Diaqua­bis[1-hydroxy-2-(imidazol-3-ium-1-yl)-1,1′-ethyl­idenediphophonato-κ2O,O′]zinc(II)

Freire, E.; Vega, D.R.

doi:10.1107/S1600536809042858

metal-organic compounds

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Volume 65| Part 11| November 2009| Pages m1428-m1429

https://doi.org/10.1107/S1600536809042858

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Diaquabis[1-hydroxy-2-(imidazol-3-ium-1-yl)-1,1′-ethylidenediphophonato-κ²O,O′]zinc(II)

Eleonora Freire ^a ^*‡ and Daniel R. Vega ^a

^aGerencia de Investigación y Aplicaciones, Centro Atómico Constituyentes, Comisión Nacional de Energía Atómica and, Escuela de Ciencia y Tecnología, Universidad Nacional General San Martín, Buenos Aires, Argentina
^*Correspondence e-mail: freire@tandar.cnea.gov.ar

(Received 5 October 2009; accepted 19 October 2009; online 23 October 2009)

In the title complex, [Zn(C₅H₉NO₇P₂)₂(H₂O)₂], the zinc atom is coordinated by two bidentate zoledronate [zoledronate = (2-(1-imidazole)-1-hydroxy-1,1′-ethylidenediphophonate)] ligands and two water molecules. The coordination number is 6. There is one half-molecule in the asymmetric unit with the zinc atom located on a crystallographic inversion centre. The anion exists as a zwitterion with an overall charge of −1; the protonated nitrogen in the ring has a positive charge and the two phosphonates groups each have a single negative charge. There are two intramolecular O—H⋯O hydrogen bonds. The molecules are linked into a chain by intermolecular O—H⋯O hydrogen bonds. Adjacent chains are further linked by O—H⋯O hydrogen bonds involving the aqua ligands. An N—H⋯O interaction is also observed.

Related literature

For general background to bisphosphonates, see: Fleisch et al. (1968 ); Green et al. (1994 ); Fleisch (2000 ); Ross et al. (2004 ); Smith (2005 ); Ralston et al. (1989 ); Reid et al. (2005 ); Rauch & Glorieux (2005 ); Chesnut et al. (2004 ). For structures of transition metal (Ni, Co and Cu) complexes with the zoledronate anion, see: Cao et al. (2007, 2008). For metal complexes of other bisphosphonates (Etidronate and Pamidronate), see: Fernández et al. (2002 ); Li et al. (2008 ); Chen et al. (2008 ); Uchtman (1972 ). For a pentacoordinated zinc(II)–zoledronate complex, see: Freire & Vega (2009 ). For bond distances and angles in related structures, see: Coiro & Lamba (1989 ); Vega et al. (1996 , 1998 ). For hydrogen-bond motifs, see: Bernstein et al. (1995 ).

Experimental

Crystal data

[Zn(C₅H₉N₂O₇P₂)₂(H₂O)₂]
M_r = 643.57
Triclinic, $[P \overline 1]$
a = 7.457 (1) Å
b = 8.408 (2) Å
c = 9.843 (2) Å
α = 105.06 (3)°
β = 112.23 (3)°
γ = 97.05 (3)°
V = 534.5 (2) Å³
Z = 1
Mo Kα radiation
μ = 1.54 mm⁻¹
T = 293 K
0.18 × 0.11 × 0.05 mm

Data collection

Rigaku AFC6 diffractometer diffractometer
Absorption correction: ψ scan (North et al., 1968 ) T_min = 0.82, T_max = 0.92
2426 measured reflections
1990 independent reflections
1236 reflections with I > 2σ(I)
R_int = 0.050
3 standard reflections every 150 reflections intensity decay: <3%

Refinement

R[F² > 2σ(F²)] = 0.052
wR(F²) = 0.152
S = 1.04
1990 reflections
160 parameters
H-atom parameters constrained
Δρ_max = 0.84 e Å⁻³
Δρ_min = −0.94 e Å⁻³

Table 1
Selected geometric parameters (Å, °)

Zn1—O11	2.042 (4)
Zn1—O21	2.079 (4)
Zn1—O1W	2.096 (4)

