The insoluble octanuclear mixed-metal cluster Na2[VW3O4(O2CEt)8]2 (1) was prepared by the redox reaction of W(CO)6 with NaVO3 in propionic anhydride. The crystal is triclinic of space group P1 with a 1.2973(4), b 1.4063(3), c 1.2396(5) nm, a 109.92(2), b 117.33(2), g 90.53(2)? dc = 2.29 g/cm3, Z = 1, final R = 0.030 for 5499 observed reflections [I > 3s(I)]. The structure of the compound consists of an interesting centrosym. anion, where two [W3O4]4+ units are connected by two V atoms to complete a circular specie. The average W-W bond length is 0.25328(6) nm and the average distance between V and W atoms is 0.3654 nm. The anions are connected by Na+ to form a 1-dimensional infinite chain structure. Each Na atom is coordinated to five O atoms with average Na-O distance of 0.2314 nm. The short Na-O distance and chain structure are responsible for the insoly. of the cluster 1.

Key words: CRYSTAL STRUCTURE DETERMINATION, SODIUM COMPOUNDS, FOUR-CIRCLE DIFFRACTOMETER, VANADIUM COMPLEX, TUNGSTEN COMPLEX