Nickel alendronate

Sikorska, M.; Gazda, M.; Chojnacki, J.

doi:10.1107/S1600536812022532

metal-organic compounds

CRYSTALLOGRAPHIC
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ISSN: 2056-9890

Volume 68| Part 6| June 2012| Pages m820-m821

doi:10.1107/S1600536812022532

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Nickel alendronate

Małgorzata Sikorska,^a Maria Gazda ^b and Jaroslaw Chojnacki ^a ^*

^aChemical Faculty, Gdansk University of Technology, Narutowicza 11/12, Gdansk PL-80233, Poland, and ^bFaculty of Applied Physics and Mathematics, Gdansk University of Technology, Narutowicza 11/12, Gdansk PL-80233, Poland
^*Correspondence e-mail: jaroslaw.chojnacki@pg.gda.pl

(Received 19 April 2012; accepted 17 May 2012; online 26 May 2012)

The title compound {systematic name: bis(μ₂-dihydrogen 4-azaniumyl-1-hydroxybutane-1,1-diphosphonato)bis[aqua(dihydrogen 4-azaniumyl-1-hydroxybutane-1,1-diphosphonato)nickel(II)] dihydrate}, [Ni₂(C₄H₁₂NO₇P₂)₄(H₂O)₂]·2H₂O, was synthesiized under hydrothermal conditions. Its structure is isotypic with the Co^II analogue. The crystal structure is built up from centrosymmetric dinuclear complex molecules and the structure is reinforced by a net of intermolecular O—H⋯O and N—H⋯O hydrogen bonds. One water molecule is bound to the Ni^II atom in the octahedral coordination sphere, while the second is part of the intermolecular hydrogen-bond system.

Related literature

For the isotypic Co^II compound, see: Man et al. (2006 ). For the structures and therapeutic properties of bisphosphonates, see: Russell (2011 ). For zinc alendronate, see: Dufau et al. (1995 ).

Experimental

Crystal data

[Ni₂(C₄H₁₂NO₇P₂)₄(H₂O)₂]·2H₂O
M_r = 1181.83
Monoclinic, P 2₁ /c
a = 12.5042 (3) Å
b = 13.5214 (2) Å
c = 12.4538 (3) Å
β = 109.667 (4)°
V = 1982.78 (9) Å³
Z = 2
Mo Kα radiation
μ = 1.39 mm⁻¹
T = 297 K
0.33 × 0.29 × 0.16 mm

Data collection

Oxford Diffraction KM-4-CCD Sapphire2 diffractometer
Absorption correction: analytical [CrysAlis PRO (Oxford Diffraction 2010 $[Oxford Diffraction (2010). CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, England.]$ ), based on expressions derived by Clark & Reid (1995 )] T_min = 0.747, T_max = 0.854
20727 measured reflections
3522 independent reflections
3237 reflections with I > 2σ(I)
R_int = 0.026

Refinement

R[F² > 2σ(F²)] = 0.046
wR(F²) = 0.124
S = 1.07
3522 reflections
298 parameters
6 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 2.44 e Å⁻³
Δρ_min = −0.67 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1NA⋯O11ⁱ	0.89	2.27	3.000 (4)	140
N1—H1NB⋯O4ⁱⁱ	0.89	2.13	2.980 (5)	159
N1—H1NC⋯O5ⁱⁱⁱ	0.89	1.93	2.806 (4)	168
N2—H2NA⋯O2^iv	0.89	2.43	3.215 (5)	147
N2—H2NB⋯O1	0.89	2.31	3.111 (5)	149
N2—H2C⋯O8^iv	0.89	2.30	3.169 (6)	167
O2—H2⋯O5ⁱⁱ	0.82	1.68	2.487 (4)	170
O6—H6⋯O3^v	0.82	1.73	2.539 (4)	168
O9—H9⋯O12^vi	0.82	1.89	2.665 (4)	157
O11—H11⋯O8^iv	0.82	1.78	2.585 (4)	165
O13—H13⋯O12^vi	0.82	2.08	2.898 (4)	172
O15—H15A⋯O3^v	0.83 (2)	2.00 (2)	2.815 (4)	168 (5)
O15—H15B⋯O16	0.82 (2)	2.29 (5)	2.882 (8)	130 (6)
O16—H16A⋯O8^vii	0.88 (2)	2.57 (5)	3.365 (9)	151 (10)
O16—H16B⋯O8^iv	0.88 (2)	2.03 (3)	2.902 (8)	169 (13)
Symmetry codes: (i) x+1, y, z+1; (ii) $[-x+2, y-{\script{1\over 2}}, -z+{\script{3\over 2}}]$ ; (iii) -x+2, -y+1, -z+2; (iv) $[x, -y+{\script{1\over 2}}, z-{\script{1\over 2}}]$ ; (v) -x+2, -y+1, -z+1; (vi) -x+1, -y+1, -z+1; (vii) $[-x+1, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]$ .

