<Superscript>13</Superscript>C-labeled bilirubin: synthesis of 3<Superscript>1</Superscript>(3<Superscript>2</Superscript>),17<Superscript>1</Superscript>(17<Superscript>2</Superscript>)-di-[<Superscript>13</Superscript>C]-mesobilirubin-XIIIα

Abstract  The title compound, labeled with ¹³C in the ethyl groups was synthesized from K¹³CN and low-molecular-weight components. The synthetic relay compound was 3¹(3²)[¹³C]-xanthobilirubinic acid methyl ester in a synthetic route that leads to a label in the ethyl β-substituent of a dipyrrinone model for bilirubin. This labeled dipyrrinone was oxidatively coupled to the dimethyl ester of mesobiliverdin-XIIIα, thereby providing a route to a ¹³C-labeled mesobiliverdin and mesobilirubin, with one carbon of each ethyl being 98% ¹³C-enriched. Graphical Abstract        

Identification of Anionic Supramolecular Complexes of Sulfonamide Receptors with Cl<Superscript>−</Superscript>, NO<Stack><Subscript>3</Subscript><Superscript>−</Superscript></Stack>, Br<Superscript>−</Superscript>, and I<Superscript>−</Superscript> by APCI-MS

As part of a mass spectrometric investigation of the binding properties of sulfonamide anion receptors, an atmospheric pressure chemical ionization mass spectrometric (APCI-MS) method involving direct infusion followed by thermal desorption was employed for identification of anionic supramolecular complexes in dichloromethane (CH₂Cl₂). Specifically, the dansylamide derivative of tris(2-aminoethyl)amine (tren) (1), the chiral 1,3-benzenesulfonamide derivatives of (1R,2S)-(+)-cis-1-amino-2-indanol (2), and (R)-(+)-bornylamine, (3), were shown to bind halide and nitrate ions in the presence of (n−Bu)₄N⁺X⁻ (X⁻ = Cl⁻, NO₃⁻, Br⁻, I⁻). Solutions of receptors and anions in CH₂Cl₂ were combined to form the anionic supramolecular complexes, which were subsequently introduced into the mass spectrometer via direct infusion followed by thermal desorption. The anionic supramolecular complexes [M+X]⁻, (M=1–3, X⁻=Cl⁻, NO₃⁻, Br⁻, I⁻) were observed in negative mode APCI-MS along with the deprotonated receptors [M−H]⁻. Full ionization energy of the APCI corona pin (4.5 kV) was necessary for obtaining mass spectra with the best signal-to-noise ratios.     

Cyclotron production of <Superscript>211</Superscript>At/<Superscript>211g</Superscript>Po by <Superscript>209</Superscript>Bi(α,2n) reaction

Astatine-211 (T _1/2 = 7.214 h) is an α-emitter at secular equilibrium by EC with its ultra-short-lived α-emitting daughter, polonium-211g (T _1/2 = 0.516 s), with a high Linear Energy Transfer (LET — 130 eV·nm⁻¹) and a half-life suitable for metabolic radiotherapy; the overall α branching of the ²¹¹At/^211gPo system is 100%. The direct production of ²⁰⁹Bi(α,2n)²¹¹At/^211gPo seems the most satisfactory method; Bi targets were irradiated at JRC-Ispra Cyclotron of European Commission, EC, using α-energy higher than 28.61 MeV in order to produce, via ²⁰⁹Bi(α,3n) reaction, small amounts of the γ-emitter ²¹⁰At (used as internal spike).     

Production possibility of <Superscript>186</Superscript>Re via the <Superscript>192</Superscript>Os(p,α3n)<Superscript>186</Superscript>Re nuclear reaction

Experimentally measured cross-sections are presented for the first time for the ¹⁹²Os(p,α3n)¹⁸⁶Re nuclear reaction up to 67 MeV. Highly enriched thin ¹⁹²Os targets (15 pcs), prepared by electro-deposition onto Cu backings, were irradiated with an external proton beam delivered by the SSC cyclotron of iThemba LABS. The excitation function curve of the ¹⁹²Os(p,α3n)¹⁸⁶Re reaction shows a maximum cross-section of ~82 mb at about 24 MeV. According to the yield calculations based on the present results, the available cumulative no-carrier-added ¹⁸⁶Re yield is 7.76 MBq/μAh (0.21 mCi/μAh) over the energy region 13.4 → 27.3 MeV.     

