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Crystal structures of Sr(ClO4)2·3H2O, Sr(ClO4)2·4H2O and Sr(ClO4)2·9H2O.

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

Bottom Line: The structure of the nona-hydrate contains one Sr(2+) cation coordinated by seven water mol-ecules and by two O atoms of two perchlorate tetra-hedra (point group symmetry ..m), forming a tricapped trigonal prism (point group symmetry m2m).The structure contains additional non-coordinating water mol-ecules, which are located on twofold rotation axes.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 each of the three 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, strontium perchlorate trihydrate {di-μ-aqua-aquadi-μ-perchlorato-strontium, [Sr(ClO4)2(H2O)3] n }, strontium perchlorate tetra-hydrate {di-μ-aqua-bis-(tri-aqua-diperchloratostrontium), [Sr2(ClO4)4(H2O)8]} and strontium perchlorate nona-hydrate {hepta-aqua-diperchloratostrontium dihydrate, [Sr(ClO4)2(H2O)7]·2H2O}, were crystallized at low temperatures according to the solid-liquid phase diagram. The structures of the tri- and tetra-hydrate consist of Sr(2+) cations coordinated by five water mol-ecules and four O atoms of four perchlorate tetra-hedra in a distorted tricapped trigonal-prismatic coordination mode. The asymmetric unit of the trihydrate contains two formula units. Two [SrO9] polyhedra in the trihydrate are connected by sharing water mol-ecules and thus forming chains parallel to [100]. In the tetra-hydrate, dimers of two [SrO9] polyhedra connected by two sharing water mol-ecules are formed. The structure of the nona-hydrate contains one Sr(2+) cation coordinated by seven water mol-ecules and by two O atoms of two perchlorate tetra-hedra (point group symmetry ..m), forming a tricapped trigonal prism (point group symmetry m2m). The structure contains additional non-coordinating water mol-ecules, which are located on twofold rotation axes. 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 each of the three structures.

No MeSH data available.


Perchlorate tetra­hedra in the structure of Sr(ClO4)2·3H2O linking the chains (oriented parallel to [100]) into (100) layers.
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fig4: Perchlorate tetra­hedra in the structure of Sr(ClO4)2·3H2O linking the chains (oriented parallel to [100]) into (100) layers.

Mentions: In strontium perchlorate trihydrate, chains are formed with alternating Sr2+ cations (Fig. 2 ▶). These zigzag chains are oriented parallel to [100] and are linked by edge-sharing with the perchlorate tetra­hedra (Fig. 4 ▶) into a layered arrangement parallel to (001), as shown in Fig. 5 ▶. Within the structure of the tetra­hydrate, each perchlorate anion coordinates to the dimeric unit of two Sr2+ cations (Fig. 6 ▶). At the same time, it also coordinates to another dimeric unit. Thus, each dimeric unit is connected pairwise by perchlorate anions with four others. This yields in (001) layers stacked along [001], as visualized in Fig. 7 ▶. The nona­hydrate structure contains additional lattice water mol­ecules, which are both donor and acceptor groups, resulting in a tetra­hedral arrangement of O—H⋯O hydrogen bonds. Two hydrogen bonds are formed towards the [SrO2(OH2)7] coordination polyhedra and two towards perchlorate tetra­hedra (Fig. 8 ▶a, Table 1 ▶). The [SrO2(OH2)7] polyhedra additionally are linked via other O—H⋯O hydrogen bonds. The resulting arrangement can be seen in a larger section of the structure (Fig. 8 ▶b). O—H⋯O hydrogen bonds also dominate the crystal packing in the two other structures, in each case leading to the formation of a three-dimensional network (Tables 2 ▶ and 3 ▶).


Crystal structures of Sr(ClO4)2·3H2O, Sr(ClO4)2·4H2O and Sr(ClO4)2·9H2O.

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

Perchlorate tetra­hedra in the structure of Sr(ClO4)2·3H2O linking the chains (oriented parallel to [100]) into (100) layers.
© Copyright Policy - open-access
Related In: Results  -  Collection

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fig4: Perchlorate tetra­hedra in the structure of Sr(ClO4)2·3H2O linking the chains (oriented parallel to [100]) into (100) layers.
Mentions: In strontium perchlorate trihydrate, chains are formed with alternating Sr2+ cations (Fig. 2 ▶). These zigzag chains are oriented parallel to [100] and are linked by edge-sharing with the perchlorate tetra­hedra (Fig. 4 ▶) into a layered arrangement parallel to (001), as shown in Fig. 5 ▶. Within the structure of the tetra­hydrate, each perchlorate anion coordinates to the dimeric unit of two Sr2+ cations (Fig. 6 ▶). At the same time, it also coordinates to another dimeric unit. Thus, each dimeric unit is connected pairwise by perchlorate anions with four others. This yields in (001) layers stacked along [001], as visualized in Fig. 7 ▶. The nona­hydrate structure contains additional lattice water mol­ecules, which are both donor and acceptor groups, resulting in a tetra­hedral arrangement of O—H⋯O hydrogen bonds. Two hydrogen bonds are formed towards the [SrO2(OH2)7] coordination polyhedra and two towards perchlorate tetra­hedra (Fig. 8 ▶a, Table 1 ▶). The [SrO2(OH2)7] polyhedra additionally are linked via other O—H⋯O hydrogen bonds. The resulting arrangement can be seen in a larger section of the structure (Fig. 8 ▶b). O—H⋯O hydrogen bonds also dominate the crystal packing in the two other structures, in each case leading to the formation of a three-dimensional network (Tables 2 ▶ and 3 ▶).

Bottom Line: The structure of the nona-hydrate contains one Sr(2+) cation coordinated by seven water mol-ecules and by two O atoms of two perchlorate tetra-hedra (point group symmetry ..m), forming a tricapped trigonal prism (point group symmetry m2m).The structure contains additional non-coordinating water mol-ecules, which are located on twofold rotation axes.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 each of the three 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, strontium perchlorate trihydrate {di-μ-aqua-aquadi-μ-perchlorato-strontium, [Sr(ClO4)2(H2O)3] n }, strontium perchlorate tetra-hydrate {di-μ-aqua-bis-(tri-aqua-diperchloratostrontium), [Sr2(ClO4)4(H2O)8]} and strontium perchlorate nona-hydrate {hepta-aqua-diperchloratostrontium dihydrate, [Sr(ClO4)2(H2O)7]·2H2O}, were crystallized at low temperatures according to the solid-liquid phase diagram. The structures of the tri- and tetra-hydrate consist of Sr(2+) cations coordinated by five water mol-ecules and four O atoms of four perchlorate tetra-hedra in a distorted tricapped trigonal-prismatic coordination mode. The asymmetric unit of the trihydrate contains two formula units. Two [SrO9] polyhedra in the trihydrate are connected by sharing water mol-ecules and thus forming chains parallel to [100]. In the tetra-hydrate, dimers of two [SrO9] polyhedra connected by two sharing water mol-ecules are formed. The structure of the nona-hydrate contains one Sr(2+) cation coordinated by seven water mol-ecules and by two O atoms of two perchlorate tetra-hedra (point group symmetry ..m), forming a tricapped trigonal prism (point group symmetry m2m). The structure contains additional non-coordinating water mol-ecules, which are located on twofold rotation axes. 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 each of the three structures.

No MeSH data available.