Di­bromo­tetrakis(4-methyl­imidazole)copper(II) dihydrate

In the structure of the title compound, [CuBr₂(C₄H₆­N₂)₄]·2H₂O, the Cu^II atoms are surrounded by four 4-methyl­imidazole ligands within a slightly distorted square plane. The coordination sphere is completed by two contacts to bromide ligands which are elongated due to Jahn–Teller distortion. The coordination polyhedra around the Cu^II cations can be described as strongly distorted octahedral. There are two crystallographically independent half-complexes in the asymmetric unit, in which the Cu^II cations are located on centres of inversion; the two crystallographically independent 4-methyl­imidazole ligands, the bromide anions and the water mol­ecules occupy general positions. The complexes are connected via N—H...Br, N—H...O and O—H...O hydrogen bonding.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.007 Å
• H-atom completeness 99%
• Disorder in solvent or counterion
• R factor = 0.043
• wR factor = 0.111
• Data-to-parameter ratio = 20.8

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level B:



PLAT_420  Alert B D-H Without Acceptor       O(1)   -   H(11O)            ?


 Alert Level C:



WEIGH_01  Alert C Extra text has been found in the
          _refine_ls_weighting_scheme field. This should be in the
          _refine_ls_weighting_details field.
          Weighting scheme given as calc w = 1/[\s^2^(Fo^2^)+(0.0519P)^2^+0.893
          Weighting scheme identified as calc

PLAT_302  Alert C Anion/Solvent Disorder .......................      20.00 Perc.

General Notes



FORMU_01  There is a discrepancy between the atom counts in the
          _chemical_formula_sum and the formula from the _atom_site* data.
          Atom count from _chemical_formula_sum:C16 H28 Br2 Cu1 N8 O2
          Atom count from the _atom_site data:  C16 H27.6 Br2 Cu1 N8 O2

CELLZ_01
         From the CIF: _cell_formula_units_Z    2
         From the CIF: _chemical_formula_sum  C16 H28 Br2 Cu N8 O2
         TEST: Compare cell contents of formula and atom_site data

         atom    Z*formula  cif sites diff
         C         32.00     32.00    0.00
         H         56.00     55.20    0.80
         Br         4.00      4.00    0.00
         Cu         2.00      2.00    0.00
         N         16.00     16.00    0.00
         O          4.00      4.00    0.00
          Difference between formula and atom_site contents detected.
          WARNING: H atoms missing from atom site list. Is this intentional?


 0 Alert Level A = Potentially serious problem

 1 Alert Level B = Potential problem

 2 Alert Level C = Please check

---

S1. Comment

In the crystal structure of the title compound, (I), the Cu^II atoms are coordinated by four N atoms of 4-methylimidazole ligands, forming a slightly distorted quadratic plane. The Cu—N distances of 2.003 (3), 2.014 (3), 1.993 (3) and 2.029 (3) Å are comparable to those in other 4-methylimidazole–copper(II) complexes, such as dichlorotetrakis(4-methylimidazole)copper(II) and dibromotetrakis(4-methylimidazole)copper(II) (Näther et al., 2002a,b), and tetrakis(4-methylimidazolyl)bis(perchlorato-O)copper(II) (Su et al., 1992), as well as tetrakis(4-methylimidazol-1-yl)bis(cyanamidonitrate)copper(II) (Kohout et al., 1999). The coordination sphere of the Cu^II atoms is completed by two longer contacts to two symmetry equivalent Br atoms located above and below the tetragonal plane. The Cu—Br distances of 3.2851 (8) Å (Cu1—Br1) and 3.1957 (9) Å (Cu2—Br2) are strongly elongated due to Jahn-Teller distortion and the coordination polyhedrons around the Cu^II atoms can be described as strongly distorted octahedrons. The asymmetric unit contains two crystallographically independent half-complexes in which the 4-methylimidazole ligands, the water molecules and the Br atoms occupy general positions, whereas the Cu^II atoms are located on centres of inversion. In contrast to the non-hydrated compound dibromotetrakis(4-methylimidazole)copper(II) (Näther et al., 2002b), the title compound contains additional water molecules and crystallizes as the dihydrate. Therefore, this compound represents a pseudo-polymorphic modification of the former compound. There are short N—H···Br and O—H···Br distances between the NH H atoms of the 4-methylimidazole ligand, as well as the OH H atoms of the water molecules, and the Br atoms. The distances and angles of this interaction indicate hydrogen bonding. The water molecules are additionally connected to the 4-methylimidazole ligand via N—H···O hydrogen bonding. From all of these intermolecular interactions, a three-dimensional hydrogen bonded network results.

