The title compound, Na+·C5H9N2O7P2-·4H2O, is an isomer of zoledronate, a potent bone antiresorptive bisphosphonate drug having significant activity against several parasitic protozoa. The crystal structure of isozoledronate consists of bisphosphonate dimers coordinated by two Na+ ions. The dimers are held together through an extensive hydrogen-bonding network. The crystals exhibit non-merohedral twinning that roughly superimposes the a and b axes, and inverts the c axis.
Supporting information
CCDC reference: 201261
Crystals of (I) were grown by vapour diffusion of ethanol into water. All
crystals examined exhibited non-merohedral twinning, which roughly
superimposed the a and b axes and inverted the c axis. Two distinct
triclinic cells were identified using SMART (Bruker, 2001) and
integrated using SAINT (Bruker, 2001). Unit-cell parameters were
determined from both components using SAINT. The twin law by rows was
(0 1 0, 1 0 0, 1/2 1/2 - 1). Non-overlapping reflections from the primary
orientation were used for phasing. Four frame series were filtered for
statistical outliers and then sorted, merged, scaled and corrected for
absorption using TWINABS, an unpublished upgrade of SADABS (Bruker,
2001) written for non-merohedral twins. A unique section of reciprocal space
was measured. However, owing to the close proximity of the non-merohedral
twins, reflections filtered as statistical outliers left the fraction of data
measured at full theta slightly less than ideal (0.88). Combined data with
complete or no overlap were used for refinement. Crystal decay was monitored
by collecting identical frames at the beginning and end of the experiment. No
correction for decay as a function of X-ray exposure time was applied.
Systematic conditions suggested the ambiguous space group. Inversion symmetry
was imposed on the dimer. R—H distances were restrained to ideal values,
with an effective s.u. of 0.02 Å, and H—O—H angles were also restrained
to ideal values (s.u. 0.04°). The remaining H-atom parameters were
independently refined without restraints. The relative volume of the secondary
orientation converged at 0.2687 (7). The choice of space group was confirmed by
successful convergence of the full-matrix least-squares refinement on F2
(SHELXL97; Sheldrick, 2001). The highest peaks in the final difference
Fourier map were located along the C—P bonds; the final map had no other
significant features. A final analysis of the variance between observed and
calculated structure factors showed no dependence on amplitude or resolution.
Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Bruker, 2001); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: CIFTAB in SHELXL97 (Sheldrick, 2001).
Monosodium
[1-hydroxy-2-(1
H-imidazol-3-ium-4-yl)ethane-1,1-diyl]bis(phosphonate)
tetrahydrate
top
Crystal data top
