Structural Characterization of Paramagnetic Octahedral Homoscor‐Pionate (Polypyrazolylborate) Cobalt Complexes by 1H and 13C NMR Spectroscopy and by FAB‐Mass Spectrometry

Abstract

Abstract1H and 13C NMR spectroscopy as well as the FAB mass spectrometry have been applied to six bis[tris(pyrazol‐1‐yl)borates]Co(ll) and one bis[tetrakis(pyrazol‐1‐yl)borate]Co(ll). These octahedral complexes are paramagnetic and it was therefore very difficult to obtain their 13C NMR. The isotropic shifts are very large and characteristic of the different positions of the pyrazole and the boron substituents. FAB‐MS also is an interesting method to characterize these complexes, since they give abundant molecular ions and specific fragmentation.