Compounds of the type M(N ∩ N-κN)(nq) 2 and M 2 (µ 2 -N ∩ N)-M(N ∩ N-κ 2 N)(Q) were formed (Q = nq, pbq). The structures of the complexes have been established by NMR in solution (µ 2 -pbq) 2 , in which nq = 1,4-naphthoquinone, pbq = 1,4-benzoquinone, and N ∩ N is a monodentate or bridging ligand of and by X-ray diffraction in the solid state; crystal structures of Pd(bpy-κ 2 N)(η 2 -pbq) ( 1) Pd(dafo-κN)(η 2 -nq) 2 ( 14) and the α-diimine type, were obtained from reactions of Pd(dba) 2 in toluene with the 3,3Ј-annelated-2,2Ј-bipyridines: 4,5-di-Pd 2 (µ 2 -dafo)(µ 2 ,η 2 :η 2 -pbq) 2 ( 16) have been determined. Of the ligands, dafo and dafe are the only ones apt to form com-azafluoren-9-one (dafo) and 4,5-diazafluorene (dafe) in the presence of the appropriate p-quinone. In the corresponding plexes containing a monodentate or bridging N ∩ N ligand. This behaviour is ascribed to the geometrical constraints of reactions with 2,2Ј-bipyridine (bpy), 1,10-phenanthroline (phen), 2,2Ј-bipyrimidine (bpym), N,NЈ-dicyclohexyl-1,4-di-dafo and dafe; the annelation by one carbon atom at the 3,3Јpositions in these ligands causes an increase in bite angle aza-1,3-butadiene (chex-dab), bis[N-(o,oЈ-diisopropyl)phenylimino]acenaphthene (o,oЈ-iPr 2 -bian) and 5,6-dihydro-from approximately 77°to 82°. 1,10-phenanthroline (dh-phen) only complexes of the type