Na(C5H9N2O7P2)·4H2O | Z = 2 |
Mr = 366.14 | F(000) = 380 |
Triclinic, P1 | Dx = 1.781 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 6.6664 (19) Å | Cell parameters from 864 reflections |
b = 6.6765 (19) Å | θ = 2.6–28.1° |
c = 15.5711 (18) Å | µ = 0.41 mm−1 |
α = 84.075 (4)° | T = 193 K |
β = 82.803 (5)° | Prism, colourless |
γ = 85.776 (5)° | 0.22 × 0.22 × 0.10 mm |
V = 682.6 (3) Å3 | |
Data collection top
Siemens Platform CCD area-detector diffractometer | 3252 independent reflections |
Radiation source: normal-focus sealed tube | 2769 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.000 |
profile data from ω scans | θmax = 25.4°, θmin = 2.7° |
Absorption correction: multi-scan (SAINT and SADABS; Bruker, 2001) | h = −7→8 |
Tmin = 0.915, Tmax = 0.960 | k = −7→8 |
3252 measured reflections | l = 0→18 |
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)] = 0.029 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.077 | All H-atom parameters refined |
S = 1.04 | w = 1/[σ2(Fo2) + (0.046P)2 + 0.0847P] where P = (Fo2 + 2Fc2)/3 |
3252 reflections | (Δ/σ)max < 0.001 |
259 parameters | Δρmax = 0.28 e Å−3 |
20 restraints | Δρmin = −0.27 e Å−3 |
Crystal data top
Na(C5H9N2O7P2)·4H2O | γ = 85.776 (5)° |
Mr = 366.14 | V = 682.6 (3) Å3 |
Triclinic, P1 | Z = 2 |
a = 6.6664 (19) Å | Mo Kα radiation |
b = 6.6765 (19) Å | µ = 0.41 mm−1 |
c = 15.5711 (18) Å | T = 193 K |
α = 84.075 (4)° | 0.22 × 0.22 × 0.10 mm |
β = 82.803 (5)° | |
Data collection top
Siemens Platform CCD area-detector diffractometer | 3252 independent reflections |
Absorption correction: multi-scan (SAINT and SADABS; Bruker, 2001) | 2769 reflections with I > 2σ(I) |
Tmin = 0.915, Tmax = 0.960 | Rint = 0.000 |
3252 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.029 | 20 restraints |
wR(F2) = 0.077 | All H-atom parameters refined |
S = 1.04 | Δρmax = 0.28 e Å−3 |
3252 reflections | Δρmin = −0.27 e Å−3 |
259 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 | Uiso*/Ueq | |
N1 | 1.1410 (2) | 0.2747 (2) | 0.10652 (10) | 0.0164 (4) | |
H1 | 1.194 (3) | 0.286 (3) | 0.1536 (12) | 0.030 (6)* | |
C2 | 1.2389 (3) | 0.2330 (3) | 0.03025 (13) | 0.0186 (4) | |
H2 | 1.382 (2) | 0.220 (3) | 0.0173 (13) | 0.022 (6)* | |
N3 | 1.1050 (3) | 0.2244 (3) | −0.02430 (10) | 0.0174 (4) | |
H3 | 1.130 (4) | 0.194 (4) | −0.0769 (11) | 0.039 (7)* | |
C4 | 0.9146 (3) | 0.2604 (3) | 0.01783 (12) | 0.0164 (4) | |
H4 | 0.796 (3) | 0.264 (3) | −0.0086 (12) | 0.023 (6)* | |
C5 | 0.9349 (3) | 0.2899 (3) | 0.10087 (12) | 0.0140 (4) | |
C6 | 0.7764 (3) | 0.3262 (3) | 0.17512 (12) | 0.0163 (4) | |
H6A | 0.833 (3) | 0.384 (3) | 0.2223 (12) | 0.023 (6)* | |
H6B | 0.677 (3) | 0.423 (3) | 0.1499 (12) | 0.013 (5)* | |
C7 | 0.6660 (3) | 0.1333 (3) | 0.21377 (11) | 0.0132 (4) | |
Na1 | 0.83701 (12) | 0.21278 (12) | 0.44202 (5) | 0.0207 (2) | |
