title: Investigation of the zinc(II)-benzoate-2-pyridinealdoxime reaction system.
abstract: The employment of pyridine-2-carbaldehyde oxime (paoH) in zinc(II) benzoate chemistry, in the absence or presence of azide ions, is described. The syntheses, crystal structures and spectroscopic characterization are reported for the complexes [Zn(O(2)CPh)(2)(paoH)(2)] (1), [Zn(12)(OH)(4)(O(2)CPh)(16)(pao)(4)] (2) and [Zn(4)(OH)(2)(pao)(4)(N(3))(2)] (3). The Zn(II) centre in octahedral 1 is coordinated by two monodentate PhCO(2)(-) groups and two N,N'-chelating paoH ligands. The metallic skeleton of 2 describes a tetrahedron encapsulated in a distorted cube. The {Zn(12)(μ-OH)(4)(μ(3)-ΟR)(4)}(16+) core of the cluster can be conveniently described as consisting of a central {Zn(4)(μ(3)-ΟR)(4)}(4+) cubane subunit (RO(-) = pao(-)) linked to four {Zn(2)(μ-OH)}(3+) subunits via the OH(-) group of each of the latter, which becomes μ(3). The molecule of 3 has an inverse 12-metallacrown-4 topology. Two triply bridging hydroxido groups are accommodated into the metallacrown ring. Each pao(-) ligand adopts the η(1) : η(1) : η(1) : μ coordination mode, chelating one Zn(II) atom and bridging a Zn(II)(2) pair. Complexes 1 and 2 display photoluminescence with maxima at ∼355 nm and ∼375 nm, upon maximum excitation at 314 nm; the origin of the photoluminescence is discussed.
authors.affiliation: Department of Chemistry, University of Patras, Greece.
authors.forename: Konstantis F
authors.initials: KF
authors.lastname: Konidaris
authors.forename: Vlasoula
authors.initials: V
authors.lastname: Bekiari
authors.forename: Eugenia
authors.initials: E
authors.lastname: Katsoulakou
authors.forename: Catherine P
authors.initials: CP
authors.lastname: Raptopoulou
authors.forename: Vassilis
authors.initials: V
authors.lastname: Psycharis
authors.forename: Evy
authors.initials: E
authors.lastname: Manessi-Zoupa
authors.forename: George E
authors.initials: GE
authors.lastname: Kostakis
authors.forename: Spyros P
authors.initials: SP
authors.lastname: Perlepes
mesh_terms: D001565:Benzoates / Q000737:chemistry*; D008163:Luminescent Measurements; D008958:Models, Molecular; D008968:Molecular Conformation; D010091:Oximes / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry*
chemical_list: D001565:Benzoates; D010091:Oximes; D011725:Pyridines; C060977:pyridine-2-aldoxime; D015032:Zinc