The simple hydrothermal self-assemblies between metal salts, organic polycarboxylic acids and N₂H₄·H₂O, sometimes in the presence of phenanthroline (phen), created four di(mono)acylhydrazidate-coordinated compounds [Pb₂(DPHKH)₂(phen)₂]·2H₂O 1, [Cd(ODPTH)(phen)]·0.25H₂O 2, [Pb₂(MPTH)₄(phen)₂] 3, [Cd₂(MPTH)₄(phen)₂]·H₂O 4 as well as one diacylhydrazide molecule [H₂(ODPTH)] 5 (DPHKH = 4,4′-diphthalhydrazidatoketone hydrazone, MPTH = 3-methylphthalhydrazidate, ODPTH = 4,4′-oxydiphthalhydrazidate). Note that the di(mono)acylhydrazidate molecules in the title compounds originated from the in situ acylation reactions between organic polycarboxylic acids and N₂H₄·H₂O. Interestingly, another kind of ligand in situ reaction was found in the formation process of DPHKH in compound 1: the nucleophilic addition reaction of a ketone with N₂H₄·H₂O.