소량의 요오드 화합물이 윤활류에 함유될 때 금속표면사이의 마찰을 감소시키고 내마모성을 향상시키는데 이는 금속표면에 박층상구조의 이요오드화물이 형성되기 때문이라고 한다. 그러나 금속표면에서의 화학반응성, 마모와 극압실험 및 hot wire method에 의한 결과에 의하면 윤활기구는 이 요오드화물의 박층상 구조가 아니고 다른 기구에 의한 것임을 알았다. 유기 요오드화합물중에서 특히 N-iodopyridinium dichlorodate는 double charge transfer complex로써 다른 methyl iodide계의 화합물 보다 금속표면 사이의 마찰을 더욱 감소시키고 윤활기구는 interhalogen의 화학반응에 의한 것임을 알았다.
Small amounts of iodine compound in mineral oils are usually effective in reducing friction of metallic surfaces. Such improvement in frictional behaviour of wear characteristics was explained by the formation of a diiodide layer lattice structure at the metallic contact surfaces. The lubrication mechanism, however, by which organoiodine compounds functions is not based on the formation of such lattice structure iodide. It was tested and shown, by a static surface chemical reactivity test, wear and EP tests, and a hot wire method, that compound such as N-iodopyridinium dichlorodate, a double charge transfer complex, reacted with metals as an interhalogen compound and that the resultant thin film product reduced appreciable the friction of metallic surfaces, more than compounds such as methyl iodide, diiodomethane, and iodoform. These results suggest that the action of iodine, included in organoiodine compounds, is not that of a classical layer structure iodide, and an entirely new mechanism may be derived from a further studies on charge transfer complex compounds of organoiodine compounds.
