TRANSITION-METAL DERIVATIVES OF A FUNCTIONALIZED CYCLOPENTADIENYL LIGAND .15. SYNTHESIS AND STRUCTURES OF AMINO CYCLOPENTADIENYL DERIVATIVES OF RHODIUM(I) AND RHODIUM(III) INCLUDING WATER-SOLUBLE COMPOUNDS

The synthesis of monometallic rhodium(III) and rhodium(I) derivatives of dialkylamino-functionalized cyclopentadienyl using the correspondin g cyclopentadiene as starting material is facilitated by the presence of the basic amino group. This procedure affords the chloro salts of t he substituted rhodicinium cation [(eta(5)-C5H4(CH2)(2)-NMe2H)(2)Rh-II I](3+) ([1][Cl](3)) from the reaction of the [2-(dimethylamino)ethyl]c yclopentadiene with (Na3RhCl6)-Cl-III . 12H(2)O. Similarly the cationi c half-sandwich complexes [(eta(5)-C5H4(CH2)(n)NMe2H)Rh-1(cod)](+) (n = 2, [2][Cl], n = 3, [5][Cl]) are obtained from the reaction of the co rresponding dialkylamino cyclopentadiene with [RhCl-(cod)](2). These t ypes of cationic complexes, 1, 2, and 5, bear pendant ammonium groups. The most classical procedure, starting from the lithium or more effic iently from the sodium cyclopentadienide salt, was used to synthesize neutral complexes [(eta(5)-C5H4(CH2)(n)NMe2)Rh-I(cod)] (n = 2, 3; n = 3, 4). The structure of the chloride bis(hexafluorophosphate) salt, 5) -C5H4(CH2)(2)NMe2H)(2)Rh-III](3+)(Cl-)(PF6-)(2), ([1][Cl][PF6](2)) was solved in the triclinic space group <P(1)over bar> with one molecule in the unit cell, the dimensions of which are a = 6.617(2) Angstrom, b = 7.436(2) Angstrom, c = 13.965(3) Angstrom, alpha = 76.39(2)degrees, beta = 82.31(3)degrees, gamma = 87.26(2)degrees, and V = 661.8(3) Ang strom(3). The noncentrosymmetric character of this solid is attributed to the chloride ion. The tetrafluoroborate salt [(eta(5)-C5H4(CH2)(2) NMe2H)Rh-I(cod)](+)(BF4-) ([2][BF4]) crystallizes in the tetragonal sp ace group P4(2)/n with eight molecules in the unit cell, the dimension s of which are a = 21.183(2) Angstrom, b = 21.179(3) Angstrom, c = 8.3 24(2) Angstrom, and V = 3734(1) Angstrom(3). Least squares refinement leads to values for the conventional R index of [1][Cl][PF6](2) (0.048 4 for 2191 reflections used) and of [2][BF4] (0.0525 for 1083 reflecti ons used); in both cases I > 3 sigma(I). As expected, compounds like [ 2][Cl](3), [1][Cl][PF6](2), [2][Cl], [2][BF4], [5][Cl], and [5][BF4] a re soluble in water.