Dichloride Hexahydrate Research Articles

Orientations of the Water Molecules in Cobalt Dichloride Hexahydrate by Nuclear Magnetic Resonance

The orientations of the water molecules in cobalt dichloride hexahydrate have been established by study of the proton resonance spectrum. The directions of the experimentally determined proton-proton vectors are compared with a hydrogen bonding scheme which is determined from the crystal structure reported by Mizuno. The scheme is then modified to fit the experimental data. The proposed atomic parameters for the hydrogen atoms are x , y , z =(0.097, 0.313, 0.268); (0.427,0.205, 0.205); (0.191, 0.000, 0.549); (0.226, 0.500, 0.162).

An X-ray Study on the Structure of Cobalt Dichloride Hexahydrate

The crystal structure of CoCl 2 ·6H 2 O has been determined by the X-ray single crystal method. The unit cell is monoclinic with a =10.34 Å, b =7.06 Å, c =6.67 Å and β=122°20'. The space group is C 2 h 3 – C 2/ m and the unit cell contains two molecules. Two Cl - ions and four water molecules are octahedrally coordinated to Co 2+ ion to form the group [CoCl 2 ·4H 2 O].These groups are held together parallel to the b axis by O…H–O type hydrogen bonds. The other two water molecules of the formula unit are far from Co 2+ ion. The crystal has the layer structure parallel to (001), and this causes the perfect cleavage. The structure proposed for this salt by Stroganov et al. seems to be incorrect.