We obtained β-diketone – ferrocenoylacetone by Kleisen condensation. Hydrazones of monocarboxylic acids (H2L) were synthesized by the interaction of hydrazides of carboxylic acids with ferrocenoylacetone. On their basis, complexes with transition metals were obtained. The synthesized compounds were studied by spectroscopic methods. The research results showed that H2L in solution exists in the form of a tautomeric mixture: hydrazine, enhydrazine and cyclic 5- hydroxypy-razoline forms. According to the results of spectroscopic studies, the complexes were assigned a planar-square structure and in them the doubly deprotonated ligand residue is coordinated by a metal atom through two oxygen atoms and a nitrogen atom of the hydrazone fragment. The fourth place in the flat square of the trans-N2O2-coordination site is occupied by the ammonia molecule.