O1 | 0.5836 (2) | 0.0608 (2) | 0.14323 (8) | 0.0164 (3) | |
H1A | 0.513 (4) | −0.040 (4) | 0.1605 (18) | 0.045 (8)* | |
O2 | 0.96870 (19) | 0.0481 (2) | 0.31484 (8) | 0.0189 (3) | |
O3 | 0.9747 (2) | −0.1488 (2) | 0.18177 (8) | 0.0196 (3) | |
O4 | 0.7222 (2) | −0.2211 (2) | 0.31403 (9) | 0.0201 (3) | |
H4A | 0.799 (4) | −0.325 (3) | 0.3184 (18) | 0.057 (9)* | |
O6 | 0.31938 (19) | 0.3641 (2) | 0.24684 (8) | 0.0157 (3) | |
O5 | 0.53436 (19) | 0.2770 (2) | 0.37243 (8) | 0.0189 (3) | |
O7 | 0.3417 (2) | 0.0112 (2) | 0.32022 (9) | 0.0186 (3) | |
H7A | 0.218 (3) | 0.025 (4) | 0.3183 (17) | 0.046 (8)* | |
O8 | 1.2015 (3) | 0.1361 (2) | 0.50374 (10) | 0.0299 (4) | |
H8A | 1.233 (5) | 0.171 (5) | 0.5510 (14) | 0.077 (11)* | |
H8B | 1.298 (4) | 0.183 (5) | 0.4692 (17) | 0.080 (12)* | |
O9 | 0.6735 (2) | 0.3534 (2) | 0.57010 (9) | 0.0230 (3) | |
H9A | 0.636 (4) | 0.261 (3) | 0.6055 (15) | 0.044 (8)* | |
H9B | 0.605 (4) | 0.457 (3) | 0.5829 (16) | 0.045 (8)* | |
O10 | 0.9998 (2) | 0.4954 (2) | 0.36354 (9) | 0.0193 (3) | |
H10A | 1.074 (3) | 0.546 (4) | 0.3934 (14) | 0.043 (8)* | |
H10B | 1.079 (3) | 0.451 (4) | 0.3218 (13) | 0.044 (8)* | |
O11 | 1.3723 (2) | −0.2652 (2) | 0.14860 (10) | 0.0217 (3) | |
H11A | 1.249 (3) | −0.225 (5) | 0.153 (2) | 0.076 (12)* | |
H11B | 1.375 (4) | −0.372 (3) | 0.1817 (14) | 0.039 (8)* | |
P1 | 0.85337 (7) | −0.05516 (8) | 0.25666 (3) | 0.01313 (13) | |
P2 | 0.45611 (7) | 0.20966 (7) | 0.29463 (3) | 0.01322 (13) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
N1 | 0.0145 (8) | 0.0214 (9) | 0.0136 (8) | −0.0015 (7) | −0.0030 (7) | −0.0013 (7) |
C2 | 0.0152 (11) | 0.0194 (11) | 0.0199 (10) | 0.0006 (8) | 0.0016 (8) | −0.0015 (8) |
N3 | 0.0211 (9) | 0.0176 (9) | 0.0127 (8) | −0.0012 (7) | 0.0015 (7) | −0.0019 (7) |
C4 | 0.0157 (10) | 0.0160 (10) | 0.0177 (10) | −0.0031 (8) | −0.0034 (8) | 0.0007 (8) |
C5 | 0.0148 (10) | 0.0109 (9) | 0.0162 (9) | −0.0031 (7) | −0.0021 (7) | 0.0009 (7) |
C6 | 0.0182 (11) | 0.0148 (10) | 0.0154 (10) | −0.0006 (8) | 0.0000 (8) | −0.0017 (8) |
C7 | 0.0116 (9) | 0.0161 (10) | 0.0121 (9) | −0.0002 (7) | −0.0018 (7) | −0.0031 (7) |
Na1 | 0.0218 (4) | 0.0215 (5) | 0.0187 (4) | −0.0011 (3) | −0.0017 (3) | −0.0025 (3) |
O1 | 0.0170 (7) | 0.0201 (8) | 0.0130 (7) | −0.0034 (6) | −0.0033 (5) | −0.0018 (6) |
O2 | 0.0143 (7) | 0.0239 (8) | 0.0196 (7) | 0.0010 (6) | −0.0044 (6) | −0.0061 (6) |
O3 | 0.0175 (7) | 0.0236 (8) | 0.0167 (7) | 0.0052 (6) | 0.0000 (6) | −0.0050 (6) |
O4 | 0.0171 (7) | 0.0160 (8) | 0.0246 (8) | 0.0006 (6) | 0.0023 (6) | 0.0040 (6) |
O6 | 0.0138 (7) | 0.0175 (7) | 0.0152 (7) | 0.0016 (5) | −0.0008 (5) | −0.0015 (5) |
O5 | 0.0156 (7) | 0.0252 (8) | 0.0160 (7) | 0.0023 (6) | −0.0024 (5) | −0.0054 (6) |
O7 | 0.0107 (7) | 0.0193 (7) | 0.0245 (7) | −0.0005 (6) | −0.0019 (6) | 0.0036 (6) |
O8 | 0.0413 (10) | 0.0300 (9) | 0.0174 (8) | −0.0060 (8) | 0.0015 (8) | −0.0010 (7) |
