title: A novel, tunable manganese coordination system based on a flexible "spacer" unit: noncovalent templation effects.
abstract: The reaction of bis(hexafluoroacetylacetonato)manganese(II) trihydrate (2), an approximately 90 degrees corner unit, with flexible linking unit 4,4'-trimethylenedipyridine (1) allows for the potential formation of three different types of solid-state coordination species: infinite helical polymers, closed dimeric systems, and infinite one-dimensional polymers. While the un-templated starting material is known to give a coordination helix, the other two possible species can be realized through the selective use of a variety of simple, organic guests: toluene (3), diphenylmethane (4), cis-stilbene (5), 1,3-diphenylpropane (6), benzyl alcohol (7), nitrobenzene (8), and cyanobenzene (9). When solutions of 1 and 2 are crystallized in the presence of all of these clathrates, the dimeric macrocycles result in all cases, except for that of 6, in which a syndiotactic, wedge-shaped polymer forms. Employing a linker that is less rigid than is typically used in crystal engineering, such as 1, enables the nucleophilic donor subunit to be more than just a simple "spacer", instead making it an essential, tunable component in the overall crystal lattice. In so doing, a great deal of molecular "information" is lost, but this is compensated for by an in-depth investigation into the weaker host-guest and/or guest-guest interactions, such as nonclassical hydrogen bonding and an assortment of hydrophobic interactions, present in the various systems.
authors.affiliation: Department of Chemistry, University of Utah, 315 South 1400 East, Room 2020, Salt Lake City, Utah 84112, USA.
authors.forename: F M
authors.initials: FM
authors.lastname: Tabellion
authors.forename: S R
authors.initials: SR
authors.lastname: Seidel
authors.forename: A M
authors.initials: AM
authors.lastname: Arif
authors.forename: P J
authors.initials: PJ
authors.lastname: Stang