Technetium complexes carbonyls

Keywords Technetium Carbonyl complexes Technetium cyclopentadienyl Vitamin B12 Molecular imaging... 

Most of the substitution reactions with the homoleptic Tc(I) isocyanide complexes presented in the preceding section had to be performed at elevated temperatures and were often characterized by low yield. The reason for this behaviour is the exceptionally high kinetic and thermodynamic stability of this class of compounds. From this point of view, 4a are not very convenient or flexible starting materials, although they are prepared directly from 3a in quantitative yield. The exceptionally high kinetic and thermodynamic stability is mirrored by the fact that it was not possible to substitute more than two isocyanides under any conditions. On the other hand, oxidation to seven-coordinated Tc(III) complexes occurs very readily. Technetium compounds of this type, which are not expected to be very inert, could open up a wide variety of new compounds, but this particular field has not been investigated very thoroughly. A more convenient pathway to mixed isocyanide complexes that starts with carbonyl complexes of technetium will be described in Sects. 2.3 and 3.2. 

Waibel, R., R. Alberto, J. Willuda, R. Finnern, R. Schibli, A. Stichelberger, A. Egli, U. Abram, J.P. Mach, A. Pluckthun, and P.A. Schubiger, Stable one-step technetium-99m labeling of His-tagged recombinant proteins with a novel Tc (I)-carbonyl complex. Nat Biotechnol, 1999.17(9) 897-901. 

Binary metal carbonyl complexes, with technetium, 5, 835 Binary technetium isocyanides, preparation and properties,... 

Mixed metal carbonyl complexes sonochemical decomposition, 1, 310 with technetium, 5, 835... 

PA. Stable one-step technetium-99m labeling of His-tagged recombinant proteins with a novel Tc(I)-carbonyl complex. Nat. Biotechnol. 1999 17 897-901. 

Binuclear carbonyl complexes with M—M bond analogous to Mn2(CO)io have been prepared for technetium and rhenium. The rhenium analogue has been synthesized by the carbon monoxide reduction of Rc207 or KRe04 (eq (5)) [3] or by reduction of anhydrous Re(III) or Re(V) chloride by sodium under CO pressure (eq (6)). [15]. The physical and structural properties of Tc2(CO),o and Re2(CO)io are listed in Table 9.1. 

Metal carbonyl complexes of steroids have been synthesized by the groups of Jo-hannsen and Katzenellenbogen (Arterburn et al. 2003 Bigott et al. 2005 Luyt et al. 2003 Wust et al. 1998, 1999). Various 17j -progesterone and 7a-estradiole dithioether and cyclopentadiene complexes of technetium/rhenium(I) tricarbonyl have been pre-... 

The technetium carbonyl catalysts, [Tc2(CO)io]° and [Tc2(CO)io]°/P(n-C4H9)3 promote the hydroformylation reactions of cyclohexenc, propene, and 1-octene in solution at 235 °C and a pressure of 20 MPa. [Tc2(CO)io] VP(n-C4Hg)3 showed the best results in activity and selectivity within the anologous subgroup VII complexes studied, but proved to be a rather poor catalyst compared with the cobalt or rhodium carbonyl compounds [22]. 

Very recently technetium carbonyl triphenylphosphinc complexes containing 1.4-benzodiazepinc derivatives were synthesized by reaction of [Tc(CO)3Cl(PPh3)2] in refluxing CH2Cl2/EtOH with 7-chloro-5-(2-chlorophenyl)-l,3-dihydro-2H-l,4-bcnzo-diazepine-2-one-4-oxide (LH) and other derivative ligands. Pale yellow crystals of the... 

Reaction of [Tc(CO)3Br]4° with an excess of TI-IF produced the crystalline, probably dimeric compound [Tc(CO)3Br THF]2 . In acetonitrile the analogous complex [Tc(CO)3BrCH3CN]2° w as reported to bo formed [651]. The mass spectra of technetium carbonyl compounds were studied extensively [652]. 

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