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The title compound, [Sr(C3H7NO2)4]Br2, contains one monomeric octa­coordinated strontium complex cation and two Br anions. The Sr atom lies on a twofold axis. Coordination occurs via the amide [similar Sr—O: average 2.539 (4) Å] and hydr­oxy O atoms [Sr—O = 2.535 (4)–2.703 (3) Å], and the geometry may be described as a distorted square-anti­prismatic arrangement with the Sr atom located 1.481 (2)Å away from the least-squares planes of the two symmetry-related square bases. In the crystal structure, the cations and anions are linked by N—H...Br and O—H...Br hydrogen bonds, generating a three-dimensional network.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807052646/bg2119sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536807052646/bg2119Isup2.hkl
Contains datablock I

CCDC reference: 667239

Key indicators

  • Single-crystal X-ray study
  • T = 293 K
  • Mean [sigma](C-C) = 0.008 Å
  • R factor = 0.045
  • wR factor = 0.111
  • Data-to-parameter ratio = 26.2

checkCIF/PLATON results

No syntax errors found



Alert level C PLAT241_ALERT_2_C Check High Ueq as Compared to Neighbors for O2 PLAT341_ALERT_3_C Low Bond Precision on C-C Bonds (x 1000) Ang ... 8 PLAT601_ALERT_2_C Structure Contains Solvent Accessible VOIDS of . 32.00 A   3
Alert level G REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is correct. If it is not, please give the correct count in the _publ_section_exptl_refinement section of the submitted CIF. From the CIF: _diffrn_reflns_theta_max 30.04 From the CIF: _reflns_number_total 3407 Count of symmetry unique reflns 1992 Completeness (_total/calc) 171.03% TEST3: Check Friedels for noncentro structure Estimate of Friedel pairs measured 1415 Fraction of Friedel pairs measured 0.710 Are heavy atom types Z>Si present yes PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature 293 K PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature . 293 K PLAT791_ALERT_1_G Confirm the Absolute Configuration of C2 = . S PLAT791_ALERT_1_G Confirm the Absolute Configuration of C7 = . S PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints ....... 2
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 3 ALERT level C = Check and explain 6 ALERT level G = General alerts; check 4 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 2 ALERT type 2 Indicator that the structure model may be wrong or deficient 2 ALERT type 3 Indicator that the structure quality may be low 1 ALERT type 4 Improvement, methodology, query or suggestion 0 ALERT type 5 Informative message, check

Comment top

Strontium provides some of the most important radioactive isotopes in the environment; e.g., 90Sr (Finlay et al., 2005), a by-product of the fission of uranium and plutonium in nuclear reaction or nuclear weapons, of which large amounts were produced during the Tchernobyl nuclear power plant disaster in 1986. It was later found in milk and vegetables. It is chemically similar to calcium and tends to deposit in bones and teeth. The half-life of 90Sr is 29.1 years emitting beta particules. Another isotope, 89Sr, is the active ingredient in Metastonρe.g, a radiopharmaceutical used for bone pain secondary to metastatic prostate cancer (Makhijani, 2003). Cold strontium ranelate (Prodelosρe.g) is the first antiosteoporotic treatment to simultaneously increase bone formation and decrease bone resorption (Reginster et al., 2007). In order to find new ligands of strontium as osteoporosous drugs, a new complex of strontium dibromide and R-lactamide has been studied. Compound (1) (Fig. 1) contains one monomeric octa-coordinated strontium complex cation, [Sr(C3H7NO2)4]2+, and two Br- anions. In the cation, the Sr atom lies on a twofold axis and is surrounded by four R-lactamide ligands coordinated in a bidentate fashion via amide atom O1 (or O6) and hydroxy atom O2 (or O7) and their symmetry equivalents. The Sr coordination in the cation can be approximately described as a very distorted square antiprism arrangement [with square bases: O1 O2 O6i O7i and O1i O2i O6 O7; i: 1 - x, 1 - y, z] with the Sr atom shifted away from these (symmetry realated) least-squares planes by 1.481 (2) Å. The Sr—O (amide) distances are similar within three estimated standard deviations [Sr—O1 (or O1i): 2.533 (3) and Sr—O6 (or O6i): 2.544 (4) Å]; among the Sr—O (hydroxy) distances Sr—O2 (or O2i): 2.535 (4) Å is equivalent to precedent values within three estimated standard deviations but very different from the two other distances Sr—O7 (or O7i): 2.703 (3) Å. All these values can be compared to those found in the poly[[tetaaquatris(monomethyl fumarato)distrontium(II)]monomethyl fumarate] in which the Sr atom is octa- coordinated by oxygen atoms which range from 2.499 (2) to 2.812 (2)Å (Stahl et al., 2006). Among the two possible coordination modes (N,O or O,O) in metal complexes with lactamide or its derivatives described in the literature, the title compound presents the O,O mode like those in the complexes with the [Zn(lactamide)3]2+ (Bekaert et al., 2005) or the [B(lactamide)2]+ (Bekaert et al., 2007) cations.