Validation of <Superscript>239,240</Superscript>Pu, <Superscript>238</Superscript>Pu separation method using molecular recognition product AnaLig<Superscript>®</Superscript> Pu02 gel and extraction chromatography TRU<Superscript>®</Superscript> resin

Two separation techniques for plutonium determination using AnaLig^® Pu02 molecular recognition technology product (MRT) and extraction chromatography TRU^® resin were tested. The methods performance was investigated by analysis of National Physical Laboratory (NPL-Alpha-Beta High, ABH 2003, 2005) intercomparison test samples. The results obtained for both procedures were compared in terms of activities and recoveries. Data analysis showed good agreement with the reference values. The AnaLig^® Pu02 separation method for ^239,240Pu, ²³⁸Pu determination was successfully validated with the same performance as the TRU^® resin method.     

Relativistic coupled cluster calculations of the electronic structure of KrH<Superscript>+</Superscript>, XeH<Superscript>+</Superscript> and RnH<Superscript>+</Superscript>

Potential energy curves of NgH⁺ cations (Ng = Kr, Xe, Rn) were obtained by using four-component relativistic CCSD(T) coupled cluster calculations. Dissociation energies, equilibrium bond lengths, electronic properties, such as dipole moments and electric field gradients at the nuclei, and the related spectroscopic parameters of the electronic ground state have been determined. The results obtained for KrH⁺ and XeH⁺ are in good agreement with available experimental data, while those for RnH⁺ have been determined for the first time at this level of theory.     

A simple and quick method for the preparation of radionuclide <Superscript>87</Superscript>Y/<Superscript>87m</Superscript>Sr generator using the <Superscript>nat</Superscript>Rb(α,xn)<Superscript>87</Superscript>Y reaction

A rapid method for the preparation of ⁸⁷Y/^87mSr radionuclide generator from a rubidium chloride target irradiated with 35 MeV α-particles is described. A simple two-step procedure is used to obtain a carrier-free ^87mSr isotope with a high enough radiochemical yield and high purity in the final aqueous fraction.     

Experimental Determination of the Isotherm at 15°C of the System Mg<Superscript>2+</Superscript>/Cl<Superscript>−</Superscript>, SO<Subscript>4</Subscript><Superscript>2</Superscript>–H<Subscript>2</Subscript>O

Summary.  The diagram of the ternary system Mg²⁺/Cl⁻, SO₄ ²⁻–H₂O was established at 15°C by means of analytical and conductimetric measurements. Three compounds were found in this diagram, which are MgSO₄·6H₂O, MgSO₄·7H₂O, and MgCl₂·6H₂O. The solubility field of MgSO₄·7H₂O is important whereas those of MgSO₄·6H₂O and MgCl₂·6H₂O are small. The compositions (mass-%) of the two invariant points determined by the two methods are: MgSO₄:MgCl₂=2.73:33.80 and MgSO₄: MgCl₂=3.38:28.91. Both the measured and the calculated isotherm at 15°C have been used for modelling of the diagram Mg²⁺/Cl⁻, SO₄ ²⁻–H₂O between 0 and 35°C. The polythermal invariant point was approximately located between 15 and 10°C.  Corresponding author. E-mail: ariguib@planet.tn Received October 16, 2002; accepted (revised) December 3, 2002 Published online April 24, 2003 RID="a" ID="a" Dedicated to Prof. Dr. Heinz Gamsj?ger on the occasion of his 70^th birthday     

The effect of NO<Stack><Subscript>3</Subscript><Superscript>−</Superscript></Stack> and OH<Superscript>−</Superscript> ions on the laser ablation of Cs<Superscript>+</Superscript> ion on Type 304 stainless steel