O11—Zn1—O21	90.65 (16)
O11—Zn1—O1W	86.18 (18)
O21—Zn1—O1W	92.63 (18)

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O22—H22⋯O23ⁱ	0.82	1.90	2.676 (6)	159
O12—H12⋯O13ⁱⁱ	0.82	1.79	2.607 (6)	176
O1—H1⋯O23ⁱ	0.82	2.28	2.910 (6)	134
O1W—H1WA⋯O12	0.82	2.43	3.078 (6)	137
O1W—H1WB⋯O13ⁱⁱⁱ	0.82	1.94	2.745 (6)	167
N2—H2⋯O21^iv	0.86	1.90	2.740 (7)	164
Symmetry codes: (i) -x+2, -y+2, -z+2; (ii) -x+2, -y+2, -z+1; (iii) x-1, y, z; (iv) -x+2, -y+1, -z+2.

Data collection: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1988 $[Molecular Structure Corporation (1988). MSC/AFC Diffractometer Control Software. MSC, The Woodlands, Texas, USA.]$ ); cell refinement: MSC/AFC Diffractometer Control Software; data reduction: MSC/AFC Diffractometer Control Software; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: https://doi.org/10.1107/S1600536809042858/bq2165sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536809042858/bq2165Isup2.hkl

checkCIF report

Comment top

The present work is part of a project directed to the preparation and characterization of coordination complexes obtained by the interaction among metals and organic molecules of relevant pharmacological interest like bisphosphonates. Bisphosphonate compounds, which are characterized by a P—C—P backbone, are analogues of naturally occurring pyrophosphates. As effective inhibitors of bone resoption, bisphosphonates are used in the treatment of various bone diseases and disorders of calcium metabolism, osteolityc tumor bone disease, non tumor induced hypercalcemia, Paget and osteoporosis (Fleisch, 2000; Ross et al., 2004; Smith, 2005; Ralston et al., 1989; Reid et al., 2005; Rauch et al., 2005 and Chesnut et al., 2004). The P—C—P base structure allows the bisphosphonates to bind to many metallic cations in particular divalent metal ions and as a result bisphosphonates may stick bone surfaces in vivo (Fleisch et al., 1968). Third generation bisphosphonates, like zoledronate, are characterized by having a cyclic side chain and belong to the nitrogen containing bisphosphonate group which are the most effective for medical treatment (Green et al., 1994). A large number of metal derivatives of other bisphosphonates, like Etidronate and Pamidronate are known where the bisphosphonate ligand displays a variety of coordination modes (Ferńandez, 2002; Li et al., 2008; Chen et al., 2008; Uchtman, 1972). In contrast, few metal derivatives of Zoledronic acid have been reported in CSD (Allen, 2002). The present compound is isostructural with two Co and Ni complexes (Cao et al., 2007).

So, we present herein the crystal structure of a Zinc-Zoledronate complex: monozinc dizoledronate dihydrate, (I), Zn.2(P₂O₇N₂C₅H₉).2(H₂O). We also synthesized a pentacoordinated complex of zinc (II), (Freire & Vega, 2009). The zoledronate anion exists as a zwitterion with an overall charge of -1; the protonated nitrogen in the ring has a positive charge and the two phosphonates groups each have a single negative charge.

The ZnO₆ coordination sphere (Fig. 1) is defined by O11, O21, O1W and and their (1 - x, 1 - y, 1 - z) counterparts generated by the inversion center on Zn1. Zn – O distances range from 2.041 (4) to 2.095 (4) Å, and octahedral angles between 86.2 (2) and 92.7 (2)°. The O11—Zn1—O21 zoledronate bite angle is 90.6 (2)° and the angle between two oxygen atoms of different zoledronates is O11A Zn1 O21 89.4 (2)°.