Data collection: CrysAlis PRO (Oxford Diffraction, 2010 $[Oxford Diffraction (2010). CrysAlis PRO. Oxford Diffraction Ltd, Yarnton, England.]$ ); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997 ) and Mercury (Macrae et al., 2008 ); software used to prepare material for publication: WinGX (Farrugia, 1999 ), Mercury, publCIF (Westrip, 2010 ) and PLATON (Spek, 2009 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536812022532/zj2074sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536812022532/zj2074Isup2.hkl

checkCIF report

Comment top

Bisphosphonates are organic analogues of pyrophosphates with the P–O–P bridge replaced with a hydrolytically resistant P–C–P moiety. Their structure and therapeutic properties have been of vivid scientific interest for over 40 years (Russell, 2011). Bisphosphonates play essential role in modification of biomineralization in bones. Apart from the most important calcium salts, transition metal complexes are also being studied in respect to complex formation constants and X-ray structures e.g. to estimate and elucidate potential side effects of bisphosphonate drugs against osteoporosis. It was noticed (Man et al. 2006) that the length of side alkyl chain is crucial for determination of aggregation of metal bisphosphonates. For instance, in the case of Co bisphosphonates with six-carbon chain the mononuclear product was found, while the four-carbon hydrocarbon chain facilitated formation of the dinuclear complexes while shorter hydrocarbon side chains led to more or less complicated polymeric structures. Magnetic properties of the cobalt compounds have risen some interest and were examined in details.

Alendronic acid [CH(OH){(CH₂)₃NH₂}{(PO(OH)₂}₂] in metal complexes usually occurrs as the zwitterionic monoanion with two P–OH groups deprotonated and the amino group protonated. Next two P–OH groups remain intact. Consequently divalent metals give neutral complexes (usually chelates) with metal to ligand ratio of 1:2.

The title compound was obtained from sodium salt of 4-amino-1-hydroxy-1,1-butylidenebisphosphonic acid and nickel(II) chloride in acidic aqueous solution. Both acidification and rising the temperature to ca 130 °C were necessary to obtain single crystals of X-ray quality. The product is insoluble in water and common organic solvents. The afforded crystals were investigated by single-crystal X-ray diffraction and additionally by microanalysis and powder diffraction in order to test the purity and composition of the whole batch.

The structure of the obtained compound, C₁₆H₅₂N₄Ni₂O₃₀P₈*2(H₂O), turned out to be isomorphic with structure of cobalt derivative which was determined by Man et al. 2006. Structure composed of dinuclear complexes (though not isomorphic with the described above) was also found for zinc alendronate (Dufau et al. 1995). The text below recapitulates the main structural features of the determined structure.

Crystals are build up from centrosymmetric dinuclear complex molecules. Each metal atom coordination is close to octahedral, with one terminal water molecule, one terminal and two bridging bisphosphonate anions. All bisphosphonato ligands are chelating and contain one NH₃⁺ and two —P(O)(O^-)(OH) groups. The terminal ligands are bidentate, while the bridging ones are tridentate: one PO₃H group is monodentate 1κ-O and the other is bridging bidentate 1κ-O',2κ-O'', using both nagatively charged O atoms and one oxygen atom from P=O group. Bond lengths allow only for general identification of P=O and P—O^- (ca 1.50 Å) or P–OH groups (ca 1.57 Å).

The system of hydrogen bonds is rather complex, see the relevant table. Packing of molecules is reinforced by O—H···O and by charge assisted (+)N—H···O hydrogen bonds. However, all internal hydrogen bonds can be easily recognized by the symmetry code of the acceptor atom being [-x + 1, -y + 1, -z + 1] (intramolecular inversion) or none. The alkylammonium chain N1 extends away from the core and forms only intermolecular hydrogen bonds with ligating and non ligating phosphonate O-atoms. Interesting R₂²(16) centrosymmetric motif is formed by N1 ··· O5 bond around the b axis (see Figure 2.) The other alkylamonium chain is bent towards the central dinuclear core to facilitate intramolecular hydrogen bonding between the ammonium terminus and the O atoms. In fact, N2 ammonium groups form intramolecular as well as intermolecular hydrogen bonds. Hydroxyl group bound to carbon forms internal hydrogen bond O13—H ···O12[1 - x,1 - y,1 - z] and O14—H···O4[1 - x,1 - y,1 - z] and O14—H···O7. Water molecule (O15) bound to nickel atom forms hydrogen bonds with the next water molecule (O16) in the second coordination sphere. Apart from that extended intermolecular hydrogen bond network is present.

Microanalysis and powder diffraction pattern confirm the expected composition. Some discrepances between monocrystalic simulated intensities and experimental powder XRD intensities stem most likely from not uniform distribution of orientation of microcrystalites in the "powder" sample. Nevertheless, positions of all recorded peaks are correct.

Related literature top

For the isotypic Co^II compound, see: Man et al. (2006). For the structures and therapeutic properties of bisphosphonates, see: Russell (2011). For zinc alendronate, see: Dufau et al. (1995).

