title: Calix[4]pyrrole Schiff base macrocycles: novel binucleating ligands for Cu(I) and Cu(II).
abstract: New bimetallic copper(I) and copper(II) complexes of dipyrromethane-derived Schiff base macrocycles are reported. Two different structural motifs were identified, providing support for the notion that ligands of this type can support a variety of coordination modes. In the case of the Cu(I) complexes, the metal centers were found to have a distorted tetrahedral geometry and be coordinated to two imine nitrogens on each side of the ligand, with the exact structure depending on the choice of Schiff base macrocycle. In contrast to what is seen for Cu(I), with Cu(II) as the coordinated cation the Cu(II) metal centers assumed distorted square planar geometries, and both pyrrole N-Cu and imine N-Cu interactions were confirmed by single-crystal X-ray diffraction analysis. This structural analysis revealed a copper-copper distance of 3.47 A, while SQUID magnetic susceptibility data provided evidence for antiferromagnetic coupling between the two metal centers.
authors.affiliation: Department of Chemistry and Biochemistry, 1 University Station A5300, University of Texas at Austin, Austin, TX 78712-0165, USA.
authors.forename: Jacqueline M
authors.initials: JM
authors.lastname: Veauthier
authors.forename: Elisa
authors.initials: E
authors.lastname: Tomat
authors.forename: Vincent M
authors.initials: VM
authors.lastname: Lynch
authors.forename: Jonathan L
authors.initials: JL
authors.lastname: Sessler
authors.forename: Utkir
authors.initials: U
authors.lastname: Mirsaidov
authors.forename: John T
authors.initials: JT
authors.lastname: Markert
mesh_terms: D003300:Copper / Q000737:chemistry*; D004563:Electrochemistry; D008024:Ligands; D047028:Macrocyclic Compounds / Q000737:chemistry*; D015394:Molecular Structure; D010984:Platinum / Q000737:chemistry; D011758:Pyrroles / Q000737:chemistry*; D012545:Schiff Bases / Q000737:chemistry*
chemical_list: D008024:Ligands; D047028:Macrocyclic Compounds; D011758:Pyrroles; D012545:Schiff Bases; D010984:Platinum; D003300:Copper