Poly[[μ-aqua-aqua­[μ4-ethyl (dichloro­methyl­ene)diphospho­nato]sesqui­calcium(II)] acetone hemisolvate 4.5-hydrate]

Jonna Jokiniemi; Sirpa Peräniemi; Jouko Vepsäläinen; Markku Ahlgrén

doi:10.1107/S1600536809010150

. 2009 Mar 25;65(Pt 4):m436–m437. doi: 10.1107/S1600536809010150

Poly[[μ-aqua-aqua[μ₄-ethyl (dichloromethylene)diphosphonato]sesquicalcium(II)] acetone hemisolvate 4.5-hydrate]

Jonna Jokiniemi ^a,^*, Sirpa Peräniemi ^b, Jouko Vepsäläinen ^b, Markku Ahlgrén ^a

PMCID: PMC2968796 PMID: 21582374

Abstract

The title compound, {[Ca_1.5(C₃H₅Cl₂O₆P₂)(H₂O)₂]·0.5CH₃COCH₃·4.5H₂O}_n, has a two-dimensional polymeric structure. The asymmetric unit contains two crystallographically independent Ca²⁺ cations connected by a chelating and bridging ethyl (dichloromethylene)diphosphonate(3⁻) ligand and an aqua ligand. One of the Ca atoms, lying on a centre of symmetry, has a slightly distorted octahedral geometry, while the other Ca atom is seven-coordinated in a distorted monocapped trigonal-prismatic geometry. The polymeric layers are further connected by extensive O—H⋯O hydrogen bonding into a three-dimensional supramolecular network. The acetone solvent molecule and one uncoordinated water molecule are located on twofold rotation axes.

Related literature

For applications of metal complexes of bisphosphonates, see: Clearfield et al. (2001 ▶); Clearfield (1998 ▶); Fu et al. (2007 ▶); Serre et al. (2006 ▶). For calcium bisphosphonate complexes, see: Lin et al. (2007 ▶); Mathew et al. (1998 ▶). For metal complexes of bisphosphonate ester derivatives, see: Jokiniemi et al. (2007 ▶, 2008 ▶).

Experimental

Crystal data

[Ca_1.5(C₃H₅Cl₂O₆P₂)(H₂O)₂]·0.5C₃H₆O·4.5H₂O
M _r = 476.17
Monoclinic,
a = 31.2205 (3) Å
b = 10.1546 (1) Å
c = 11.6510 (1) Å
β = 103.107 (1)°
V = 3597.51 (6) Å³
Z = 8
Mo Kα radiation
μ = 1.02 mm⁻¹
T = 150 K
0.25 × 0.15 × 0.10 mm

Data collection

Nonius KappaCCD diffractometer
Absorption correction: multi-scan (XPREP in SHELXTL; Sheldrick, 2008 ▶) T _min = 0.823, T _max = 0.905
31118 measured reflections
4209 independent reflections
3617 reflections with I > 2σ(I)
R _int = 0.055

Refinement

R[F ² > 2σ(F ²)] = 0.030
wR(F ²) = 0.073
S = 1.10
4209 reflections
213 parameters
H-atom parameters constrained
Δρ_max = 0.47 e Å⁻³
Δρ_min = −0.58 e Å⁻³

Data collection: COLLECT (Nonius, 1997 ▶); cell refinement: DENZO/SCALEPACK (Otwinowski & Minor, 1997 ▶); data reduction: DENZO/SCALEPACK; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Brandenburg, 2005 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809010150/xu2487sup1.cif

e-65-0m436-sup1.cif^{(25.4KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809010150/xu2487Isup2.hkl

e-65-0m436-Isup2.hkl^{(202.2KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Selected bond lengths (Å).

Ca1—O1	2.3778 (14)
Ca1—O11	2.2278 (14)
Ca1—O21	2.3279 (15)
Ca2—O1	2.5726 (15)
Ca2—O2	2.4024 (15)
Ca2—O11ⁱ	2.4049 (15)
Ca2—O12	2.3466 (14)
Ca2—O13ⁱⁱ	2.3320 (15)
Ca2—O13ⁱ	2.5858 (15)
Ca2—O22	2.3158 (15)

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Symmetry codes: (i) Inline graphic ; (ii) .

