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The reaction of [ReX(CO)5] (X=Br, H) with the bidentate phosphinite ligand 1,2-bis(diphenylphosphinite)ethane (L–L), synthesized by reaction of PPh2Cl and ethylene glycol in a 2:1 ratio in the presence of NEt3, at room temperature, affords the mononuclear rhenium(I) complexes fac-[ReBr(CO)3(L–L)] (1) and fac-[ReH(CO)3(L–L)] (2). The coordination geometry of the complexes was established by diffraction studies and confirmed by spectroscopic data of both complexes. Compound 1 crystallizes in the P21/c (No. 14) monoclinic space group while the hydride complex does so in P21 (No. 4). The coordination polyhedron around the rhenium atom in both cases is a slightly distorted octahedron with three carbonyl groups in facial positions. The link of the bidentate ligand to the metal atom leads to a seven-membered ReP2O2C2 ring, adopting a conformation better described as a twisted chair.

We have developed a technetium labeling technology based on a new organometallic chemistry, which involves simple mixing of the novel reagent, a 99m Tc(I)-carbonyl compound, with a His-tagged recombinant protein. This method obviates the labeling of unpaired engineered cysteines, which frequently create problems in large-scale expression and storage of disulfide-containing proteins. In this study, we labeled antibody single-chain Fv fragments to high specific activities (90 mCi/mg), and the label was very stable to serum and all other challenges tested. The pharmacokinetic characteristics were indistinguishable from iodinated scFv fragments, and thus scFV fragments labeled by the new method will be suitable for biodistribution studies. This novel labeling method should be applicable not only to diagnostic imaging with 99mTc, but also to radioimmunotherapy approaches with 186/188 Re, and its use can be easily extended to almost any recombinant protein or synthetic peptide.

The Tc(I) mixed-ligand complex, trans-[Tc(dppe)2(butNC)2](PF6) (dppe=bis(diphenylphosphino)ethane, butNC=tert-butyl-isocyanide) has been prepared from [Tc(tu−S)63+ (tu-S=thiourea) and a mixture of both ligands. The compound crystallizes triclinic in the space group P1 (a=9.999(5), b=12.059(5), c=13.776(7) A, α=113.55(2), β=92.18(3), γ=101.50(3)°, Z=1). The technetium atom has a slightly distorted octahedral coordination sphere with the isocyanide ligands in trans-position to each other. By cyclic voltammetry, at a Pt electrode, trans-[Tc(dppe)2(butNC)2](PF6) undergoes a single electron reversible oxidation at E12ox=0.91 V versus SCE.

Pale yellow crystals of the title compound, (C 8 H 11 N 4 D) 2 [Th(NO 3 ) 6 ].4CH 4 O, are formed when thorium nitrate and acetylpyridine thiosemicarbazone are refluxed in methanol. Thorium is 12-coordinate. The complex anion possesses inversion symmetry. The almost planar 2-[1-(thiosemicarbazono)ethyl]pyridinium cations show bond lengths which indicate a considerable delocalization of electron density.

The β-emitting 99Tc isotope is a high-yield fission product in 235U and 239Pu nuclear reactors, raising special concern in nuclear waste management due to its long half-life and the high mobility of pertechnetate (TcO4−). In the conditions of deep nuclear waste repositories, retention of Tc is achieved via biotic and abiotic reduction of TcO4− to compounds like amorphous TcO2·xH2O precipitates. It is generally accepted that these precipitates have linear (Tc(μ-O)2(H2O)2)n chains, with trans H2O. Although corresponding Tc Tc and Tc O distances have been obtained from Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy, this structure is largely based on analogy with other compounds. Here, we combine Density-Functional Theory with EXAFS measurements of fresh and aged samples to show that, instead, TcO2·xH2O forms zigzag chains that undergo a slow aging process whereby they combine to form longer chains and, later, a tridimensional structure that might lead to a new TcO2 polymorph.

Formation de complexes de l'indium(III) avec des thiocarbamates, des xanthates, des thiophosphates alkyles. Ces complexes ont ete isoles a l'etat cristallin. Donnees spectrometriques et analyse elementaire