title: Structural properties of cyclopentanone-bridged bis-macrocyclic ligand dicopper(II) complexes in the solid and in solution: a successful test of the MM-EPR method.
abstract: The copper(II)-assisted condensation of 2,3,2-tet (3,7-diazanonane-1,9-diamine) with formaldehyde and cyclopentanone yields the mono- and bis-macrocyclic Mannich condensation products L(1) and L(2), as well as the Schiff-base product L(3), all with cyclam-type tetraaza macrocycles, coordinated to copper(II). The combination of molecular mechanics and EPR spectroscopy (MM-EPR) reveals that all three isomers of [Cu(2)(L(2))(OH(2))(n)](2+) (n = 0-4), with the expected trans-III (R,R,S,S) configuration of the 14-membered tetraaza macrocycles, are of similar stability, and that the isomer whose structure is solved by X-ray crystallography has a different structure in solution.
authors.affiliation: Anorganisch-Chemisches Institut der Universität Heidelberg, INF 270, D-69120 Heidelberg, Germany. comba@akcomba.oci.uni-heidelberg.de
authors.forename: Peter
authors.initials: P
authors.lastname: Comba
authors.forename: Marion
authors.initials: M
authors.lastname: Kerscher
authors.forename: Yaroslaw D
authors.initials: YD
authors.lastname: Lampeka
authors.forename: Lutz
authors.initials: L
authors.lastname: Lötzbeyer
authors.forename: Hans
authors.initials: H
authors.lastname: Pritzkow
authors.forename: Lyudmyla V
authors.initials: LV
authors.lastname: Tsymbal