METAL-CARBONYL SYNTHESES .21. STRAIGHTFORWARD SYNTHESIS OF A SYNTHETICALLY USEFUL ALKOXY(CARBONYL)METALLATE

Anionic methoxy complexes are formed upon carbonylation of ammonium perrhenate in methanol at 230 - 240-degrees-C. Thus, the dinuclear ionic complex [N(CH3)4][Re2(CO)6(mu-OCH3)3] (2) results in 80% yield at CO pressures of ca. 100 bar, while the trinuclear derivative [N(CH3)4][Re3(CO)9(mu-OCH3)3(mu-3-OCH3)] (3) is due to lower pressure conditions (ca. 50 bar); 2 yields the bis(carbene) complex 4 of formula fac-Re(CO)3L2I upon treatment with a bis(imidazolium) iodide, thus demonstrating that carbonylrhenium chemistry not necessarily depends on the availability of Re2(CO)10.