Experimental top

Sodium alendronate (65 mg) was dissolved in 6 cm³ of water warmed to ca 70 °C. Then 4 ml of aqueous solution containing 95.2 mg of NiCl₂.6H₂O (0.4 mmole) and 0.5 ml of 2M HCl (1 mmole) were added. The pressure resistant container was closed and heated on an oil bath to 130 °C (inducing ca 3 bar overpressure) for 96 h. The content was let to cool slowly together with the oil bath and the obtained crystals were suitable for X-ray structural analysis. Elemental analysis (calculated for C₁₆H₅₂N₄Ni₂O₃₀P₈*2(H₂O): C 16.34(16.26); H 4.71(4.77); N 4.75(4.74); S 0.0(0.0). Apparatus: Vario El Cube CHNS (Elementar), powder diffraction: X'Pert Philips diffractometer (Cu K_α radiation).

Computing details top

Data collection: CrysAlis PRO (Oxford Diffraction, 2010); cell refinement: CrysAlis PRO (Oxford Diffraction, 2010); data reduction: CrysAlis PRO (Oxford Diffraction, 2010); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia 1997) and Mercury (Macrae et al., 2008); software used to prepare material for publication: WinGX (Farrugia, 1999), Mercury (Macrae et al., 2008), publCIF (Westrip, 2010) and PLATON (Spek, 2009).

Figures top

	Fig. 1. Molecular structure of C₁₆H₅₂N₄Ni₂O₃₀P₈ showing atom labeling scheme. Solvent water molecule not shown, displacement ellipsoids 50%.
	Fig. 2. Packing diagram for C₁₆H₅₂N₄Ni₂O₃₀P₈ viewed along the b axis. Please note influence of different bending of the alkylammonium groups on hydrogen bonding system. Colours: central molecule - grey, molecules linked by N1—H···O5 bond - red, other neighbour molecules - blue

Bis(µ₂-dihydrogen 4-azaniumyl-1-hydroxybutane-1,1-diphosphonato)bis[aqua(dihydrogen 4-azaniumyl-1-hydroxybutane-1,1-diphosphonato)nickel(II)] dihydrate top

Crystal data top

[Ni₂(C₄H₁₂NO₇P₂)₄(H₂O)₂]·2H₂O	F(000) = 1224
M_r = 1181.83	D_x = 1.98 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 16141 reflections
a = 12.5042 (3) Å	θ = 2.3–28.8°
b = 13.5214 (2) Å	µ = 1.39 mm⁻¹
c = 12.4538 (3) Å	T = 297 K
β = 109.667 (4)°	Block, green
V = 1982.78 (9) Å³	0.33 × 0.29 × 0.16 mm
Z = 2

Data collection top

Oxford Diffraction KM-4-CCD Sapphire2 diffractometer	3522 independent reflections
Graphite monochromator	3237 reflections with I > 2σ(I)
Detector resolution: 8.1883 pixels mm^-1	R_int = 0.026
ω scans	θ_max = 25.1°, θ_min = 2.3°
Absorption correction: analytical [CrysAlis PRO (Oxford Diffraction 2010), based on expressions derived by Clark & Reid (1995)]	h = −14→14
T_min = 0.747, T_max = 0.854	k = −16→16
20727 measured reflections	l = −14→14

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)] = 0.046	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.124	H atoms treated by a mixture of independent and constrained refinement
S = 1.07	w = 1/[σ²(F_o²) + (0.0687P)² + 6.2695P] where P = (F_o² + 2F_c²)/3
3522 reflections	(Δ/σ)_max = 0.001
298 parameters	Δρ_max = 2.44 e Å⁻³
6 restraints	Δρ_min = −0.67 e Å⁻³

Crystal data top

[Ni₂(C₄H₁₂NO₇P₂)₄(H₂O)₂]·2H₂O	V = 1982.78 (9) Å³
M_r = 1181.83	Z = 2
Monoclinic, P2₁/c	Mo Kα radiation
a = 12.5042 (3) Å	µ = 1.39 mm⁻¹
b = 13.5214 (2) Å	T = 297 K
c = 12.4538 (3) Å	0.33 × 0.29 × 0.16 mm
β = 109.667 (4)°

Data collection top

Oxford Diffraction KM-4-CCD Sapphire2 diffractometer	3522 independent reflections
Absorption correction: analytical [CrysAlis PRO (Oxford Diffraction 2010), based on expressions derived by Clark & Reid (1995)]	3237 reflections with I > 2σ(I)
T_min = 0.747, T_max = 0.854	R_int = 0.026
20727 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.046	6 restraints
wR(F²) = 0.124	H atoms treated by a mixture of independent and constrained refinement
S = 1.07	Δρ_max = 2.44 e Å⁻³
3522 reflections	Δρ_min = −0.67 e Å⁻³
298 parameters

Special details top

Experimental. Absorption correction: CrysAlisPro, Oxford Diffraction 2010, Analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by Clark & Reid 1995.

