In this paper, solid state synthesis of a series of Mo(W)-Cu(Ag)-S cluster compounds at low heating temperatures has been reported. It has been found that the regularity of cluster formation of thiomolybdate (or thiotungstate) with copper (or silver) is closely relevant to the solid state reaction temperatures. The possible mechanism of cluster formation of Mo(W)-Cu(Ag)-S cluster compounds with nuclearity from four to seven has been suggested.

Key words: INFRARED SPECTROPHOTOMETRY, COPPER COMPLEX, MOLYBDENUM COMPLEX, CLUSTER COMPOUND, SULFIDE COMPLEX, FOUR-CIRCLE DIFFRACTOMETER