Studies of technetium complexes. 9. Use of the tetrachloronitridotechnetate(VI) anion for the preparation of nitrido complexes of technetium. Crystal structure of bis(8-quinolinethiolato)nitridotechnetium(V)

Abstract

15 100-75-1; d-Phe-l-Phe, 2577-22-2; ~i-[(en),Co(l-Phe-I-Phe-OCH~)]~~, 99603-02-8; ~i-[(en)~Co(d-Phe-l-Phe-OCH~)]~*, 99603-03-9; A-[ (en),C~(l-Phe-l-Phe-OCH,)]~~, 99603-53-9; A-[ (en),Co(d-Phe-l-Phe-OCH3)ISt, 99559-65-6. (1 5) Bcnianszky, M. The TcV'NC1.,-anion is shown to be a useful intermediate for the preparation of T e N complexes. Reaction of AsPh,[TcNCI,] with LiBr in acetone gives AsPh4[TcNBr4], and reaction of TcNCI, with CsCl gives Cs2[TcNC15]. The TcNCIC anion undergoes reduction on reaction with PPh3, KNCS, Na[S2CNEt2], and 8-quinolinethiol (C9H6NSH) to give the TcV=N complexes [TcNCI2(PPh3),], [NEt,],[TcN(NCS),(CH,CN)], [TcN(S2CNEt2),], and [TcN(C9H6NS),], respectively. A single-crystal X-ray structure determination of bis(8-quimolinethiolato)nitridotechnetium(V), [TcN(C,H,NS),], is reported. Crystals are monoclinic, space group C2/c, with a = 15.92 (1) A, 6 = 7.347 (6) A, c = 15.33 (2) A, j3 = 110.89 (8)", and 2 = 4. Full-matrix least-squares refinement gave R = 0.029 for 1618 independent reflections. The coordination geometry of technetium is distorted square pyramidal with the apical TFN bond of length 1.623 (4) A. Tc-S and Tc-N(quinoline) bond distances are 2.3559 (7) and 2.135 (2) A, respectively.

Final Report, Research Program to Investigate the Fundamental Chemistry of Technetium

“…While these studies met with no more success in the preparation of coordination complexes of Tc(IV), they did yield important confirmation of literature reports that these reductants can under certain conditions generate metal nitride species (Chatt 1969). We have verified this by confirming isolation of a Tc(V) nitride complex by reduction of pertechnetate by hydrazine in the presence of dithiocarbamate as a complexing ligand (Baldas 1986). This observation is significant in light of the fact that nitrogen-based reductants such as hydrazine and hydroxylamine are commonly used to generate Tc(IV) in situ for environmental speciation and stability studies (Pikaev 1996).…”

“…This observation is significant in light of the fact that nitrogen-based reductants such as hydrazine and hydroxylamine are commonly used to generate Tc(IV) in situ for environmental speciation and stability studies (Pikaev 1996). The technetium nitride moiety is quite robust under a range of conditions, and its behavior is very different from that of Tc(IV) (Baldas 1991, Baldas 1986, Baldas 1984. Reduction of pertechnetate with hydroxylamine in the presence of complexants appears to be significantly slower than reductions using hydrazine under comparable conditions.…”

Structure of trans-aquanitrido(1,4,8,11-tetraazacyclotetradecan-5-onato-N,N',N'',N''')technetium(V) chloride dihydrate

“…intermediate between true bonds and van der Waals contacts. Analysis of the overall coordination geometries shows that the lengthening of the Tc---OH2 bond is associated with the increasing pyramidalization of the Tc coordination polyhedron, measured by the N~--~I'c--Lcu mean angle, a, which is 101 ° in the present compound and 104 and 105 ° in the other related Tc v nitrido tetraaza macrocyclic complex , while in typical square-pyramidal complexes a values fall in the range 105-108 ° (Marchi et al, 1988;Baldas, Bonnyman, Pojer, Williams & Mackay, 1981;Baldas et al, 1986). Fig.…”

“…Baldas and coworkers (Baldas, Bonnyman & Williams, 1986;Baldas, Bass, Bonnyman & Williams, 1984;Baldas & Bonnyman, 1985) (Griffith, 1972). Thenceforward, new technetium nitrido complexes which could be potential radiopharmaceutical agents have been characterized and investigated.…”

Synthesis and biodistribution in mice of 99mTcN–DBODC–DMSEt

“…Pioneering investigation on nitrido technetium(V) chemistry performed by Baldas and coworkers in the 1980s 1 has been sharply tuned into nuclear medicine applications with the synthesis of the neutral myocardial imaging agent [ 99m TcN-NOET]. 2 Another typical example about nitrido technetium(V) complexes are asymmetrical complexes in recent years.…”