The preparation of additional and useful building blocks for the construction of supramolecular entities with quadruply bonded Mo-2(4+) units has been explored, and five new mixed-ligand complexes with three types of ligands and various basicities are reported. The ligands used were the DAniF (N,N'-di-p-anisylformamidinate) anion, the acetate anion, and neutral acetonitrile molecules. The formamidinate ligands are the least labile, and the acetonitrile molecules are the most labile. This difference as well as a relatively strong trans directing influence by the formamidinate anions in ligand substitution reactions allows designed synthesis of various mixed-ligand building blocks, including rare pairs of cis and trans isomers. The new compounds are cis-Mo-2(DAniF)(2)(O2CCH3)(2) (1), trans-Mo-2(DAniF)(2)-(O2CCH3)(2) (2), trans-[Mo-2(DAniF)(2)(O2CCH3)(CH3CNeq)(2)]BF4 (3), trans-[Mo-2(DAniF)(2)(CH3CNeq)(4)] (BF4)(2) (4), and [Mo-2(O2CH3)(CH3CNeq)(6)(CH3CNax)](BF4)(3) (5), where eq and ax designate equatorial and axial ligands, respectively. A comparison with some previously synthesized complexes is given along with a discussion of the overall reactivity of all compounds.