Ferromagnetic exchange in a dinuclear copper(II) complex mediated by a methanolate bridging ligand.

The copper(II) complex Cu(2)L(OMe)(H(2)O)(3), [middle dot]3H(2)O [H(3)L = 2-(2-hydroxyphenyl)-1,3-bis[4-(2-hydroxyphenyl)-3-azabut-3-enyl]-1,3-imidazolidine] was obtained and recrystallised in methanol to yield crystals of [[Cu(2)L(OMe)]](2).2.5MeOH.4H(2)O, 1.2.5MeOH.4H(2)O. Its single X-ray study shows that it contains two crystallographically different but chemically equivalent dinuclear [Cu(2)L(OMe)] 1 molecules in the asymmetric unit cell. The copper atoms of each dinuclear moiety are in distorted square-pyramidal environments, with both pyramids sharing an apical phenolate and a basal methanolate oxygen atom. Magnetic characterisation of 1.3H(2)O shows a quite strong intramolecular ferromagnetic coupling between both metal atoms. Extended Huckel calculations reveal that the intradinuclear magnetic interaction seems to be mediated by the exogenous methanolate bridging ligand.

[1]  Xiaoming Liu,et al.  Antisymmetric exchange in two tricopper(II) complexes containing a [Cu3(micro3-OMe)]5+ core. , 2004, Dalton transactions.

[2]  M. R. Bermejo,et al.  A Binuclear Copper(II) Acetate Complex Showing a 3D Supramolecular Network with Hydrophilic Pockets: Its Unusual Magnetic Behaviour , 2003 .

[3]  S. García‐Granda,et al.  Structural and functional models for the dinuclear copper active site in catechol oxidases. Synthesis, X-ray crystal structures, magnetic and spectroscopic properties of mu-methoxo-bridged dinuclear copper(II) complexes with N-substituted sulfonamide ligands. , 2003, Journal of inorganic biochemistry.

[4]  H. Adams,et al.  Copper(II) complexes of unsymmetric compartmental ligands bearing adjacent {N2O}, {N,S,O} donor sets and {N2O}, {N,O} donor sets , 2003 .

[5]  K. Wieghardt,et al.  Single‐Atom O‐Bridged Urea in a Dinickel(II) Complex together with NiII4, CuII2 and CuII4 Complexes of a Pentadentate Phenol‐Containing Schiff Base with (O,N,O,N,O)‐Donor Atoms , 2003 .

[6]  M. R. Bermejo,et al.  Spontaneous carbon dioxide fixation: a µ4-carbonate bridged tetranuclear zinc(II) complex of a heptadentate Schiff base , 2002 .

[7]  U. Thewalt,et al.  Dioxygen Activation Using Schiff Base Macrocyclic Dinuclear Copper(I) Complexes: Structurally Characterized Dioxygen Reaction Products , 2002 .

[8]  M. Kinoshita,et al.  Molecular Magnetism—New Magnetic Materials , 2002 .

[9]  S. Alvarez,et al.  Further Theoretical Evidence for the Exceptionally Strong Ferromagnetic Coupling in Oxo-Bridged Cu(II) Dinuclear Complexes , 2002 .

[10]  J. Reedijk,et al.  X-ray crystal structures, spectroscopic and magnetic measurements of dinuclear alkoxo-bridged copper(II) compounds with substituted bis(2-benzimidazolyl)alkane ligands. First X-ray structure of a copper(II) dinuclear propoxo-bridged compound , 2002 .

[11]  L. Spiccia,et al.  Syntheses, crystal structures, magnetic properties, and EPR spectra of tetranuclear copper(II) complexes featuring pairs of "roof-shaped" Cu2X2 dimers with hydroxide, methoxide, and azide bridges. , 2001, Inorganic chemistry.

[12]  Zhi-da Chen,et al.  Influence of structural parameters of Cu2O2 core on magnetic coupling in alkoxo-bridged Cu(II) binuclear system , 2000 .

[13]  K. Murray,et al.  Dicopper(II) complexes of a phenolate-hinged ditopic ligand with solvent-derived ancillary ligands bound at the potentially dimetallic exogenous site , 2000 .

[14]  J. Reedijk,et al.  Alkoxo-bridged dinuclear copper(II) compounds with 2-amino-picolines as ligands: Synthesis, spectroscopy, magnetism and X-ray crystal structures , 1999 .

[15]  Lisheng Cai,et al.  Binuclear versus mononuclear copper complexes as catalysts for asymmetric cyclopropanation of styrene , 1999 .

[16]  S. Alvarez,et al.  MAGNETIC COUPLING IN END-ON AZIDO-BRIDGED TRANSITION METAL COMPLEXES : A DENSITY FUNCTIONAL STUDY , 1998 .

