ORGANOMETALLIC MACROCYCLIC CHEMISTRY - SYNTHESIS OF CATIONIC HALF-SANDWICH IRIDIUM(I) COMPLEXES OF 1,4,7-TRITHIACYCLONONANE ([9]ANES3) - CRYSTAL-STRUCTURES OF [IR([9]ANES3)(C2H4)2]PF6, [IR([9]ANES3)(C8H12)]PF6AND [IR([9]ANES3)(C4H6)]PF6.0.5ET2O

Reaction of [Ir2L4Cl2] (L = C8H14 or 0.5C8H12) or [IrL4Cl] (L = C2H4 o r 0.5C4H6) with 1 molar equivalent of 1,4,7-trithiacyclononane ([9]ane S3) and NH4PF6 in acetone, tetrahydrofuran or CH2Cl2 under N2 at 293 K afforded the complexes [Ir([9]aneS3)L2]PF6. The single-crystal struct ures of [Ir([9]aneS3)(C2H4)2]PF6 and [Ir([9]aneS3)(C8H12)]PF6 have bee n determined and show that the complex cations adopt distorted five-co -ordinate geometries. For [Ir([9]aneS3)(C2H4)2]PF6, Ir-S(1) 2.317(2), Ir-S(4) 2.402(2), Ir-S(7) 2.384(2), Ir-C(11) 2.173(9), Ir-C(12) 2.194( 10), Ir-C(13) 2.146(8), Ir-C(14) 2.118(7), C(11)=C(12) 1.366(13) and C (13)=C(14) 1.443(11) angstrom. For [Ir([9]aneS3)(C8H12)]PF6, Ir-S(1) 2 .319(5), Ir-S(4) 2.343(4), Ir-S(7) 2.419(4), Ir-C(11) 2.166(14), Ir-C( 12) 2.199(14 Ir-C(15) 2.188(15), Ir-C(16) 2.141(15), C(11)=C(12) 1.411 (19) and C(15)=C(16) 1.418(21) angstrom. The single-crystal structure of [Ir([9]aneS3)(C4H6)]PF6.0.5Et2O shows this complex to have a five-c oordinate stereochemistry analogous to that adopted by [Fe(CO)3(C4H6)] with Ir-S(1) 2.321(2), Ir-S(4) 2.331(2), Ir-S(7) 2.325(2), Ir-C(11) 2 .149(9), Ir-C(12) 2.141(9), Ir-C(13) 2.146(9), Ir-C(14) 2.115(10), C(1 1)=C(12) 1.433(13), C(12)-C(13) 1.381(13) and C(13)=C(14) 1.461(14) an gstrom. Variable-temperature H-1 and C-13 NMR spectroscopic data on [M ([9]aneS3)(C2H4)2]+ and [M([9]aneS3)(C4H6)]+ (M = Rh or Ir) are consis tent with the highly electrophilic character of the cationic fragments [M([9]aneS3)]+. On the basis of J(C-H) coupling data and of an analys is of bond-length distributions and observed dihedral angles in the co mplex, the butadiene ligand in [Ir([9]aneS3)(C4H6)]+ is assigned as et a4 bonded but with a significant sigma2 component.