Complexes of Cu2(μ‐OAc)4(H2O)2 with 1,10‐Phenanthroline and Comparison with those of 2,2′‐Bipyridine. Crystal Structure of the Dimer [Cu(OAc)2(phen)](μ‐H2O)

The two complexes of composition Cu2(OAc)4(phen)(H2O)2 (1) andCu2(OAc)4(phen)2(H2O) (2) have been synthesized and characterized by chemical analysis and IR and electronic spectroscopies. Compound 2 has the structure of a dimer with a phenanthroline molecule and two monodentate acetate groups coordinated to each copper atom and a water molecule as the only bridging ligand between them. Each copper atom has a distorted square-planar pyramidal coordination, determined by two oxygen atoms at 1.94(3) and 1.959(3) A, two nitrogen atoms at 2.023(4) A and the oxygen atom of the bridging water molecule at 2.289(2) A. The distance between the two copper atoms is of 4.29 A and the angle Cu(1)-O(3)-Cu(1A) 139.2(2)°. The water molecule is involved in two intramolecular hydrogen bonds with non coordinated oxygen atoms. The distance between the molecules of phenanthroline is 3.75 A. Magnetic and EPR results for Cu2(OAc)4(phen)(H2O)2 (1), Cu2(OAc)4(phen)2(H2O) (2), Cu2(OAc)4(bipy) (3) and Cu2(OAc)4(bipy)2(H2O)2 (4) have been analysed and compared. For 1 and 3 an antiferromagnetic dimer unit [Cu2(μ-OAc)4] with 2J = −325 and −292 cm−1, respectively, and other two copper atoms without significant magnetic interaction are present. Triplet signals are detected in the EPR spectra. In 2 and 4 there is no practically magnetic exchange and the orthorhombic signals are observed in the EPR spectra.

[1]  F. Howell,et al.  CHARACTERIZATION AND CRYSTAL STRUCTURE OF COPPER(II) COMPLEX WITH BETAINE HAVING A WATER-WHEEL-LIKE STRUCTURE , 1999 .

[2]  G. Christou,et al.  Dinuclear copper(II) complexes with the new [Cu2(μ-OR)(μ-OAc)2]+ (R = alkyl) core: preparation and characterization of [Cu2(OR)(OAC)2(bpy)2]+ (R = Me, Et, Prn) salts , 1995 .

[3]  S. Meenakumari,et al.  Incorporation of chelating 2,2′-bipyridine (bipy) ligands at the equatorial sites of Cu2(μ-O2CMe)4(H2O)2: an x-ray structure of [Cu2(μ-O2CMe)2(H2O)(bipy)2](PF6)2 , 1993 .

[4]  G. Christou,et al.  The reactions of Cu2(O2CMe)4(H2O)2 with 2,2′-bipyridine (bpy): Influence of the Cu: bpy ratio, and the structure of a linear polymer comprising two alternating types of Cu2 units , 1992 .

[5]  G. Christou,et al.  Preparation and properties of the triply bridged, ferromagnetically coupled dinuclear copper(II) complexes [Cu2(OAc)3(bpy)2](ClO4) and [Cu2(OH)(H2O)(OAc)(bpy)2](ClO4)2 , 1990 .

[6]  A. W. Addison,et al.  Synthesis, structure, and spectroscopic properties of copper(II) compounds containing nitrogen–sulphur donor ligands; the crystal and molecular structure of aqua[1,7-bis(N-methylbenzimidazol-2′-yl)-2,6-dithiaheptane]copper(II) perchlorate , 1984 .

[7]  K. Nakamoto.  Infrared and Raman Spectra of Inorganic and Coordination Compounds , 1978 .

[8]  J. Catterick,et al.  Structures and Physical Properties of Polynuclear Carboxylates , 1977 .

[9]  S. Fletcher,et al.  Refined crystal structure of tetra-µ-acetato-bisaquodicopper(II) , 1973 .

[10]  L. C. Snyder,et al.  ESR of the Triplet States of Randomly Oriented Molecules , 1964 .