S2. Experimental

The title compound was prepared by the reaction of 335.1 mg (4 mmol) 4-methylimidazole and 223.4 mg (1 mmol) copper(II) bromide in 5 ml water. The reaction mixture was stirred over a period of 3 d, filtered and was washed with dimethyl ether. The precipitate consists of a blue crystalline powder and a few blue single crystals which are suitable for X-ray structure determination.

S3. Refinement

The aromatic H atoms were positioned with idealized geometry (C—H = 0.93 Å and N—H = 0.86 Å). The positions of the methyl H atoms were idealized (C—H = 0.96 Å), then refined as rigid groups allowed to rotate but not tip. The water H atoms were located in the difference map and the bond lengths were set to ideal values (O—H = 0.82 Å). All H atoms were refined with fixed isotropic displacement parameters [U_iso(H) = 1.5U_eq(C_methyl), 1.5U_eq(O), 1.2U_eq(C_methylene) or 1.2U_eq(N)], using a riding model. One water O atom is disordered over two positions and these were refined with a split model (O2 and O3) and site-occupation factors of 0.8 for O2 and 0.2 for O3. The H atoms attached to O3 were not considered. Atom O3 was refined with isotropic displacement parameters.

Computing details

Data collection: DIF4 (Stoe & Cie, 1992); cell refinement: DIF4; data reduction: REDU4 (Stoe & Cie, 1992); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP in SHELXTL (Bruker, 1998); software used to prepare material for publication: CIFTAB in SHELXL97.

Figures

Fig. 1. The crystal structure of the title compound with labelling and and displacement ellipsoids drawn at the 50% probability level [symmetry codes: (i) -x + 1, -y + 1, -z + 1].

(I)

Crystal data

[CuBr2(C4H6N2)4]·2H2O	Z = 2
Mr = 587.82	F(000) = 590
Triclinic, P1	Dx = 1.658 Mg m^−3
a = 9.891 (2) Å	Mo Kα radiation, λ = 0.71073 Å
b = 10.613 (2) Å	Cell parameters from 78 reflections
c = 13.063 (3) Å	θ = 10–18°
α = 94.854 (13)°	µ = 4.35 mm^−1
β = 100.87 (2)°	T = 293 K
γ = 116.933 (13)°	Block, blue
V = 1177.8 (4) Å^3	0.14 × 0.08 × 0.06 mm

Data collection

AED-II four-circle diffractometer	3712 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.037
Graphite monochromator	θmax = 28.0°, θmin = 1.6°
ω–θ scans	h = 0→13
Absorption correction: numerical (X-SHAPE; Stoe & Cie, 1998)	k = −14→12
Tmin = 0.687, Tmax = 0.881	l = −17→16
6010 measured reflections	4 standard reflections every 120 min
5686 independent reflections	intensity decay: none

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.043	H-atom parameters constrained
wR(F^2) = 0.111	Calculated w = 1/[σ^2(Fo^2) + (0.0519P)^2 + 0.8939P] where P = (Fo^2 + 2Fc^2)/3
S = 1.01	(Δ/σ)max = 0.001
5686 reflections	Δρmax = 1.34 e Å^−3
274 parameters	Δρmin = −1.22 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0052 (8)

