“…reaction of the known compound 3-(2-pyridyl)-1H-pyrazole with the bis(bromomethyl)-aromatic compound in a 2:1 ratio under phase transfer conditions. Thus, L 1 was prepared using 1,2-bis(bromomethyl)benzene [16,17], L 2 using 2,3-bis(bromomethyl)-naphthalene [18], and so on. These ligands are all tetradentate, and accordingly, reaction with metal cations that prefer an octahedral coordination geometry requires 1.5 ligands per metal ion to provide the necessary six donor atoms (assuming that noncoordinating anions are used).…”