[{Cp*Cr(μ₃‐H)}₄]—a Paramagnetic Chromium Hydride with a Cubane Structure

For the exploration of the organometallic chemistry of divalent chromium, the readily synthesized CrII complex 1 is a simple starting material. The chloro bridges can be exchanged for alkyl groups (R = Me, nBu, CH2SiMe3), and the resulting complexes 2 react with H2 to give the tetranuclear hydrido complex 3 with a cubane structure. Unexpectedly, 3 shows almost ideal Curie paramagnetism according to magnetic measurements.