The packing is charaterized by a number of H-bonds (Table 2). In particular, Br- anions are linked to the cation by N–H···Br and O–H···Br hydrogen bonds, generating a three dimensional network.

Related literature top

The crystal structure of tetra[(R)-lactamide-κ2O,O']strontium(II) dibromide was compared with bis[(R)-lactamido-κ2O,O']boron(III) bromide (Bekaert et al., 2007) and tris[(R)-lactamido-κ2 O,O']zinc(II) tetrabromozincate (Bekaert et al., 2005).

For related literature, see: Finlay et al. (2005); Makhijani (2003); Reginster et al. (2007); Stahl et al. (2006).

Experimental top

The title compound was prepared as follows: S-lactamide (0.356 g, 4 mmole) was dissolved in 20 ml of hot ethanol. Strontium dibromide (0.247 g, 1 mmole) was added to this solution with the help of an ultrasonic bath; the reaction medium was kept at 40° C for 48 h. Colourless plates of the title compound slowly appeared in the solution, whereupon crystals suitable for X-ray diffraction were obtained.

Refinement top

H atoms except those bonded to hydroxy O atoms were positioned geometrically and refined using a riding model, with C—H = 0.96–0.98 Å and N—H = 0.86 Å with Uiso(H) = 1.2 (1.5 for methyl groups) times Ueq(C, O). H atoms bonded to hydroxy O atoms were located in a difference map and refined with an O—H distance restrained to 0.82 (1) Å and a common displacement parameter.

