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The title compound, calcium bis(3-ammonio-1-hydroxy­propyl­idene-1,1-bis­phospho­nate) dihydrate, Ca2+·2C3H10N­O7P2-·2H2O, consists of calcium octahedra arranged in columns along the c axis and coordinated by hydrogen-bonded molecular anions. The Ca2+ cation lies on a twofold axis. Pamidronate adopts a twisted conformation of the hydroxy­alkyl­amine backbone that enables the formation of an intramolecular N-H...O hydrogen bond. The molecular anion is chelating monodentate as well as bidentate, with an O...O bite distance of 3.0647 (15) Å.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S010827010201497X/ob1076sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S010827010201497X/ob1076Isup2.hkl
Contains datablock I

CCDC reference: 197314

Comment top

gem-Bisphosphonates are commonly used in clinical practice as safe and efficacious therapeutic agents for the treatment of a number of bone disorders, such as osteoporosis, Paget's disease and hypercalcemia associated with malignancy (Compston, 1994; Russell & Rogers, 1999; Rodan & Martin, 2000). These compounds have the PO3 groups bridged by the geminal C atom, an atomic connectivity, though chemically and enzymatically non-hydrolizable, resembling that of inorganic pyrophosphate. As has been recognized previously, these compounds are able to affect the growth of calcium hydroxyapatite crystals. In connection with this, the Ca salts of the bisphosphonates etidronate [calcium dihydrogen ethane-1-hydroxy-1,1-diphosphonate dihydrate, CaH2EHDP·2H2O; Cambridge Structural Database (CSD; Allen et al., 1983) refcode CAEHDP; Uchtman, 1972] and clodronate (calcium dichloromethylene-1,1-diphosphonate pentahydrate, CaH2Cl2MDP·5H2O; CSD refcode CAVKUF; Nardelli et al., 1983) have been crystallographically studied and their chelating capabilities unveiled. Subsequently, biological activity was associated with the mechanism of action of the bisphosphonates (Felix & Fleisch, 1981). At present, it is known that the surface of bone is resorbed by specialized cells, so the bisphosphonates are incorporated, but not metabolized, by the osteoclasts, thus leading selectively to their loss of activity and death (Fisher et al., 1999; Rogers et al., 2000; Coxon et al., 2001; van Beek et al., 2002).

In a similar manner, bisphosphonates have been found to be inhibitors of diverse enzymes (Bau et al., 1988; Smirnova et al., 1988; Reiersen et al., 1994; Atack & Fletcher, 1994; Gordon-Weeks et al., 1999) and, as such, they are currently being investigated as herbicides (Chuiko et al., 1999; Cromartie et al., 1999) and antiparasitics (Docampo, 2001). In this latter context, molecular modelling work has been carried out to develop a new therapeutic agent for the treatment of American trypanosomiasis (Fernández, 2002). The basis of the design is one of the clinically used bisphosphonates, so to obtain experimental data of the conformation of the ligand in a complex with a divalent metal cation, possibly the true substrate for the enzyme, we undertook the single-crystal X-ray analysis of the title compound, (I), and the results are presented here. \sch

In the molecular anion of (I) (Fig. 1), which can also be denoted CaH2PAM, the geminal C1 atom is substituted with a pair of negatively charged PO3H- groups, an OH group and an alkylamine lateral chain containing the tetrahedral N atom. As with the previously studied free acid, H3PAM (Shkol'nikova et al., 1990), and the pentahydrated disodium salt, Na2HPAM (Vega et al., 2002), (I) has zwitterionic character, with atom N1 bearing the positive charge, but here the overall charge is -1, so the zwitterion forms a 2:1 complex with Ca2+.