[17]  D. Velmurugan,et al.  Synthesis and Characterization of New Symmetrical Binucleating Ligands and Their &mgr;-Phenoxo-Bridged Bicopper(II) Complexes: Structural, Electrochemical, and Magnetic Studies. , 1998, Inorganic chemistry.

[18]  A. Spek,et al.  Synthesis, spectroscopic properties and X-ray crystal structures of two dinuclear alkoxo-bridged copper(II) compounds with the ligand bis(1-methyl-2-benzimidazolyl) propane. A unique alkoxo-bridged Cu(II) dinuclear compound with an additional bidentate bridging triflate anion , 1997 .

[19]  E. Ruiz,et al.  Toward the Prediction of Magnetic Coupling in Molecular Systems: Hydroxo- and Alkoxo-Bridged Cu(II) Binuclear Complexes , 1997 .

[20]  P. Cheng,et al.  Binuclear Copper(II) Complexes with Robsori‐Type Ligands. Synthesis, characterization, crystal structure, and magnetic properties , 1997 .

[21]  B. Krebs,et al.  Synthesis, structure and catecholase activity study of dinuclear copper(II) complexes† , 1997 .

[22]  S. Emori,et al.  MAGNETO-STRUCTURAL CORRELATIONS IN ALKOXO-BRIDGED COPPER (II) COMPOUNDS , 1996 .

[23]  J. Bridson,et al.  Magnetostructural Correlations in Bis(&mgr;(2)-phenoxide)-Bridged Macrocyclic Dinuclear Copper(II) Complexes. Influence of Electron-Withdrawing Substituents on Exchange Coupling. , 1996, Inorganic chemistry.

[24]  D. Gatteschi.  Magnetic molecular materials , 1996 .

[25]  R. Caballol,et al.  Ab Initio CI Determination of the Exchange Coupling Constant of Doubly-Bridged Nickel(II) Dimers. , 1996, Inorganic chemistry.

[26]  O. Kahn.  Magnetism of Heterobimetallics: Toward Molecular-Based Magnets , 1995 .

[27]  R. Blessing,et al.  An empirical correction for absorption anisotropy. , 1995, Acta crystallographica. Section A, Foundations of crystallography.

[28]  J. McCusker,et al.  Synthesis and characterization of dinuclear copper(II) complexes of the dinucleating ligand 2,6-bis[(bis((1-methylimidazol-2-yl)methyl)amino)methyl]-4-methylphenol , 1991 .

[29]  D. Proserpio,et al.  MO theory made visible , 1990 .

[30]  T. Doman,et al.  Synthesis, crystal structure and magnetic properties of a pyrazolate-bridged binuclear copper(II) complex , 1990 .

[31]  M. Sakamoto,et al.  Crystal structures and magnetic properties of bi- and tetra-nuclear copper(II) complexes of 2,6-diformyl-4-methylphenol di(benzoylhydrazone) , 1989 .

[32]  M. Drew,et al.  Dicopper(II) complexes of a binucleating N4 macrocycle containing mono- and di-atomic bridges; magnetic interactions mediated by alkoxo- and diaza-bridging ligands. Crystal structures of [Cu2(L1)(pz)2][ClO4]2, [Cu2(L1)(OEt)2(NCS)2], and [Cu2(L1)(OMe)2(MeCN)2][BPh4]2 , 1988 .

[33]  K. Karlin,et al.  Models for met-hemocyanin derivatives: structural and spectroscopic comparisons of analogous phenolate and X (X = OH-, OMe-, N3-, Cl-, OAc-, OBz-) doubly bridged dinuclear copper(II) complexes , 1987 .

[34]  F. Urbach,et al.  Structural and spectroscopic aspects of a strained dicopper complex with a tripodal binucleating ligand , 1987 .

[35]  V. McKee,et al.  Further insight into magnetostructural correlations in binuclear copper(II) species related to methemocyanin: x-ray crystal structure of 1,2-.mu.-nitrito complex , 1985 .

[36]  V. McKee,et al.  Copper(II) hemocyanin models , 1981 .

[37]  K. Karlin,et al.  Activation of O2 by a binuclear copper(I) compound. Hydroxylation of a new xylyl-binucleating ligand to produce a phenoxy-bridged binuclear copper(II) complex; X-ray crystal structure of [Cu2{OC6H3[CH2N(CH2CH2py)2]2-2,6}(OMe)](py = 2-pyridyl) , 1981 .

[38]  L. Banci,et al.  Crystal and molecular structure and ESR spectra of a dimeric dialkoxo-bridged five-coordinate copper(II) complex , 1980 .

[39]  K. Bowers,et al.  Anomalous paramagnetism of copper acetate , 1952, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.