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

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > 2σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
Ni1	0.69424 (4)	0.54490 (3)	0.47489 (4)	0.01836 (16)
P1	0.90380 (8)	0.39706 (7)	0.61692 (8)	0.0182 (2)
P2	0.93083 (8)	0.61463 (7)	0.67849 (8)	0.0198 (2)
P3	0.48228 (9)	0.27678 (8)	0.55326 (9)	0.0240 (2)
P4	0.45576 (8)	0.41194 (7)	0.34777 (8)	0.0172 (2)
N1	1.1817 (3)	0.2965 (3)	1.0790 (3)	0.0287 (8)
H1NA	1.2515	0.2964	1.1300	0.043*
H1NB	1.1698	0.2403	1.0396	0.043*
H1NC	1.1313	0.3020	1.1149	0.043*
N2	0.7320 (3)	0.3093 (4)	0.2984 (4)	0.0491 (11)
H2NA	0.7813	0.3066	0.2610	0.074*
H2NB	0.7470	0.3618	0.3441	0.074*
H2C	0.6618	0.3140	0.2487	0.074*
O1	0.7949 (2)	0.4259 (2)	0.5266 (2)	0.0250 (6)
O2	0.8834 (2)	0.2960 (2)	0.6677 (2)	0.0246 (6)
H2	0.9390	0.2603	0.6781	0.037*
O3	1.0060 (2)	0.3913 (2)	0.5783 (2)	0.0254 (6)
O4	0.8202 (2)	0.6342 (2)	0.5835 (2)	0.0240 (6)
O5	0.9503 (2)	0.6825 (2)	0.7794 (2)	0.0277 (6)
O6	1.0338 (2)	0.6234 (2)	0.6349 (2)	0.0270 (6)
H6	1.0115	0.6177	0.5653	0.040*
O7	0.3862 (2)	0.3254 (2)	0.5773 (2)	0.0240 (6)
O8	0.5022 (3)	0.1702 (2)	0.5902 (3)	0.0340 (7)
O9	0.5971 (2)	0.3324 (2)	0.6132 (2)	0.0301 (6)
H9	0.5896	0.3911	0.5960	0.045*
O10	0.5735 (2)	0.4502 (2)	0.3740 (2)	0.0244 (6)
O11	0.3940 (2)	0.4038 (2)	0.2154 (2)	0.0249 (6)
H11	0.4364	0.3770	0.1863	0.037*
O12	0.3763 (2)	0.47229 (19)	0.3918 (2)	0.0212 (6)
O13	0.8408 (2)	0.4841 (2)	0.7805 (2)	0.0244 (6)
H13	0.7813	0.5021	0.7324	0.037*
O14	0.3381 (2)	0.2459 (2)	0.3447 (3)	0.0320 (7)
H14	0.3055	0.2448	0.3918	0.048*
O15	0.7615 (3)	0.5602 (3)	0.3433 (3)	0.0350 (7)
C1	0.9316 (3)	0.4880 (3)	0.7328 (3)	0.0203 (8)
C2	1.0451 (3)	0.4727 (3)	0.8315 (3)	0.0257 (8)
H2A	1.1049	0.4653	0.7987	0.031*
H2B	1.0612	0.5324	0.8773	0.031*
C3	1.0521 (3)	0.3859 (3)	0.9103 (4)	0.0299 (9)
H3A	0.9952	0.3928	0.9469	0.036*
H3B	1.0372	0.3249	0.8667	0.036*
C4	1.1690 (4)	0.3818 (3)	0.9998 (3)	0.0304 (9)
H4A	1.2255	0.3765	0.9624	0.037*
H4B	1.1830	0.4428	1.0433	0.037*
C5	0.4540 (3)	0.2832 (3)	0.3985 (3)	0.0243 (8)
C6	0.5333 (3)	0.2156 (3)	0.3597 (3)	0.0271 (9)
H6A	0.5072	0.1479	0.3587	0.033*
H6B	0.5261	0.2331	0.2820	0.033*
C7	0.6591 (4)	0.2194 (4)	0.4324 (4)	0.0369 (10)
H7A	0.6723	0.2793	0.4779	0.044*
H7B	0.6755	0.1638	0.4845	0.044*
C8	0.7420 (4)	0.2174 (4)	0.3681 (5)	0.0463 (13)
H8A	0.8187	0.2119	0.4217	0.056*
H8B	0.7271	0.1601	0.3184	0.056*
H15A	0.829 (2)	0.577 (5)	0.357 (5)	0.069*
H15B	0.732 (4)	0.584 (5)	0.280 (3)	0.069*
