title: Binuclear and trinuclear complexes of exoO(2)-cyclam.
abstract: Complexes of the ligand 2,3-dioxo-1,4,8,11-tetraaza-cyclotetradecane (exoO(2)-cyclam) have been prepared of formula [M(1){M(2)(exoO(2)-cyclam)}(2)][BPh(4)](2) where M(1)M(2) = CoCo (3), ZnZn (4), MnCu (5), FeCu (6), CoCu (7), NiCu (8), ZnCu (9), and [(bipy)(2)Ru{Cu(exoO(2)-cyclam)}][NO(3)](2) (10). Complex 10 crystallised in the space group C2/c and shows Jahn-Teller distorted Cu(II) with axial nitrate ligands. The {Cu(exoO(2)-cyclam)} moiety chelates to the Ru with Ru-O distances of 2.082(5) A. Complexes 5-10 show a Cu(II)/Cu(III) redox process and additional metal-centred (6, 8, 10) processes and ligand-centred (10) processes. The electrochemical and UV-Vis spectroelectrochemical study of suggested two closely-spaced oxidations based on the Cu and Ru centres which suggests that substituted derivatives of will be of interest for enhanced charge separation in dye-sensitised solar cells. Magnetic susceptibility measurements revealed dominant antiferromagnetic coupling within the trinuclear species 3, 5-8. Complex 10 showed Curie-Weiss behaviour with weak intermolecular interactions.
authors.affiliation: Department of Chemistry, Imperial College, London, UKSW7 2AZ.
authors.forename: Vivienne A
authors.initials: VA
authors.lastname: White
authors.forename: Russell D L
authors.initials: RD
authors.lastname: Johnstone
authors.forename: Keri L
authors.initials: KL
authors.lastname: McCall
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Long
authors.forename: Alexandra M Z
authors.initials: AM
authors.lastname: Slawin
authors.forename: Neil
authors.initials: N
authors.lastname: Robertson
mesh_terms: D003300:Copper / Q000737:chemistry; D018360:Crystallography, X-Ray; D004563:Electrochemistry; D006571:Heterocyclic Compounds / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D008024:Ligands; D008280:Magnetics; D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D012238:Rhodium / Q000737:chemistry
chemical_list: D006571:Heterocyclic Compounds; D008024:Ligands; D009942:Organometallic Compounds; C024560:cyclam; D003300:Copper; D012238:Rhodium