Self‐assembly of Dinuclear Double‐stranded Copper(II) Helicates with 3‐Ethoxy‐2‐hydroxyphenyl Substituted Diimines. Synthesis, Molecular Structure, and Host‐guest Recognition of H 2 O

Reaction of equimolar amounts of Cu(OAc) 2 · H 2 O and bis[4‐(3‐ethoxysalicylideneamino)phenyl]methane ( H 2 L 1 ) or bis[4‐(3‐ethoxysalicylideneamino)phenyl]sulfide ( H 2 L 2 ) in a 1:1 THF/MeOH mixture leads to the formation of structure‐analogous Cu II helicates of the composition [{Cu 2 L 2 }(H 2 O) 2 }] · 4H 2 O. The helicates form left‐ and right‐handed hydrogen bonded strands using the bound water molecules as glue. Finally, a compact 3D arrangement of the molecules is achieved by weak π ··· π and CH ··· π interactions. The Cu II ions possess a strongly distorted tetrahedral arrangement with a N 2 O 2 donor set of the involved diimines. In addition, the molecular structure of the ligand H 2 L 2 was determined and solution studies of the complex formation using UV/Vis and ESI‐MS were performed.