catena-poly[[[(2,2′-bipyridine-2κ2 N,N′)-μ-cyanido-1:2κ2 N:C-cyanido-2κC-tris­(methanol-1κO)(nitrato-1κ2 O,O′)iron(II)yttrium(III)]-di-μ-cyanido-1:2′κ2 N:C;2:1′κ2 C:N] methanol solvate hemihydrate]

The title complex, {[Fe(II)Y(III)(CN)(4)(NO(3))(C(10)H(8)N(2))(CH(3)OH)(3)]·CH(3)OH·0.5H(2)O}(n), is built up of ladder-like chains oriented along the c axis. Each ladder consists of two strands based on alternating Fe(II) and Y(III) ions connected by cyanide bridges. Two such parallel chains are connected by additional cyanide anions (the 'rungs' of the ladder), which likewise connect Fe(II) and Y(III) ions, such that each [Fe(bipy)(CN)(4)](2-) (bipy is 2,2'-bipyridine) unit coordinates with three Y(III) ions and each Y(III) ion connects with three different [Fe(bipy)(CN)(4)](2-) units. The Fe(II) atom is six-coordinated in a distorted octa-hedral geometry and the Y(III) atom cation is eight-coordinated in a distorted dodeca-hedral environment. The uncoordinated methanol solvent mol-ecules are involved in hydrogen-bonding inter-actions with the one terminal cyanide group and a coordinated methanol mol-ecule from another [Y(III)(NO(3))(CH(3)OH)(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 CH(3)OH ligands from [Y(III)(NO(3))(CH(3)OH)(3)] units in neighboring chains. The water molecule exhibits half-occupation.