Synthesis, Structure and Magnetism of Bis[1,2,4‐tris(trimethylsilyl)cyclopentadienyl]europium

Bis[tris(trimethylsilyl)cyclopentadienyl]europium, Eu{C 5 H 2 [Si(CH 3 ) 3 ] 3 } 2 (1) , has been synthesized by a modified transmetallation route between Tl{C 5 H 2 [Si(CH 3 ) 3 ] 3 } and europium powder in toluene. 1 crystallizes in the monoclinic space group C2/c (No. 15) with a = 20.293(5) Å, b = 20.221(5) Å, c = 9.654(2) Å, β = 106.412(5)°, V = 3800.1(15) Å 3 , Z = 4. The unit cell contains monomeric molecules that adopt a bent metallocene conformation with two partially staggered Cp‴ ligands. Magnetic susceptibility measurements in the temperature range 2–300 K display ideal Curie paramagnetic behaviour of the 4f 7 system with Curie constant C = 9.6 × 10 −5 m 3 K mol −1 corresponding to temperature independent μ eff = 7.8.