Limits...
Crystal structures of Ca(ClO4)2·4H2O and Ca(ClO4)2·6H2O.

Hennings E, Schmidt H, Voigt W - Acta Crystallogr Sect E Struct Rep Online (2014)

Bottom Line: The structure of the hexa-hydrate contains two different Ca(2+) cations, each coordinated by six water mol-ecules and two O atoms of two perchlorate tetra-hedra, forming [Ca(H2O)6(ClO4)]2 dimers by sharing two ClO4 tetra-hedra.The dimers are arranged in sheets parallel (001) and alternate with layers of non-coordinating ClO4 tetra-hedra.O-H⋯O hydrogen bonds between the water mol-ecules as donor and ClO4 tetra-hedra and water mol-ecules as acceptor groups lead to the formation of a three-dimensional network in the two structures.

View Article: PubMed Central - HTML - PubMed

Affiliation: TU Bergakademie Freiberg, Institute of Inorganic Chemistry, Leipziger Strasse 29, D-09596 Freiberg, Germany.

ABSTRACT
The title compounds, calcium perchlorate tetra-hydrate and calcium perchlorate hexa-hydrate, were crystallized at low temperatures according to the solid-liquid phase diagram. The structure of the tetra-hydrate consists of one Ca(2+) cation eightfold coordinated in a square-anti-prismatic fashion by four water mol-ecules and four O atoms of four perchlorate tetra-hedra, forming chains parallel to [01-1] by sharing corners of the ClO4 tetra-hedra. The structure of the hexa-hydrate contains two different Ca(2+) cations, each coordinated by six water mol-ecules and two O atoms of two perchlorate tetra-hedra, forming [Ca(H2O)6(ClO4)]2 dimers by sharing two ClO4 tetra-hedra. The dimers are arranged in sheets parallel (001) and alternate with layers of non-coordinating ClO4 tetra-hedra. O-H⋯O hydrogen bonds between the water mol-ecules as donor and ClO4 tetra-hedra and water mol-ecules as acceptor groups lead to the formation of a three-dimensional network in the two structures. Ca(ClO4)2·6H2O was refined as a two-component inversion twin, with an approximate twin component ratio of 1:1 in each of the two structures.

No MeSH data available.


Related in: MedlinePlus

Formation of perchlorate-bridged dimers in Ca(ClO4)2·6H2O and location of ‘free’ perchlorate tetra­hedra in the gaps between the dimers (highlighted in dark green). Only the strongest hydrogen bonds are shown, represented by dashed lines.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4257416&req=5

fig4: Formation of perchlorate-bridged dimers in Ca(ClO4)2·6H2O and location of ‘free’ perchlorate tetra­hedra in the gaps between the dimers (highlighted in dark green). Only the strongest hydrogen bonds are shown, represented by dashed lines.

Mentions: In addition to the two coordinating perchlorate tetra­hedra in Ca(ClO4)·6H2O, two ‘free’ perchlorate tetra­hedra are present in the crystal structure. These ‘free’ ClO4 tetra­hedra are arranged in sheets and alternate with the [Ca(H2O)6(ClO4)]2 sheets along [001] (Fig. 4 ▶). The ‘free’ perchlorate tetra­hedra are connected to the dimers via O—H⋯O hydrogen bonds, as shown in Fig. 4 ▶. The dimers are additionally connected through further O—H⋯O hydrogen bonds (Table 2 ▶) into a three-dimensional network (Fig. 5 ▶).


Crystal structures of Ca(ClO4)2·4H2O and Ca(ClO4)2·6H2O.

Hennings E, Schmidt H, Voigt W - Acta Crystallogr Sect E Struct Rep Online (2014)

Formation of perchlorate-bridged dimers in Ca(ClO4)2·6H2O and location of ‘free’ perchlorate tetra­hedra in the gaps between the dimers (highlighted in dark green). Only the strongest hydrogen bonds are shown, represented by dashed lines.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4257416&req=5

fig4: Formation of perchlorate-bridged dimers in Ca(ClO4)2·6H2O and location of ‘free’ perchlorate tetra­hedra in the gaps between the dimers (highlighted in dark green). Only the strongest hydrogen bonds are shown, represented by dashed lines.
Mentions: In addition to the two coordinating perchlorate tetra­hedra in Ca(ClO4)·6H2O, two ‘free’ perchlorate tetra­hedra are present in the crystal structure. These ‘free’ ClO4 tetra­hedra are arranged in sheets and alternate with the [Ca(H2O)6(ClO4)]2 sheets along [001] (Fig. 4 ▶). The ‘free’ perchlorate tetra­hedra are connected to the dimers via O—H⋯O hydrogen bonds, as shown in Fig. 4 ▶. The dimers are additionally connected through further O—H⋯O hydrogen bonds (Table 2 ▶) into a three-dimensional network (Fig. 5 ▶).

Bottom Line: The structure of the hexa-hydrate contains two different Ca(2+) cations, each coordinated by six water mol-ecules and two O atoms of two perchlorate tetra-hedra, forming [Ca(H2O)6(ClO4)]2 dimers by sharing two ClO4 tetra-hedra.The dimers are arranged in sheets parallel (001) and alternate with layers of non-coordinating ClO4 tetra-hedra.O-H⋯O hydrogen bonds between the water mol-ecules as donor and ClO4 tetra-hedra and water mol-ecules as acceptor groups lead to the formation of a three-dimensional network in the two structures.

View Article: PubMed Central - HTML - PubMed

Affiliation: TU Bergakademie Freiberg, Institute of Inorganic Chemistry, Leipziger Strasse 29, D-09596 Freiberg, Germany.

ABSTRACT
The title compounds, calcium perchlorate tetra-hydrate and calcium perchlorate hexa-hydrate, were crystallized at low temperatures according to the solid-liquid phase diagram. The structure of the tetra-hydrate consists of one Ca(2+) cation eightfold coordinated in a square-anti-prismatic fashion by four water mol-ecules and four O atoms of four perchlorate tetra-hedra, forming chains parallel to [01-1] by sharing corners of the ClO4 tetra-hedra. The structure of the hexa-hydrate contains two different Ca(2+) cations, each coordinated by six water mol-ecules and two O atoms of two perchlorate tetra-hedra, forming [Ca(H2O)6(ClO4)]2 dimers by sharing two ClO4 tetra-hedra. The dimers are arranged in sheets parallel (001) and alternate with layers of non-coordinating ClO4 tetra-hedra. O-H⋯O hydrogen bonds between the water mol-ecules as donor and ClO4 tetra-hedra and water mol-ecules as acceptor groups lead to the formation of a three-dimensional network in the two structures. Ca(ClO4)2·6H2O was refined as a two-component inversion twin, with an approximate twin component ratio of 1:1 in each of the two structures.

No MeSH data available.


Related in: MedlinePlus