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
Cu1	0.5000	0.0000	0.5000	0.0419 (2)
Br1	0.25630 (6)	0.10068 (5)	0.57013 (4)	0.05603 (16)
N1	0.6720 (4)	0.1239 (3)	0.6299 (2)	0.0353 (7)
C1	0.6837 (5)	0.2437 (4)	0.6866 (3)	0.0393 (9)
H1	0.6099	0.2757	0.6728	0.047*
C2	0.8175 (5)	0.3098 (4)	0.7657 (3)	0.0373 (9)
N2	0.8888 (4)	0.2278 (3)	0.7558 (3)	0.0401 (8)
H2N	0.9772	0.2440	0.7954	0.048*
C3	0.7987 (5)	0.1175 (4)	0.6740 (3)	0.0423 (10)
H3	0.8225	0.0463	0.6515	0.051*
C4	0.8862 (7)	0.4420 (5)	0.8492 (4)	0.0601 (13)
H4A	0.8042	0.4607	0.8626	0.090*
H4B	0.9600	0.5224	0.8255	0.090*
H4C	0.9388	0.4281	0.9134	0.090*
N3	0.5795 (4)	0.1730 (3)	0.4305 (2)	0.0354 (7)
C11	0.7287 (5)	0.2536 (5)	0.4223 (4)	0.0482 (11)
H11	0.8110	0.2345	0.4461	0.058*
C12	0.7406 (6)	0.3646 (5)	0.3749 (4)	0.0517 (11)
N4	0.5950 (4)	0.3521 (4)	0.3540 (3)	0.0429 (8)
H4N	0.5672	0.4085	0.3236	0.051*
C13	0.5019 (5)	0.2362 (4)	0.3889 (3)	0.0427 (10)
H13	0.3962	0.2050	0.3842	0.051*
C14	0.8734 (7)	0.4843 (7)	0.3457 (6)	0.094 (2)
H14A	0.8704	0.5727	0.3624	0.141*
H14B	0.8637	0.4627	0.2710	0.141*
H14C	0.9712	0.4941	0.3850	0.141*
Cu2	1.0000	1.0000	1.0000	0.03475 (17)
Br2	0.77909 (5)	0.69608 (5)	1.05275 (4)	0.05014 (15)
N5	0.9534 (4)	0.9060 (4)	0.8466 (2)	0.0345 (7)
C5	0.8430 (5)	0.7696 (5)	0.7917 (3)	0.0380 (9)
H5	0.7675	0.7011	0.8189	0.046*
C6	0.8606 (5)	0.7497 (5)	0.6920 (3)	0.0410 (9)
N6	0.9823 (5)	0.8758 (4)	0.6860 (3)	0.0460 (9)
H6N	1.0189	0.8943	0.6311	0.055*
C7	1.0362 (5)	0.9664 (5)	0.7791 (3)	0.0400 (9)
H7	1.1204	1.0592	0.7944	0.048*
C8	0.7721 (7)	0.6229 (6)	0.6022 (4)	0.0663 (15)
H8A	0.7317	0.6513	0.5409	0.099*
H8B	0.6867	0.5482	0.6222	0.099*
H8C	0.8410	0.5877	0.5859	0.099*
N7	0.8208 (4)	1.0412 (3)	0.9648 (2)	0.0321 (7)
C15	0.6751 (5)	0.9600 (5)	0.8934 (3)	0.0383 (9)
H15	0.6402	0.8698	0.8526	0.046*
C16	0.5911 (5)	1.0310 (5)	0.8920 (3)	0.0391 (9)
N8	0.6852 (4)	1.1564 (4)	0.9634 (3)	0.0435 (8)
H8N	0.6616	1.2229	0.9793	0.052*
C17	0.8212 (5)	1.1583 (4)	1.0049 (3)	0.0410 (9)
H17	0.9049	1.2334	1.0556	0.049*
C18	0.4302 (5)	0.9954 (6)	0.8308 (4)	0.0572 (13)
H18A	0.3697	0.8934	0.8041	0.086*
H18B	0.4377	1.0453	0.7724	0.086*
H18C	0.3800	1.0246	0.8766	0.086*
O1	0.4387 (6)	0.4237 (4)	0.7359 (3)	0.0865 (13)
H1O1	0.4233	0.4064	0.7939	0.130*
H2O1	0.4143	0.3469	0.6984	0.130*
O2	0.5915 (6)	0.3500 (5)	1.0417 (5)	0.0900 (19)	0.80
H1O2	0.4987	0.3288	1.0229	0.135*	0.80
H2O2	0.6167	0.4305	1.0283	0.135*	0.80
O3	0.5581 (19)	0.3524 (18)	0.9434 (14)	0.052 (4)*	0.20

