On the Problem of the Tetrafluoroborate Ion State in Complexes with Nitrogen-Containing Organic Bases

Using a number of Cu(II), Zn(II), and Cd(II) tetrafluoroborate complexes with nitrogen-containing organic bases as examples, the possible existence of two states of the BF₄^– ion, namely, the "half-coordination" and counter-ion states, was studied. It was found that in [ML₂(BF₄)₂] complexes with strong organic bases (L), the "half-coordination" of the anion exists. As the electron-donating ability of the ligand increases, the interaction between the tetrafluoroborate ion and the metal atom becomes more efficient.