CRYSTAL STRUCTURE OF ZN(NO3)2.2H2O

Crystals of Zn(NO3)2 • 2H2O were prepared by evaporation of ZnO solutions in HNO3 (fuming).The crystals are monoclinic with a = 5.754 ± 0.006, °2' ±20' and Z = 2 formula units per unit cell. The space group is [formula omitted]. The crystal has been refined by least-squares calculations to a final R value of 9.3 °/o. Hydrogen atoms were located by difference syntheses. The zinc atoms are surrounded by a distorted octahedron composed of four oxygen atoms belonging to the nitrate ions and of two oxygen atoms belonging to two water molecules. The zinc-oxygen distances have values between 2.03 and 2.22 Å, the N-O distances are 1.22, 1.23 and 1.24 Å. Zinc nitrate dihydrate has a layer structure. The layers are parallel to (100) and are linked together by hydrogen bonds (2.93 Å). Each H2O molecule forms two hydrogen bonds with oxygen atoms of the nitrate groups (2.84, 2.93 Å). © 1969, Walter de Gruyter. All rights reserved.