Syntheses and Properties of Metal Chelates of the Group IV Elements with the Ligands of Azo Compounds

Syntheses and Properties of Titanium, Zirconium and Silicon Chelates with the Ligands of Azo Compounds Containing Electron Withdrawing Substituents

Abstract

In order to obtain metal chelates of the group IV elements with the ligands of azo compounds and to investigate their properties as a pigment, titanium, zirconium and silicon chelates with the ligands of 2, 2′-dihydroxy azo compounds containing the electron withdrawing substituents such as chloro and nitro group were synthesized. The reaction of metal tetraalkoxide or silicon tetrachloride with the ligands gave the 1 : 2 chelates of metal to the ligand. Titanium, zirconium and silicon chelates were black, reddish brown and dark brown powder solids, respectively. Thermal stability and lightfastness of these chelates were compared with those of chelates containing the ligands without substituent and with electron donating substituent. The introduction of electron withdrawing group into the ligand increased lightfastness of these chelates and thermal stability of titanium and zirconium chelates. The properties of these chelates as a coloring material for the polystyrene resin were also investigated.