Studies on the stability of four-membered ring chelates .5. The stability of dialkyl dithiocarbamate chelates

This paper systematically studies the structure and the internal mechanism of the stability of sulphur-coordinated four-membered rings in chelates of dialkyl dithiocarbamate. It was found that the conjugated pi electron structure of the free ligand is Pi(4)(6), while in the metal chelate it is Pi(4)(4). The stable chelates have strong sigma- and pi-coordinated bonds. The actual strain of the sulphur-coordinated four-membered ring in chelates is not as strong as assumed. It mainly depends on the atomic radius of the metal. The stronger the electronegativity of the metal, the stronger the pi-coordinated bond. The stabler the four-membered ring, the weaker the intensity of the C-S vibrational band.