Interaction of carbon dioxide with acetylene complexes of titanocene Cp 2Ti(RC 2R) (R Ph, SiMe 3). Synthesis and structure of binuclear σ-alkenylcarboxylate complexes of titanium (III) Cp 2TiC(R)C(R) COOTiCp 2 and unexpected transformation of these complexes into titanafuranone metallacycles under the action of air oxygen

Abstract

It has been shown that carbon dioxide reacts with acetylene complexes of titanocene Cp 2Ti(RC 2R) (RPh, SiMe 3) at room temperature and atmospheric pressure to form binuclear σ-alkenylcarboxylate complexes of trivalent titanium Cp 2TiC(R)C(R)COOTiCp 2 containing two fused chelate cycles and a tricoordinated oxygen atom. The interaction of these binuclear carboxylate complexes with air oxygen at 20°C results in rapid formation of titanafuranone metallacycles Cp 2 Ti(R)=C(R)C(O)O . X-ray diffraction studies of complexes Cp 2TiC(SiMe 3)C(SiMe 3)COOTiCp 2 and Cp 2 Ti(Ph)=C(Ph)C(O)O have been carried out.