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cu1	0.0448 (4)	0.0277 (3)	0.0296 (3)	0.0048 (3)	−0.0105 (3)	0.0080 (3)
Br1	0.0563 (3)	0.0599 (3)	0.0416 (3)	0.0186 (2)	0.0121 (2)	0.0145 (2)
N1	0.0379 (18)	0.0299 (16)	0.0291 (15)	0.0127 (14)	−0.0019 (13)	0.0059 (12)
C1	0.042 (2)	0.034 (2)	0.039 (2)	0.0187 (18)	0.0036 (17)	0.0043 (16)
C2	0.044 (2)	0.0307 (19)	0.0292 (18)	0.0122 (17)	0.0069 (16)	0.0046 (15)
N2	0.0360 (18)	0.0363 (18)	0.0364 (17)	0.0147 (15)	−0.0077 (14)	0.0024 (14)
C3	0.044 (2)	0.036 (2)	0.038 (2)	0.0188 (19)	−0.0039 (18)	0.0027 (17)
C4	0.077 (4)	0.045 (3)	0.043 (3)	0.021 (3)	0.009 (2)	−0.005 (2)
N3	0.0378 (18)	0.0339 (17)	0.0281 (15)	0.0143 (14)	0.0006 (13)	0.0085 (13)
C11	0.040 (2)	0.050 (3)	0.056 (3)	0.020 (2)	0.012 (2)	0.018 (2)
C12	0.048 (3)	0.047 (3)	0.053 (3)	0.015 (2)	0.016 (2)	0.016 (2)
N4	0.050 (2)	0.0365 (18)	0.0437 (19)	0.0195 (16)	0.0137 (16)	0.0180 (15)
C13	0.042 (2)	0.041 (2)	0.043 (2)	0.0181 (19)	0.0060 (18)	0.0161 (18)
C14	0.066 (4)	0.091 (5)	0.129 (6)	0.026 (4)	0.042 (4)	0.068 (4)
Cu2	0.0341 (4)	0.0500 (4)	0.0245 (3)	0.0271 (3)	0.0014 (3)	0.0015 (3)
Br2	0.0419 (3)	0.0429 (2)	0.0517 (3)	0.01442 (19)	−0.00070 (19)	0.00441 (19)
N5	0.0369 (17)	0.0441 (18)	0.0270 (15)	0.0250 (15)	0.0042 (13)	0.0048 (13)
C5	0.039 (2)	0.045 (2)	0.033 (2)	0.0242 (18)	0.0045 (16)	0.0087 (17)
C6	0.057 (3)	0.044 (2)	0.0313 (19)	0.035 (2)	0.0055 (18)	0.0045 (17)
N6	0.066 (2)	0.055 (2)	0.0329 (18)	0.038 (2)	0.0208 (17)	0.0109 (16)
C7	0.043 (2)	0.047 (2)	0.037 (2)	0.0267 (19)	0.0111 (17)	0.0084 (17)
C8	0.096 (4)	0.059 (3)	0.043 (3)	0.049 (3)	−0.004 (3)	−0.010 (2)
N7	0.0319 (16)	0.0382 (17)	0.0288 (15)	0.0195 (14)	0.0067 (12)	0.0055 (13)
C15	0.034 (2)	0.047 (2)	0.0291 (18)	0.0194 (18)	0.0019 (15)	−0.0025 (16)
C16	0.033 (2)	0.053 (2)	0.036 (2)	0.0215 (19)	0.0107 (16)	0.0158 (18)
N8	0.0373 (19)	0.044 (2)	0.061 (2)	0.0271 (16)	0.0140 (17)	0.0170 (17)
C17	0.036 (2)	0.036 (2)	0.049 (2)	0.0171 (18)	0.0060 (18)	0.0066 (18)
C18	0.041 (3)	0.091 (4)	0.043 (2)	0.035 (3)	0.007 (2)	0.017 (2)
O1	0.138 (4)	0.061 (2)	0.078 (3)	0.057 (3)	0.034 (3)	0.029 (2)
O2	0.056 (3)	0.047 (3)	0.176 (6)	0.032 (2)	0.029 (3)	0.023 (3)

