Synthesis and structural characterization of a novel tetranuclear Cu(II) complex: [Cu4L2(pic)4(H2O)2]·2H2O

A novel Salen-type bisoxime ligand, 6,6′-dimethoxy-2,2′-[(1,4-butylene)dioxybis(nitrilomethylidyne)]diphenol (H2L) and its tetranuclear Cu(II) complex, [Cu4L2(pic)4(H2O)2]·2H2O, have been synthesized and characterized by elemental analyses, IR, TG-DTA and 1H-NMR etc. The X-ray crystal structure of the complex reveals that formation of a tetranuclear structure, which consists of four copper(II) atoms, two pentadentate L2−units, four picratols, two coordinated water molecules and two crystallizing water molecules. Around four copper ions are all octahedral geometries. It was demonstrated that the picratols in the tetranuclear copper(II) complex show a novel tridentate coordination mode.

[1]  Structural survey of technetium complexes , 1994 .

[2]  W. Geary.  The use of conductivity measurements in organic solvents for the characterisation of coordination compounds , 1971 .

[3]  J. Reglinski,et al.  Supporting conformational change at metal centres. Part 1: octahedral systems , 2002 .

[4]  Shigehisa Akine,et al.  Synthesis and Characterization of Novel Ligands 1,2-Bis(salicylideneaminooxy)ethanes. , 2001 .

[5]  Shigehisa Akine,et al.  Oxime-based salen-type tetradentate ligands with high stability against imine metathesis reaction. , 2005, The Journal of organic chemistry.

[6]  S. Nguyen,et al.  Directed assembly of transition-metal-coordinated molecular loops and squares from salen-type components. Examples of metalation-controlled structural conversion. , 2004, Journal of the American Chemical Society.

[7]  P. Friedel,et al.  Langmuir-Blodgett layers from Schiff base copper(II) complexes , 1997 .

[8]  F. Dahan,et al.  Influence of anionic ligands (X) on the nature and magnetic properties of dinuclear LCuDgX3.nH2O complexes (LH2 standing for tetradentate Schiff base ligands deriving from 2-hydroxy-3-methoxybenzaldehyde and X being Cl, N3C2, and CF3COO). , 2000, Inorganic chemistry.

[9]  P. Lacroix.  Second‐Order Optical Nonlinearities in Coordination Chemistry: The Case of Bis(salicylaldiminato)metal Schiff Base Complexes , 2001 .

[10]  Gopi Kuppuraj,et al.  Metal–salen complexes as efficient catalysts for the oxygenation of heteroatom containing organic compounds—synthetic and mechanistic aspects , 2005 .

[11]  Shigehisa Akine,et al.  Octanuclear zinc(II) and cobalt(II) clusters produced by cooperative tetrameric assembling of oxime chelate ligands. , 2006, Inorganic chemistry.

[12]  I. Fragalà,et al.  Synthesis and second-order nonlinear optical properties of bis(salicylaldiminato)M(II) metalloorganic materials , 2000 .

[13]  Shigehisa Akine,et al.  Cooperative formation of trinuclear zinc(II) complexes via complexation of a tetradentate oxime chelate ligand, salamo, and zinc(II) acetate. , 2004, Inorganic chemistry.

[14]  Y. Lan,et al.  Synthesis, Characterization and Fluorescence of Cryptates of Sm(Iii), Eu(Iii), Tb(Iii), Dy(Iii) with a Hexabenzo Cryptand , 1999 .

[15]  Weisheng Liu,et al.  SYNTHESIS, CHARACTERIZATION AND STRUCTURE OF COMPLEXES OF LANTHANUM(III) PICRATE WITH N, N, N', N'-TETRAPHENYL-3,6,9-TRIOXAUNDECANEDIAMIDE , 1996 .

[16]  Shigehisa Akine,et al.  Novel synthetic approach to trinuclear 3d-4f complexes: specific exchange of the central metal of a trinuclear zinc(II) complex of a tetraoxime ligand with a lanthanide(III) ion. , 2002, Angewandte Chemie.