Each phosphonate has one protonated O atom, the extra electronic charge being shared by the remaining two non protonated O atoms. This fact define two distinct types of P—O bonds, as shown by the mean value in the following values of bond distances and angles: P—OH 1,572 (8), P - O 1.503 (5) Å, O—P—OH 109.45 (13), O—P—O 115.60 (14) °, this measure is in agreement with the results found for related molecules (Coiro et al., 1989; Vega et al., 1996; Vega et al., 1998). The phosphonates groups have slighty "staggered" conformations sight in the P1···P2 direction. When this staggering is observed the non bonded torsion angle O13—P1··· P2—O23 is 4.1 °. The imidazol ring is plane, maximum deviation from the L.S. mean plane is 0.0058 Å for C5. The ring and C2 are not coplanar, the angle determined between the plane of the ring and the bond N1—C2 is 3.2 ° and C2 is 0.0861 Å far from the plane of the ring. The torsion angle C1—C2—N1—C3 is of 104.1 (8) ° and it is possible to describe it like + Anti-Clinal (+ac).

In this compound there are two intramolecular hydrogen bonds O1W—H1WA···. O12 and the one generated by the center of symmetry (Fig. 1). These molecules form a chain by means of hydrogen bonds provided by O22—H22··· O23 (-x + 2,-y + 2,-z + 2) and O1—H1··· O23 (-x + 2,-y + 2,-z + 2) (Fig. 2). This chain joins other neighboring and similar chains by means of the hydrogen bonds O1W—H1WB··· O13 (x - 1, y, z), O12—H12··· O13 (-x + 2,-y + 2,-z + 1), and N2—H2··· O21 (-x + 2,-y + 1,-z + 2) (see Table 2), determining a three-dimensional net. In all this hydrogen-bonding network the presence of two homodromic rings (Bernstein et al., 1995) is observed: P2—O22—H22··· O23 (-x + 2,-y + 2,-z + 2) ···H1—O1—C1—P2 (R₂¹(7)), P1—O12—H12··· O13—P1—O12—H12 (-x + 2,-y + 2,-z + 1)··· O13—P1 (R₂²(8)).

Related literature top

For general background to bisphosphonates, see: Fleisch et al. (1968); Green et al. (1994); Fleisch (2000); Ross et al. (2004); Smith (2005); Ralston et al. (1989); Reid et al. (2005); Rauch et al. (2005); Chesnut et al. (2004). For structures of transition metal (Ni, Co and Cu) complexes with the zoledronate anion, see: Cao et al. (2007, 2008). For metal complexes of other bisphosphonates (Etidronate and Pamidronate), see: Fernández et al. (2002); Li et al. (2008); Chen et al. (2008); Uchtman (1972). For a pentacoordinated zinc(II)–zoledronate complex, see: Freire & Vega (2009). For bond distances and angles in related structures, see: Coiro & Lamba (1989); Vega et al. (1996, 1998). For hydrogen-bond motifs, see: Bernstein et al. (1995).

Experimental top

Zoledronic Acid was obtained from Gador S. A. laboratory. The present compound was obtained as subproduct in a Zoledronate recrystallization process.

Structure description top

For general background to bisphosphonates, see: Fleisch et al. (1968); Green et al. (1994); Fleisch (2000); Ross et al. (2004); Smith (2005); Ralston et al. (1989); Reid et al. (2005); Rauch et al. (2005); Chesnut et al. (2004). For structures of transition metal (Ni, Co and Cu) complexes with the zoledronate anion, see: Cao et al. (2007, 2008). For metal complexes of other bisphosphonates (Etidronate and Pamidronate), see: Fernández et al. (2002); Li et al. (2008); Chen et al. (2008); Uchtman (1972). For a pentacoordinated zinc(II)–zoledronate complex, see: Freire & Vega (2009). For bond distances and angles in related structures, see: Coiro & Lamba (1989); Vega et al. (1996, 1998). For hydrogen-bond motifs, see: Bernstein et al. (1995).

Computing details top

Data collection: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1988); cell refinement: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1988); data reduction: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1988); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures top

	Fig. 1. : Molecular view of (I), showing the labeling scheme used. Hydrogen bonding is shown in dashed lines.
	Fig. 2. : View of the intra chain H-bonds in (I).

