Supramolecular Recognition Forces: An Examination of Weak Metal−Metal Interactions in Host−Guest Formation

Molecular receptors consisting of two parallel-disposed terpy−M−Cl units (M = Pd2+, Pt2+) are used to form host−guest adducts
with aromatic molecules and with neutral square-planar Pt2+
complexes. Host−guest formation is controlled by several factors
including π−π interactions and, in some cases, weak Pt−Pt
interactions between the host and the guest. This latter interaction
was examined by comparing the host−guest stability of adducts
formed by isoelectronic Pt2+ and Au3+ complexes with the Pt2+
receptor. Consistently, the former is more stable.