MULTIPLE BONDS BETWEEN MAIN GROUP ELEMENTS AND TRANSITION-METALS .93. METHYLRHENIUM AND ETHYLRHENIUM OXIDES - PREPARATION AND STRUCTURAL CHEMISTRY

The dinuclear methylrhenium oxides (CH3)4Re2O4 (3a) and (CH3)6Re2O3 (4) are conveniently synthesized by means of organozinc, -titanium, and -aluminium reagents from the simple precursor compounds Re2O7, CH3ReO3, and (CH3)3SiOReO3. The two diamagnetic d1-d1 systems (Re(VI)) can be oxidized by means of amine oxides: the novel Re(VII)-complex (CH3)4Re2O5 as the pyridine adduct 5 thus results from 3a and pyridine N-oxide and has been characterized by an X-ray diffraction study. By way of contrast, the dinuclear structure is split upon treatment of 4 with trimethylamine oxide, with (CH3)3ReO2 (6) thus being formed. The novel ethyl derivative (C2H5)4Re2O4 (3b), prepared from Re2O7 and diethylzink, has been characterized structurally (X-ray diffraction).