2,11-Dialkylated 1,12-Diazaperylene Copper(I) Complexes: First Supramolecular Column Assemblies by π-π Stacking between Homoleptic Tetrahedral Metal Complexes, Exhibiting Low-Energy MLCT Transitions

2,11-Dialkylated 1,12-diazaperylenes (alkyl = Me, Et, iPr) dmedap, detdap and dipdap have been synthesized by reductive cyclization of 3,3'-dialkylated 1,1'-biisoquinolines 3a-c, resulting in the first copper(I) complexes of a "large-surface" ligand. The new copper(I) complexes show low-energy MLCT absorptions unprecedented for bis(alpha-diimin)-copper(I) complexes. The solid structures of the complexes [Cu(dipdap)(2)]BF4 center dot CH2Cl2 center dot 1.5H(2)O, [Cu(dipdap)(2)]OTf center dot CH2Cl2, [Cu(dipdap)(2)]I center dot C2H4Cl2 center dot THF center dot 2H(2)O, [Cu(dmedap)(2)]OTf and [Cu(dipdap)(2)]AQSO(3)center dot H2O (AQSO(3) = sodium 9,10-dihydro-9,10-dioxo-2-anthracenesulfonate) are reported. In [Cu(dipdap)(2)]BF4 center dot CH2Cl2 center dot 1.5H(2)O, each copper(I) complex cation interacts with two others by pi-pi stacking interactions forming a novel supramolecular column structural motif running along the crystallographic c axis. In the crystalline compound [Cu(dipdap)(2)]AQSO(3)center dot H2O, aggregation between two complex cations and two additional anions by pi-pi stacking interactions is observed, leading to a tetrameric assembly. Furthermore, the three complex compounds [Cu(L)(2)]BF4 (L = dmedap, detdap, dipdap) were tested for sensory applications in aqueous buffer solutions in electrochemical studies of the complex immobilized on glassy carbon electrodes. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)