Mo(VI) dithiocarbamate with no pre-existing Mo–S–Mo core as an active lubricant additive

MoDTC molecular additives reduce friction in boundary lubricated steel-steel contacts through formation of MoS2 sheets. The chemical pathway from to is investigated for optimizing formation. Our experiments show that a molecule containing sulfur only its thiocarbamate ligands forms sheets during friction, demonstrating the presence peripheral can be sufficient provide required source. This not competitive with core but also more efficient at high contact pressures. Mechanistic investigations on transformation reveal thermal activation alone thus suggesting pressure and/or shear are necessary generation this system.