title: Transition Metal Derivatives of a ((Dimethylamino)ethyl)cyclopentadienyl Ligand. Synthesis and Structures of Amino-Containing Cyclopentadienyl Derivatives of Cobalt(I) and -(III) Including Water-Soluble Compounds.
abstract: The synthesis of monometallic cobalt(III) and -(I) complexes of ((dimethylamino)ethyl)cyclopentadienyl are reported. The presence of the basic amino group facilitates these synthesis using the corresponding cyclopentadiene complexes as starting material. A cobaltocenium green complex [{eta(5)-C(5)H(4)(CH(2))(2)N(H)Me(2)}(2)Co(III)](3+)(Cl(-))(3) (3) was obtained from C(5)H(5)(CH(2))(2)NMe(2) (1) or from its salt M[C(5)H(4)(CH(2))(2)NMe(2)] (M = Na, Li) (2) upon reaction with Co(II)Cl(2) in THF. The structure of the complex [{(eta(5)-C(5)H(4)(CH(2))(2)NMe(2))(eta(5)-C(5)H(4)(CH(2))(2)N(H)Me(2))}Co(I)(II)](PF(6))(2) (4), prepared from 3 by treatment with NH(4)PF(6) in aqueous solutions, was solved in the triclinic space group P&onemacr; with one molecule in the unit cell, the dimensions of which were a = 6.314(2) Å, b = 7.137(2) Å, c = 13.452(2) Å, alpha = 103.66(2) degrees, beta = 90.25(2) degrees, gamma = 92.89(2) degrees, and V = 588.2(3) Å(3). Adjacent molecules in the unit cell of 4 are hydrogen bonded via a H(+) through their -NMe(2) side chains. The reaction of Co(2)(CO)(8) with C(5)H(5)(CH(2))(2)NMe(2) (1) leads to the formation of [{eta(5)-C(5)H(4)(CH(2))(2)NMe(2)}Co(I)(CO)(2)] (5). Treatment of 5 with HBF(4) in ether solutions yielded [{eta(5)-C(5)H(4)(CH(2))(2)N(H)Me(2)}Co(I)(CO)(2)](+)BF(4)(-) (6). Oxidation of 5 with I(2) or Cl(2) gas yielded [{eta(5)-C(5)H(4)(CH(2))(2)NMe(2)}Co(III)I(2)] (7a) and [{eta(5)-C(5)H(4)(CH(2))(2)NMe(2)}Co(III)Cl(2)] (7b). Addition of HBF(4) to complex 7a resulted in the breaking of the Co(III)-NMe(2) bond, producing the dimeric complex [{(eta(5)-C(5)H(4)(CH(2))(2)N(H)Me(2))Co(III)I(2)}(2)](2+)(BF(4)(-))(2) (9). The bridged diiodo dimer 10, [{(eta(5)-C(5)H(4)(CH(2))(2)NMe(2))CoI}(2)](2+)(BF(4)(-))(2), on the other hand, could be obtained from complex 7a upon addition of AgBF(4) in CH(2)Cl(2).
authors.affiliation: Laboratory of Inorganic and General Chemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece, Chemistry Department, University of Southern California, Los Angeles, California 90089, and Laboratoire de Chimie de Coordination du CNRS, Unité No. 8241 liée par convention à l'Université Paul Sabatier et à l'Institut National Polytechnique, 205 Route de Narbonne, 31077 Toulouse Cedex, France.
authors.forename: A. I.
authors.initials: AI
authors.lastname: Philippopoulos
authors.forename: R.
authors.initials: R
authors.lastname: Bau
authors.forename: R.
authors.initials: R
authors.lastname: Poilblanc
authors.forename: N.
authors.initials: N
authors.lastname: Hadjiliadis