| Popis: |
The synthesis and characterization of 3d metal chloride chelates with the mono-N-oxide of 2,2'-bipyridine (N-bipy0) is reported. The N-bipyO ligand acts generally as a bidentate 0,N-chelating agent in the new complexes. The characterization of these compounds was based on spectral, magnetic and conductance studies. [Cr(N-bipy0)2Cl2]Cl -4H20 involves a low symmetry hexacoordinated complex cation and one anionic chloride group. Fe(N-bipyO)Cl3 was shown to be a high-spin complex of the type [Fe(N-bipyO)2 Cl2][FeC14]. Complexes of the general formula [M (N-bipy0)Cl2]'C2HSOH are tetrahedral and high-spin for M = Mn or Co, and square planar, partially spinpaired (S = 1,luerr = 3.51 BM) for M = Fe. [Zn(N-bipy O)Cl2] is tetrahedral, while [Ni(N-bipy0)2Cl2]-H2O is a low symmetry, hexacoordinated, high-spin compound. The latter complex dissociated in N,N-dimethylformamide, behaving as a 1:1 electrolyte. Cu(N-bipyO)Cl2 is the only polynuclear complex of the series; its normal μeff (1.99 BM) suggests that chloride rather than N-bipyO bridges are present in this compound. The water or ethanol molecules present in certain new complexes, appear to be in the form of lattice rather than coordinated moieties on the basis of the it evidence. The lattice ethanol is easily removed by treatment at 65° C under reduced pressure, but the water of crystallization is held rather tenaciously and can be only partially removed by similar treatment. |
