Metallorganische Synthesen mit freien Cyclopentadienyl-Radikalen, I. Zweikernige Carbonylnickel-Komplexe mit mehrfach alkylierten Cyclopentadienyl-Liganden Metalorganic Syntheses with Free Cyclopentadienyl Radicals, I. Dinuclear Carbonyl Nickel Complexes with Alkylated Cyclopentadienyl Ligands

Cyclopentadienyl nickel com plexes [(C 5 H 2rBu3 -l,2 ,4)N i(M -C O ) ] 2 (1) and [(C 5 H/Pr4 )N i(//-C O ) ] 2 (2) have been synthesized from nickel tetracarbonyl and the corre­ sponding lithium cyclopentadienide, and [(C 5 /Pr5 )N i(//-C O ) ] 2 (3) has been obtained in high yield from nickel tetracarbonyl and the free pentaisopropylcyclopentadienyl radical. The crystal structure o f 1 shows a com plex on a crystallographic mirror plane with a bent N i C N i C core whereas the crystal structure o f 2 exhibits two independent planar m ole­ cules possessing crystallographic inversion symmetry.