Synthesis, structure, and magnetism of some polynuclear copper (II) complexes

Abstract

The synthesis and structures of four copper(II) dipivaloylmethane (DPM) complexes; Cu(DPM)(,2), Cu(,4)(OCH(,3))(,4)(DPM)(,4), Cu(,4)(O)(Pz)(,2)(DPM)(,4), and Cu(,9)(OHO)(OH)(,6)(DPM)(,9); are presented. The relationship between the structural geometry of these complexes and their magnetic behavior is also discussed. The Cu(DPM)(,2) complex is square planar. The Cu(,4)(OCH(,3))(,4)(DPM)(,4) structure is that of a step tetramer, while that of Cu(,4)(O)(Pz)(,2)(DPM)(,4) is a (mu)(,4)-oxo bridged complex with tetrahedral symmetry. The Cu(,9)(OHO)(OH)(,6)(DPM)(,9) structure has the overall geometry of a triangular prism. Reasons for the inconstant structural types for these and other known Cu(II)-DPM complexes are also examined. In addition, the synthesis and structure of tetrapyrazole copper(II) nitrate, Cu(Pz)(,2)(NO(,3))(,2), and (mu)(,4)-oxo-hexa-(mu)-bromo-tetrakis-{(3-quinulidione) copper(II)}, Cu(,4)(O)Br(,6)(3-quin)(,4) are presented. The structure of Cu(Pz)(,4)(NO(,3))(,2) is that of a distorted octahedron. The copper arrangement for Cu(,4)(O)Br(,6)(3-quin)(,4) is that of a regular tetrahedron.