The invention relates to new metal complexes having N-aminoamidinate ligands, more particularly metal complexes having N,N′-bis(dimethylamino)acetamidinate, N,N′-bis(dimethylamino)formamidinate, N-dimethylaminoacetamidinate or N-dimethylamino-N′-isopropyl-acetamidinate ligands as well as to their preparation and use. The metal complexes are characterized by a five-membered chelate ring. The metal complexes are formed with the metals from the main groups of the PTE, but also with transition-group elements such as tantalum (Ta), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu) or zinc (Zn), and also with precious metals such as palladium (Pd). The complexes of the invention find use as precursors for the preparation of functional layers by means of gas-phase thin-film processes such as CVD, MO-CVD and ALD. Additionally they may be used as catalysts for olefin hydroamination and for olefin polymerization.