412304-56-4Relevant articles and documents
Chelated hydrazido(3-)rhenium(V) complexes: On the way to the nitrido-M(V) core (M = Tc, Re)
Mevellec, Franck,Lepareur, Nicolas,Roucoux, Alain,Noiret, Nicolas,Patin, Henri,Bandoli, Giuliano,Porchia, Marina,Tisato, Francesco
, p. 1591 - 1597 (2002)
Neutral and asymmetrical hydrazido(3-)rhenium(V) heterocomplexes of the type [Re(η2-L4)(Ln)(PPh3)] (η2-L4 = NNC(SCH3)S; H2L1 = S-methyl β-N-((2-hydroxyphenyl)ethylidene)dithiocarbazate, 1, H2L2 = S-methyl β-N-((2-hydroxyphenyl)methylidene)dithiocarbazate, 2) are prepared via ligand-exchange reactions in ethanolic solutions starting from [ReV(O)Cl4]- in the presence of PPh3 or from [ReV(O)Cl3(PPh3)2]. The distorted octahedral coordination sphere of these compounds is saturated by a chelated hydrazido group, a facially ligated ONS Schiff base, and PPh3. Reduction-substitution reactions starting from [NH4][ReVIIO4] in acidic ethanolic mixtures containing PPh3 and H2Ln (or its dithiocarbazic acid precursor H3L4) produce another example of chelated hydrazido(3-) rhenium(V) derivative, namely [Re(η2-L4)Cl2(PPh3) 2], 3. On the contrary, the N-methyl-substituted dithiocarbazic acid H2L3 reacts with perrhenate to give the known nitrido complex [Re(N)Cl2(PPh3)2]. Rhenium(V) complexes incorporating the robust η2-hydrazido moiety represent key intermediates helpful for the comprehension of the reaction pathway which generates nitridorhenium(V) species starting from oxo precursors. An essential requirement for the stabilization of such chelated hydrazido-Re(V) units is the triple deprotonation at the hydrazine nitrogens, thereby providing efficient π-electron circulation in the resulting five-membered ring. The thermal stability of these units is affected by the nature of the anchoring donor, thione sulfur ensuring stronger chelation than nitrogen and oxygen. The η2-hydrazido complexes are characterized by conventional physicochemical techniques, including the X-ray crystal structure determination of 1 and 3.
Solid state study on rhenium dimethylphosphinoethane complexes: X-ray crystal structures of trans-[ReO2 (dmpe)2]PF 6·2H2O, trans-[ReO(OH)(dmpe)2](CF 3SO3)2, trans-[ReN(Cl)(dmpe) 2]CF3SO3 and trans-[ReCl2(dmpe) 2]ReO4
Engelbrecht,Jurisson,Cutler,Den Drijver,Roodt
, p. 83 - 99 (2008/10/09)
The reaction of trans-[ReO2(en)2]Cl with dimethylphosphinoethane (dmpe) yielded the yellow complex trans-[ReO2 (dmpe)2]Cl (1), which, upon reaction with CF3SO 3H, yields orange crystals of the oxo-hydroxo complex trans-[ReO (OH)(dmpe)2](CF3SO3)2 (2). Reaction of trans-[ReNCl2(PPh3)2] with dmpe resulted in orange crystals of trans-[ReN(Cl)(dmpe)2]-CF3SO 3 (3). Adjustment of the pH of a solution of trans-[ReN(Cl)(dmpe) 2]CF3SO3 to 11.7 with NaOH resulted in the formation of yellow crystals of trans-[ReCl2(dmpe) 2]ReO4 (4). A shortening of the Re-P bond distances were observed as the axial ligands (i.e., core: O=ReV-OH V=O V-Cl III-Cl) increased the electron density on the metal center, allowing for better Re-P π back bonding. The preliminary pKa determination for the protonation of [ReO2(dmpe)2]+ to form [ReO(OH)(dmpe)2]2+ showed the pKa2 to be 2(dmpe)2]+: monoclinic space group P21/c with a = 11.5299(7) A, b = 15.2397(9) A, c = 15.0230(9) A, β = 97.7260(10)°, Z = 4; trans-[ReO(OH)(dmpe)2]2+: monoclinic space group P2 1/c with a = 8.0426(4) A, b = 11.5472(6) A, c = 16.0303(8) A, β = 101.9360(10)°, Z = 2; trans-[ReN(Cl) (dmpe)2]+: orthorhombic space group Pmc21 with a = 11.5068(10) A, b = 9.6656(8) A, c = 12.1772(11) A, Z = 2; trans-[Re(Cl)2(dmpe)2]+: monoclinic space group P21/c with a = 19.375(3) A, b = 8.6840(12) A, c = 15.910(2) A, β = 111.270(3)°, Z = 4. The conformation of the two dmpe ligands in all of the complexes described were λδ (eclipsed). Copyright
Co-ordination chemistry of S-methyl 2-methyldithiocarbazate and formation of [M≡N]2+(M = Tc or Re) species
Marchi, Andrea,Uccelli, Licia,Marvelli, Lorenza,Rossi, Roberto,Giganti, Melchiore,Bertolasi, Valerio,Ferretti, Valeria
, p. 3105 - 3109 (2007/10/03)
Reaction of [TcOCl4]- and [ReOCl3(PPh3)2] with S-methyl 2-methyldithiocarbazate [H2L = H2NNMeC(S)SMe] under mild conditions gave the oxo-technetium(V) and -rhenium(V) S,N-chelated complexes [MO(HL)2]Cl (M = Tc or Re). These were transformed to the corresponding nitrido-complexes [MNCl2(PPh3)2] under reflux and in the presence of HCl and PPh3. The technetium(IV) complex [TcCl4(PPh3)2] under reflux and in presence of an excess of H2L and NEt3 gave the nitrido-compound [TcN(HL)2]. This was also obtained when [TcNCl2(PPh3)2] was used as precursor in the presence of NEt3. The complex [TcNCl2{NPr(CH2CH2PPh2) 2}] reacted with an excess of H2L to give the monosubstituted compound [TcN(HL){NPr(CH2CH2PPh2)2}]X (X = Cl, BF4 or BPh4). A crystal structure determination of the complex [ReO(HL)2]Cl showed a distorted square-pyramidal geometry with the oxygen atom in apical position. The Cl- ion is bound to NH groups by means of two hydrogen bonds. A set of reactions using 99mTc were carried out in order to understand the formation of the 99mTcN core.
