Tetraalkylammonium tetrathiomolybdate derivatives containing different alkyl groups as ligands have been synthesized. It has been found that the compounds exhibit antiwear and antifriction properties in dioctyl phthalate, a medium that models synthetic lubricating oil. A change in the surface profile (decrease in roughness) by the action of molybdenum sulfide produced from nitrogen-containing molybdenum compounds in tribocontact has been shown by atomic force spectroscopy.