Type 304 stainless steel specimens artificially contaminated with CsCl solution were treated with KOH solution and KNO₃ solution, respectively. Cs⁺ ion removal tests by a Q-switched Nd:YAG laser at 1064 nm at a given fluence of 57.3 J/cm² were performed. The surface morphology and the relative atomic mole ratio of the specimen surface were investigated by SEM and EPMA. The order of Cs⁺ ion removal efficiency of laser was no-treatment < KOH < KNO₃ during the 42 shots. From the investigation of XPS peaks around 532.7 and 292.9 eV, KNO₃ on a surface of specimen was found to be fully decomposed during the laser irradiation. It was suggested that Cs₂O particulates formed by the reaction between the reactive oxygen generated from the nitrate ion and Cs⁺ ion on the metal surface could be easily suspended. For the KOH system, FeOOH was formed during the laser irradiation and it changed into Fe₂O₃. It was also suggested that Cs₂O particulates were formed by the reaction between the reactive oxygen generated from the decomposition of K₂O and Cs⁺ ion on the metal surface..     

Synthesis of the [<Superscript>2</Superscript>H,<Superscript>15</Superscript>N]-labeled antiviral drug “triazavirine”

Selective methods for the incorporation of stable isotopes ¹⁵N and ²H into the structure of antiviral medicine “triazavirine” 1 were developed. The synthesized isotopically modified “triazavirine” 1– ² H ₃ , ¹⁵ N ₃ contained the labeled atoms in both the azole and the azine rings. ¹³C and ¹⁵N NMR spectra of the isotope-containing sample 1– ² H ₃ , ¹⁵ N ₃ were thoroughly analyzed.     

Preparation of <Superscript>235m</Superscript>U targets for <Superscript>235</Superscript>U(n,n′)<Superscript>235m</Superscript>U cross section measurements

This paper describes the preparation of samples for an experiment to measure the cross-section for ²³⁵U(n,n′)^235mU in a fast fission spectrum of neutrons provided by a fast pulsed reactor/critical assembly. Samples of ^235mU have been prepared for the calibration of the internal conversion electron detector that is used for the ^235mU measurement. Two methods are described for the preparation of ^235mU. The first method used a U-Pu chemical separation based on anion-exchange chromatography and the second method used an alpha recoil collection method. Thin, uniform samples of ^235mU+²³⁵U were prepared for the experiment using electrodeposition.     

Influence of ion size on the stability of chloroplumbates containing PbCl<Stack><Subscript>5</Subscript><Superscript>−</Superscript></Stack> or PbCl<Stack><Subscript>6</Subscript><Superscript>2−</Superscript></Stack>

The enthalpies of formation of PbCl₄, PbCl₅⁻ and PbCl₆²⁻, originating from quantum mechanics, have enabled the thermodynamic behaviour of these ions with respect to Cl-detachment to be assessed. The stability of salts containing PbCl₅⁻ and PbCl₆²⁻ as a function of the dimensions of these anions and complementary cations was studied using an approach combining the Kapustinskii-Yatsimirskii equation with basic thermochemical relationships. It was found that hexachloroplumbates of monovalent metal cations will not dissociate into metal chlorides and PbCl₄, provided the complementary cations are suitably large in size. Hexachloroplumbates of divalent metal cations have not yet been synthesised since no known metal cations attain the requisite large size. Such salts will not dissociate if the divalent metal cations are able to complex suitably large electron-donating ligands. The pentachloroplumbates of both monovalent and divalent metal cations are unstable, since no known metal cations have appropriately large ionic radii. The approach adopted appears to be useful for the examination of the thermal behaviour, stability and reactivity of chloroplumbates.     