O16	0.6399 (6)	0.5061 (6)	0.1101 (7)	0.116 (2)
H16A	0.584 (8)	0.532 (8)	0.054 (8)	0.175*
H16B	0.605 (9)	0.448 (4)	0.102 (11)	0.175*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Ni1	0.0144 (3)	0.0229 (3)	0.0179 (3)	0.00050 (18)	0.00562 (19)	−0.00056 (18)
P1	0.0149 (5)	0.0217 (5)	0.0171 (5)	0.0014 (4)	0.0041 (4)	−0.0012 (4)
P2	0.0161 (5)	0.0231 (5)	0.0200 (5)	−0.0026 (4)	0.0058 (4)	−0.0022 (4)
P3	0.0248 (5)	0.0255 (5)	0.0238 (5)	0.0026 (4)	0.0110 (4)	0.0032 (4)
P4	0.0159 (5)	0.0212 (5)	0.0151 (5)	0.0002 (4)	0.0059 (4)	−0.0006 (3)
N1	0.0223 (17)	0.039 (2)	0.0218 (17)	0.0053 (15)	0.0038 (14)	0.0006 (15)
N2	0.033 (2)	0.070 (3)	0.049 (3)	−0.013 (2)	0.0197 (19)	−0.004 (2)
O1	0.0211 (14)	0.0250 (14)	0.0234 (14)	0.0036 (11)	0.0003 (11)	−0.0042 (11)
O2	0.0201 (13)	0.0247 (14)	0.0289 (14)	0.0018 (11)	0.0079 (12)	0.0019 (11)
O3	0.0195 (13)	0.0352 (16)	0.0228 (14)	0.0004 (11)	0.0090 (11)	−0.0017 (12)
O4	0.0188 (13)	0.0249 (14)	0.0265 (14)	−0.0006 (11)	0.0052 (11)	0.0003 (11)
O5	0.0279 (14)	0.0288 (15)	0.0289 (15)	−0.0080 (12)	0.0128 (12)	−0.0084 (12)
O6	0.0199 (14)	0.0383 (17)	0.0236 (14)	−0.0073 (12)	0.0084 (11)	−0.0020 (13)
O7	0.0228 (14)	0.0291 (15)	0.0216 (13)	0.0060 (11)	0.0093 (11)	0.0047 (11)
O8	0.0457 (18)	0.0267 (16)	0.0394 (17)	0.0087 (13)	0.0271 (15)	0.0096 (13)
O9	0.0259 (15)	0.0345 (16)	0.0280 (15)	0.0012 (12)	0.0063 (12)	0.0035 (13)
O10	0.0162 (13)	0.0342 (16)	0.0228 (14)	−0.0026 (11)	0.0067 (11)	−0.0059 (11)
O11	0.0189 (13)	0.0356 (16)	0.0199 (13)	0.0009 (11)	0.0063 (11)	−0.0044 (11)
O12	0.0197 (13)	0.0259 (14)	0.0203 (13)	0.0014 (11)	0.0096 (11)	−0.0012 (11)
O13	0.0178 (13)	0.0358 (16)	0.0216 (13)	−0.0002 (12)	0.0093 (11)	0.0016 (12)
O14	0.0263 (15)	0.0354 (16)	0.0338 (16)	−0.0070 (13)	0.0092 (13)	−0.0078 (13)
O15	0.0235 (15)	0.056 (2)	0.0284 (16)	−0.0013 (14)	0.0128 (13)	0.0013 (14)
C1	0.0149 (17)	0.0248 (19)	0.0218 (18)	−0.0012 (15)	0.0070 (15)	−0.0015 (15)
C2	0.0184 (19)	0.035 (2)	0.0205 (19)	−0.0012 (16)	0.0025 (15)	−0.0009 (16)
C3	0.022 (2)	0.034 (2)	0.027 (2)	−0.0007 (17)	0.0001 (17)	0.0004 (17)
C4	0.027 (2)	0.038 (2)	0.0219 (19)	−0.0021 (18)	0.0030 (17)	0.0015 (17)
C5	0.024 (2)	0.025 (2)	0.0231 (19)	−0.0009 (16)	0.0079 (16)	0.0001 (16)
C6	0.029 (2)	0.027 (2)	0.027 (2)	0.0000 (17)	0.0113 (17)	−0.0069 (16)
C7	0.032 (2)	0.043 (3)	0.037 (2)	0.004 (2)	0.013 (2)	0.000 (2)
C8	0.029 (2)	0.056 (3)	0.052 (3)	0.011 (2)	0.012 (2)	−0.014 (3)
O16	0.117 (5)	0.110 (5)	0.128 (6)	−0.028 (4)	0.048 (4)	−0.009 (4)