O9 | 0.0270 (9) | 0.0183 (9) | 0.0223 (8) | −0.0007 (7) | 0.0013 (6) | −0.0014 (7) |
O10 | 0.0172 (8) | 0.0198 (8) | 0.0209 (8) | 0.0018 (6) | −0.0026 (6) | −0.0037 (6) |
O11 | 0.0173 (8) | 0.0199 (8) | 0.0269 (8) | −0.0017 (6) | −0.0014 (6) | 0.0015 (7) |
P1 | 0.0112 (3) | 0.0151 (3) | 0.0128 (2) | 0.00070 (19) | −0.00098 (19) | −0.00133 (19) |
P2 | 0.0113 (2) | 0.0157 (3) | 0.0123 (2) | 0.00069 (19) | −0.00083 (19) | −0.00129 (19) |
Geometric parameters (Å, º) top
N1—C2 | 1.327 (3) | Na1—O8i | 2.4150 (19) |
N1—C5 | 1.384 (2) | Na1—O8 | 2.719 (2) |
N1—H1 | 0.866 (15) | O1—H1A | 0.85 (3) |
C2—N3 | 1.315 (3) | O2—P1 | 1.5060 (14) |
C2—H2 | 0.947 (16) | O3—P1 | 1.4983 (14) |
N3—C4 | 1.370 (3) | O4—P1 | 1.5912 (14) |
N3—H3 | 0.856 (16) | O4—H4A | 0.833 (17) |
C4—C5 | 1.353 (3) | O6—P2 | 1.5235 (13) |
C4—H4 | 0.931 (15) | O5—P2 | 1.4991 (13) |
C5—C6 | 1.492 (3) | O7—P2 | 1.5687 (15) |
C6—C7 | 1.559 (3) | O7—H7A | 0.825 (17) |
C6—H6A | 0.990 (15) | O8—Na1i | 2.4150 (19) |
C6—H6B | 0.980 (14) | O8—H8A | 0.847 (17) |
C7—O1 | 1.429 (2) | O8—H8B | 0.843 (17) |
C7—P2 | 1.8411 (19) | O9—H9A | 0.815 (16) |
C7—P1 | 1.8421 (18) | O9—H9B | 0.828 (16) |
Na1—O10 | 2.3927 (17) | O10—H10A | 0.829 (16) |
Na1—O9 | 2.3955 (17) | O10—H10B | 0.846 (16) |
Na1—O5 | 2.3986 (16) | O11—H11A | 0.842 (17) |
Na1—O2 | 2.4029 (15) | O11—H11B | 0.837 (16) |
| | | |
C2—N1—C5 | 109.08 (16) | O2—Na1—O8i | 79.37 (6) |
C2—N1—H1 | 126.7 (15) | O10—Na1—O8 | 82.90 (6) |
C5—N1—H1 | 124.2 (15) | O9—Na1—O8 | 94.75 (6) |
N3—C2—N1 | 108.45 (18) | O5—Na1—O8 | 173.89 (6) |
N3—C2—H2 | 126.6 (13) | O2—Na1—O8 | 89.46 (5) |
N1—C2—H2 | 124.9 (13) | O8i—Na1—O8 | 81.92 (7) |
C2—N3—C4 | 109.07 (17) | C7—O1—H1A | 111.4 (18) |
C2—N3—H3 | 126.3 (17) | P1—O2—Na1 | 128.03 (8) |
C4—N3—H3 | 124.5 (17) | P1—O4—H4A | 106 (2) |
C5—C4—N3 | 107.52 (17) | P2—O5—Na1 | 136.23 (8) |
C5—C4—H4 | 128.6 (13) | P2—O7—H7A | 114.7 (19) |
N3—C4—H4 | 123.9 (13) | Na1i—O8—Na1 | 98.08 (7) |
C4—C5—N1 | 105.86 (17) | Na1i—O8—H8A | 95 (2) |
C4—C5—C6 | 129.75 (18) | Na1—O8—H8A | 126 (2) |
N1—C5—C6 | 124.37 (17) | Na1i—O8—H8B | 127 (2) |
C5—C6—C7 | 113.37 (16) | Na1—O8—H8B | 113 (2) |
C5—C6—H6A | 111.7 (12) | H8A—O8—H8B | 99 (2) |
C7—C6—H6A | 109.0 (12) | Na1—O9—H9A | 108.4 (19) |
C5—C6—H6B | 104.4 (11) | Na1—O9—H9B | 138.1 (18) |
C7—C6—H6B | 108.2 (11) | H9A—O9—H9B | 108 (2) |
H6A—C6—H6B | 110.1 (16) | Na1—O10—H10A | 111.6 (18) |
O1—C7—C6 | 106.18 (14) | Na1—O10—H10B | 107.3 (18) |
O1—C7—P2 | 108.75 (12) | H10A—O10—H10B | 105 (2) |
C6—C7—P2 | 107.82 (13) | H11A—O11—H11B | 105 (2) |
O1—C7—P1 | 110.29 (12) | O3—P1—O2 | 116.91 (8) |
C6—C7—P1 | 108.68 (12) | O3—P1—O4 | 109.30 (8) |
P2—C7—P1 | 114.75 (9) | O2—P1—O4 | 109.17 (8) |
O10—Na1—O9 | 102.25 (6) | O3—P1—C7 | 108.58 (8) |
O10—Na1—O5 | 94.05 (5) | O2—P1—C7 | 107.32 (8) |
