have also found that interaction energy of NH₃H⁺···DBeH is stronger than that of NH₃D⁺···HBeH and isotopic deshielding effect of magnetic shielding becomes large in lighter isotope. © 2013 Wiley Periodicals, Inc.     

Synthesis,crystal structure,and DNA binding of a new oxalato-bridged binuclear zinc(II) complex

A new binuclear zinc(II) complex bridged by μ-oxalate, and end-capped with 2,2′-bipyridine (bpy), [Zn₂(ox)(bpy)₄](ClO₄)₂ · H₂O, has been synthesized and characterized by elemental analyses, molar conductance, IR, and electronic spectra and single-crystal X-ray diffraction. The single-crystal X-ray analysis reveals that the [Zn₂(ox)(bpy)₄]²⁺ cation has two zinc(II) centers bridged by a planar bis(bidentate) oxalate group with Zn···Zn distance of 5.482(3) Å; each zinc(II) is in a distorted octahedral environment. The crystal structure is stabilized by non-classical C–H···O hydrogen bonds and π–π stacking interactions to form a 3-D supramolecular structure. The interaction of the complex with calf-thymus DNA (CT-DNA) was explored by using electronic and fluorescence spectra and viscosity measurements. The results reveal that the complex intercalates with CT-DNA with intrinsic binding constant of 4.1 × 10⁴ M^?1.     

Nongeneral Character of the Resonance Parameters Σ<Stack><Subscript>R</Subscript><Superscript>+</Superscript></Stack> of Silicon-, Germanium-, and Tin-Containing Substituents in Radical Cations

The resonance parameters σ _R ⁺ of substituents Y in radical cations YD^+· [where D is a π- or n-type center, and Y = MMe₃, CH₂MMe₃ (M = Si, Ge, Sn), C(SiMe₃)₃] depend on the nature of both Y and D. Using radical cations YD^+· (Y = CH₂SiMe₃, SnMe₃) as examples, it was found that the two conjugation parameters, constants σ _R ⁺ of substituents Y and perturbation energy calculated by the modified molecular orbital perturbation method, are linearly related to each other. The energies of donor and acceptor components of the overall resonance effect of CH₂SiMe₃ and SnMe₃ with respect to radical cation centers D^+· were estimated for the first time. The donor energy constituent in YD^+· is considerably greater than in neutral DY molecules.     

Magnetic investigation of Er(C2O4) (C2O4)·3H2O

Single crystal susceptibilities of Er(C₂O₄) (C₂O₄H)·3H₂O are reported over the 1.5–20 K interval, and EPR spectra at 4.2 K of Y (C₂O₄) (C₂O₄H·3H₂O doped with Er³⁺ are also reported. The susceptibilities follow the CurieWeiss law, with g_| = 12.97 ± 0.05, g_⊥ = 2.98 ± 0.05, θ_| = ?0.25 ± 0.05 K, and θ_⊥ = ?0.12 ± 0.05 K.     

Synthesis,characterization, and biological activities of macrocyclic polyamine complexes

Two new dinuclear macrocyclic complexes, [Ni₂L¹(OAc)]·ClO₄ (1) and [Co₂L²(OAc)]·1.5(ClO₄)·0.5Na·2(CH₃OH) (2) (where H₂L¹ and H₂L² are the condensation products of N,N-bis(3-aminopropyl)-4-methoxybenzylamine with 2,6-diformyl-4-brominephenol and 2,6-diformyl-4-methylphenol in the presence of metal ions, respectively) have been synthesized and characterized by infrared spectra, elemental analysis, electrospray mass spectra, and X-ray single crystal diffraction. The interactions of the complexes with CT-DNA have been measured by UV-absorption titrations and fluorescence quenching experiments.     

The Radical Anions of [2.2]Paracyclophane-1,9-diene and Some of its Derivatives. An Unexpected Conformational Interconversion

The radical anions of [2.2]paracyclophane-1,9-diene ( 2 ) and its 1,10,12,13,15,16-hexadeuterio derivative 2 -D₆, as well as those of 4,5,7,8-tetramethyl[2.2]paracyclophane-1,9-diene ( 3 ) and its 12,13,15,16-tetradeuterio derivative 3 -D₄, have been studied by ESR spectroscopy. The coupling constants for 2 ^?· at 178 K are 0.422 mT for four equivalent olefinic protons and 0.046 and 0.020 mT, each for a set of four equivalent aromatic protons. This hyperfine pattern is consistent with either benzene ring bearing two pairs of equivalent protons and it points to a lowering of the anticipated D_2h symmetry. The ESR spectra of 2 ^?· are strongly temperature dependent, due to modulation of the two coupling constants of 0.046 and 0.020 mT; these have opposite signs and average to 0.013 mT at 273 K. The experimental findings are interpreted in terms of a transition state of D_2h symmetry, 33 kJ/mol above two interconverting equivalent conformations of lower symmetry. Several pieces of evidence suggest that this symmetry is D₂, i.e., the benzene rings in 2 ^?· are twisted in opposite directions about the vertical axis. Temperature dependence of the ESR spectra, resulting from modulation of the hyperfine interactions with the aromatic protons, is also observed for 2 -D₆^?· and 3 ^?·. In the case of 3 ^?·, the olefinic protons are, as expected, only equivalent in pairs, the pertinent coupling constants being 0.560 and 0.325 mT. Upon standing at low temperatures, 2 ^?· and 3 ^?· gradually convert into the radical anions of [2.2]paracyclophane ( 1 ) and its 4,5,7,8-tetramethyl derivative, respectively. At higher temperatures, cleavage of one bridging chain in 2 ^?· also occurs, with the formation of the radical anion of (E)-4,4′-dimethylstilbene ( 7 ). Both reactions of 2 ^?· must involve the transient radical anion of [2.2]paracyclophane-1-ene ( 4 ) as proved by the observation of the spectra of 1 ^?· and 7 ^?· with 4 as the starting material.     