Geometric parameters (Å, º) top

Ni1—O1	2.011 (3)	O7—Ni1ⁱ	2.017 (3)
Ni1—O7ⁱ	2.017 (3)	O9—H9	0.8200
Ni1—O10	2.054 (3)	O11—H11	0.8200
Ni1—O4	2.082 (3)	O12—Ni1ⁱ	2.139 (3)
Ni1—O15	2.089 (3)	O13—C1	1.449 (4)
Ni1—O12ⁱ	2.139 (3)	O13—H13	0.8200
P1—O1	1.497 (3)	O14—C5	1.466 (5)
P1—O3	1.511 (3)	O14—H14	0.8200
P1—O2	1.563 (3)	O15—O16	2.882 (8)
P1—C1	1.838 (4)	O15—H15A	0.83 (2)
P2—O5	1.508 (3)	O15—H15B	0.82 (2)
P2—O4	1.510 (3)	C1—C2	1.547 (5)
P2—O6	1.562 (3)	C2—C3	1.513 (6)
P2—C1	1.839 (4)	C2—H2A	0.9700
P3—O7	1.486 (3)	C2—H2B	0.9700
P3—O8	1.507 (3)	C3—C4	1.512 (5)
P3—O9	1.570 (3)	C3—H3A	0.9700
P3—C5	1.841 (4)	C3—H3B	0.9700
P4—O10	1.490 (3)	C4—H4A	0.9700
P4—O12	1.523 (3)	C4—H4B	0.9700
P4—O11	1.571 (3)	C5—C6	1.541 (5)
P4—C5	1.855 (4)	C6—C7	1.529 (6)
N1—C4	1.491 (6)	C6—H6A	0.9700
N1—H1NA	0.8900	C6—H6B	0.9700
N1—H1NB	0.8900	C7—C8	1.508 (6)
N1—H1NC	0.8900	C7—H7A	0.9700
N2—C8	1.496 (7)	C7—H7B	0.9700
N2—H2NA	0.8900	C8—H8A	0.9700
N2—H2NB	0.8900	C8—H8B	0.9700
N2—H2C	0.8900	O16—H16A	0.88 (2)
O2—H2	0.8200	O16—H16B	0.88 (2)
O6—H6	0.8200

O1—Ni1—O7ⁱ	171.66 (11)	P4—O12—Ni1ⁱ	135.27 (16)
O1—Ni1—O10	87.07 (11)	C1—O13—H13	109.5
O7ⁱ—Ni1—O10	99.26 (11)	C5—O14—H14	109.5
O1—Ni1—O4	90.06 (11)	Ni1—O15—O16	123.4 (2)
O7ⁱ—Ni1—O4	83.75 (11)	Ni1—O15—H15A	121 (4)
O10—Ni1—O4	176.74 (11)	O16—O15—H15A	115 (4)
O1—Ni1—O15	87.52 (13)	Ni1—O15—H15B	129 (4)
O7ⁱ—Ni1—O15	87.12 (12)	H15A—O15—H15B	101 (3)
O10—Ni1—O15	89.36 (12)	O13—C1—C2	107.8 (3)
O4—Ni1—O15	92.05 (12)	O13—C1—P1	109.3 (2)
O1—Ni1—O12ⁱ	92.37 (11)	C2—C1—P1	114.5 (3)
O7ⁱ—Ni1—O12ⁱ	93.08 (10)	O13—C1—P2	106.1 (2)
O10—Ni1—O12ⁱ	89.82 (10)	C2—C1—P2	107.9 (3)
O4—Ni1—O12ⁱ	88.77 (10)	P1—C1—P2	110.97 (19)
O15—Ni1—O12ⁱ	179.18 (12)	C3—C2—C1	117.2 (3)
O1—P1—O3	115.32 (16)	C3—C2—H2A	108.0
O1—P1—O2	107.48 (16)	C1—C2—H2A	108.0
O3—P1—O2	110.75 (16)	C3—C2—H2B	108.0
O1—P1—C1	107.43 (16)	C1—C2—H2B	108.0
O3—P1—C1	109.11 (16)	H2A—C2—H2B	107.2
O2—P1—C1	106.33 (17)	C4—C3—C2	109.7 (3)
O5—P2—O4	113.25 (16)	C4—C3—H3A	109.7
O5—P2—O6	108.80 (16)	C2—C3—H3A	109.7
O4—P2—O6	111.05 (16)	C4—C3—H3B	109.7
O5—P2—C1	106.31 (17)	C2—C3—H3B	109.7
O4—P2—C1	109.97 (16)	H3A—C3—H3B	108.2
O6—P2—C1	107.18 (17)	N1—C4—C3	112.2 (4)
O7—P3—O8	115.04 (17)	N1—C4—H4A	109.2
O7—P3—O9	111.41 (17)	C3—C4—H4A	109.2
O8—P3—O9	106.36 (18)	N1—C4—H4B	109.2
O7—P3—C5	107.87 (17)	C3—C4—H4B	109.2
O8—P3—C5	108.56 (18)	H4A—C4—H4B	107.9
O9—P3—C5	107.33 (17)	O14—C5—C6	107.1 (3)
O10—P4—O12	116.83 (15)	O14—C5—P3	105.9 (3)
O10—P4—O11	110.80 (16)	C6—C5—P3	112.6 (3)
O12—P4—O11	105.41 (15)	O14—C5—P4	106.9 (3)
O10—P4—C5	112.03 (17)	C6—C5—P4	111.6 (3)
O12—P4—C5	107.24 (16)	P3—C5—P4	112.4 (2)
O11—P4—C5	103.50 (17)	C7—C6—C5	115.9 (3)
C4—N1—H1NA	109.5	C7—C6—H6A	108.3
C4—N1—H1NB	109.5	C5—C6—H6A	108.3
H1NA—N1—H1NB	109.5	C7—C6—H6B	108.3
C4—N1—H1NC	109.5	C5—C6—H6B	108.3
H1NA—N1—H1NC	109.5	H6A—C6—H6B	107.4
H1NB—N1—H1NC	109.5	C8—C7—C6	116.0 (4)
C8—N2—H2NA	109.5	C8—C7—H7A	108.3
C8—N2—H2NB	109.5	C6—C7—H7A	108.3
H2NA—N2—H2NB	109.5	C8—C7—H7B	108.3
C8—N2—H2C	109.5	C6—C7—H7B	108.3
H2NA—N2—H2C	109.5	H7A—C7—H7B	107.4
H2NB—N2—H2C	109.5	N2—C8—C7	110.8 (4)
P1—O1—Ni1	139.66 (17)	N2—C8—H8A	109.5
P1—O2—H2	109.5	C7—C8—H8A	109.5
P2—O4—Ni1	134.46 (17)	N2—C8—H8B	109.5
P2—O6—H6	109.5	C7—C8—H8B	109.5
P3—O7—Ni1ⁱ	131.97 (17)	H8A—C8—H8B	108.1
P3—O9—H9	109.5	O15—O16—H16A	135 (9)
P4—O10—Ni1	145.03 (17)	O15—O16—H16B	114 (8)
P4—O11—H11	109.5