O9—Na1—O5 | 91.07 (6) | O4—P1—C7 | 104.88 (8) |
O10—Na1—O2 | 83.19 (6) | O5—P2—O6 | 115.87 (8) |
O9—Na1—O2 | 173.48 (6) | O5—P2—O7 | 110.52 (8) |
O5—Na1—O2 | 84.91 (5) | O6—P2—O7 | 108.71 (8) |
O10—Na1—O8i | 156.91 (6) | O5—P2—C7 | 111.01 (8) |
O9—Na1—O8i | 96.27 (6) | O6—P2—C7 | 106.68 (8) |
O5—Na1—O8i | 99.32 (6) | O7—P2—C7 | 103.23 (8) |
| | | |
C5—N1—C2—N3 | 1.1 (2) | Na1—O2—P1—O3 | −179.17 (8) |
N1—C2—N3—C4 | −0.4 (2) | Na1—O2—P1—O4 | −54.50 (11) |
C2—N3—C4—C5 | −0.5 (2) | Na1—O2—P1—C7 | 58.65 (11) |
N3—C4—C5—N1 | 1.2 (2) | O1—C7—P1—O3 | 39.48 (14) |
N3—C4—C5—C6 | −177.26 (19) | C6—C7—P1—O3 | −76.54 (14) |
C2—N1—C5—C4 | −1.4 (2) | P2—C7—P1—O3 | 162.69 (9) |
C2—N1—C5—C6 | 177.13 (18) | O1—C7—P1—O2 | 166.70 (12) |
C4—C5—C6—C7 | 74.3 (3) | C6—C7—P1—O2 | 50.69 (14) |
N1—C5—C6—C7 | −103.8 (2) | P2—C7—P1—O2 | −70.08 (12) |
C5—C6—C7—O1 | −56.66 (19) | O1—C7—P1—O4 | −77.27 (13) |
C5—C6—C7—P2 | −173.07 (13) | C6—C7—P1—O4 | 166.71 (12) |
C5—C6—C7—P1 | 61.98 (18) | P2—C7—P1—O4 | 45.94 (12) |
O10—Na1—O2—P1 | −123.31 (10) | Na1—O5—P2—O6 | −147.48 (10) |
O5—Na1—O2—P1 | −28.60 (10) | Na1—O5—P2—O7 | 88.32 (12) |
O8i—Na1—O2—P1 | 71.89 (10) | Na1—O5—P2—C7 | −25.60 (14) |
O8—Na1—O2—P1 | 153.77 (10) | O1—C7—P2—O5 | 177.03 (11) |
Na1i—Na1—O2—P1 | 116.20 (9) | C6—C7—P2—O5 | −68.25 (13) |
O10—Na1—O5—P2 | 92.86 (12) | P1—C7—P2—O5 | 52.99 (12) |
O9—Na1—O5—P2 | −164.78 (12) | O1—C7—P2—O6 | −55.89 (14) |
O2—Na1—O5—P2 | 10.08 (12) | C6—C7—P2—O6 | 58.84 (13) |
O8i—Na1—O5—P2 | −68.25 (13) | P1—C7—P2—O6 | −179.92 (9) |
Na1i—Na1—O5—P2 | −61.30 (15) | O1—C7—P2—O7 | 58.60 (13) |
O10—Na1—O8—Na1i | −162.55 (7) | C6—C7—P2—O7 | 173.32 (11) |
O9—Na1—O8—Na1i | 95.67 (7) | P1—C7—P2—O7 | −65.44 (11) |
O2—Na1—O8—Na1i | −79.34 (6) | | |
Symmetry code: (i) −x+2, −y, −z+1. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O6ii | 0.87 (2) | 1.90 (2) | 2.751 (2) | 168 (2) |
N3—H3···O3iii | 0.86 (2) | 1.92 (2) | 2.678 (2) | 148 (2) |
N3—H3···O1iii | 0.86 (2) | 2.65 (2) | 3.248 (2) | 128 (2) |
O1—H1A···O11iv | 0.85 (3) | 1.86 (3) | 2.667 (2) | 156 (3) |
O4—H4A···O10v | 0.83 (2) | 1.88 (2) | 2.6722 (19) | 157 (3) |
O7—H7A···O2iv | 0.83 (2) | 1.67 (2) | 2.4914 (19) | 179 (3) |
O8—H8A···O4i | 0.85 (2) | 2.22 (2) | 3.061 (2) | 170 (3) |
O8—H8B···O5ii | 0.84 (2) | 2.12 (2) | 2.960 (2) | 173 (3) |
O9—H9A···O7vi | 0.82 (2) | 2.06 (2) | 2.826 (2) | 157 (3) |
O9—H9A···O4vi | 0.82 (2) | 2.57 (2) | 3.134 (2) | 127 (2) |
O9—H9B···O5vii | 0.83 (2) | 2.09 (2) | 2.907 (2) | 171 (3) |
O10—H10A···O9viii | 0.83 (2) | 2.02 (2) | 2.816 (2) | 160 (2) |
O10—H10B···O6ii | 0.85 (2) | 1.95 (2) | 2.7736 (19) | 163 (2) |
O11—H11A···O3 | 0.84 (2) | 1.87 (2) | 2.708 (2) | 170 (3) |
O11—H11B···O6ix | 0.84 (2) | 1.98 (2) | 2.793 (2) | 165 (2) |
Symmetry codes: (i) −x+2, −y, −z+1; (ii) x+1, y, z; (iii) −x+2, −y, −z; (iv) x−1, y, z; (v) x, y−1, z; (vi) −x+1, −y, −z+1; (vii) −x+1, −y+1, −z+1; (viii) −x+2, −y+1, −z+1; (ix) x+1, y−1, z. |