Geometric parameters (Å, º)

Cu1—N1^i	2.003 (3)	N5—C7	1.324 (5)
Cu1—N1	2.003 (3)	N5—C5	1.379 (5)
Cu1—N3	2.014 (3)	C5—C6	1.357 (6)
Cu1—N3^i	2.014 (3)	C5—H5	0.9300
N1—C3	1.310 (5)	C6—N6	1.357 (6)
N1—C1	1.361 (5)	C6—C8	1.494 (6)
C1—C2	1.354 (6)	N6—C7	1.335 (5)
C1—H1	0.9300	N6—H6N	0.8600
C2—N2	1.359 (5)	C7—H7	0.9300
C2—C4	1.489 (6)	C8—H8A	0.9600
N2—C3	1.338 (5)	C8—H8B	0.9600
N2—H2N	0.8600	C8—H8C	0.9600
C3—H3	0.9300	N7—C17	1.306 (5)
C4—H4A	0.9600	N7—C15	1.386 (5)
C4—H4B	0.9600	C15—C16	1.349 (6)
C4—H4C	0.9600	C15—H15	0.9300
N3—C13	1.306 (5)	C16—N8	1.360 (6)
N3—C11	1.361 (5)	C16—C18	1.496 (6)
C11—C12	1.346 (6)	N8—C17	1.342 (5)
C11—H11	0.9300	N8—H8N	0.8600
C12—N4	1.357 (6)	C17—H17	0.9300
C12—C14	1.497 (7)	C18—H18A	0.9600
N4—C13	1.340 (5)	C18—H18B	0.9600
N4—H4N	0.8600	C18—H18C	0.9600
C13—H13	0.9300	O1—H1O1	0.8200
C14—H14A	0.9600	O1—H2O1	0.8200
C14—H14B	0.9600	O2—O3	1.269 (17)
C14—H14C	0.9600	O2—H1O2	0.8201
Cu2—N7	1.993 (3)	O2—H2O2	0.8200
Cu2—N7^ii	1.993 (3)	O3—H1O2	1.2750
Cu2—N5	2.029 (3)	O3—H2O2	1.1913
Cu2—N5^ii	2.029 (3)
N1^i—Cu1—N1	180.0	N7^ii—Cu2—N5^ii	91.15 (12)
N1^i—Cu1—N3	92.93 (12)	N5—Cu2—N5^ii	180.000 (2)
N1—Cu1—N3	87.07 (12)	C7—N5—C5	105.1 (3)
N1^i—Cu1—N3^i	87.07 (12)	C7—N5—Cu2	124.5 (3)
N1—Cu1—N3^i	92.93 (12)	C5—N5—Cu2	130.3 (3)
N3—Cu1—N3^i	180.0	C6—C5—N5	110.1 (4)
C3—N1—C1	105.6 (3)	C6—C5—H5	125.0
C3—N1—Cu1	129.9 (3)	N5—C5—H5	125.0
C1—N1—Cu1	124.3 (3)	N6—C6—C5	105.2 (4)
C2—C1—N1	110.6 (4)	N6—C6—C8	123.6 (4)
C2—C1—H1	124.7	C5—C6—C8	131.2 (5)
N1—C1—H1	124.7	C7—N6—C6	108.9 (3)
C1—C2—N2	104.7 (3)	C7—N6—H6N	125.6
C1—C2—C4	132.5 (4)	C6—N6—H6N	125.6
N2—C2—C4	122.8 (4)	N5—C7—N6	110.7 (4)
C3—N2—C2	108.6 (3)	N5—C7—H7	124.6
C3—N2—H2N	125.7	N6—C7—H7	124.6
C2—N2—H2N	125.7	C6—C8—H8A	109.5
N1—C3—N2	110.6 (4)	C6—C8—H8B	109.5