Structure description top

Strontium provides some of the most important radioactive isotopes in the environment; e.g., 90Sr (Finlay et al., 2005), a by-product of the fission of uranium and plutonium in nuclear reaction or nuclear weapons, of which large amounts were produced during the Tchernobyl nuclear power plant disaster in 1986. It was later found in milk and vegetables. It is chemically similar to calcium and tends to deposit in bones and teeth. The half-life of 90Sr is 29.1 years emitting beta particules. Another isotope, 89Sr, is the active ingredient in Metastonρe.g, a radiopharmaceutical used for bone pain secondary to metastatic prostate cancer (Makhijani, 2003). Cold strontium ranelate (Prodelosρe.g) is the first antiosteoporotic treatment to simultaneously increase bone formation and decrease bone resorption (Reginster et al., 2007). In order to find new ligands of strontium as osteoporosous drugs, a new complex of strontium dibromide and R-lactamide has been studied. Compound (1) (Fig. 1) contains one monomeric octa-coordinated strontium complex cation, [Sr(C3H7NO2)4]2+, and two Br- anions. In the cation, the Sr atom lies on a twofold axis and is surrounded by four R-lactamide ligands coordinated in a bidentate fashion via amide atom O1 (or O6) and hydroxy atom O2 (or O7) and their symmetry equivalents. The Sr coordination in the cation can be approximately described as a very distorted square antiprism arrangement [with square bases: O1 O2 O6i O7i and O1i O2i O6 O7; i: 1 - x, 1 - y, z] with the Sr atom shifted away from these (symmetry realated) least-squares planes by 1.481 (2) Å. The Sr—O (amide) distances are similar within three estimated standard deviations [Sr—O1 (or O1i): 2.533 (3) and Sr—O6 (or O6i): 2.544 (4) Å]; among the Sr—O (hydroxy) distances Sr—O2 (or O2i): 2.535 (4) Å is equivalent to precedent values within three estimated standard deviations but very different from the two other distances Sr—O7 (or O7i): 2.703 (3) Å. All these values can be compared to those found in the poly[[tetaaquatris(monomethyl fumarato)distrontium(II)]monomethyl fumarate] in which the Sr atom is octa- coordinated by oxygen atoms which range from 2.499 (2) to 2.812 (2)Å (Stahl et al., 2006). Among the two possible coordination modes (N,O or O,O) in metal complexes with lactamide or its derivatives described in the literature, the title compound presents the O,O mode like those in the complexes with the [Zn(lactamide)3]2+ (Bekaert et al., 2005) or the [B(lactamide)2]+ (Bekaert et al., 2007) cations.

The packing is charaterized by a number of H-bonds (Table 2). In particular, Br- anions are linked to the cation by N–H···Br and O–H···Br hydrogen bonds, generating a three dimensional network.

The crystal structure of tetra[(R)-lactamide-κ2O,O']strontium(II) dibromide was compared with bis[(R)-lactamido-κ2O,O']boron(III) bromide (Bekaert et al., 2007) and tris[(R)-lactamido-κ2 O,O']zinc(II) tetrabromozincate (Bekaert et al., 2005).

For related literature, see: Finlay et al. (2005); Makhijani (2003); Reginster et al. (2007); Stahl et al. (2006).

Computing details top

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994); cell refinement: CAD-4 EXPRESS (Enraf–Nonius, 1994); data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: CAMERON (Watkin et al., 1996); software used to prepare material for publication: WinGX (Version 1.63.02; Farrugia, 1999).

Figures top
[Figure 1] Fig. 1. Molecular view of the complex showing atomic numbering and some N–H···Br and O–H···Br hydrogen bonds in dotted lines. Displacement ellipsoids drawn at the 50% probability level. Symmetry codes: i: (1 - x, 1 - y, z), ii: (x + 1/2, 1/2 - y, -z) and iii: (x + 1/2, 1/2 - y, 1 - z).
Tetrakis[(R)-propionamide-κ2O,O']strontium(II) dibromide top
Crystal data top
[Sr(C3H7NO2)4]Br2F(000) = 600
Mr = 603.82Dx = 1.708 Mg m3
Orthorhombic, P21212Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P22abCell parameters from 25 reflections
a = 10.385 (2) Åθ = 3.2–10.4°
b = 17.919 (2) ŵ = 5.74 mm1
c = 6.308 (1) ÅT = 293 K
V = 1173.8 (3) Å3Parallelepiped, colourless
Z = 20.25 × 0.16 × 0.12 mm
Data collection top
Enraf–Nonius CAD-4
diffractometer
2379 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.067
Graphite monochromatorθmax = 30.0°, θmin = 2.3°
ω–2θ scansh = 1414
Absorption correction: empirical (using intensity measurements)
[multi-scan (Blessing, 1995)]
k = 025
Tmin = 0.27, Tmax = 0.50l = 08
7106 measured reflections3 standard reflections every 60 min
3407 independent reflections intensity decay: 1%
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.045H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.111 w = 1/[σ2(Fo2) + (0.0439P)2]
where P = (Fo2 + 2Fc2)/3
S = 0.99(Δ/σ)max < 0.001
3407 reflectionsΔρmax = 0.68 e Å3
130 parametersΔρmin = 1.77 e Å3
2 restraintsAbsolute structure: Flack (1983), 1415 Friedel pairs
Primary atom site location: structure-invariant direct methodsAbsolute structure parameter: 0.017 (15)
Crystal data top
[Sr(C3H7NO2)4]Br2V = 1173.8 (3) Å3
Mr = 603.82Z = 2
Orthorhombic, P21212Mo Kα radiation
a = 10.385 (2) ŵ = 5.74 mm1
b = 17.919 (2) ÅT = 293 K
c = 6.308 (1) Å0.25 × 0.16 × 0.12 mm
Data collection top
Enraf–Nonius CAD-4
diffractometer
2379 reflections with I > 2σ(I)
Absorption correction: empirical (using intensity measurements)
[multi-scan (Blessing, 1995)]
Rint = 0.067
Tmin = 0.27, Tmax = 0.503 standard reflections every 60 min
7106 measured reflections intensity decay: 1%
3407 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.045H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.111Δρmax = 0.68 e Å3
S = 0.99Δρmin = 1.77 e Å3
3407 reflectionsAbsolute structure: Flack (1983), 1415 Friedel pairs
130 parametersAbsolute structure parameter: 0.017 (15)
2 restraints
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.

