Synthesis Of Technetium Research Articles

Direct Synthesis of Non-Alkyl Functionalized Bis-Arene Complexes of Rhenium and 99(m)Technetium

The synthesis of technetium and rhenium bis-arene sandwich complexes, [M(η6-C6H6)2]+, requires AlCl3 according to Fischer–Hafner conditions. Its high reactivity limits syntheses to alkylated aromatic hydrocarbons but is generally incompatible with aromatic hydrocarbons, bearing heteroatoms in their side chains “R”. In a nuclear medical context, a synthesis to complexes of the [M(η6-C6H5-R)2]+ type directly from [ReO4]− or [99mTcO4]− is desirable because postsynthetic derivatizations are not possible for 99mTc. Here, we present direct syntheses to [M(η6-C6H5-R)2]+, starting from [ReO4]− or [99(m)TcO4]− with “C6H5-R” representing differently substituted anilines such as N-methylaniline, N,N-dimethylaniline, diphenylaniline (triphenylamine), and phenylpiperidine. Depending on the reaction conditions, mixed-ring sandwich complexes of the [Re(η6-arene)(η6-C6H6)]+ type are obtained with diphenylaniline and triphenylmethane. The X-ray crystal structures of the complexes are presented together with their photophy...

Design and Synthesis of Functionalized Cyclopentadienyl Tricarbonylmetal Complexes for Technetium-94m PET Imaging of Estrogen Receptors

Cyclopentadienyl tricarbonylmetal (CpTM, M = Re, (94m)Tc) complexes, some based on a typical nonsteroidal estrogen, were prepared with the aim of developing technetium- and rhenium-labeled imaging agents for estrogen receptor (ER) positive breast tumors. CpT[(94m)Tc] compounds with simple cyclopentadienyl substituents were first synthesized using a modified double ligand transfer reaction. The in vivo biodistribution of one of these CpT[(94m)Tc] complexes was determined by tissue dissection and microPET imaging. Novel C-ring substituted analogues of cyclofenil, a nonsteroidal compound known to bind the ER, were also prepared, and their ER binding was measured. Because of their low ER affinity, however, labeling and imaging studies of these compounds were not pursued. It is notable that the highest ER binding analogue, a CpTRe cyclofenil derivative, could be synthesized from the corresponding ferrocenyl cyclofenil analogue by the double ligand transfer reaction. This further demonstrates the versatility of the double ligand transfer reaction and indicates that the synthesis of technetium and rhenium radiolabeled agents for breast tumor imaging and therapy is also likely to be successful.

ChemInform Abstract: Synthesis of Technetium(V) Complexes Containing Sterically Bulky Thiolate Ligands. Molecular Structure of Tetrabutylammonium Oxotetrakis(2,4,6‐trimethylbenzenethiolato)technetate(V).

AbstractThe square‐pyramidal oxotetrakis(arenethiolato)technetate(V) complexes (III) are prepared according to the scheme.

The synthesis of technetium(V) complexes containing sterically bulky thiolate ligands. The molecular structure of tetrabutylammonium oxotetrakis(2,4,6-trimethylbenzenethiolato)technetate(V)

The reactions between [TcOCl 4] − and the sterically bulky thiols ArSH (Ar = 2,4,6-Me 3C 6H 2, 2,4,6- Pr i 3C 6H 2 and 2,6-Ph 2C 6H 3) in methanol afford complexes of formula [TcO(SAr) 4] − which may be isolated as salts with bulky organic cations. The molecular structure of [Bu n 4N][TcO(2,4,6-Me 3C 6H 2S) 4] was determined by X-ray diffraction methods. The Tc(V) centre was found to adopt the expected square pyramidal geometry in which an oxo group occupies the apical site and the four thiolate sulphurs the basal sites. The TcO distance is 1.659(11) Å and the average TcS distance 2.38(2) Å. The average cis STcS, trans STcS and OTcS angles are respectively 82.7(6)°, 138.4(3)° and 110.8(4)°.

Synthesis of Technetium and Rhenium Phthalocyanines by Recoil Implantation

Synthesis of Technetium and Rhenium Phthalocyanines by Recoil Implantation