Experimental details
Crystal data |
Chemical formula | Na(C5H9N2O7P2)·4H2O |
Mr | 366.14 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 193 |
a, b, c (Å) | 6.6664 (19), 6.6765 (19), 15.5711 (18) |
α, β, γ (°) | 84.075 (4), 82.803 (5), 85.776 (5) |
V (Å3) | 682.6 (3) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.41 |
Crystal size (mm) | 0.22 × 0.22 × 0.10 |
|
Data collection |
Diffractometer | Siemens Platform CCD area-detector diffractometer |
Absorption correction | Multi-scan (SAINT and SADABS; Bruker, 2001) |
Tmin, Tmax | 0.915, 0.960 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 3252, 3252, 2769 |
Rint | 0.000 |
(sin θ/λ)max (Å−1) | 0.603 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.029, 0.077, 1.04 |
No. of reflections | 3252 |
No. of parameters | 259 |
No. of restraints | 20 |
H-atom treatment | All H-atom parameters refined |
Δρmax, Δρmin (e Å−3) | 0.28, −0.27 |
Selected geometric parameters (Å, º) topN1—C2 | 1.327 (3) | O3—P1 | 1.4983 (14) |
N1—C5 | 1.384 (2) | O4—P1 | 1.5912 (14) |
C2—N3 | 1.315 (3) | O6—P2 | 1.5235 (13) |
N3—C4 | 1.370 (3) | O5—P2 | 1.4991 (13) |
C4—C5 | 1.353 (3) | O7—P2 | 1.5687 (15) |
O2—P1 | 1.5060 (14) | | |
| | | |
C5—C6—C7 | 113.37 (16) | P2—C7—P1 | 114.75 (9) |
| | | |
C5—C6—C7—P1 | 61.98 (18) | | |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O6i | 0.866 (15) | 1.898 (16) | 2.751 (2) | 168 (2) |
N3—H3···O3ii | 0.856 (16) | 1.915 (19) | 2.678 (2) | 148 (2) |
N3—H3···O1ii | 0.856 (16) | 2.65 (2) | 3.248 (2) | 128 (2) |
O1—H1A···O11iii | 0.85 (3) | 1.86 (3) | 2.667 (2) | 156 (3) |
O4—H4A···O10iv | 0.833 (17) | 1.884 (19) | 2.6722 (19) | 157 (3) |
O7—H7A···O2iii | 0.825 (17) | 1.666 (17) | 2.4914 (19) | 179 (3) |
O8—H8A···O4v | 0.847 (17) | 2.224 (17) | 3.061 (2) | 170 (3) |
O8—H8B···O5i | 0.843 (17) | 2.121 (18) | 2.960 (2) | 173 (3) |
O9—H9A···O7vi | 0.815 (16) | 2.058 (18) | 2.826 (2) | 157 (3) |
O9—H9A···O4vi | 0.815 (16) | 2.57 (2) | 3.134 (2) | 127 (2) |
O9—H9B···O5vii | 0.828 (16) | 2.086 (17) | 2.907 (2) | 171 (3) |
O10—H10A···O9viii | 0.829 (16) | 2.024 (18) | 2.816 (2) | 160 (2) |
O10—H10B···O6i | 0.846 (16) | 1.952 (18) | 2.7736 (19) | 163 (2) |
O11—H11A···O3 | 0.842 (17) | 1.874 (19) | 2.708 (2) | 170 (3) |
O11—H11B···O6ix | 0.837 (16) | 1.975 (18) | 2.793 (2) | 165 (2) |
Symmetry codes: (i) x+1, y, z; (ii) −x+2, −y, −z; (iii) x−1, y, z; (iv) x, y−1, z; (v) −x+2, −y, −z+1; (vi) −x+1, −y, −z+1; (vii) −x+1, −y+1, −z+1; (viii) −x+2, −y+1, −z+1; (ix) x+1, y−1, z. |
