NICKEL THIOETHER CHEMISTRY - SYNTHESES OF NICKEL(II) COMPLEXES OF TETRA-THIA AND PENTA-THIA MACROCYCLIC LIGANDS - THE SINGLE-CRYSTAL STRUCTURES OF [NI([16]ANES4)(OH2)2][BF4]2 AND [NI([15]ANES5)][PF6]2 ([16]ANES4 = 1,5,9,13-TETRATHIACYCLOHEXADECANE, [15]ANES5 = 1,4,7,10,13-PENTATHIACYCLOPENTADECANE)

Treatment of [Ni(OH2)6][BF4]2 with 1 molar equivalent of [1 2]aneS4 ([12]aneS4 = 1,4,7,10-tetrathiacyclododecane) or [16]aneS4 ([16]aneS4 = 1,5,9,13-tetrathiacyclohexadecane) in MeNO2 in the presence of acetic anhydride for 30 min affords blue solutions from which the complexes [Ni([12]aneS4)(OH2)2]2+ and [Ni([16]aneS4)(OH2)2]2+ can be isolated. The complex [Ni([16]aneS4)-(OH2)2][BF4]2 crystallises in the triclinic space group P1BAR, with the octahedral nickel atom lying on a crystallographic centre of symmetry, the aqua ligands mutually trans, Ni-S 2.4290(10), 2.4231 (10), Ni-O 2.083(3) angstrom, and the macrocycle co-ordinated in the equatorial plane. Treatment of [Ni(OH2)6]-[BF4]2 or [Ni(OH2)6][PF6]2 with [15]aneS5 in MeNO2 in the presence of acetic anhydride affords purple solutions of the complex [Ni([15]aneS5)]2+. A single-crystal structure determination on [Ni([15]aneS5)]-[PF6]2, which crystallises in the monoclinic space group P2(1), shows the cation to adopt a square-pyramidal geometry, Ni-S(apical) 2.413(5), Ni-S(basal) 2.146(7), 2.169(6), 2.177(6), 2.198(6) angstrom. The complex cation [Ni([15]aneS5)]2+ forms six-co-ordinate adducts with MeCN, pyridine and chloride.