Synthesis of [99TcX(CO)5] (X = Cl, Br, I) at ambient pressure

Na[Tc(CO)(CNp-F-ArDArF2)4]: an isocyanide analogue of the elusive Na[Tc(CO)5]

“…An additional problem results from the radioactivity of technetium, since the protocol for the preparation of [Tc 2 (CO) 10 ] under high CO pressure is not well compatible with current radiation protection regulations. 23 m -Terphenyl isocyanides (Fig. 1) revealed in numerous cases to be excellent surrogates for carbon monoxide, which allow the synthesis and structural characterization of several metal carbonyl analogues, which are otherwise intrinsically too unstable to be isolated.…”

Synthesis of [99Tc(CO)6]+ Cation under Ambient Conditions

“…To prepare technetium(I) hexacarbonyl, we chose [ 99 TcBr(CO) 5 ] as the starting compound, taking into account the fact that this higher carbonyl complex can be obtained at an ambient pressure. [9] The bromide ligand in the pentacarbonyl bromide is strongly bound with the technetium atom and cannot be directly substituted with carbon monoxide. To promote carbonylation, we replaced the bromide ligand with the readily leaving perchlorate group.…”

“…All the syntheses were performed at high CO pressures, [4][5][6][7][8] which does not comply with the modern safety requirements adopted in the majority of developed countries. Recently we reported the atmospheric-pressure synthesis of [ 99 TcHal(CO) 5 ], [9] which makes a wide range of higher technetium carbonyls synthetically accessible without using high CO pressures (subsequent transformations of [ 99 TcHal(CO) 5 ] into diverse tetra-and pentacarbonyl complexes are performed at ambient pressure [10][11][12][13] ). At the same time, preparation of the highest technetium carbonyl [ 99 Tc(CO) 6 ] + still required a high pressure of carbon monoxide.…”

Water-soluble carbonyl complexes of 99Tc(I) and Re(I) with adamantane-cage aminophosphines PTA and CAP

“…Concomitantly, the donor strength of the P atom decreases due to inductive effects, which, in turn, leads to an increase in the CO vibration frequencies (cf. frequencies of the corresponding bands in the spectra of technetium pentacarbonyl complexes with anionic ligands) [12,16]. At acid concentrations above 3 mol/mol, no further shift of the carbonyl band was observed.…”

“…K2 99 TcX6 (X = Cl and Br) were prepared by reduction of NH4 99 TcO4 with concentrated HX in the presence of excess KX [11]. [ 99 TcX(CO)5] (X = Cl and Br) can be prepared similarly to [ 99 TcI(CO)5], but these complexes can also be prepared at ambient pressure by carbonylation of K2 99 TcX6 with a mixture of formic and concentrated sulfuric acid at 175-180 °C for 1-2 h [12]; in this study, we used the latter procedure. [ReCl(CO)5] was prepared by high-pressure carbonylation of K2ReCl6 with a mixture of formic and hydrochloric acids at 210 °C for 4 h [10].…”