Two novel aroylhydrazone complexes [Y(HL 1 ) 4 (H 2 O) 4 ](NO 3 ) 3 (MeOH) 6 1, [Ni(HL 2 )SO 4 ](H 2 O) 6 2, (HL 1 =4,5‐diazafluorene‐9‐one isonicotinoylhydrazoneand HL 2 =2‐pyridylaldehyde furoylhydrazone) were synthesized and structurally characterized by means of X‐ray single‐crystal diffraction. There are strong intermolecular π–π stacking interactions in the complexes 1 and 2, especially complex 1 was stabilized by the intermolecular and intramolecular π–π stacking interactions. [ABSTRACT FROM AUTHOR]