Dimensionally Controlled Assembly of an External Stimuli‐Responsive [Co2Fe2] Complex into Supramolecular Hydrogen‐Bonded Networks. Issue 22 (6th February 2017)

• Record Type: Journal Article
• Authors: Sekine, Yoshihiro; Nihei, Masayuki; Oshio, Hiroki
• Is Part Of: Chemistry. Volume 23:Issue 22(2017)
• Page Start: 5193
• Page End: 5197
• Publication Date: 2017-02-06
• Subjects: cobalt -- cyanides -- electron transfer -- hydrogen bonds -- iron; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201605817
• Languages: English
• ISSNs: 0947-6539

Abstract

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, [Co2 Fe2 (CN)6 (tp*)2 (bpy*)4 ] 2+ (abbreviated to1 2+ ) (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 of1 2+ with p ‐hydroquinone (H2 Q), a hydrogen‐bond donor (HBD) with two donor sites, led to a one‐dimensional aggregate, 1 (BPh4 )2 ⋅(H2 Q)⋅2 H2 O (2 ), while a two‐dimensional sheet with a honeycomb structure, 1 3 (PF6 )6 ⋅(H3 PG)2 ⋅4 CH3 CN⋅8 H2 O (3 ), was obtained by co‐crystallization with phloroglucinol (H3 PG) acting as a three‐way structure‐directing HBD. Magnetic measurements revealed that2 and3 exhibited thermal and light‐induced electron‐transfer‐coupled spin transitions (ETCSTs). Abstract : Stimuli‐responsive cyanide‐bridged [Co2 Fe2 ] tetranuclear complexes were assembled by the use of directional hydrogen bonding. Magnetic measurements revealed that complex2 and3 exhibited thermal‐ and light‐induced ETCST behavior (see scheme, ETCST= electron‐transfer‐coupled spin transition; HS/LS=high spin/low spin).