From Table 1, it is evident that the geometry around the P atoms is tetrahedral. The O—P—C bond angles are somewhat less than the ideal tetrahedral value [105.6 (14)–109.9 (14)°], while the O—P—O angles involving the two deprotonated O atoms are the largest in both groups; the P—O(deprotonated) distances indicate a double delocalized bond and the P—O(protonated) bonds are single. These are very similar to the geometric parameters found in the single PO3H- group in H3PAM, but they differ slightly from those in Na2HPAM, where this group has an unequal distribution of the negative charge among the deprotonated O atoms (Vega et al., 2002).

The P—C bond lengths are comparable in the three structures, with values of 1.848 (2) and 1.854 (2) Å in H3PAM, 1.845 (4) and 1.869 (3) Å in Na2HPAM, and 1.846 (2) and 1.851 (2) Å in (I). However, the P—C—P angle in (I) is 2° wider than in the other two compounds.

The mutual orientation of the PO3 groups enables the formation of a planar W arrangement of the O—P—C—P—O chain, where one protonated and one deprotonated O atom lies in the plane [O2—P1—C1—P2 164.6 (1)° and O6—P2—C1—P1 165.6 (2)°]. A similar configuration is observed in Na2HPAM (171.4 and 161.0°), while in the plane of the W in H3PAM (174.5 and 162.9°), there are two protonated O atoms.

The main structural difference between the three compounds is found in the conformation of the O—C—C—C—N backbone, which adopts a gauche- conformation in (I), as shown by the value of the C1—C2—C3—N1 torsion angle of -72.1 (2)°. However, in H3PAM (168.9°) and Na2HPAM (153.6°) this backbone is trans. In addition, the hydroxyl group in (I) is nearly 30° more inclined toward the lateral chain [O7—C1—C2—C3 34.7 (2)°] than in the other two structures [66.5 (1)° in H3PAM and 59.6 (1)° in Na2HPAM]. Therefore, the twisted conformation of the backbone of pamidronate in the calcium salt, (I), facilitates an intramolecular N1—H5···O7 hydrogen bond (Table 2), which leads to the six-membered ring made up of all the hydroxyalkylamine atoms. However, this cannot be formed by H3PAM or Na2HPAM, because the extended conformation of the backbone separates N1 from O7 by more than 4 Å.

The Ca2+ cation lies on a twofold axis parallel to b (Fig. 2). The coordination sphere around the Ca2+ cation is octahedral and consists of six phosphonyl O atoms, half of them being symmetry independent. The Ca2+ cation lies on the plane defined by atoms O5, O3(1 - x, -y, -z) and their symmetry equivalents (r.m.s. deviation from the plane 0.028 Å). There are two O1 atoms, 2.2867 (12) Å above and below this plane, forming an O1···Ca···O1(1 - x, y, -z - 1/2) angle of 167.7 (12)°. The Ca···O contact distances are between 2.2878 (12) and 2.3871 (12) Å (Table 1), and the O1···O5 bite distance is 3.0647 (15) Å.

The remaining phosphonyl O atoms, namely the deprotonated atom O6 as well as the protonated atoms O2 and O4, are not coordinated and there are no other contacts below 3.2 Å to indicate additional coordination to Ca2+. The alcoholic atom O7 is separated by ca 3.9 Å from the metal cation, and hence it cannot function as a tridentate ligand; this is different from what is observed in Na2HPAM.

The hydrate water molecule is located near the positive end of the zwitterion in (I), so, as with one of the water molecules in the disodium salt, it is not in the coordination sphere of the metal cation.

On inspecting Fig. 2, it is evident that the Ca2+ cations are stacked in a columnar fashion (as with the Na+ cations in the disodium salt) along the c axis and this is sustained by a three-dimensional framework of hydrogen-bonded pamidronate ligands. The latter are disposed in the column as expected from their zwitterionic character: the negative end faces the Ca2+ cation in the centre, while the positive end is stretched outside.

The molecular anion is chelating bidentate, using one deprotonated O atom from each PO3 group (O1, O5) and, at the same time, it is chelating monodentate to a symmetry-related Ca2+ cation via another deprotonated phosphonyl O atom (O3).

