title: Dimensionally Controlled Assembly of an External Stimuli-Responsive [Co2Fe2] Complex into Supramolecular Hydrogen-Bonded Networks.
abstract: A stimuli-responsive tetranuclear complex was assembled into new aggregates with controllable dimensionality through directional hydrogen bonds (HBs). A cyanide-bridged tetranuclear complex cation, [Co2Fe2(CN)6(tp*)2(bpy*)4]2+(abbreviated to 12+) (tp*=hydrotris(3,5-dimethylpyrazol-1-yl)borate and bpy*=4,4'-di-methyl-2,2'-bipyridine) has two terminal cyanide nitrogens and acts as a hydrogen-bond acceptor (HBA) with a linear bridging mode. Co-crystallization of 12+with p-hydroquinone (H2Q), a hydrogen-bond donor (HBD) with two donor sites, led to a one-dimensional aggregate, 1(BPh4)2⋅(H2Q)⋅2 H2O (2), while a two-dimensional sheet with a honeycomb structure, 13(PF6)6⋅(H3PG)2⋅4 CH3CN⋅8 H2O (3), was obtained by co-crystallization with phloroglucinol (H3PG) acting as a three-way structure-directing HBD. Magnetic measurements revealed that 2 and 3 exhibited thermal and light-induced electron-transfer-coupled spin transitions (ETCSTs).
authors.affiliation: Graduate School of Pure and Applied Sciences, University of Tsukuba, Tennodai 1-1-1, Tsukuba, 305-8571, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Sekine
authors.affiliation: Graduate School of Pure and Applied Sciences, University of Tsukuba, Tennodai 1-1-1, Tsukuba, 305-8571, Japan.|JST, PRESTO, Honcho 4-1-8, Kawaguchi, Saitama, 332-0012, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Nihei
authors.affiliation: Graduate School of Pure and Applied Sciences, University of Tsukuba, Tennodai 1-1-1, Tsukuba, 305-8571, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Oshio
keywords: cobalt; cyanides; electron transfer; hydrogen bonds; iron