Synthesis and crystal structures of copper(II) and silver(I) complexes of a biphenyl-bridged bipyrazolyl ligand

A semirigid bipyrazolyl ligand, 4,4'-bis[(3aEuro(3),5aEuro(3)-diethyl-1H-pyrazol-4aEuro(3)-yl)methylene)]-1,1'-biphenyl (H2L), and four of its Ag(I) and Cu(II) complexes have been prepared and structurally characterized. X-ray analysis demonstrates that the Ag(I) complexes are dinuclear molecular rectangle, while the Cu(II) complexes display a twisted rectangular structure. Two different conformations, namely cis and trans, have been observed for this bipyrazolyl ligand.