The structure and orientation of heptylxanthate adsorbed on a ZnS surface h
ave been studied by the FTIR-ATR technique. By using polarized light and th
e dichroic ratio, we found the average tilt angle to be approximately 44 de
grees. The adsorbed layer studied was prepared by self-assembly from soluti
on or by spraying the solution onto the surfaces of the ATR crystal for a s
hort time and then rinsing with water. From the spectra we can conclude tha
t there is a mixture of adsorbed heptylxanthate and formed diheptyldixantho
gen on the ZnS surface. A bridging coordination of the adsorbed heptylxanth
ate is proposed.