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 > σ(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
xyzUiso*/Ueq
Sr10.50000.50000.22123 (9)0.02564 (14)
Br20.46507 (5)0.22333 (3)0.18621 (9)0.04246 (16)
O10.6729 (4)0.4010 (2)0.1870 (6)0.0382 (8)
N10.8257 (5)0.3235 (3)0.3141 (8)0.0451 (11)
H1A0.85000.31050.18910.054*
H1B0.86310.30490.42370.054*
C10.7299 (5)0.3726 (3)0.3381 (9)0.0339 (11)
O20.6163 (5)0.4554 (2)0.5510 (5)0.0532 (12)
C20.6915 (5)0.3896 (3)0.5667 (8)0.0358 (11)
H20.76920.40030.64940.043*
C30.6207 (6)0.3266 (4)0.6677 (10)0.0531 (15)
H3A0.59870.33980.81070.080*
H3B0.67430.28300.66850.080*
H3C0.54350.31660.58890.080*
O60.3820 (4)0.4505 (2)0.1029 (5)0.0395 (8)
N60.2431 (5)0.3752 (3)0.2688 (7)0.0512 (13)
H6A0.27060.38860.39160.061*
H6B0.18210.34290.25860.061*
C60.2940 (5)0.4038 (3)0.0976 (8)0.0315 (10)
O70.3377 (3)0.3834 (2)0.2705 (6)0.0310 (7)
C70.2392 (5)0.3787 (3)0.1129 (7)0.0293 (10)
H70.20850.32710.10160.035*
C80.1284 (6)0.4296 (4)0.1775 (11)0.0549 (16)
H8A0.09440.41350.31140.082*
H8B0.06190.42740.07200.082*
H8C0.15920.47990.18990.082*
H2A0.616 (6)0.478 (3)0.664 (5)0.048 (13)*
H7A0.377 (5)0.3439 (18)0.284 (10)0.048 (13)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Sr10.0258 (3)0.0306 (3)0.0205 (2)0.0015 (2)0.0000.000
Br20.0340 (3)0.0484 (3)0.0450 (3)0.0041 (2)0.0001 (2)0.0050 (2)
O10.046 (2)0.046 (2)0.0221 (17)0.0127 (16)0.0012 (16)0.0005 (15)
N10.045 (3)0.055 (3)0.036 (2)0.021 (2)0.009 (2)0.000 (2)
C10.032 (3)0.033 (3)0.036 (3)0.003 (2)0.005 (2)0.001 (2)
O20.075 (3)0.059 (3)0.026 (2)0.034 (2)0.0096 (19)0.0134 (18)
C20.039 (3)0.042 (3)0.027 (2)0.013 (2)0.004 (2)0.004 (2)
C30.051 (3)0.070 (4)0.038 (3)0.002 (3)0.007 (3)0.009 (3)
O60.043 (2)0.050 (2)0.0253 (16)0.0210 (18)0.0001 (15)0.0049 (16)
N60.053 (3)0.074 (4)0.027 (2)0.032 (3)0.001 (2)0.003 (2)
C60.028 (3)0.038 (3)0.029 (2)0.002 (2)0.0001 (19)0.000 (2)
O70.0345 (17)0.0374 (18)0.0212 (16)0.0033 (14)0.0022 (13)0.0008 (14)
C70.030 (3)0.036 (3)0.022 (2)0.006 (2)0.0018 (18)0.0018 (18)
C80.033 (3)0.079 (4)0.053 (4)0.005 (3)0.007 (3)0.007 (3)
Geometric parameters (Å, º) top
Sr1—O1i2.533 (3)C2—H20.9800
