Self‐Assembly from Discrete Clusters to 2D Network Based on [Fe(phen)(CN) 4 ] – and [Fe(bipy)(CN) 4 ] – : Synthesis, Structures and Magnetic Properties

A series of cyanido‐bridged complexes {[Fe III (phen) (CN) 4 ] 2 [NiL 1 ]} · 4H 2 O ( 1 ), {[Fe III (bipy)(CN) 4 ] 2 [NiL 1 ]} · 4H 2 O ( 2 ), [Fe III (bipy)(CN) 4 ] 2 [NiL 2 ] ( 3 ), {[Fe III (phen)(CN) 4 ] 2 [CuL 3 ]} · 5H 2 O ( 4 ), {[Fe II (phen)(CN) 4 ][Ni(ea) 2 ]} 2 · 2H 2 O ( 5 ), {[Fe II (phen)(CN) 4 ] [NiL 2 ] · 2H 2 O} n ( 6 ), {[Fe III (bipy)(CN) 4 ] 2 [Ni(H 2 O) 2 ]} · 6.5H 2 O} n ( 7 ) and {[Fe II (bipy)(CN) 4 ][Ni(ea) 2 ] · H 2 O} n ( 8 ) were synthesized using H[Fe(phen)(CN) 4 ] · 2H 2 O and H[Fe(bipy)(CN) 4 ] · 2H 2 O as precursors [L 1 = 5,5,7,12,12,14‐hexamethyl‐1,4,8,11‐tetraazacyclotetradecane, L 2 = 3,10‐bis(2‐phenylethyl)‐1,3,5,8, 10,12‐hexaazacyclotetradecane, L 3 = 3,10‐bis(2‐hydroxyethyl)‐1,3,5,8,10,12‐hexaazacyclotetradecane, phen = 1,10‐phenanthroline, bipy = 2,2′‐bipyridine, ea = ethanolamine). Complexes 1 – 4 are trinuclear clusters, and 5 is a tetranuclear square. In 6 , the [Fe II (phen)(CN) 4 ] 2– anions alternately bridge the [NiL 2 ] 2+ cations to generate a 1D wavy chain. The structure of 7 possesses a 4,2‐ribbonlike chain, which contains a Ni II 2 (CN) 4 Fe III 2 square with each Ni II atom shared by two adjacent squares. Each Fe II and Ni II atom in 8 acts as a three‐connected node through the cyanido‐bridges to generate a 2D network with a 4,8 2 topological net. Ferromagnetic couplings are found between the low‐spin Fe III ions and the Ni II ions through the cyanido groups in 1 – 3 and 7 , and a metamagnetic behavior and a frequency dependence of the out‐of‐phase ac susceptibility are observed in 7 . (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)