The intermolecular hydrogen-bonding scheme (Table 2) involves two O(phosphonyl)···O(phosphonyl) interactions [mean 2.543 (5) Å], one O(phosphonyl)···O(hydroxy) [2.765 (2) Å], two O(phosphonyl)···OW [2.84 (14) Å] and two O(phosphonyl)···N [2.967 (4) Å]. As with H3PAM and Na2HPAM, atom N1 is a hydrogen-bond donor to a pair of phosphonyl O atoms, but due to the fact that it forms an intramolecular contact with atom O7, these interactions appear to be weaker (ca 0.2 Å larger) than in the other compounds. The remaining interaction occurs with the hydrate water in (I) and Na2HPAM, or with a symmetry-related hydroxyl O atom in H3PAM, and agrees well in the three structures, with N···O distances in the range 2.838 (2) [(I)] to 2.878 (2) Å (H3PAM).

The comparison of the crystal structure of (I) with those of CaH2EHDP (Uchtman, 1972) and CaH2Cl2MDP (Nardelli et al., 1983) shows good agreement concerning the calcium-chelating properties of the anions. Although the coordination number of the Ca2+ cation differs, being 6 in (I), 7 in CaH2Cl2MDP and 8 in CaH2EHDP, and noting that, in the latter two compounds, the ligands act as dianions in 1:1 Ca2+ complexes, other relevant features are common to all three compounds. Firstly, the ligand is chelating monodentate and/or bidentate, but in no case is there tridentate chelation, as has invariably been seen with the corresponding Na+ salts. Secondly, the bidentate Ca···O(phosphonyl) distances are within a narrow range of 2.31–2.42 Å, a fact possibly related to the presence of the pair of monoprotonated PO3H- groups attached to the geminal C atom. Lastly, and most importantly, they have in common an O···O bite distance of between 2.9 and 3.1 Å. As suggested by Nardelli et al. (1983), who observed that this atomic disposition compares well with that found in the O atoms more tightly bound to Ca2+ in calcium hydroxyapatite, this explains the biological activity and argues against a tridentate calcium-chelating behaviour of the gem-bisphosphonates.

Experimental top

A sample of disodium pamidronate was obtained from Laboratorios Gador S·A., Buenos Aires, Argentina. The calcium salt was prepared as described by Uchtman (1972). A powdered sample of disodium pamidronate (Mr 369.11) was added to CaHPO4·2H2O (Mr 172.09; calcium hydrogen phosphate dihydrate; Riedel-de Haën, Germany) and then placed in an excess of water. Crystals of (I) suitable for X-ray diffraction were obtained by evaporating this solution in an oven at 315 K.

Refinement top

The H atoms attached to C were fixed at 0.99 Å from their hosts and refined using a riding model, with Uiso(H) constrained to 1.3Ueq of their carrier atoms. The other H atoms had their positional and displacement parameters freely refined. The highest positive peak in the Fourier difference map was 1.32 Å from atom H10.

Computing details top

Data collection: SMART-NT (Bruker, 1998); cell refinement: SMART-NT; data reduction: SAINT-NT (Bruker, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP in SHELXTL/PC (Sheldrick, 1991); software used to prepare material for publication: PARST (Nardelli, 1995) and WinGX (Farrugia, 1999).