Negative ion mass spectra of metal complexes: Secondary electron capture and CS2 elimination from nickel (ii) dithiocarbamates

Negative ion mass spectra of series of bis-(N, N-dithiocarbamato)nickel(II) complexes of formula [NiS₂C·NR¹R²]₂ (where·NR¹R² ? ·NEt₂ ·NPr₂, ·NBu₂, pyrrolidinyl, piperidyl, morpholinyl, and ·NEtPh) have been obtained by secondary electron capture. Intense molecular anions are given for all compounds, with most fragments originating from these ions. Metastable data indicate that CS₂ is eliminated from all molecular anions.     

Darstellung und Eigenschaften der Diphthalocyaninate des Yttriums und Indiums

Synthesis and Properties of the Diphthalocyaninates of Yttrium and Indium Blue di(phthalocyaninato(2–))metalates of tervalent yttrium and indium are obtained by the reaction of yttrium acetate or anhydrous indium chloride with molten phthalodinitrile in the presence of potassium methylate and isolated as complex salts with organic cations. Anodic oxidation of (ⁿBu₄N)[M(Pc^2?)₂] (M = Y, In) yields crystals of green paramagnetic di(phthalocyaninato)metal(III)-dichloromethane solvate, [M(Pc)₂] · CH₂Cl₂ (μ_eff = 1.8/1.9 B.M. (Y/In)). Red brown di(phthalocyaninato)metal(III)-polybromide, [M(Pc^?)₂]Br_x is prepared by oxidation with bromine in excess. The redox properties of the di(phthalocyaninato)metalates(III) are investigated by cyclic voltammetry and difference pulse polarography. A quasi reversible (ΔE ? 60 mV) one electron process at 0.09 V (Y) and ?0.07 V (In) is assigned to the redox couple [M(Pc^2?)₂]^?/[M(Pc)₂]. Electronic absorption spectra as well as MIR/FIR and resonance Raman spectra are reported. The characteristic features of the three oxidation states and the influence of the ionic radius and the electron configuration of the metal ion are discussed.     

The distonic ion ·CH2CH2CH+OH,keto ion CH3CH2CH=O +·, enol ion CH3CH=CHOH+·, and related C3H6O+· radical cations. Stabilities and isomerization proclivities studied by dissociation and neutralization-reionization

Metastable ion decompositions, collision-activated dissociation (CAD), and neutralization-reionization mass spectrometry are utilized to study the unimolecular chemistry of distonic ion ^·CH₂CH₂CH^?OH (2^+·) and its enol-keto tautomers CH₃CH=CHOH^?· (1 ^+·) and CH₃CH₂CH=O ^+· (3^+·). The major fragmentation of metastable 1^+·–3^+· is H^· loss to yield the propanoyl cation, CH₃CH₂C≡O⁺. This reaction remains dominant upon collisional activation, although now some isomeric CH₂=CH-CH⁺ OH is coproduced from all three precursors. The CAD and neutralization-reionization (⁺NR⁺) spectra of keto ion 3 ^+· are substantially different from those of tautomers 2^+· and 1^+·. Hence, 3^+· without sufficient energy for decomposition (i. e. , “stable” 3^+·) does not isomerize to the ther-modynamically more stable ions 2^+· or 1^+·, and the 1,4-H rearrangement H-CH₂CH₂CH=O^+·(3 ^+·) → CH₂CH₂CH⁺ O-H (2 ^+·) must require an appreciable critical energy. Although the fragment ion abundances in the ⁺ NR ⁺ (and CAD) spectra of 1 ^+· and 2 ^+· are similar, the relative and absolute intensities of the survivor ions (recovered C₃H₆O^+· ions in the ⁺NR⁺ spectra) are markedly distinct and independent of the internal energy of 1 ^+· and 2 ^+·. Furthermore, 1 ^+· and 2 ^+· show different MI spectra. Based on these data, distonic ion 2 ^+· does not spontaneously rearrange to enol ion 1 ^+· (which is the most stable C₃H₆O^+· of CCCO connectivity) and, therefore, is separated from it by an appreciable barrier. In contrast, the molecular ions of cyclopropanol (4 ^+·) and allyl alcohol (5 ^+·) isomerize readily to 2 ^+·, via ring opening and 1,2-H^? shift, respectively. The sample found to generate the purest 2 ^+· is α-hydroxy-γ-butyrolactone. Several other precursors that would yield 2 ^+· by a least-motion reaction cogenerate detectable quantities of enol ion 1 ^+·, or the enol ion of acetone (CH₂=C(CH₃)OH^+·, 6 ^+·), or methyl vinyl ether ion (CH₃OCH=CH ₂ ^+· , 7 ^+·). Ion 6 ^+· is coproduced from samples that contain the —CH₂—CH(OH)—CH₂— substructure, whereas 7 ^+· is coproduced from compounds with methoxy substituents. Compared to CAD, metastable ion characteristics combined with neutralization-reionization allow for a superior differentiation of the ions studied.     