Sr1—O12.533 (3)C3—H3A0.9600
Sr1—O22.535 (4)C3—H3B0.9600
Sr1—O2i2.535 (4)C3—H3C0.9600
Sr1—O62.544 (4)O6—C61.239 (6)
Sr1—O6i2.544 (4)N6—C61.307 (7)
Sr1—O7i2.703 (3)N6—H6A0.8600
Sr1—O72.703 (3)N6—H6B0.8600
O1—C11.232 (6)C6—C71.513 (7)
N1—C11.337 (7)O7—C71.429 (6)
N1—H1A0.8600O7—H7A0.82 (4)
N1—H1B0.8600C7—C81.523 (7)
C1—C21.526 (7)C7—H70.9800
O2—C21.417 (6)C8—H8A0.9600
O2—H2A0.82 (4)C8—H8B0.9600
C2—C31.490 (8)C8—H8C0.9600
O1i—Sr1—O1170.23 (17)C2—O2—H2A111 (4)
O1i—Sr1—O2128.95 (12)Sr1—O2—H2A124 (4)
O1—Sr1—O260.74 (12)O2—C2—C3112.8 (5)
O1i—Sr1—O2i60.74 (12)O2—C2—C1104.1 (4)
O1—Sr1—O2i128.95 (12)C3—C2—C1112.4 (5)
O2—Sr1—O2i69.71 (18)O2—C2—H2109.1
O1i—Sr1—O680.46 (13)C3—C2—H2109.1
O1—Sr1—O691.65 (13)C1—C2—H2109.1
O2—Sr1—O6141.18 (13)C2—C3—H3A109.5
O2i—Sr1—O6122.69 (15)C2—C3—H3B109.5
O1i—Sr1—O6i91.65 (13)H3A—C3—H3B109.5
O1—Sr1—O6i80.46 (13)C2—C3—H3C109.5
O2—Sr1—O6i122.69 (15)H3A—C3—H3C109.5
O2i—Sr1—O6i141.18 (13)H3B—C3—H3C109.5
O6—Sr1—O6i73.01 (15)C6—O6—Sr1124.7 (3)
O1i—Sr1—O7i84.87 (12)C6—N6—H6A120.0
O1—Sr1—O7i96.26 (12)C6—N6—H6B120.0
O2—Sr1—O7i81.50 (13)H6A—N6—H6B120.0
O2i—Sr1—O7i87.64 (14)O6—C6—N6122.7 (5)
O6—Sr1—O7i131.51 (11)O6—C6—C7120.1 (5)
O6i—Sr1—O7i61.46 (11)N6—C6—C7117.1 (4)
O1i—Sr1—O796.26 (12)C7—O7—Sr1114.3 (3)
O1—Sr1—O784.87 (12)C7—O7—H7A112 (5)
O2—Sr1—O787.64 (14)Sr1—O7—H7A112 (4)
O2i—Sr1—O781.50 (13)O7—C7—C6108.9 (4)
O6—Sr1—O761.46 (11)O7—C7—C8108.6 (4)
O6i—Sr1—O7131.51 (11)C6—C7—C8109.9 (4)
O7i—Sr1—O7166.78 (15)O7—C7—H7109.8
C1—O1—Sr1124.3 (3)C6—C7—H7109.8
C1—N1—H1A120.0C8—C7—H7109.8
C1—N1—H1B120.0C7—C8—H8A109.5
H1A—N1—H1B120.0C7—C8—H8B109.5
O1—C1—N1122.8 (5)H8A—C8—H8B109.5
O1—C1—C2121.5 (5)C7—C8—H8C109.5
N1—C1—C2115.6 (5)H8A—C8—H8C109.5
C2—O2—Sr1125.6 (3)H8B—C8—H8C109.5
Symmetry code: (i) x+1, y+1, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O7—H7A···Br20.82 (4)2.43 (3)3.203 (4)158 (6)
N1—H1A···Br2ii0.862.723.572 (5)171
N1—H1B···Br2iii0.862.733.568 (5)167
O2—H2A···O6iv0.82 (4)1.95 (4)2.759 (5)169 (6)
N6—H6A···O7v0.862.243.071 (6)161
N6—H6B···Br2vi0.862.593.424 (5)164
Symmetry codes: (ii) x+1/2, y+1/2, z; (iii) x+1/2, y+1/2, z+1; (iv) x+1, y+1, z+1; (v) x, y, z1; (vi) x1/2, y+1/2, z.