Figures top
[Figure 1] Fig. 1. A view of (I) showing the atom-numbering scheme, with displacement ellipsoids drawn at the 50% probability level. H atoms are shown as small spheres of arbitrary radii.
[Figure 2] Fig. 2. A simplified packing diagram for (I), showing the Ca coordination sphere (thin solid lines) and zwitterionic hydrogen bonds (dotted lines), as well as some involving N atoms and water (dashed lines). Atoms labelled with a dollar sign (add), an ampersand (add), a hash (#), a prime ('), a tilde () or an asterisk (*) are at symmetry positions (1 - x, -y, -z), (1 - x, y, -z - 1/2), (1 - x, 1 - y, -z), (x + 1/2, 1/2 - y, z + 1/2), (3/2 - x, 1/2 - y, -z) or (x + 1/2, y + 1/2, z), respectively.
(I) top
Crystal data top
Ca(C3H10NO7P2)2·2H2OF(000) = 1128
Mr = 544.24Dx = 1.818 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
a = 14.2921 (9) ÅCell parameters from 844 reflections
b = 14.2755 (9) Åθ = 3.9–26.0°
c = 11.1465 (7) ŵ = 0.72 mm1
β = 119.031 (1)°T = 120 K
V = 1988.4 (2) Å3Prism, colourless
Z = 40.16 × 0.12 × 0.11 mm
Data collection top
Bruker SMART-6000 CCD area-detector
diffractometer
2778 reflections with I > 2σ(I)
ω scansRint = 0.016
Absorption correction: integration
(XPREP in SHELXTL-NT; Bruker, 1998)
θmax = 30.5°, θmin = 2.2°
Tmin = 0.876, Tmax = 0.915h = 2020
10866 measured reflectionsk = 2020
3036 independent reflectionsl = 1515
Refinement top
Refinement on F20 restraints
Least-squares matrix: fullH atoms treated by a mixture of independent and constrained refinement
R[F2 > 2σ(F2)] = 0.035 w = 1/[σ2(Fo2) + (0.0541P)2 + 4.9457P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.100(Δ/σ)max = 0.007
S = 1.06Δρmax = 1.55 e Å3
3036 reflectionsΔρmin = 0.43 e Å3
164 parameters
Crystal data top
Ca(C3H10NO7P2)2·2H2OV = 1988.4 (2) Å3
Mr = 544.24Z = 4
Monoclinic, C2/cMo Kα radiation
a = 14.2921 (9) ŵ = 0.72 mm1
b = 14.2755 (9) ÅT = 120 K
c = 11.1465 (7) Å0.16 × 0.12 × 0.11 mm
β = 119.031 (1)°
Data collection top
Bruker SMART-6000 CCD area-detector
diffractometer
3036 independent reflections
Absorption correction: integration
(XPREP in SHELXTL-NT; Bruker, 1998)
2778 reflections with I > 2σ(I)
Tmin = 0.876, Tmax = 0.915Rint = 0.016
10866 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0350 restraints
wR(F2) = 0.100H atoms treated by a mixture of independent and constrained refinement
S = 1.06Δρmax = 1.55 e Å3
3036 reflectionsΔρmin = 0.43 e Å3
164 parameters
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
C10.57397 (13)0.21390 (11)0.02342 (17)0.0128 (3)
