A novel inorganic sandwiched-type ruthenium-containing polyoxometalate, K8Na3H9Ru4O4W9O332·30H2O (Ru4W18), featuring a central parallelogram-shaped tetranuclear ruthenium oxo cluster Ru4 that bridges two trivacant W9O3312− units, was synthesised in this study. The Ru4W18. . .
Xiong et al. (Thu,) studied this question.