2 TYPES OF INTRAMOLECULAR LEWIS BASE ADDUCTS WITH THE [2-(DIMETHYLAMINO)ETHYL] CYCLOPENTADIELLYL LIGAND - SYNTHESIS AND CRYSTAL-STRUCTURES OF (ETA(5)ETA(1)-C5H4[(CH2)(2)NME(2)])NI-I AND (ETA(5)-MU-C5H4[(CH2)(2)NME(2)])(ME(3)P)NI-INI2

The synthesis and reactivity of nickel complexes with the [2-(dimethyl amino)ethyl]cyclopentadienyl ligand (Cp(N)) are described. The reactio n of NiBr2 with Cp(N)Li leads to the new paramagnetic nickelocene deri vative (Cp(N))(2)Ni (1), which has been characterized by H-1 and C-13 NMR, elemental analysis,and mass spectroscopy. Synproportionation of t his complex with Ni(CO)(4) affords quantitatively the dimeric nickel c omplex [Cp(N)(CO)Ni](2) (2). Reductive cleavage of 2 with KC8 and trap ping of the anionic intermediate with Me(3)SnCl gives the stannyl-nick el complex Cp(N)(CO)Ni-SnMe(3) (4). Reaction of 2 with Ga2Cl4 yields t he gallium-nickel complex (eta(5)-mu-Cp(N))(CO)Ni-GaCl2 (7) with intra molecular coordination of the dimethylamino group to the gallium cente r. Oxidative cleavage of 2 with iodine and liberation of CO leads to t he intramolecular chelate (eta(5):eta(1)-Cp(N))Ni-I (3). The compounds (eta(5)-mu-Cp(N))(PR(3))Ni-InI2 with R = C6H5 (5) and CH3 (6) are obt ained in good yields by insertion of low-valent indium halides InX (X = Br, I) into the Ni-I bond of 3. X-ray diffraction determinations wer e carried out for 3 and 6, and for 6, a comparably short Ni-In distanc e of 241.80(7) pm was found.