title: Syntheses and structures of isoindoline complexes of Zn(II) and Cu(II): an unexpected trinuclear Zn(II) complex.
abstract: Deprotonation of the tridentate isoindoline ligand 1,3-bis[2-(4-methylpyridyl)imino]-isoindoline, 4'-MeLH, and reaction with hydrated zinc(II) perchlorate produces an unexpected trinuclear Zn(II) complex, [Zn(3)(4'-MeL)(4)](ClO(4))(2).5H(2)O (1), whereas reaction with hydrated copper(II) perchlorate in methanol produces the expected mononuclear product, [Cu(4'-MeL)(H(2)O)(2)]ClO(4) (2). X-ray diffraction shows that the trinuclear Zn(II) complex (1) contains a linear zinc backbone, and the arrangement of ligands about the outer chiral zinc(II) atoms is helical. The two terminal zinc ions exhibit approximate C(2) site symmetry, with tetrahedral coordination by two pyrrole and two pyridyl nitrogen atoms of the potentially tridentate isoindoline ligands. The central zinc ion exhibits approximate tetrahedral symmetry, with coordination by four pyridyl nitrogen atoms of four different isoindoline ligands. Pyridyl-pyrrole intramolecular pi-stacking interactions contribute to the stability of the trinuclear cation. The structure of the mononuclear copper(II) complex cation in 2 is best described as a distorted trigonal bipyramid. The isoindoline anion binds Cu(II) in both axial positions and one of the equatorial positions; water molecules occupy the other two equatorial positions.
authors.affiliation: Department of Chemistry, Western Washington University, Bellingham, WA 98225, USA.
authors.forename: Oren P
authors.initials: OP
authors.lastname: Anderson
authors.forename: Agnete
authors.initials: A
authors.lastname: la Cour
authors.forename: Andrew
authors.initials: A
authors.lastname: Dodd
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Garrett
authors.forename: Mark
authors.initials: M
authors.lastname: Wicholas
mesh_terms: D002412:Cations / Q000737:chemistry; D003300:Copper / Q000737:chemistry*; D006860:Hydrogen Bonding; D007211:Indoles / Q000737:chemistry*; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry*; D014961:X-Ray Diffraction; D015032:Zinc / Q000737:chemistry*
chemical_list: D002412:Cations; D007211:Indoles; D008024:Ligands; D009942:Organometallic Compounds; D011725:Pyridines; D003300:Copper; D015032:Zinc