Experimental details

Crystal data
Chemical formula[Sr(C3H7NO2)4]Br2
Mr603.82
Crystal system, space groupOrthorhombic, P21212
Temperature (K)293
a, b, c (Å)10.385 (2), 17.919 (2), 6.308 (1)
V3)1173.8 (3)
Z2
Radiation typeMo Kα
µ (mm1)5.74
Crystal size (mm)0.25 × 0.16 × 0.12
Data collection
DiffractometerEnraf–Nonius CAD-4
Absorption correctionEmpirical (using intensity measurements)
[multi-scan (Blessing, 1995)]
Tmin, Tmax0.27, 0.50
No. of measured, independent and
observed [I > 2σ(I)] reflections
7106, 3407, 2379
Rint0.067
(sin θ/λ)max1)0.704
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.045, 0.111, 0.99
No. of reflections3407
No. of parameters130
No. of restraints2
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.68, 1.77
Absolute structureFlack (1983), 1415 Friedel pairs
Absolute structure parameter0.017 (15)

Computer programs: CAD-4 EXPRESS (Enraf–Nonius, 1994), XCAD4 (Harms & Wocadlo, 1995), SIR92 (Altomare et al., 1994), SHELXL97 (Sheldrick, 1997), CAMERON (Watkin et al., 1996), WinGX (Version 1.63.02; Farrugia, 1999).

Selected bond lengths (Å) top
Sr1—O12.533 (3)Sr1—O62.544 (4)
Sr1—O22.535 (4)Sr1—O72.703 (3)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O7—H7A···Br20.82 (4)2.43 (3)3.203 (4)158 (6)
N1—H1A···Br2i0.862.723.572 (5)171
N1—H1B···Br2ii0.862.733.568 (5)167
O2—H2A···O6iii0.82 (4)1.95 (4)2.759 (5)169 (6)
N6—H6A···O7iv0.862.243.071 (6)161
N6—H6B···Br2v0.862.593.424 (5)164
Symmetry codes: (i) x+1/2, y+1/2, z; (ii) x+1/2, y+1/2, z+1; (iii) x+1, y+1, z+1; (iv) x, y, z1; (v) x1/2, y+1/2, z.
 

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