PREPARATION AND CRYSTAL-STRUCTURE OF HEXAS (ISOPROPYLAMMONIUM) DECAVANADATE TETRAHYDRATE

We describe the preparation and crystal structure of hexas (isopropyla mmonium) decavanadate tetrahydrate. (C3H10N)(6)V10O28.4H(2)O is monocl inic, C2/c, with Z = 4 and the following unit-cell dimensions : a = 25 .475(5), b = 10.767(2), c = 19.046(4)Angstrom, beta = 112.54(2)degrees . The atomic arrangement has been determined with a set of 3789 indepe ndent reflections and a final R value of 0.029. The atomic arrangement is a layer organization. Cationic and anionic entities alternate in p lanes perpendicular to the b direction. The decavanadate anion [V10O28 ](6-) observed in the present structure is centrosymmetric. A detailed geometrical analysis of this anion is given and the hydrogen-bond net work described.