Triboluminescence of zirconium η<Superscript>5</Superscript>-complexes

This work describes a comparative study of tribo- and photoluminescence of metallocenes (Cp₂HfCl₂, Cp₂TiCl₂, Cp₂ZrCl₂, (CpMe)₂ZrCl₂, rac-Me₂C(3-Bu^t-Cp)₂ZrCl₂, Ind*₂ZrCl₂). Occurring under mechanodestruction of polycrystals, triboluminescence of zirconium bis-cyclopentadienyl complexes, Cp₂ZrCl₂, (CpMe)₂ZrCl₂, and rac-Me₂C(3-Bu^t-Cp)₂ZrCl₂ has been revealed for the first time. The triboluminescence spectrum in air is similar to the photoluminescence spectrum of zirconocene polycrystals. The triboluminescence spectrum does not show *N₂ luminescence. Ne and Ar lines are observed in the triboluminescence spectrum in the atmosphere of these gases. An increase in the number of substituents in zirconocene ligands leads to a bathochromic shift of the emission band maximum in triboluminescence spectra of the complexes. Possible mechanisms of zirconocene triboluminescence excitation are discussed.     

Thermodynamic Properties of Zincate-Manganites of LaM<Subscript>2</Subscript> <Superscript>II</Superscript>ZnMnO<Subscript>6</Subscript> (М<Superscript>II</Superscript> = Mg,Ca, Sr,Ba) Composition

Temperature dependences of the heat capacity of new zincate-manganites of LaM₂^IIZnMnO₆ (M^II = Mg, Ca, Sr, Ba) composition are studied via experimental calorimetry in the interval of 298.15–673 K. It is found that all compounds have λ-shape effects on the curve of dependence C_p° ~ ?(T) with respect to phase transitions of the second kind. Equations for the temperature dependence of the heat capacity are derived with allowance for phase transition temperatures, and thermodynamic functions H°(T) ? H°(298.15), S°(T) and Φ^xx(T) are calculated on the basis of experimental data on C_p°(T) and the calculated S°(298.15) value.     

Structure and stability of endohedral complexes <Superscript>4/2</Superscript>X@(HAlNH)<Subscript>2</Subscript> (X = N,P, As,C<Superscript>−</Superscript>, Si<Superscript>−</Superscript>)

The structures of a closo-hedral cluster (HAlNH)₁₂ and endohedral complexes ^4/2X@(HAlNH)₁₂ (X = N, P, As, C⁻, Si⁻) are studied by density functional theory (DFT) at the B3LYP/6-31G(d) level. The geometries, natural bond orbital (NBO), vibrational frequency (ν₁), energetic parameters, magnetic shielding constants (σ), and nucleus independent chemical shifts (NICSs) are discussed. It is found that all guest species are minima at the cage center. Inclusion energies (ΔE _inc) of all species are negative except those of ⁴N and ^4/2P. In all species, the endohedral quartet states (⁴X) are energetically less favorable than their doublet states (²X). The calculations predict that caged X states only donate <0.50 e to the cage and preserve their unencapsulated ground states.     

Crystallinity of Dynasan<Superscript>®</Superscript>114 and Dynasan<Superscript>®</Superscript>118 matrices for the production of stable Miglyol<Superscript>®</Superscript>-loaded nanoparticles

This study focuses on the physicochemical characterization of lipid materials useful for the production of the so-called solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC). The chosen lipids were Dynasan^®114 (glyceril trimyristate) and Dynasan^®118 (glyceril tristearate) as solid lipids (SL), melting temperature above 80 °C, and Miglyol^®812 (caprylic/capric triglyceride) and Miglyol^®840 (propylene glycol dicaprylate/dicaprate) as liquid lipids (LL), crystallizing below ?15 °C. Raw lipids (pure or SL:LL mixtures) were analyzed by differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD), and Polarized Light Microscopy (PLM), before and after tempering at 80 °C for 1 h. The selected SL:LL combination was 70% (Dynasan^®114 and 118) and 30% (Miglyol^®812 and 840) for the production of SLN and NLC by high-pressure homogenization (HPH), respectively. Particles with a mean size of 200 nm (polydispersity index <0.329) and zeta potential of ?15 mV were obtained, and their long-term stability was confirmed for 3 months of storage at 7 °C.     

