title: Lability-controlled syntheses of heterometallic clusters.
abstract: A bulky bidentate ligand was used to stabilize a macrocyclic [Fe(III)8Co(II)6] cluster. Tuning the basicity of the ligand by derivatization with one or two methoxy groups led to the isolation of a homologous [Fe(III)8Co(II)6] species and a [Fe(III)6Fe(II)2Co(III)2Co(II)2] complex, respectively. Lowering the reaction temperatures allowed isolation of [Fe(III)6Fe(II)2Co(III)2Co(II)2] clusters with all three ligands. Temperature-dependent absorption data and corresponding experiments with iron/nickel systems indicated that the iron/cobalt self-assembly process was directed by the occurrence of solution-state electron-transfer-coupled spin transition (ETCST) and its influence on reaction intermediate lability.
authors.affiliation: Graduate School of Pure and Applied Sciences, University of Tsukuba, Tennodai 1-1-1, Tsukuba 305-8571 (Japan).
authors.forename: Graham N
authors.initials: GN
authors.lastname: Newton
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Mitsumoto
authors.forename: Rong-Jia
authors.initials: RJ
authors.lastname: Wei
authors.forename: Fumichika
authors.initials: F
authors.lastname: Iijima
authors.forename: Takuya
authors.initials: T
authors.lastname: Shiga
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nishikawa
authors.forename: Hiroki
authors.initials: H
authors.lastname: Oshio
keywords: ETCST; cyanide bridges; heterometallic complexes; mixed-valent compounds; self-assembly