O3—P1—O1—Ni1	−101.7 (3)	O1—P1—C1—P2	−54.6 (2)
O2—P1—O1—Ni1	134.3 (3)	O3—P1—C1—P2	71.1 (2)
C1—P1—O1—Ni1	20.2 (3)	O5—P2—C1—O13	59.5 (3)
O10—Ni1—O1—P1	−167.7 (3)	O4—P2—C1—O13	−63.4 (3)
O4—Ni1—O1—P1	10.7 (3)	O6—P2—C1—O13	175.8 (2)
O15—Ni1—O1—P1	102.8 (3)	O5—P2—C1—C2	−55.7 (3)
O12ⁱ—Ni1—O1—P1	−78.0 (3)	O4—P2—C1—C2	−178.7 (2)
O5—P2—O4—Ni1	−138.7 (2)	O6—P2—C1—C2	60.5 (3)
O6—P2—O4—Ni1	98.6 (2)	O4—P2—C1—P1	55.1 (2)
C1—P2—O4—Ni1	−19.9 (3)	O6—P2—C1—P1	−65.7 (2)
O1—Ni1—O4—P2	−10.8 (2)	O13—C1—C2—C3	49.4 (5)
O7ⁱ—Ni1—O4—P2	174.8 (2)	P1—C1—C2—C3	−72.4 (4)
O15—Ni1—O4—P2	−98.3 (2)	P2—C1—C2—C3	163.5 (3)
O12ⁱ—Ni1—O4—P2	81.6 (2)	C1—C2—C3—C4	179.1 (4)
O8—P3—O7—Ni1ⁱ	−168.3 (2)	C2—C3—C4—N1	−179.1 (4)
O9—P3—O7—Ni1ⁱ	70.6 (3)	O7—P3—C5—O14	−50.5 (3)
C5—P3—O7—Ni1ⁱ	−47.0 (3)	O8—P3—C5—O14	74.7 (3)
O12—P4—O10—Ni1	16.8 (4)	O9—P3—C5—O14	−170.7 (2)
O11—P4—O10—Ni1	137.5 (3)	O7—P3—C5—C6	−167.2 (3)
C5—P4—O10—Ni1	−107.5 (3)	O8—P3—C5—C6	−41.9 (3)
O1—Ni1—O10—P4	121.6 (3)	O9—P3—C5—C6	72.6 (3)
O7ⁱ—Ni1—O10—P4	−63.8 (3)	O7—P3—C5—P4	65.8 (2)
O15—Ni1—O10—P4	−150.8 (3)	O8—P3—C5—P4	−168.9 (2)
O12ⁱ—Ni1—O10—P4	29.2 (3)	O9—P3—C5—P4	−54.3 (2)
O10—P4—O12—Ni1ⁱ	−106.8 (2)	O10—P4—C5—O14	−166.6 (2)
O11—P4—O12—Ni1ⁱ	129.6 (2)	O12—P4—C5—O14	63.9 (3)
C5—P4—O12—Ni1ⁱ	19.8 (3)	O11—P4—C5—O14	−47.2 (3)
O1—Ni1—O15—O16	104.2 (3)	O10—P4—C5—C6	−49.9 (3)
O7ⁱ—Ni1—O15—O16	−82.2 (3)	O12—P4—C5—C6	−179.3 (3)
O10—Ni1—O15—O16	17.1 (3)	O11—P4—C5—C6	69.5 (3)
O4—Ni1—O15—O16	−165.8 (3)	O10—P4—C5—P3	77.6 (2)
O1—P1—C1—O13	62.1 (3)	O12—P4—C5—P3	−51.8 (2)
O3—P1—C1—O13	−172.3 (2)	O14—C5—C6—C7	−161.5 (4)
O2—P1—C1—O13	−52.8 (3)	P3—C5—C6—C7	−45.5 (4)
O1—P1—C1—C2	−177.0 (3)	P4—C5—C6—C7	81.9 (4)
O3—P1—C1—C2	−51.3 (3)	C5—C6—C7—C8	−139.6 (4)
O2—P1—C1—C2	68.2 (3)	C6—C7—C8—N2	66.2 (5)

