BIS(CYCLOPENTADIENYL)TECHNETIUM(III) CHLORIDE AND TRIS(CYCLOPENTADIENYL)TECHNETIUM(III), NEW ORGANOMETALLIC COMPOUNDS OF TRIVALENT TECHNETIUM

Technetium tetrachloride reacts with potassium cyclopentadienide in tetrahydrofuran to give the diamagnetic, air-stable (C5H5)2TcCl (1). Single crystal X-ray diffraction analysis shows a short ring-metal distance of 187.7(5) pm, which is comparable with the corresponding distance in nickelocene, indicating high covalency. Reaction of the compound with KC5H5 gives the red (C5H5)3Tc (4), in which one cyclopentadienyl ring is σ-bonded. Mass spectroscopic investigations of the latter compound give evidence for the existence of (C5H5)4Tc. The reactivity of (C5H5)2TcCl is discussed. © 1990.