Dicyclopentadienyl molybdenum crosslinked complexes which can be represented by general formula (1) below are provided, the use thereof as friction-modifiers and lubricating compositions which contain these compounds are also provided. In this formula X is the element oxygen or the element sulphur, Y is the element oxygen or Y is absent, and R1 to R10 are groups selected individually from the group comprising hydrogen, the methyl group and the ethyl group.