Bimetallic assemblies, [Ni(en)(2)](3)[M(CN)(6)](2)center dot 3H(2)O (en = H2NCH2CH2NH2; M = Fe, Co)

The reaction between tris(ethylenediamine)nickel(II) cations and hexacyanom etallate(III) anions (M = Fe, Co) yields ordered bimetallic assemblies, cat ena-poly[[tris(ethylenediamine)nickel-bis(mu-hexacyanoiron-N,N')] trihydrat e] and catena-poly[[tris(ethylenediamine)nickel-bis(mu-hexacyano-cobalt-N,N ')] trihydrate], [{Ni(C2H8N2)(2)}(3){M(CN)(6)}(2)]. 3H(2)O, in which both c is and trans [Ni(en)(2)] and [M(CN)(6)] moieties are linked to give S-shape d Ni-NC-M-CN-Ni-NC-M-CN-Ni units which are crosslinked to give ribbons para llel to the b axis. The two compounds are isomorphous with mean metal-ligan d distances Fe-C = 1.940 (3), Co-C = 1.844 (3) and Ni-N = 2.102 (2) Angstro m for the iron, and 2.105 (3) Angstrom for the cobalt compound. These compo unds appear to be identical with those formulated as [Ni(en)(2)](3)[M(CN)(6 )](2). 2H(2)O [Ohba, Maruona, Okawa, Enoki & Latour (1994). J. Am. Chem. So c. 116, 11566-11567; Ohba, Fukita & Okawa (1997). J. Chem. Soc. Dalton Tran s. pp. 1733-1737] which were indexed on a smaller unit cell and described a s disordered.