Table 2. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1B⋯O3	0.99	1.81	2.794 (2)	171
O1—H1A⋯O12ⁱⁱ	0.99	1.83	2.637 (2)	137
O2—H2A⋯O3	0.84	1.88	2.717 (2)	172
O2—H2B⋯O21ⁱⁱⁱ	0.85	1.90	2.746 (2)	177
O3—H3A⋯O6^iv	0.86	1.93	2.782 (2)	175
O3—H3B⋯O4ⁱⁱⁱ	0.86	1.89	2.734 (2)	169
O4—H4A⋯O22	0.85	2.00	2.841 (2)	166
O4—H4B⋯O2^iv	0.85	1.93	2.754 (2)	163
O5—H5A⋯O4	0.85	2.02	2.838 (2)	163
O5—H5B⋯O6	0.85	2.05	2.901 (3)	171
O6—H6A⋯O8	0.85	2.02	2.831 (2)	161
O6—H6B⋯O7^v	0.84	2.26	2.832 (2)	125
O7—H7⋯O5	0.84	1.98	2.799 (2)	166

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Symmetry codes: (ii) Inline graphic ; (iii) ; (iv) ; (v) .

supplementary crystallographic information

Comment

Metal bisphosphonates have been attracting closer attention in light of their important applications in industrial processes such as ion-exchange, catalysis and sorption (Clearfield et al., 2001, Clearfield, 1998, Fu et al., 2007). Metal bisphosphonates usually adopt layered or pillared layered structures (Fu et al., 2007, Mathew et al., 1998). Other structural types, such as 1-D and 3-D open networks, have also been prepared in order to study the properties of bisphosphonate solid materials (Lin et al., 2007, Fu et al., 2007). Most of the effective materials consist of open frameworks and microporous structures (Fu et al., 2007, Serre et al., 2006). In recent investigations, we studied the complexing properties of amide ester derivatives of (dichloromethylene)bisphosphonate, Cl₂MBP (Jokiniemi et al., 2007, 2008). The introduction of various ester substituents into phosphonate groups can results in novel structures of metal bisphosphonates and lead to interesting functionalities. Of the numerous metal phosphonate compounds now known, only a small number have been prepared with alkali earth metals. We now present the crystal structure of the Ca(II) complex of the monoethyl ester derivative of Cl₂MBP obtained by gel crystallization.

The title compound consists of two-dimensional layers parallel to the (100) plane. The Ca1 atom lies on the centre of symmetry with two symmetrically chelating (Cl₂CP₂O₆Et)^3- ligands and two aqua ligands in axial positions; the geometry is slightly distorted octahedron with Ca1–O bond lengths of 2.228 (1)–2.378 (1) Å (Table 1, Fig. 1). The three trans bond angles are 180.0°, while the cis bond angles range from 84.12 (5) to 95.88 (5)°. The aqua ligand O1 bridges Ca1 and the adjacent Ca2 atom with Ca···Ca distance of 4.4283 (4) Å. The Ca2 atom is seven-coordinated in distorted monocapped trigonal prismatic geometry and is coordinated by five phosphonate O atoms from three different (Cl₂CP₂O₆Et)^3- ligands. The coordination sphere is completed by two aqua ligands. The Ca2–O bond lengths are 2.316 (2)–2.586 (2) Å. The (Cl₂CP₂O₆Et)^3- ligand is coordinated to four Ca²⁺ cations through five O atoms forming two six-membered chelate rings with Ca1 and Ca2 atoms, and the P1 atom forms a four-membered chelate ring with the adjacent Ca2D atom (x, -y, z - 1/2). Thus, the two oxygen atoms (O11, O13) act as monoatomic bridges between two Ca atoms.

The layers are further connected by extensive hydrogen bonding (O···O 2.637 (2)–2.901 (3) Å, 125–177°) into a 3-D network with the interlayer distance of 15.2036 (2) Å (Fig. 2, Table 2). The O8 and C2 atoms of the acetone molecule, as well as the water molecule O7, are located on the individual two-fold rotation axis. The ethyl groups and chlorine atoms point out from the layers.

Experimental

Na₃Cl₂CP₂O₆Et (10.0 mg, 0.030 mmol) and CaCl₂.2H₂O (4.3 mg, 0.030 mmol) were dissolved separately in water (2.25 ml), the solutions were mixed, and tetramethoxysilane (TMOS 0.5 ml) was added. The two-phase system was shaken until homogeneous. After gel formation, a precipitant, acetone (1.0 ml), was added above the gel to induce crystallization. After about three months, colourless crystals suitable for X-ray analysis were formed uniformly throughout the gel as thin needles. The elemental analyses were performed several times and the results were consistent indicating that the acetone molecule and 3.5 water molecules were evaporated when the crystals were dried in air.