N1—C3—H3	124.7	H8A—C8—H8B	109.5
N2—C3—H3	124.7	C6—C8—H8C	109.5
C2—C4—H4A	109.5	H8A—C8—H8C	109.5
C2—C4—H4B	109.5	H8B—C8—H8C	109.5
H4A—C4—H4B	109.5	C17—N7—C15	105.1 (3)
C2—C4—H4C	109.5	C17—N7—Cu2	125.1 (3)
H4A—C4—H4C	109.5	C15—N7—Cu2	129.7 (3)
H4B—C4—H4C	109.5	C16—C15—N7	110.0 (4)
C13—N3—C11	105.4 (3)	C16—C15—H15	125.0
C13—N3—Cu1	127.6 (3)	N7—C15—H15	125.0
C11—N3—Cu1	126.9 (3)	C15—C16—N8	105.4 (3)
C12—C11—N3	110.6 (4)	C15—C16—C18	132.8 (4)
C12—C11—H11	124.7	N8—C16—C18	121.7 (4)
N3—C11—H11	124.7	C17—N8—C16	108.2 (3)
C11—C12—N4	105.1 (4)	C17—N8—H8N	125.9
C11—C12—C14	133.4 (5)	C16—N8—H8N	125.9
N4—C12—C14	121.5 (4)	N7—C17—N8	111.2 (4)
C13—N4—C12	108.0 (4)	N7—C17—H17	124.4
C13—N4—H4N	126.0	N8—C17—H17	124.4
C12—N4—H4N	126.0	C16—C18—H18A	109.5
N3—C13—N4	110.9 (4)	C16—C18—H18B	109.5
N3—C13—H13	124.5	H18A—C18—H18B	109.5
N4—C13—H13	124.5	C16—C18—H18C	109.5
C12—C14—H14A	109.5	H18A—C18—H18C	109.5
C12—C14—H14B	109.5	H18B—C18—H18C	109.5
H14A—C14—H14B	109.5	H1O1—O1—H2O1	106.9
C12—C14—H14C	109.5	O3—O2—H1O2	71.6
H14A—C14—H14C	109.5	O3—O2—H2O2	65.5
H14B—C14—H14C	109.5	H1O2—O2—H2O2	90.1
N7—Cu2—N7^ii	180.000 (2)	O2—O3—H1O2	37.6
N7—Cu2—N5	91.15 (12)	O2—O3—H2O2	38.8
N7^ii—Cu2—N5	88.85 (12)	H1O2—O3—H2O2	56.0
N7—Cu2—N5^ii	88.85 (12)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2N···Br2^iii	0.86	2.60	3.443 (3)	168
N4—H4N···O1^iv	0.86	2.02	2.863 (5)	165
N6—H6N···Br1^v	0.86	2.70	3.410 (4)	141
N8—H8N···O2^vi	0.86	1.96	2.803 (6)	167
N8—H8N···O3^vi	0.86	2.09	2.883 (17)	154
O1—H1O1···O3	0.82	2.41	3.044 (18)	135
O1—H1O1···Br2^vii	0.82	3.02	3.773 (4)	154
O1—H2O1···Br1	0.82	2.58	3.371 (4)	163
O2—H1O2···Br2^vii	0.82	2.62	3.430 (5)	169
O2—H2O2···Br2	0.82	2.49	3.255 (5)	157

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