X-RAY STRUCTURES OF DECAMETHYLPLATINOCENE DICATION IN THE CRYSTAL OF [PT(ETA(5)-C5ME5)(2)](2-)(2) AND DECAMETHYLIRIDOCENIUM CATION IN THE CRYSTAL OF TA(5)-C5ME5)(2)](+)(BPH4-)CENTER-DOT-CH2CL2()(PF6)

The molecular crystal structures of the [Ir(eta(5)-C5Me5)(2)](+) catio n in the complex of [Ir(eta(5)-C5Me5)(2)](+)(BPh4)(-). CH2Cl2 (1), (sp ace group <P(1)over bar>, Z = 2), and dication [Pt(eta(5)-C5Me5)](2+) in the complex of [Pt(eta(5)-C5Me5)(2)](2+)(PF6)(2)(-) (2), (space gro up <I(4)over bar 2d>, Z = 8) were proved by an X-ray investigation at 153 K (R = 0.0661 and 0.0528 for 1 and 2 respectively). X-ray analysis revealed that in both structures the cations and anions are ordered, cation [Ir(eta(5)-C5Me5)(2)](+) has the staggered conformation, wherea s the dication [Pt(eta(5)-C5Me5)](2+) has the ideal eclipsed one. The distances from the metal to the C5Me5 ring in 1 (1.817(6)Angstrom and 1.821(6)Angstrom) are close to those in the neutral complex Os(eta(5)- C5Me5)(2) (3) (1.810(7)Angstrom). The similar distance in the dication [Pt(eta(5)-C5Me5)(2)](2+) in 2 (1.84(1)Angstrom)is slightly elongated in comparison with 1 and 3. (C) 1997 Elsevier Science S.A.