N. Karayannis, J. V. Minkiewicz, L. L. Pytlewski
1969
Citations
0
Influential Citations
18
Citations
Journal
Inorganica Chimica Acta
Abstract
Abstract Complexes of 4-ethoxypyridine N-oxide (EPNO) with metal halides and perchlorates were synthesized and characterized by means of spectral, magnetic, conductance and, in certain cases, X-ray powder diffraction studies. Mn(EPNO)Cl2 and Pd(EPNO)2Cl2 are the first examples of pyridine N-oxide complexes of this type for these metal ions. Co(EPNO)2Cl2 shows differences in its solution spectra from analogous complexes of other substituted pyridine N-oxides. Although some metal perchlorates form analogous cationic complexes to those reported for pyridine N-oxides, those of MnII, CoII, NiII and ZnII form pentacoordinated cationic complexes, of the type [M(EPNO5](ClO4)2. The MnII, CoII and NiII perchlorate complexes are of the high-spin type. The presence of both penta- and hexa-coordinated species in equilibrium in solutions of the CoII and NiII perchlorate complexes containing excess free ligand has been established by means of spectral evidence. Satisfactory correlation of the NO stretching vibration of EPNO and some of its metal complexes with the νNO of other 4-substituted pyridine N-oxides and their correspondig complexes has been observed in νNO vs. σ+ plots.