Molecular Recognition: Use of Metal‐Containing Molecular Clefts for Supramolecular Self‐Assembly and Host–Guest Formation

Molecular clefts consisting of a rigid spacer linked to two parallel cofacially disposed terpy‐M–X (M = Pd2+, Pt2+) units, which can vary in separation from 6.6 to 7.2 Å, have been used as molecular receptors and for self‐assembly with linear and triangular linkers to produce rectangles and trigonal prisms, respectively. Aromatic molecules form multiple host–guest adducts with the molecular cleft receptors and with the rectangles and trigonal prisms. Planar complexes of Pt2+ also form host–guest adducts. The forces that control this molecular recognition, namely, π‐π interactions, charge‐induced dipole interactions, charge‐charge forces, weak metal‐metal interactions and solvation effects, are discussed and assigned to the various adducts. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)