Firing-activated interaction of montmorillonite with tin(Iv) and copper(ii) phthalocyanine dyes

Abstract

Copyright © The Authors 2021. The adsorption of phthalocyanines Pcs complexes onto montmorillonite MMT clay differs from that of the other complexes like porphyrins, in that the adsorption process can be completed only after firing treatment of the solid mixture. The MMT particles act as a complex-hosting matrix, and the actual adsorption process of the complexes onto the MMT occurs only after firing. This firing treatment generates different colors on firing the solid mixtures to different temperatures. When tin(IV) phthalocyanine dichloride Sn(IV)PcCl2 complex is adsorbed onto the MMT, the chloride ligands are replaced by oxygen, and the complex is more protected from decomposition due to firing and solution effects. Both complexes, diamagnetic Sn(IV)PcCl2 and the paramagnetic Cu(II)Pc are found in a free radical state on the MMT surface or intercalated in the interlayer after firing, produced by electron transfer from the complexes to the MMT. It was found by X-ray powder diffraction investigation that firing treatment of the air-dried metal Pc-MMT samples induces intercalation of the complexes in the MMT interlayer.