The work deals with the design, molecular structure and magnetic properties of new polymetallic complexes with imidazolate and carboxylate bridge ligands. The aim of this interdisciplinary study is: i) to know the factors that govern the magnetic interaction between metal centers through bridge ligands, ii) to prepare new molecular materials, with magnetic properties or combination of magneto-optical, magneto-electric properties, etc., with potential applications in the field of molecular electronics. Synthesizing a variety of homo and heteronuclear complexes with Imidazolate and Carboxylate bridge ligands, we have enriched the research library in this field by realizing correlations between the structure and the magnetic property of the complexes: trinuclear isostructural Cis and Trans, homopolynuclear chains and a tetranuclear complex