Potential metal organic-framework precursors, Zn4O complexes with various alicyclic or aromatic carboxylate ligands, were prepared, in many cases quantitatively, from ZnO and the relevant carboxylic acids in the presence of trace amounts of water. The complexes obtained were characterized with various classical (titration) and instrumental (IR and NMR spectroscopies) methods and molecular modeling (PM3 and PM6 semiempirical quantum chemical methods and HF/6-31G** ab initio calculations). Structural peculiarities reflected in the success or failure in the synthesis could be rationalized with the combination of IR and NMR spectroscopies and molecular modeling.