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