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Steps towards [(C5Me5)TcO3]: Novel synthesis of [(C5Me5)Tc(CO)3] from [{Tc(μ3−OH)(CO)3}4] and oxidation of [(C5Me5)M(CO)3] (M = Tc, Re) with Br2

Authors :
P. August Schubiger
Ulrich Abram
Thomas A. Kaden
A. Egli
Sonja Abram
Roger Alberto
Roger Schibli
Source :
Polyhedron. 17:1133-1140
Publication Year :
1998
Publisher :
Elsevier BV, 1998.

Abstract

[NEt4]2[Tc(Cl)3(CO)3] was prepared directly from [NBu4][TcO4]. Dissolution of [NEt4]2[Tc(Cl)3(CO)3] in water yielded the aqua ion [Tc(OH2)3(CO)3]+ which, upon titration with 1 eq. of OH−, gave the tetranuclear complex [{Tc(μ3-OH)(CO)3}4] in quantitative yield and of which the structure could be elucidated. Reaction of [{Tc(μ3−OH)(CO)3}4] with HC5Me5 gave the important starting material [(C5Me5)M(CO)3] (M = Tc, Re). To achieve complexes in higher oxidation states with the C5Me5− ligand, oxidation was performed with [Br2] for the rhenium and the corresponding technetium complex. Oxidation in trifluoroacetic acid yielded cis/trans-[(C5Me5)M(Br)2(CO)2] (M = Tc, Re). Oxidation in dichloromethane gave in both cases the seven co-ordinate, 18e− M(III) complex [(C5Me5)MBr(CO)3]+. The structure of the rhenium complex was elucidated. It was found that oxidation took place at the metal centre and the C5Me5− ring to yield [(CO)3M(μ−Br)3M(CO)3] as the counterion.

Details

ISSN :
02775387
Volume :
17
Database :
OpenAIRE
Journal :
Polyhedron
Accession number :
edsair.doi...........13e92187ee4bbfbdf21b937eb612b08c