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, i Pr) 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(α‐diimin)copper(I) complexes. The solid structures of the complexes[Cu(dipdap) 2 ]BF 4 · CH 2 Cl 2 · 1.5H 2 O, [Cu(dipdap) 2 ]OTf · CH 2 Cl 2 , [Cu(dipdap) 2 ]I · C 2 H 4 Cl 2 · THF · 2H 2 O, [Cu(dmedap) 2 ]OTf and [Cu(dipdap) 2 ]AQSO 3 · H 2 O (AQSO 3 = sodium 9,10‐dihydro‐9,10‐dioxo‐2‐anthracenesulfonate) are reported. In [Cu(dipdap) 2 ]BF 4 · CH 2 Cl 2 · 1.5H 2 O, each copper(I) complex cation interacts with two others by π‐π stacking interactions forming a novel supramolecular column structural motif running along the crystallographic c axis. In the crystalline compound [Cu(dipdap) 2 ]AQSO 3 · H 2 O, aggregation between two complex cations and two additional anions by π‐π stacking interactions is observed, leading to a tetrameric assembly. Furthermore, the three complex compounds [Cu(L) 2 ]BF 4 (L = dmedap, detdap, dipdap) were tested for sensory applications in aqueous buffer solutions in electrochemical studies of the complex immobilized on glassy carbon electrodes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)