C20.60143 (15)0.28641 (13)0.13847 (19)0.0183 (3)
H70.67350.27210.21530.024*
H80.54970.27950.1730.024*
C30.59979 (15)0.38941 (13)0.0944 (2)0.0195 (3)
H90.53240.40120.00830.025*
H100.6010.43130.16590.025*
N10.69227 (14)0.41229 (12)0.07268 (18)0.0200 (3)
H40.688 (3)0.472 (2)0.046 (3)0.034 (8)*
H50.681 (3)0.371 (3)0.006 (4)0.058 (11)*
H60.754 (3)0.403 (2)0.152 (3)0.031 (8)*
O10.60853 (10)0.03309 (8)0.01640 (12)0.0127 (2)
O20.76291 (10)0.11959 (10)0.15736 (14)0.0149 (2)
H20.790 (3)0.143 (3)0.217 (4)0.054 (12)*
O30.61540 (10)0.07446 (9)0.21214 (13)0.0142 (2)
O40.38340 (10)0.14473 (9)0.00568 (13)0.0149 (2)
H30.386 (2)0.089 (2)0.010 (3)0.033 (8)*
O50.41014 (9)0.14499 (8)0.21459 (12)0.0128 (2)
O60.37818 (10)0.29637 (9)0.11744 (13)0.0148 (2)
O70.61691 (11)0.24941 (10)0.06182 (14)0.0188 (3)
H10.591 (4)0.216 (3)0.144 (5)0.085 (15)*
OW0.66877 (12)0.59350 (10)0.04323 (16)0.0208 (3)
H110.655 (3)0.627 (3)0.001 (4)0.044 (9)*
H120.725 (3)0.613 (2)0.034 (3)0.037 (8)*
P10.64052 (3)0.10200 (3)0.10133 (4)0.01034 (10)
P20.42795 (3)0.20047 (3)0.08919 (4)0.01079 (10)
Ca0.50.01580 (3)0.250.01066 (11)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0132 (7)0.0112 (7)0.0132 (7)0.0010 (5)0.0058 (6)0.0004 (5)
C20.0212 (8)0.0161 (8)0.0150 (7)0.0024 (6)0.0068 (6)0.0031 (6)
C30.0187 (8)0.0159 (8)0.0256 (9)0.0004 (6)0.0122 (7)0.0011 (7)
N10.0207 (7)0.0173 (7)0.0201 (8)0.0044 (6)0.0085 (6)0.0002 (6)
O10.0144 (5)0.0116 (5)0.0110 (5)0.0005 (4)0.0052 (4)0.0010 (4)
O20.0099 (5)0.0183 (6)0.0150 (6)0.0024 (4)0.0049 (5)0.0028 (5)
O30.0155 (5)0.0158 (6)0.0125 (5)0.0020 (4)0.0078 (4)0.0006 (4)
O40.0174 (6)0.0137 (6)0.0176 (6)0.0010 (4)0.0115 (5)0.0010 (4)
O50.0133 (5)0.0129 (5)0.0127 (5)0.0007 (4)0.0067 (4)0.0021 (4)
O60.0158 (5)0.0123 (5)0.0147 (6)0.0043 (4)0.0061 (5)0.0011 (4)
O70.0196 (6)0.0202 (6)0.0192 (6)0.0041 (5)0.0115 (5)0.0017 (5)
OW0.0220 (7)0.0201 (7)0.0251 (7)0.0010 (5)0.0153 (6)0.0027 (5)
P10.00973 (18)0.01049 (19)0.01048 (19)0.00078 (13)0.00466 (15)0.00019 (13)
P20.01107 (19)0.01028 (19)0.01135 (19)0.00126 (13)0.00571 (15)0.00020 (13)
Ca0.0107 (2)0.0119 (2)0.0103 (2)0.00.00580 (16)0.0
Geometric parameters (Å, º) top
C1—O71.450 (2)O2—P11.5660 (13)
C1—C21.543 (2)O2—H20.68 (4)
C1—P11.8463 (17)O3—P11.4965 (12)
C1—P21.8507 (17)O4—P21.5750 (13)
C2—C31.547 (3)O4—H30.79 (3)
C2—H70.99O5—P21.5167 (12)
C2—H80.99O6—P21.5039 (13)
C3—N11.491 (2)O7—H10.94 (5)
C3—H90.99OW—H110.76 (4)
C3—H100.99OW—H120.80 (4)
N1—H40.90 (3)Ca—O3i2.2878 (12)
N1—H51.00 (4)Ca—O1ii2.3080 (12)
N1—H60.91 (3)Ca—O5ii2.3871 (12)
O1—P11.5220 (12)