Diaquabis[1-hydroxy-2-(imidazol-3-ium-1-yl)-1,1'-ethylidenediphophonato- κ²O,O']zinc(II) top

Crystal data top

[Zn(C₅H₉N₂O₇P₂)₂(H₂O)₂]	Z = 1
M_r = 643.57	F(000) = 328
Triclinic, P1	D_x = 1.999 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.457 (1) Å	Cell parameters from 42 reflections
b = 8.408 (2) Å	θ = 8–18°
c = 9.843 (2) Å	µ = 1.54 mm⁻¹
α = 105.06 (3)°	T = 293 K
β = 112.23 (3)°	Prism, colorless
γ = 97.05 (3)°	0.18 × 0.11 × 0.05 mm
V = 534.5 (2) Å³

Data collection top

Rigaku AFC6 Difractometer diffractometer	1236 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.050
Graphite monochromator	θ_max = 25.5°, θ_min = 2.4°
ω/2θ scans	h = −9→9
Absorption correction: ψ scan (North et al., 1968)	k = −1→10
T_min = 0.82, T_max = 0.92	l = −11→11
2426 measured reflections	3 standard reflections every 150 reflections
1990 independent reflections	intensity decay: <3%

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.052	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.152	H-atom parameters constrained
S = 1.04	w = 1/[σ²(F_o²) + (0.0781P)²] where P = (F_o² + 2F_c²)/3
1990 reflections	(Δ/σ)_max < 0.001
160 parameters	Δρ_max = 0.84 e Å⁻³
0 restraints	Δρ_min = −0.94 e Å⁻³

Crystal data top

[Zn(C₅H₉N₂O₇P₂)₂(H₂O)₂]	γ = 97.05 (3)°
M_r = 643.57	V = 534.5 (2) Å³
Triclinic, P1	Z = 1
a = 7.457 (1) Å	Mo Kα radiation
b = 8.408 (2) Å	µ = 1.54 mm⁻¹
c = 9.843 (2) Å	T = 293 K
α = 105.06 (3)°	0.18 × 0.11 × 0.05 mm
β = 112.23 (3)°

Data collection top

Rigaku AFC6 Difractometer diffractometer	1236 reflections with I > 2σ(I)
Absorption correction: ψ scan (North et al., 1968)	R_int = 0.050
T_min = 0.82, T_max = 0.92	3 standard reflections every 150 reflections
2426 measured reflections	intensity decay: <3%
1990 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.052	0 restraints
wR(F²) = 0.152	H-atom parameters constrained
S = 1.04	Δρ_max = 0.84 e Å⁻³
1990 reflections	Δρ_min = −0.94 e Å⁻³
160 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