Photosensitized formation of peroxyl radicals in aqueous solutions of adenine at 77 K

Conditions for the formation of peroxyl radicals photosensitized by near-UV irradiation in frozen aqueous solutions of adenine containing 0.1 M NaCl (pH 4–7) are studied. Analysis of the EPR spectra shows that the systems under study contain two types of peroxyl radicals presumably classified earlier as O ₂ ^?· and HO _2· ^· . The effect of freezing methods on the production of the radicals is shown. The signal from O ₂ ^?· predominates in the spectra of samples with open surfaces and is likely due to the reduction of adsorbed O₂ molecules with photoejected electrons. The signal from HO ₂ ^· could be due to photoinduced interaction between the sensitizer and solvent. Possible mechanisms of these processes are considered.     

Synthese und Kristallstruktur von Y(HSO4)3-I und Y(HSO4)3 · H2O

Syntheses and Crystal Structures of Y(HSO₄)₃-I and Y(HSO₄)₃ · H₂O Lath shaped crystals of Y(HSO₄)-I are obtained by treatment of Y₂O₃ with conc. sulfuric acid at 200 °C. Y(HSO₄)₃-I crystallizes orthorhombic (Pbca, Z = 8, a = 1201.5(1), b = 953.76(8), c = 1650.4(1) pm, R_all = 0.0388). In the crystal structure Y³⁺ is coordinated by eight monodentate HSO₄^– groups. Colorless, plate like single crystals of Y(HSO₄)₃ · H₂O grew from a solution of Y₂O₃ in 85% sulfuric acid upon cooling. In the crystal structure of the triclinic compound (P1, Z = 2, a = 679.8(1), b = 802.8(2), c = 965.9(2) pm, α = 79.99(2)°, β = 77.32(2)°, γ = 77.50(2)°, R_all = 0.0264) Y³⁺ is surrounded by seven HSO₄^– groups and one molecule of water.     

Improving the visible-light photocatalytic activity of SnO<Subscript>x</Subscript>·SiO<Subscript>2</Subscript> glass systems by introducing SnO<Subscript>x</Subscript> nanoparticles

Tin silicate glass without SnO_x nanoparticles (SiO₂·SnO_x), a silica glass containing only SnO_x nanoparticles (SiO₂·SnO_xNP) and the improved product, which combines the tin silicate glass with SnO_x nanoparticles (SiO₂·SnO_x·SnO_xNP) was prepared. For the structural analysis ¹¹⁹Sn Mössbauer spectroscopy and X-ray diffraction were applied. The ¹¹⁹Sn Mössbauer spectra showed that the SiO₂·SnO_x·SnO_xNP sample had the largest Sn^II content (12.0%). It also had an outstanding methylene blue degradation with the first-order rate value with (18?±?2) × 10^?3 min^?1 with visible light irradiation.     

Darstellung und Charakterisierung von Phthalocyanin-π-Kation-Radikalen von H+, Mg2+ und Cu2+

Preparation und Characterization of Phthalocyanine-π-Cation-Radicals of H⁺, Mg²⁺, and Cu²⁺ The preparation of phthalocyanine-π-cation-radicals (Pc(?1)) of H⁺, Mg²⁺, Cu²⁺ is described. MgClPc(?1) and Cu(NO₃)Pc(?1) · HNO₃ are isolated as stoichiometrically pure, stable redbrown solids. Contrary to the phthalocyanines(?2) (Pc(?2)) these are very soluble with redviolet colour in organic solvents in the presence of R? COOH (R ? H, CF₃, CCl₃). The electronic absorption absorption spectra (UV-VIS) are remarkably solvent-dependent. This solvent effect is due to a reversible radical association. Monomeric radical species exist in nonpolar (CH₂Cl₂), dimeric in polar solvents (CH₃NO₂, C₂H₅OH). The UV-VIS, infrared (IR), and resonance-raman (RR) spectra of MgClPc(?1) and Cu(NO₃)Pc(?1) · HNO₃ are discussed and compared with the analogoues spectra of MgPc(?2) · 2 H₂O and MgPc(?2) · HCl. Although there are only minor differences in the chemical composition and the electronic structure the spectroscopic data vary significantly for every complex. Especially the IR spectrum is suitable for a quick demonstration of the π-cation-radicals. The diagnostic bands are at ca. 1350 and 1450 cm^?1.