A novel cyano-bridged bimetallic assembly [CuL 4] 3[Fe(CN) 6] 2·2H 2O (1) (L 4 = 3,10-dibutyl-1,3,5,8,10,12-hexaazacyclotetradecane), which was prepared by self-assembly of [Fe(CN) 6] 3− and [CuL 4] 2+, has been characterized by elemental analyses, ICP, IR, single crystal X-ray structure analysis and magnetic measurements. The structure of complex 1 consists of two distinct neutral moieties: one is a two-dimensional (2-D) polymeric layer and the other is a pentanuclear Cu 3Fe 2 short chain, which are supramolecular isomers and result from two different coordination modes of [Fe(CN) 6] 3− via the Fe-C N Cu linkages. Magnetic studies reveal the presence of a weak antiferromagnetic interactions between the adjacent copper(II) and iron(III) ions through cyano bridges.