	x	y	z	U_iso*/U_eq
Zn1	0.5000	0.5000	0.5000	0.0266 (4)
P1	0.8731 (2)	0.77240 (19)	0.52403 (17)	0.0172 (4)
P2	0.8422 (2)	0.77671 (19)	0.82873 (17)	0.0186 (4)
O11	0.7109 (6)	0.6106 (5)	0.4453 (4)	0.0211 (9)
O12	0.7749 (6)	0.9268 (5)	0.5228 (5)	0.0242 (10)
H12	0.8403	1.0149	0.5264	0.036*
O13	1.0242 (6)	0.7849 (5)	0.4574 (5)	0.0217 (9)
O21	0.6875 (6)	0.6116 (5)	0.7361 (5)	0.0253 (10)
O22	0.7342 (6)	0.9253 (5)	0.8129 (5)	0.0254 (10)
H22	0.8021	1.0216	0.8691	0.038*
O23	0.9654 (7)	0.8002 (5)	0.9969 (5)	0.0249 (10)
O1	1.1578 (6)	0.9545 (5)	0.8097 (5)	0.0261 (10)
H1	1.1019	1.0326	0.8140	0.039*
N1	1.2533 (8)	0.6520 (6)	0.8864 (6)	0.0224 (11)
N2	1.3599 (9)	0.5904 (8)	1.0957 (7)	0.0372 (15)
H2	1.3678	0.5388	1.1618	0.045*
C1	1.0088 (9)	0.7937 (7)	0.7310 (6)	0.0183 (13)
C2	1.1243 (10)	0.6535 (8)	0.7302 (7)	0.0271 (15)
H2A	1.0288	0.5439	0.6719	0.032*
H2B	1.2067	0.6680	0.6759	0.032*
C3	1.2149 (10)	0.5438 (9)	0.9533 (8)	0.0315 (16)
H3	1.1052	0.4509	0.9084	0.038*
C5	1.4298 (10)	0.7711 (8)	0.9896 (8)	0.0319 (16)
H5	1.4929	0.8611	0.9722	0.038*
C4	1.4926 (12)	0.7303 (10)	1.1212 (8)	0.042 (2)
H4	1.6068	0.7885	1.2127	0.051*
O1W	0.3851 (6)	0.7142 (6)	0.4904 (6)	0.0349 (12)
H1WA	0.4645	0.8074	0.5273	0.052*
H1WB	0.2703	0.7245	0.4668	0.052*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Zn1	0.0278 (7)	0.0212 (6)	0.0247 (6)	0.0057 (5)	0.0079 (5)	0.0030 (5)
P1	0.0177 (8)	0.0145 (8)	0.0173 (8)	0.0054 (6)	0.0056 (7)	0.0043 (6)
P2	0.0194 (8)	0.0157 (8)	0.0150 (8)	0.0029 (7)	0.0048 (7)	0.0008 (6)
O11	0.020 (2)	0.024 (2)	0.014 (2)	0.0010 (19)	0.0059 (18)	0.0015 (17)
O12	0.026 (2)	0.020 (2)	0.035 (3)	0.0118 (19)	0.016 (2)	0.015 (2)
O13	0.022 (2)	0.019 (2)	0.025 (2)	0.0082 (18)	0.0116 (19)	0.0051 (18)
O21	0.029 (3)	0.021 (2)	0.017 (2)	0.000 (2)	0.006 (2)	0.0027 (18)
O22	0.028 (2)	0.020 (2)	0.024 (2)	0.0100 (19)	0.009 (2)	0.0019 (19)
O23	0.035 (3)	0.021 (2)	0.015 (2)	0.005 (2)	0.007 (2)	0.0037 (18)
O1	0.021 (2)	0.018 (2)	0.030 (2)	0.0008 (19)	0.007 (2)	0.0003 (19)
N1	0.023 (3)	0.022 (3)	0.021 (3)	0.010 (2)	0.006 (2)	0.008 (2)
N2	0.052 (4)	0.039 (4)	0.032 (3)	0.018 (3)	0.020 (3)	0.025 (3)
C1	0.023 (3)	0.017 (3)	0.017 (3)	0.010 (3)	0.007 (3)	0.007 (2)
C2	0.029 (4)	0.023 (3)	0.019 (3)	0.010 (3)	0.002 (3)	0.004 (3)
C3	0.027 (4)	0.031 (4)	0.044 (4)	0.013 (3)	0.016 (3)	0.022 (3)
C5	0.027 (4)	0.026 (4)	0.037 (4)	0.008 (3)	0.007 (3)	0.012 (3)
C4	0.048 (5)	0.042 (5)	0.025 (4)	0.020 (4)	0.000 (3)	0.013 (3)
O1W	0.018 (2)	0.022 (2)	0.059 (3)	0.007 (2)	0.013 (2)	0.011 (2)

Geometric parameters (Å, º) top

Zn1—O11ⁱ	2.042 (4)	O1—H1	0.8201
Zn1—O11	2.042 (4)	N1—C3	1.317 (8)
Zn1—O21	2.079 (4)	N1—C5	1.379 (8)
Zn1—O21ⁱ	2.079 (4)	N1—C2	1.478 (7)
Zn1—O1Wⁱ	2.096 (4)	N2—C3	1.323 (9)
Zn1—O1W	2.096 (4)	N2—C4	1.341 (9)
P1—O11	1.501 (4)	N2—H2	0.8600
P1—O13	1.509 (4)	C1—C2	1.543 (8)
P1—O12	1.567 (4)	C2—H2A	0.9700
P1—C1	1.847 (6)	C2—H2B	0.9700
P2—O21	1.498 (4)	C3—H3	0.9300
P2—O23	1.502 (4)	C5—C4	1.352 (9)
P2—O22	1.578 (4)	C5—H5	0.9300
P2—C1	1.850 (6)	C4—H4	0.9300
O12—H12	0.8200	O1W—H1WA	0.8200
O22—H22	0.8200	O1W—H1WB	0.8200
O1—C1	1.448 (7)

