Molybdenum dithiocarbamate

Molybdenum dithiocarbamates are reported with the metal in the oxidation states + 2,... 

Table 5.15. Protective tribofilm formation from degradation of molybdenum dithiocarbamate (MoDTC), molybdenum dithiophosphate (MoDDP) and molybdenum amine-ester complex (MoAC) directly and in combination with ZDDPs or sulfur compounds...

In order to better understand the fundamentals of friction reduction by molybdenum dithiocarbamate and to relate it to chemical changes and transfer phenomena of the tribofilm, an ultrahigh vacuum (UHV, 10 7 Pa) tribometer was used (Grossiord et al., 1998 Martin et al., 1999). Specifically, this tribometer allows in situ Auger electron spectroscopy (AES), X-ray photoelectron... 

Figure 5.7 Reprinted from Tribol. Int., Vol. 31, C. Grossiord, J.M. Martin, Th. Le Mogne, C. Esnouf and K. Inoue, MoS2 single sheet lubrication by molybdenum dithiocarbamate, pp 737-743. Copyright 1998, with permission from Elsevier.

The various types of compound and their mechanisms of action have been reviewed by Mitchell . He concluded that the question of the extent to which the molybdenum additives decompose to produce molybdenum disulphide, if at all, was not yet resolved and certainly depended on the type of compound and the operating conditions. There was little doubt that molybdenum dithiocarbamates form molybdenum disulphide, probably by decomposition at hot spots caused by asperity interactions. It was less certain that molybdenum dithiophosphates form molybdenum disulphide, although mixtures of zinc dialkyidithiophosphate and molybdenum complexes had been shown to do so . 

Brown, A., Bell, 1., McConnachie, J. and Stiefel, E. (1999) Molybdenum Dithiocarbamates for Enhanced Eriction Control and Fuel Economy, Preprints-American Chemical Society, Division of Petroleum Chemistry, 44 (3) 326-331. 

Grossiord, C., Varlot, K., Martin, J. M., Le-Mogne, T., Esnouf, C. and Inoue, K., M0S2 single sheet lubrication by molybdenum dithiocarbamate. Tribology International, 31 (12), 1998, lUMAi. 

A selection of molybdenum dithiocarbamate complexes in oxidation states +5... 

The chemistry of molybdenum dithiocarbamate complexes has come a long way since the early work of Malatesta (767), and between 1978 and 2003 there were over 300 publications in this area, accessible oxidation states ranging from 0 to +6. 

Figure 277. Examples of heterometallic mercury-molybdenum dithiocarbamate complexes...

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