Chemical Bonding in the Complexes XeF<Stack><Subscript>5</Subscript><Superscript>+</Superscript></Stack>XF<Stack><Subscript>6</Subscript><Superscript>−</Superscript></Stack> (X = P,As, Sb,and Bi)

Ab initio quantum-chemical calculations of the complexes XeF ₅ ⁺ XF ₆ ^? (X = P, As, Sb, and Bi) were performed with the use of relativistic pseudopotentials for heavy atoms and full-electron basis sets. The chemical bonds were characterized by the parameters of critical points (electron density, its Laplacian, total electron energy, and its kinetic and potential components). It was demonstrated that the interaction between the XeF ₅ ⁺ cation and the XF ₆ ^? anion in XeF ₅ ⁺ XF ₆ ^? follows a key-lock scheme involving directed interactions of bridging fluorine atoms F_b → Xe and that the structuring function of the lone electron pair of the Xe atom is to compensate the destabilizing electrostatic interaction between the Xe and X atoms bearing excess positive charges.     

Utilization of (p, 4n) reaction for <Superscript>86</Superscript>Zr production with medium energy protons and development of a <Superscript>86</Superscript>Zr → <Superscript>86</Superscript>Y radionuclide generator

Utilization of (p, 4n) reaction channel for the production of medical radionuclides became very attractive with commercial availability of medium energy cyclotrons. Significantly higher yields and radionuclidic purity may open new perspectives for several novel and some of the radionuclides previously have not been considered due to production difficulties. In present work, we show the proof-of-principle study on the production of ⁸⁶Y for Positron Emission Tomography imaging via radionuclide generator ⁸⁶Zr → ⁸⁶Y. Production suitability of ⁸⁶Zr from natural yttrium target and radiochemical separation strategies were tested. In addition, two generator systems were proposed and evaluated.     

A study of the hydrolysis of ZrF<Stack><Subscript>6</Subscript><Superscript>2−</Superscript></Stack> and the structure of intermediate hydrolysis products by <Superscript>19</Superscript>F and <Superscript>91</Superscript>Zr NMR in the 9.4 T field

The high-field ¹⁹F and ⁹¹Zr NMR method is used to study the hydrolysis and polycondensation of hexafluorozirconate ZrF₆²⁻ in aqueous and water-peroxide solutions. During hydrolysis in aqueous solutions only ZrF₆²⁻ and F⁻ ions were observed by NMR, however, in the water-peroxide medium, an intermediate product of hydrolysis ([F₅Zr-OO-ZrF₅]⁴⁻ dimer) was detected. The dimer structure is confirmed by ¹⁹F and ⁹¹Zr NMR. In high fields (¹⁹F NMR frequency > 200 MHz), the fluorine exchange between ZrF₆²⁻ and F⁻ is slow in the ¹⁹F NMR scale and has a multisite character.     

Synthesis,structural and multinuclear natural abundance (<Superscript>13</Superscript>C, <Superscript>31</Superscript>P, <Superscript>195</Superscript>Pt) CP/MAS NMR studies of crystalline O,O′-dialkyldithiophosphate platinum(II) complexes

Platinum(II) O,O′-dicyclohexyl dithiophosphate [Pt{S₂P(O-cyclo-C₆H₁₁)₂}₂] (I) and platinum(II) O,O′-diisopropyl dithiophosphate [Pt{S₂P(O-iso-C₃H₇)₂}₂] (II) complexes were obtained and studied by solidstate ¹³C, ³¹P, and ¹⁹⁵Pt CP/MAS NMR spectroscopy. The dithiophosphate (Dtph) ligands in molecular structure I were found to be coordinated by platinum in S,S′-bidentate fashion to form the planar chromophore [PtS₄] (single-crystal X-ray diffraction data). For complex II, a new α-form (α-II) was obtained and identified by ³¹P MAS NMR spectroscopy. The ³¹P chemical shift anisotropy δ_aniso and the asymmetry parameter η of the ³¹P chemical shift tensor were calculated from the whole MAS spectra.