[CU-4(NPME(3))(3)(O2C-CH3)(5)] - A TETRAM ERIC PHOSPHORANE IMINATO COMPLEX OF COPPER(II) - SYNTHESIS, CRYSTAL-STRUCTURE, MAGNETIC-BEHAVIOR,AND EPR-SPECTRUM

The title compound and the corresponding benzoate complex [Cu-4(NPMe(3 ))(3)(O2C-C6H5)(5)] have been prepared by reactions of copper(II)aceta te and copper(II)benzoate, respectively, with Me(3)SiNPMe(3) in dichlo romethane. Both complexes are characterized by IR spectroscopy. The ac etate complex is additionally characterized by the measurement of the magnetic susceptibility, by its EPR spectrum, and by a crystal structu re determination. [Cu-4(NPMe(3))3(O2C-CH3)5]. CH2Cl2: Space group I4(1 )/a, Z = 16, structure solution with 7960 independent reflections, R = 0.044. Lattice dimensions at -70 degrees C: a = b = 3670.6; c = 1091. 9 pm. The structure consists of four Cu atoms which are arranged at th e corners of a distorted tetrahedron with Cu ... Cu distances between 290 and 318 pm. Three of the faces of the tetrahedron are linked by mu (3)-N atoms of the phosphorane iminato groups. Three of the acetate li gands form chelates, the other two are monofunctionally coordinated. T hree of the copper atoms have a planar surrounding, the forth Cu atom has a (4 + 1) coordination.