METAL-COMPLEXES OF PYRAZOLE-4,5-DIONE-4-OXIMES - CRYSTALLOGRAPHIC CHARACTERIZATION AND THEIR REACTIONS WITH DIMETHYL ACETYLENEDICARBOXYLATE

Complexes of type ML(2), ML(2)(H2O)(2) and ML(2)(py)(2) (LH = pyrazole -4,5-dione-4-oximes) have been prepared and their IR and LSIMS spectra , magnetic susceptibilities and behaviour towards triphenylphosphine a nd dimethyl acetylenedicarboxylate (DMAD) have been investigated. The structures of Zn(Mpo)(2)(H2O)(2) (MpoH = 1,3-dimethyl-1H-pyrazole-4,5- dione-4-oxime) and Mn(1-Ppo)(2)(py)(2) (1-PpoH = 3-methyl-1-phenyl-1H- pyrazole-4,5-dione-4-oxime) were determined by X-ray crystallography. In all the complexes, the ligands chelate to the metal, forming six-me mbered rings. The adducts tire monomeric, whereas the ML(2) complexes are associated in the solid state. All the complexes and their respect ive ligands react with DMAD at 80 degrees C to give the condensation p roduct, whereas at 20 degrees C, the ligands and their lithium complex give the open chain adduct.