The Copper (II) Complexes of Phenyl‐2 Pyridyl Ketone and the Triple Complexes Obtained by Adding Ethylenediamine

Copper salts of low pH (1.8–2.5) combine with phenyl‐2‐pyridyl ketone to form a ketone complex [(Py–CO–C 6 H 5 ) 2 Cu] 2+ . An electrically uncharged complex is obtained at pH > 9 [(Py–C(OH)(C 6 H 5 )O − ) 2 Cu] 0 , liberating two protons from two molecules of the ligand. The stability constant of this complex is β = 16.05. By mixing the copper salts (except the halide) containing this ligand with ethylenediamine, a charged triple complex is obtained at pH < 7 [Py–C(OH)(C 6 H 5 ) O–Cu–NH 2 C 2 H 4 NH 3 + ] 2+ . At pH > 9.5, an uncharged triple complex is obtained: {[(Py–C(OH)(C 6 H 5 )O − ) 2 Cu} 2 · NH 2 C 2 H 4 NH 2 } 0 . The copper halide salts produce only an uncharged triple complex; the halide ions are coordinated with the copper atoms. All of these complexes in their solid state, are bi‐ or polynuclear. As a result, they are magnetically subnormal.