O11ⁱ—Zn1—O11	180.0	C1—O1—H1	109.4
O11ⁱ—Zn1—O21	89.35 (16)	C3—N1—C5	108.8 (6)
O11—Zn1—O21	90.65 (16)	C3—N1—C2	126.2 (6)
O11ⁱ—Zn1—O21ⁱ	90.65 (16)	C5—N1—C2	125.0 (5)
O11—Zn1—O21ⁱ	89.35 (16)	C3—N2—C4	109.7 (6)
O21—Zn1—O21ⁱ	180.0	C3—N2—H2	125.1
O11ⁱ—Zn1—O1Wⁱ	86.18 (18)	C4—N2—H2	125.1
O11—Zn1—O1Wⁱ	93.82 (18)	O1—C1—C2	106.5 (5)
O21—Zn1—O1Wⁱ	87.37 (18)	O1—C1—P1	108.5 (4)
O21ⁱ—Zn1—O1Wⁱ	92.63 (18)	C2—C1—P1	105.0 (4)
O11ⁱ—Zn1—O1W	93.82 (18)	O1—C1—P2	110.8 (4)
O11—Zn1—O1W	86.18 (18)	C2—C1—P2	112.6 (4)
O21—Zn1—O1W	92.63 (18)	P1—C1—P2	113.1 (3)
O21ⁱ—Zn1—O1W	87.37 (18)	N1—C2—C1	114.5 (5)
O1Wⁱ—Zn1—O1W	180.000 (1)	N1—C2—H2A	108.6
O11—P1—O13	115.5 (2)	C1—C2—H2A	108.6
O11—P1—O12	108.9 (2)	N1—C2—H2B	108.6
O13—P1—O12	109.9 (2)	C1—C2—H2B	108.6
O11—P1—C1	108.2 (3)	H2A—C2—H2B	107.6
O13—P1—C1	107.9 (3)	N1—C3—N2	108.0 (6)
O12—P1—C1	106.0 (3)	N1—C3—H3	126.0
O21—P2—O23	115.7 (2)	N2—C3—H3	126.0
O21—P2—O22	108.0 (3)	C4—C5—N1	106.1 (6)
O23—P2—O22	110.9 (2)	C4—C5—H5	127.0
O21—P2—C1	107.4 (3)	N1—C5—H5	127.0
O23—P2—C1	109.4 (3)	N2—C4—C5	107.4 (6)
O22—P2—C1	104.9 (3)	N2—C4—H4	126.3
P1—O11—Zn1	134.2 (2)	C5—C4—H4	126.3
P1—O12—H12	117.6	Zn1—O1W—H1WA	118.1
P2—O21—Zn1	132.6 (3)	Zn1—O1W—H1WB	130.4
P2—O22—H22	116.2	H1WA—O1W—H1WB	110.8

O13—P1—O11—Zn1	167.0 (3)	O12—P1—C1—P2	63.4 (3)
O12—P1—O11—Zn1	−68.8 (4)	O21—P2—C1—O1	177.3 (4)
C1—P1—O11—Zn1	46.0 (4)	O23—P2—C1—O1	−56.4 (4)
O21—Zn1—O11—P1	−30.0 (4)	O22—P2—C1—O1	62.6 (4)
O21ⁱ—Zn1—O11—P1	150.0 (4)	O21—P2—C1—C2	−63.6 (5)
O1Wⁱ—Zn1—O11—P1	−117.4 (4)	O23—P2—C1—C2	62.7 (5)
O1W—Zn1—O11—P1	62.6 (4)	O22—P2—C1—C2	−178.3 (4)
O23—P2—O21—Zn1	−172.3 (3)	O21—P2—C1—P1	55.2 (4)
O22—P2—O21—Zn1	62.8 (4)	O23—P2—C1—P1	−178.5 (3)
C1—P2—O21—Zn1	−49.8 (4)	O22—P2—C1—P1	−59.5 (3)
O11ⁱ—Zn1—O21—P2	−147.8 (4)	C3—N1—C2—C1	104.1 (7)
O11—Zn1—O21—P2	32.2 (4)	C5—N1—C2—C1	−72.1 (8)
O1Wⁱ—Zn1—O21—P2	126.0 (4)	O1—C1—C2—N1	62.2 (6)
O1W—Zn1—O21—P2	−54.0 (4)	P1—C1—C2—N1	177.1 (4)
O11—P1—C1—O1	−176.6 (3)	P2—C1—C2—N1	−59.4 (6)
O13—P1—C1—O1	57.8 (4)	C5—N1—C3—N2	0.4 (8)
O12—P1—C1—O1	−59.9 (4)	C2—N1—C3—N2	−176.3 (6)
O11—P1—C1—C2	69.9 (4)	C4—N2—C3—N1	0.3 (8)
O13—P1—C1—C2	−55.8 (4)	C3—N1—C5—C4	−0.9 (8)
O12—P1—C1—C2	−173.4 (4)	C2—N1—C5—C4	175.8 (6)
O11—P1—C1—P2	−53.3 (4)	C3—N2—C4—C5	−0.9 (9)
O13—P1—C1—P2	−178.9 (3)	N1—C5—C4—N2	1.1 (8)