The title compound is an isomer of zoledronate, a potent bone antiresorptive bisphosphonate drug (marketed by Novartis as Zometa). Isozoledronate, as well as a series of other bisphosphonates, have recently been shown to have significant activity against Trypanosoma cruzi, a parasitic protozoan which is the causative agent of Chagas' disease, and Trypanosoma brucei, the causative agent of African sleeping sickness (Martin et al., 2001). It is of importance to understand the key structural features of bisphosphonates that lead to their activity. In order to develop good quantitative structure-activity relationship (QSAR) methods, information is needed on the patterns of protonation and charge distribution, since these influence the predictive power of the QSAR method. Isozoledronate has a wide range of possible protonation states and charge distributions, arising from the phosphonates and the imidazole ring, so to gain a better understanding of these charge distributions, the crystal structure of monosodium [1-hydroxy-2-(1H-imidazol-3-ium-4-yl)ethane-1,1-diyl]bis(phosphonate) tetrahydrate, isozoledronate, (I), is reported herein. \sch
In the crystal structure of (I), both N atoms (N1 and N3) in the imidazole ring are protonated, leading to a +1 charge in the ring, while both phosphonate groups have only one protonated O atom, leading to a -1 charge on each phosphonate group. The isozoledronate anion is also coordinated to one Na+ cation, leading to the zwitterionic character found in many bisphosphonates (Vega et al., 1996, 1998). Inspection of the bond distances in the imidazole ring shows two short [N1—C2 1.327 (3) and N3—C2 1.315 (3) Å] and two long [N1—C5 1.384 (2) and N3—C4 1.370 (3) Å] N—C bonds, implying partial double-bond character between atoms C2 and N1/N3, but essentially single-bond character at N1—C5 and N3—C4, consistent with an approximately equal charge distribution on the two N atoms. The other double bond in the ring is found at C4—C5.
Analysis of the bond distances in the phosphonate groups [P1—O2 1.506 (1), P1—O3 1.498 (1) and P1—O4 1.591 (1) Å, and P2—O5 1.499 (1), P2—O6 1.524 (1) and P2—O7 1.569 (2) Å] reveals one protonated O atom on each phosphonate group, namely O4 and O7, and two nonprotonated O atoms on each, namely O2 and O3, and O5 and O6, resulting in a -1 charge on each phosphonate group. The orientation of the phosphonate groups with respect to the ring is very similar to that recently found in risedronate, both with respect to the backbone C—C—C angles [C5—C6—C7 113.4 (2)° in (I), C3—C2—C1 117.4 (4)° in RHP, C3—C2—C1 117.5 (3)° in RMH and C3—C2—C1 114.8 (2)° in RDH] and to the torsion angles between the phosphonate groups and the ring [P1—C5—C6—C7 62.0 (2)° in (I), P1—C1—C2—C3 52.6 (5)° in RHP, P1—C1—C2—C3 57.7 (3)° in RMH and P1—C1—C2—C3 61.8 (3)° in RDH], where RHP, RMH and RDH are analogues of (I) (Gossman et al., 2002).
Compound (I) consists of anionic dimers coordinated by two Na+ cations, as shown in Fig. 1. These dimers are held together through an extensive hydrogen-bonding network, consisting of at least 13 hydrogen bonds.