Homoleptic NiII and FeII complexes of the “large‐surface” phenanthroline‐type ligand 1,12‐diazaperylene (dap), [Ni(dap)3](BF4)2 (1) and [Fe(dap)3](PF6)2 (2), respectively, were synthesized. In the crystal structure the complex cation [M(dap)3]2+ (M = Ni, Fe) exhibits C3 symmetry and interacts with three other cations by π‐π stacking. It forms a new metalla‐supramolecular assembly with a honeycomb structure containing nanochannels running parallel to the crystallographic c axis. Aggregation by π‐π stacking between metal complexes of “large‐surface” ligands should give new perspectives for inorganic supramolecular chemistry. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

The complex formation of the ligands 1,12-diazaperylene (dap), 1,1'-bisisoquinoline (bis), 2,2'-bipyridine (bpy) and 1,10-phenanthroline (phen) with transition metal ions (M = Fe, Co, Ni, Cu, Zn, Ru, Os, Re, Pd, Pt, Ag and Cd) in the gas phase has been studied by electrospray ionization mass spectrometry. With the exception of Ru, Os, Fe, Ni and Cu, singly charged complexes [MLn](+) (n = 1,2) were observed. The complexes of dap and bis with Ru, Os, Fe and Ni ions, and the mixed ligand complexes with bpy and phen, are preferably of the doubly charged type [ML3]2+. In addition, collision-induced dissociation (CID) measurements were employed to evaluate the relative stabilities of these complexes. The CID experiments of mixed-ligand complexes which contain both dap and phen or dap and bpy exhibit preferential elimination of bpy, indicating that bpy is a weaker ligand than phen and dap.

C 18 H 12 N 2 , tetragonal, I41/a (no. 88), a = 13.8885(6) Å, c = 13.6718(6) Å, V = 2637.2(3) Å 3 , Z = 8, Rgt(F) = 0.0295,

The cover picture shows the honeycomb structure formed by π-π stacking of homoleptic octahedral Ni II complexes of the "large-surface" ligand 1,12-diazaperylene (dap), [Ni(dap) 3 ](BF 4 ) 2 (Ni red, N green, C dark yellow, B blue, F light yellow). The [Ni(dap) 3 ] 2ϩ cation and one of the BF 4Ϫ counterions form parallel nanosized channels (ca. 9.60 Å in diameter), which run along the crystallographic c axis and are filled with the other disordered BF 4 Ϫ counterion (omitted for clarity). The C 3 symmetry of [Ni(dap) 3 ] 2ϩ is a prerequisite for forming the highly symmetrical supramolecular assembly. Details are discussed in the article by H.-J. Holdt et al. on p. 1547 ff.