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
N1—H1NA···O11ⁱⁱ	0.89	2.27	3.000 (4)	140
N1—H1NB···O4ⁱⁱⁱ	0.89	2.13	2.980 (5)	159
N1—H1NC···O5^iv	0.89	1.93	2.806 (4)	168
N2—H2NA···O2^v	0.89	2.43	3.215 (5)	147
N2—H2NB···O1	0.89	2.31	3.111 (5)	149
N2—H2C···O8^v	0.89	2.30	3.169 (6)	167
O2—H2···O5ⁱⁱⁱ	0.82	1.68	2.487 (4)	170
O6—H6···O3^vi	0.82	1.73	2.539 (4)	168
O9—H9···O12ⁱ	0.82	1.89	2.665 (4)	157
O11—H11···O8^v	0.82	1.78	2.585 (4)	165
O13—H13···O12ⁱ	0.82	2.08	2.898 (4)	172
O15—H15A···O3^vi	0.83 (2)	2.00 (2)	2.815 (4)	168 (5)
O15—H15B···O16	0.82 (2)	2.29 (5)	2.882 (8)	130 (6)
O16—H16A···O8^vii	0.88 (2)	2.57 (5)	3.365 (9)	151 (10)
O16—H16B···O8^v	0.88 (2)	2.03 (3)	2.902 (8)	169 (13)

Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) x+1, y, z+1; (iii) −x+2, y−1/2, −z+3/2; (iv) −x+2, −y+1, −z+2; (v) x, −y+1/2, z−1/2; (vi) −x+2, −y+1, −z+1; (vii) −x+1, y+1/2, −z+1/2.

Experimental details

Crystal data
Chemical formula	[Ni₂(C₄H₁₂NO₇P₂)₄(H₂O)₂]·2H₂O
M_r	1181.83
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	297
a, b, c (Å)	12.5042 (3), 13.5214 (2), 12.4538 (3)
β (°)	109.667 (4)
V (Å³)	1982.78 (9)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	1.39
Crystal size (mm)	0.33 × 0.29 × 0.16

Data collection
Diffractometer	Oxford Diffraction KM-4-CCD Sapphire2 diffractometer
Absorption correction	Analytical [CrysAlis PRO (Oxford Diffraction 2010), based on expressions derived by Clark & Reid (1995)]
T_min, T_max	0.747, 0.854
No. of measured, independent and observed [I > 2σ(I)] reflections	20727, 3522, 3237
R_int	0.026
(sin θ/λ)_max (Å⁻¹)	0.597

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.046, 0.124, 1.07
No. of reflections	3522
No. of parameters	298
No. of restraints	6
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	2.44, −0.67

Computer programs: CrysAlis PRO (Oxford Diffraction, 2010), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia 1997) and Mercury (Macrae et al., 2008), WinGX (Farrugia, 1999), Mercury (Macrae et al., 2008), publCIF (Westrip, 2010) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1NA···O11ⁱ	0.89	2.27	3.000 (4)	139.6
N1—H1NB···O4ⁱⁱ	0.89	2.13	2.980 (5)	158.7
N1—H1NC···O5ⁱⁱⁱ	0.89	1.93	2.806 (4)	168.0
N2—H2NA···O2^iv	0.89	2.43	3.215 (5)	147.3
N2—H2NB···O1	0.89	2.31	3.111 (5)	148.9
N2—H2C···O8^iv	0.89	2.30	3.169 (6)	166.6
O2—H2···O5ⁱⁱ	0.82	1.68	2.487 (4)	170.2
O6—H6···O3^v	0.82	1.73	2.539 (4)	168.0
O9—H9···O12^vi	0.82	1.89	2.665 (4)	157.3
O11—H11···O8^iv	0.82	1.78	2.585 (4)	165.4
O13—H13···O12^vi	0.82	2.08	2.898 (4)	172.3
O15—H15A···O3^v	0.83 (2)	2.00 (2)	2.815 (4)	168 (5)
O15—H15B···O16	0.82 (2)	2.29 (5)	2.882 (8)	130 (6)
O16—H16A···O8^vii	0.88 (2)	2.57 (5)	3.365 (9)	151 (10)
O16—H16B···O8^iv	0.88 (2)	2.03 (3)	2.902 (8)	169 (13)

Symmetry codes: (i) x+1, y, z+1; (ii) −x+2, y−1/2, −z+3/2; (iii) −x+2, −y+1, −z+2; (iv) x, −y+1/2, z−1/2; (v) −x+2, −y+1, −z+1; (vi) −x+1, −y+1, −z+1; (vii) −x+1, y+1/2, −z+1/2.

Acknowledgements

The authors thank the Polpharma SA company (Starogard Gdanski, Poland) for the donation of samples of sodium 4-amino-1-hydroxy-1,1-butylidenebisphosphonate (sodium alendronate).

References

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