Technetium crystal structure

Lamfers HJ, Meetsma A, Wiegers GA, Boer JL (1996) The crystal structure of some rhenium and technetium dichalcogenides. J AUoy Compd 241 34—39... 

Technetium compounds with amine/thioether coordination are the cationic trans-dioxotechnetium(V) complexes [Tc02(N2S2)]+. The complex in which N2S2 is l,4-dithia-8,ll-diazacyclotetradecane was prepared via an exchange reaction of NBu4[TcOBr4] with the ligand and fully characterized by X-ray crystal structure determination [109,110]. The coordination around technetium... 

Many compounds of technetium and rhenium are of analogous composition and of corresponding physical and chemical properties. Because of the very similar ionic radii, isotypic crystal structure formation of analogous compounds could often be observed. Technetium remarkably differs from manganese by the high stability of pertechnetate compared with permanganate. Moreover, divalent technetium does not exist as a hydrated ion but only as a stabilized complex. 

The unique seven-coordinate complex [TcO(EDTA)] is obtained by reaction of [TcOCy with H4EDTA in anhydrous dmso. The X-ray crystal structure confirmed pentagonal-bipyrami-dal geometry, with the 0x0 group and the two nitrogen donors bound in the equatorial plane. " All other structurally characterized technetium complexes with polyamino-polycarboxylates are in oxidation state IV. 

No binary xanthate structures of manganese, technetium, or rhenium have been reported. Indeed, there are relatively few crystal structures known with only a single manganese structure (two polymorphs), two phosphine adducts of technetium and three structures containing rhenium, two of which are dinuclear. 

The structures of technetium compounds are insufficiently known to give satisfactory values for ionic radii. Its covalent radius is very little less than that of rhenium both metals have the same crystal structure (h.c.p.) and the atomic volume of Re is very little greater (p. 480). 

Monomeric M(CO)4(S2PR2) (18) and dimeric [M(CO)3(S2PR2)]2 ((19), M = Mn, Re R = Et, Ph) (Scheme 4) have been described quite early,55 but the crystal structure of Mn(CO)4(S2PMe2) was reported only recently.56 Technetium derivatives, important for radiological imaging, such as 99mTcN(S2PR2)2 (R = Me, Et, Pr, Pr1), have been described.57,58... 

Introduction.—The organometallic chemistry of technetium and rhenium reported during 1974 has been surveyed. The ligand-induced redox reactions of rhenium halides have been reviewed, and the chemistry of cyanide complexes of Group Vila metals has received attention. The electrochemistry of technetium and rhenium has been the subject of two reviews, and a general monograph on the production, uses, and disposal of technetium has appeared. Recently published crystal structures of complexes of technetium and rhenium have been collated. ... 

Tc-EDTA chemistry studies demonstrated at least two types of stable complexes, one containing a Tc(V)Oj core in a hepta-coordinated environment (Davison and Jones 1982), and the other is a complicated dimer in which technetium can be present as Tc(IV) or as Tc(III) (Linder 1986 Noll et al. 1980 Seifert et al. 1982). The crystal structure of a Tc(IV) complex has been reported (Burgi et al. 1981). 

Bandoli G, Mazzi U, Roncari E, Deutsch E (1982) Crystal structures of technetium compounds. Coord Chem Rev 44 210... 

Jones AG, Dionauge GF, Davison A et al (1985) Biological distribution and structure function relationship of hexakis isonitrile Tc(I) complexes (abstract). J Nucl Med All Sci 29 200 Jurisson S, Dancey K, McPartlin M, Tasker P, Deutsch E (1984) Synthesis, characterization, and electrochemical properties of technetium complexes containing both tetradentate Schiff base ligands and monodentate tertiary phopshine ligands single crystal structure of trans-(JV,2V-ethy-lene bis(acetylacetone-iminato)bis(triphenylphos- phine)-technetium(III)-hexafluoro-phosphate. Inorg Chem 23 4743-4744... 

Loberg MD, Fields AT (1978) Chemical structure of technetium-99m-labeled N-(2,6-dimethyl-phe-nylcarbamoylmethyl)-iminodiacetic acid ( Tc-HIDA). Int J Appl Radiat Isot 29 167-173 March A, Garuti P, Duatti A et al (1990) Synthesis of technetium(V)-nitrido complexes with chelating amines a novel class of monocationic, octahedral complexes containing the [Tc = N] core. Crystal structures of [TcN(en)2Cl] (en = ethylenediamine) and [TcN(tad)Cl] (tad = 1,5,8,12-tet-raazadodecane). Inorg Chem 29 2091-2096... 

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