85129-39-1Relevant academic research and scientific papers
Cyclization of Tetra-L-alanine Induced by Complexation of Technetium
Bormans,Peeters,Vanbilloen,Blaton,Verbruggen
, p. 6240 - 6244 (1996)
Complexation of technetium with tetraalanine yields an unstable complex that converts to a monooxotechnetium(V) complex of cyclic tetraalanine. The structure of the latter was determined by single-crystal X-ray analysis. In this negatively charged complex, the technetium atom is coordinated to one oxygen and four amide nitrogen atoms. The more polar complex that is initially formed is assumed to be an oxotechnetium(V) complex of tetraalanine, with the oxotechnetium moiety coordinated to three amide nitrogen atoms and the amine nitrogen atom. In this complex, the carboxyl group would be forced in the vicinity of the free amine group, thereby facilitating amide formation and cyclization. Cyclization of tetra-L-alanine occurs on both no carrier added (technetium-99m) and carrier added (technetium-99) scale.
The Crystal Structure of Tetraphenylarsonium Tetrachlorooxotechnetate(V)
Baldas, John,Colmanet, Silvano F.
, p. 1155 - 1160 (2007/10/02)
The crystal structure of (1) has been determined by X-ray diffraction.Crystals are tetragonal, space group P4/n, a 12.664(1), c 7.822(1) Angstroem, Z = 2.Refinement based on 912 data measured with CuKα radiation converged with R 0.059.The structure consists of discrete + cations and - anions with the technetium atom in a square-pyramidal environment.In contrast to an earlier structural determination of the - anion in , the - anion in (1) possesses ideal C4ν symmetry.The Tc=O bond length is 1.593(8) Angstroem with Tc-Cl 2.309(2) Angstroem.
