Extended X-Ray-Absorption Fine-Structure Spectroscopic Study of Acetone Solutions of Zinc and Lead(Ii) Ethylxanthate

EXAFS and vibrational spectra of acetone solutions of zinc and lead(II) ethylxanthate have been recorded in order to correlate structural data with absorption bands in the mid-infrared region. Two ethylxanthate ions are monodentately coordinated to both zinc and lead(II) in acetone solution. Two acetone molecules are weakly coordinated to zinc to complete a tetrahedral configuration round zinc, while no acetone molecules were found in the inner sphere of the lead(II) complex. A band containing a large contribution from the C-S stretching, observed just above 1000 cm(-1) in solid zinc and lead(II) ethylxanthate, where the ethylxanthate ion is bridgingly and bidentately coordinated, respectively, shifts upwards by 20 and 17 cm(-1) in the corresponding zinc and lead(II) complexes, respectively, in acetone solution. An upward shift by about 8 cm(-1) is found in the nickel(II) and arsenic(III) complexes, where the coordination of the ethylxanthate ion remains unchanged but acetone molecules solvate the central ion to complete an octahedral configuration. No shift was found in iron(III) ethylxanthate, where the coordination remains unchanged and no acetone molecules solvate the iron(III) ion.