Symmetry code: (i) −x+1, −y+1, −z+1.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O22—H22···O23ⁱⁱ	0.82	1.90	2.676 (6)	159
O12—H12···O13ⁱⁱⁱ	0.82	1.79	2.607 (6)	176
O1—H1···O23ⁱⁱ	0.82	2.28	2.910 (6)	134
O1W—H1WA···O12	0.82	2.43	3.078 (6)	137
O1W—H1WB···O13^iv	0.82	1.94	2.745 (6)	167
N2—H2···O21^v	0.86	1.90	2.740 (7)	164

Symmetry codes: (ii) −x+2, −y+2, −z+2; (iii) −x+2, −y+2, −z+1; (iv) x−1, y, z; (v) −x+2, −y+1, −z+2.

Experimental details

Crystal data
Chemical formula	[Zn(C₅H₉N₂O₇P₂)₂(H₂O)₂]
M_r	643.57
Crystal system, space group	Triclinic, P1
Temperature (K)	293
a, b, c (Å)	7.457 (1), 8.408 (2), 9.843 (2)
α, β, γ (°)	105.06 (3), 112.23 (3), 97.05 (3)
V (Å³)	534.5 (2)
Z	1
Radiation type	Mo Kα
µ (mm⁻¹)	1.54
Crystal size (mm)	0.18 × 0.11 × 0.05

Data collection
Diffractometer	Rigaku AFC6 Difractometer
Absorption correction	ψ scan (North et al., 1968)
T_min, T_max	0.82, 0.92
No. of measured, independent and observed [I > 2σ(I)] reflections	2426, 1990, 1236
R_int	0.050
(sin θ/λ)_max (Å⁻¹)	0.606

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.052, 0.152, 1.04
No. of reflections	1990
No. of parameters	160
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.84, −0.94

Computer programs: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1988), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Selected geometric parameters (Å, º) top

Zn1—O11	2.042 (4)	Zn1—O1W	2.096 (4)
Zn1—O21	2.079 (4)

O11—Zn1—O21	90.65 (16)	O21—Zn1—O1W	92.63 (18)
O11—Zn1—O1W	86.18 (18)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O22—H22···O23ⁱ	0.82	1.90	2.676 (6)	158.5
O12—H12···O13ⁱⁱ	0.82	1.79	2.607 (6)	176.0
O1—H1···O23ⁱ	0.82	2.28	2.910 (6)	133.7
O1W—H1WA···O12	0.82	2.43	3.078 (6)	136.8
O1W—H1WB···O13ⁱⁱⁱ	0.82	1.94	2.745 (6)	167.3
N2—H2···O21^iv	0.86	1.90	2.740 (7)	163.8

Symmetry codes: (i) −x+2, −y+2, −z+2; (ii) −x+2, −y+2, −z+1; (iii) x−1, y, z; (iv) −x+2, −y+1, −z+2.

Footnotes

‡Member of Consejo Nacional de Ciencia y Técnica, Conicet.

Acknowledgements

We acknowledge PICT 25409, the Spanish Research Council (CSIC) for providing us with a free-of-charge licence to use the CSD system (Allen, 2002 ) and Professor Judith Howard for the donation of a Rigaku AFC6S four-circle diffractometer. EF is a member of the research staff of Conicet. The authors are grateful to Laboratorios Gador for providing the zoledronic acid.

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