A simple single-step synthesis of [⁹⁹Tc₃H₃(CO)₁₂] from [⁹⁹TcO₄]^–and its X-ray crystal structure. Application to the production of no-carrier added [¹⁸⁸Re₃H₃(CO)₁₂]

Abstract

Reduction of no-carrier added [188Re04]-(ng range) in thf-[NBu4]C1 with BH3.thf under an atmosphere of CO yields [ 188ReC13(CO)3]2-and [ 188Re3(p-H)3(CO)12]; under similar conditions as with [188Re04]-, the first p-hydrido-bridged 99Tc hydrido carbonyl complex is prepared and structurally characterised.We have recently reported a simple one-pot synthesis of the useful MI precursor complexes [NEt4]2[MC13(C0)3] (M = Tc la, Re lb) starting directly from [NBu4][MO4] under ambient conditions. 1 Dissolution of 1 in water yields the corresponding air-stable 'aqua ion' [M(OH2)3(CO)3]+ (M = 99Tc 2a, Re 2b, 188Re 2c).2 Technetium-99m carbonyl complexes of appropriately derivatized ligands may find applications in nuclear medicine, as recently demonstrated by the imaging of brain receptors using a technetium(v) complex.3 2c can be used as a direct radiolabelling agent for proteins and applied in radioimmunotherapy.4 The synthetic conditions for the preparation of l a or lb, as depicted in Scheme 1, are almost identical. We found that the main product is [M2(p-C1)3(CO)& which can, by addition of [NEt4]C1, be quantitatively converted into l a and lb. However, adaptation of the synthetic conditions to trace amounts of [188Re04]-(37 MBq = 1 ng) revealed at least two products, as evidenced by TLC [Rf = 0.39 corresponds to 2a with one unknown species at R f = 0.69). The amount of the unknown species increased with the amount of BH3.thf. Consequently, the reduction of [Tc04]-was performed exclusively in the presence of BH3.thf, 1 atm of CO in thf and at room temperature. TLC experiments confirmed the compound

Nε Functionalization of Metal and Organic Protected L‐Histidine for a Highly Efficient, Direct Labeling of Biomolecules with [Tc(OH2)3(CO)3]+

“…To , [34] full deprotection is required. In case of 8 a which contains benzyloxycarbamate (Cbz) as a protecting group, a two-step procedure was employed to produce 9 (Scheme 3).…”

Synthesis of Cyclopentadienyltricarbonyl Rhenium Phenyltropanes by Double Ligand Transfer: Organometallic Ligands for the Dopamine Transporter

“…However, until recently, the synthesis of these organometallic species has required harsh conditions and multistep procedures. Recent reports describing the preparation and use of low valent (i.e., Met(CO) 3 + ) technetium and rhenium are encouraging (14)(15)(16)(17)(18).…”

Edge‐Bridging and Face‐Bridging Hydrogen Atoms in Trinuclear Rhenium Carbonyl Hydrides

“…Repetition of this process by removing the unique bridging carbonyl group converts 10-1S to the lowest energy H 3 Re 3 (CO) 9 structure 9-1S. Even though an edge-bridging hydrogen atom remains on 9-1S, this process cannot be continued one step further to give an H 3 Re 3 (CO) 8 structure, since in 9-1S the two possible face-bridging hydrogen positions of the central Re 3 triangle are fully occupied in forming the Re 3 (μ 3 -H) 2 trigonal bipyramid of 9-1S. The lowest energy H 3 Re 3 (CO) n (n = 10, 9) structures 10-1S and 9-1S are similar to the lowest energy structures predicted [18] for the manganese analogues H 3 Mn 3 (CO) n .…”

“…In this way, all three metal atoms in the three isoelectronic species H 3 Re 3 (CO) 11 (11-3S), H 3 Re 2 (CO) 10 2-, and H 2 Os 3 (CO) 10 can be considered as having the favored 18-electron configuration. An H 3 Mn 3 (CO) 11 structure analogous to the H 3 Re 3 (CO) 11 structure 11-3S was previously found [8] at between 9 and 15 kcal/mol above the global minimum depending on the theoretical method used. Figure 7.…”

“…[7] Eventually the tech-netium derivative H 3 Tc 3 (CO) 12 was synthesized by an improved method and characterized structurally. [8] In addition, the manganese analogue H 3 Mn 3 (CO) 12 was synthesized by Johnson and Lewis by the reaction of Mn 2 (CO) 10 with a base followed by acidification. [9,10] The trinuclear metal carbonyl hydrides H 3 M 3 (CO) 12 (M = Mn, Tc, Re) form a series of stable compounds that are isoelectronic with the homoleptic trinuclear metal carbonyls MЈ 3 (CO) 12 (M = Fe, Ru, Os), all of which are also stable compounds.…”