O7—C1—C2106.99 (13)P2—O4—H3115 (2)
O7—C1—P1108.99 (11)P2—O5—Ca133.84 (7)
C2—C1—P1108.92 (11)C1—O7—H1112 (3)
O7—C1—P2106.76 (11)H11—OW—H12104 (4)
C2—C1—P2112.42 (12)O3—P1—O1116.73 (7)
P1—C1—P2112.55 (9)O3—P1—O2112.45 (7)
C1—C2—C3114.53 (15)O1—P1—O2104.92 (7)
C1—C2—H7108.6O3—P1—C1109.90 (7)
C3—C2—H7108.6O1—P1—C1106.44 (7)
C1—C2—H8108.6O2—P1—C1105.64 (7)
C3—C2—H8108.6O6—P2—O5115.57 (7)
H7—C2—H8107.6O6—P2—O4107.33 (7)
N1—C3—C2112.45 (15)O5—P2—O4110.22 (7)
N1—C3—H9109.1O6—P2—C1108.11 (7)
C2—C3—H9109.1O5—P2—C1107.99 (7)
N1—C3—H10109.1O4—P2—C1107.32 (7)
C2—C3—H10109.1O3i—Ca—O3iii111.45 (7)
H9—C3—H10107.8O3i—Ca—O190.12 (4)
C3—N1—H4110 (2)O3i—Ca—O1ii96.80 (4)
C3—N1—H5104 (2)O1—Ca—O1ii167.72 (6)
H4—N1—H5108 (3)O3i—Ca—O5ii163.63 (5)
C3—N1—H6109.6 (19)O1—Ca—O5ii89.02 (4)
H4—N1—H6110 (3)O3i—Ca—O584.88 (4)
H5—N1—H6116 (3)O1—Ca—O581.48 (4)
P1—O1—Ca142.95 (7)O1ii—Ca—O589.02 (4)
P1—O2—H2118 (3)O5ii—Ca—O578.83 (6)
P1—O3—Cai141.57 (8)
O7—C1—C2—C334.65 (19)Ca—O5—P2—C137.82 (11)
P1—C1—C2—C3152.32 (13)O7—C1—P2—O674.87 (12)
P2—C1—C2—C382.24 (17)C2—C1—P2—O642.14 (14)
C1—C2—C3—N172.1 (2)P1—C1—P2—O6165.59 (8)
Cai—O3—P1—O125.94 (15)O7—C1—P2—O550.83 (12)
Cai—O3—P1—O2147.28 (11)C2—C1—P2—O5167.85 (12)
Cai—O3—P1—C195.34 (13)P1—C1—P2—O568.70 (10)
Ca—O1—P1—O3117.08 (12)O7—C1—P2—O4169.64 (10)
Ca—O1—P1—O2117.69 (12)C2—C1—P2—O473.34 (13)
Ca—O1—P1—C16.00 (14)P1—C1—P2—O450.10 (10)
O7—C1—P1—O3167.89 (10)P1—O1—Ca—O3i103.94 (12)
C2—C1—P1—O351.49 (13)P1—O1—Ca—O3iii144.44 (12)
P2—C1—P1—O373.88 (10)P1—O1—Ca—O1ii20.55 (11)
O7—C1—P1—O164.84 (12)P1—O1—Ca—O5ii59.72 (12)
C2—C1—P1—O1178.76 (11)P1—O1—Ca—O519.14 (12)
P2—C1—P1—O153.39 (10)P2—O5—Ca—O3i89.97 (10)
O7—C1—P1—O246.35 (13)P2—O5—Ca—O3iii86.01 (18)
C2—C1—P1—O270.05 (13)P2—O5—Ca—O10.92 (10)
P2—C1—P1—O2164.58 (8)P2—O5—Ca—O1ii173.11 (10)
Ca—O5—P2—O6159.00 (9)P2—O5—Ca—O5ii91.61 (10)
Ca—O5—P2—O479.13 (11)
Symmetry codes: (i) x+1, y, z; (ii) x+1, y, z1/2; (iii) x, y, z1/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C3—H9···O60.992.463.180 (2)129
N1—H4···OW0.90 (3)1.95 (3)2.838 (2)171 (3)
N1—H5···O71.00 (4)1.93 (4)2.692 (2)132 (3)
O4—H3···O1i0.79 (3)1.77 (3)2.5476 (18)167 (3)
O7—H1···O5ii0.94 (5)1.86 (5)2.7655 (19)161 (4)
O2—H2···O6iv0.68 (4)1.86 (4)2.5380 (18)174 (5)
N1—H6···O5iv0.91 (3)2.10 (3)2.970 (2)159 (3)
N1—H5···O2v1.00 (4)2.20 (4)2.964 (2)133 (3)
OW—H11···O6vi0.76 (4)1.95 (4)2.7010 (19)176 (4)
OW—H12···O4vii0.80 (4)2.18 (4)2.979 (2)171 (3)
Symmetry codes: (i) x+1, y, z; (ii) x+1, y, z1/2; (iv) x+1/2, y+1/2, z+1/2; (v) x+3/2, y+1/2, z; (vi) x+1, y+1, z; (vii) x+1/2, y+1/2, z.

