Unreported Coordination Behavior of A Squaric Bis (Hydrazone) Ligand

Abstract

A compartmental tetrabasic hexadentate ligand (H4L) -has two symmetrical NNO sets of donor atomswas synthesized by the condensation of squaric acid with a hydrazino triazine compound. The reaction of the ligand with Pd(II), Fe(III), Co(II), Ni(II), Cu(II), VO(II) and UO2(II)- ions afforded mono- and binuclear as well as dimeric complexes. The ligational behavior of the ligand is highly affected by the type of the metal ion and its counter anion. The isolated complexes reflect the structural diversity (pentagonal bipyramid, octahedral, square pyramid and square planar) as well as the versatile coordination bonding modes. The size of the cation has proved to be of importance in directing the synthetic pathway. Structural elucidation of the isolated complexes was achieved via elemental and thermal analyses as well as spectral studies.