catena-poly[[[(2,2′-bipyridine-2κ2N,N′)-μ-cyanido-1:2κ2N:C-cyanido-2κC-tris(methanol-1κO)(nitrato-1κ2O,O′)iron(II)yttrium(III)]-di-μ-cyanido-1:2′κ2N:C;2:1′κ2C:N] methanol solvate hemihydrate]

The title complex, {[FeIIYIII(CN)4(NO3)(C10H8N2)(CH3OH)3]·CH3OH·0.5H2O}n, is built up of ladder-like chains oriented along the c axis. Each ladder consists of two strands based on alternating FeII and YIII ions connected by cyanide bridges. Two such parallel chains are connected by additional cyanide anions (the `rungs' of the ladder), which likewise connect FeII and YIII ions, such that each [Fe(bipy)(CN)4]2− (bipy is 2,2′-bipyridine) unit coordinates with three YIII ions and each YIII ion connects with three different [Fe(bipy)(CN)4]2− units. The FeII atom is six-coordinated in a distorted octahedral geometry and the YIII atom cation is eight-coordinated in a distorted dodecahedral environment. The uncoordinated methanol solvent molecules are involved in hydrogen-bonding interactions with the one terminal cyanide group and a coordinated methanol molecule from another [YIII(NO3)(CH3OH)3]2+ unit. Adjacent ladder-like chains are also held together by hydrogen bonds between the terminal cyanide ligands of the [Fe(CN)4(bipy)]2− units in one chain and the OH donors of CH3OH ligands from [YIII(NO3)(CH3OH)3] units in neighboring chains. The water molecule exhibits half-occupation.