Synthesis of Coordination Polymers and Discrete Complexes from the Reaction of Copper(II) Carboxylates with Pyrazole: Role of Carboxylates Basicity

The reaction of select copper(II) monocarboxylates Cu(RCOO)2(H2O)x (R = C4H3O, C6H5, H; x 2, 4) with pyrazole (Hpz), carried out in protic solvents, yields mono- or dinuclear species [Cu(RCOO)2(Hpz)n]m (n 4; m 1, 2), always accompanied by tri- hexanuclear derivatives based on the triangular [Cu3(?3-OH)(?-pz)3]2+ fragment. molecular structures all isolated compounds have been established through XRD determinations. In some cases, mono-, act as secondary building units, self-assembling into 1D 3D coordination polymers. benzoate cluster contains coordinated and crystallization MeOH molecules, whose removal generates a crystalline polymer that can be reconverted soaking MeOH. relatively high pKb values carboxylate anions employed syntheses are responsible for preferential formation rather than ones.