Premium
Supramolecular Recognition: Use of Cofacially Disposed Bis‐terpyridyl Square‐Planar Complexes in Self‐Assembly and Molecular Recognition
Author(s) -
Goshe Andrew J.,
Crowley James D.,
Bosnich Brice
Publication year - 2001
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/1522-2675(20011017)84:10<2971::aid-hlca2971>3.0.co;2-m
Subject(s) - chemistry , palladium , molecule , molecular recognition , supramolecular chemistry , anthracene , crystallography , tetragonal crystal system , molecular tweezers , rectangle , cyclophane , stereochemistry , crystal structure , photochemistry , organic chemistry , geometry , mathematics , catalysis
A molecular receptor consisting of a molecular spacer that constrains two terpyridyl‐palladium(II) complexes to be disposed in a parallel cofacial geometry has been prepared. The separation between the two terpyridyl‐palladium units is enforced to be ca. 7 Å, a distance sufficient to incarcerate aromatic molecules and square‐planar complexes. A number of molecules are shown to associate with this spacer‐chelator complex. In particular, 9‐methylanthracene (9‐MA) is found to form a 1 : 2 host‐guest complex. A crystal structure of this complex shows one 9‐MA in the molecular cleft formed by the two terpyridyl‐palladium units and the other 9‐MA molecule to lie above one of the terpyridyl‐palladium units. Nuclear Overhauser effects on analogous molecules that contain two anthracene guests tethered intramolecularly indicate that the structure found in the solid is similar to that in solution. Low‐temperature 1 H‐NMR studies indicate rapid exchange between the two binding sites. The spacer‐chelator complexes, when combined with appropriate molecular linkers, readily form molecular rectangles, trigonal prisms, and tetragonal prisms. One molecular rectangle is shown to associate with up to five 9‐MA molecules.