title: A [2]catenane and a [2]rotaxane as prototypes of topological and Euclidean molecular "rubber gloves".
abstract: A [2]catenane and a [2]rotaxane have been prepared from a C2-symmetric, 2,9-diphenyl-1,10-phenanthroline-based (dpp-based) macrocycle incorporating a 1,5-dioxynaphthalene subunit by means of the transition metal templated technique. In the case of the catenane, this macrocycle is interlocked with a dpp-based macrocycle that is oriented through the location of a p-tolyl substituent in the 4-position of the phenanthroline subunit. In the case of the rotaxane, the C2-symmetric macrocycle is threaded onto an oriented, dumbbell-shaped molecule, based on the same 4-p-tolyl-1,10-phenanthroline subunit, which bears tetraarylmethane stoppers. Both species are chemically achiral molecules, yet they are composed entirely of asymmetric, mirror-image conformations. Conformational enantiomerization processes therefore take place exclusively by chiral pathways, conferring on these molecules the "rubber glove" property. However, while the molecular graph (constitutional formula) of the [2]rotaxane can be deformed into a planar and, hence, rigidly achiral representation, a feature shared by a few other compounds in the literature that have been characterized as "Euclidean rubber gloves", the molecular graph of the [2]catenane cannot be deformed in this way. It therefore has the unique property of being a chemically achiral "topological rubber glove".
authors.affiliation: Laboratoire de Chimie Organo-Minérale, UMR 7513 du CNRS, Université Louis Pasteur, Institut Le Bel, Strasbourg, France. chambron@chimie.u-strasbg.fr
authors.forename: J C
authors.initials: JC
authors.lastname: Chambron
authors.forename: J P
authors.initials: JP
authors.lastname: Sauvage
authors.forename: K
authors.initials: K
authors.lastname: Mislow
authors.forename: A
authors.initials: A
authors.lastname: De Cian
authors.forename: J
authors.initials: J
authors.lastname: Fischer