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).