Experimental details

Crystal data
Chemical formulaCa(C3H10NO7P2)2·2H2O
Mr544.24
Crystal system, space groupMonoclinic, C2/c
Temperature (K)120
a, b, c (Å)14.2921 (9), 14.2755 (9), 11.1465 (7)
β (°) 119.031 (1)
V3)1988.4 (2)
Z4
Radiation typeMo Kα
µ (mm1)0.72
Crystal size (mm)0.16 × 0.12 × 0.11
Data collection
DiffractometerBruker SMART6000 CCD area-detector
diffractometer
Absorption correctionIntegration
(XPREP in SHELXTL-NT; Bruker, 1998)
Tmin, Tmax0.876, 0.915
No. of measured, independent and
observed [I > 2σ(I)] reflections
10866, 3036, 2778
Rint0.016
(sin θ/λ)max1)0.714
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.035, 0.100, 1.06
No. of reflections3036
No. of parameters164
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)1.55, 0.43

Computer programs: SMART-NT (Bruker, 1998), SMART-NT, SAINT-NT (Bruker, 1998), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), XP in SHELXTL/PC (Sheldrick, 1991), PARST (Nardelli, 1995) and WinGX (Farrugia, 1999).

Selected geometric parameters (Å, º) top
O1—P11.5220 (12)O6—P21.5039 (13)
O2—P11.5660 (13)Ca—O3i2.2878 (12)
O3—P11.4965 (12)Ca—O1ii2.3080 (12)
O4—P21.5750 (13)Ca—O5ii2.3871 (12)
O5—P21.5167 (12)
P1—C1—P2112.55 (9)O6—P2—O5115.57 (7)
O3—P1—O1116.73 (7)O6—P2—O4107.33 (7)
O3—P1—O2112.45 (7)O5—P2—O4110.22 (7)
O1—P1—O2104.92 (7)
O7—C1—C2—C334.65 (19)C1—C2—C3—N172.1 (2)
Symmetry codes: (i) x+1, y, z; (ii) x+1, y, z1/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C3—H9···O60.992.463.180 (2)129
N1—H4···OW0.90 (3)1.95 (3)2.838 (2)171 (3)
N1—H5···O71.00 (4)1.93 (4)2.692 (2)132 (3)
O4—H3···O1i0.79 (3)1.77 (3)2.5476 (18)167 (3)
O7—H1···O5ii0.94 (5)1.86 (5)2.7655 (19)161 (4)
O2—H2···O6iii0.68 (4)1.86 (4)2.5380 (18)174 (5)
N1—H6···O5iii0.91 (3)2.10 (3)2.970 (2)159 (3)
N1—H5···O2iv1.00 (4)2.20 (4)2.964 (2)133 (3)
OW—H11···O6v0.76 (4)1.95 (4)2.7010 (19)176 (4)
OW—H12···O4vi0.80 (4)2.18 (4)2.979 (2)171 (3)
Symmetry codes: (i) x+1, y, z; (ii) x+1, y, z1/2; (iii) x+1/2, y+1/2, z+1/2; (iv) x+3/2, y+1/2, z; (v) x+1, y+1, z; (vi) x+1/2, y+1/2, z.
 

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