Self‐assembling chiral metallo‐clefts; synthesis and molecular structure of N,N′‐bis(12H‐benzo[α]xanthen‐12‐ylidene)‐1,2‐ethanediamine zinc(II)‐dichloride complex

Bulky ligands for cleft‐type metal complexes were synthesized from thio ketones and diamines in yields varying from 20–80%. A molecular structure determination of one ligand N,N′‐bis(12H‐benzo[a]‐xanthen‐12‐ylidene)‐1,2‐propanediamine (19) was performed. A metallocleft was constructed by a self‐assembling process with zinc(II) chloride. A crystallographic study of this zinc complex (24) revealed surprisingly that an anti‐syn inversion of the imine moieties of the ligand had taken place during complexation.