Analysis of solvent-accessible voids and proton-coupled electron transfer of 2,6-bis­(1H-imidazol-2-yl)pyridine and its hydro­chloride

The crystal structures of the solid form of solvated 2,6-bis­(1H-imidazol-2-yl)pyridine (H₂dimpy) trihydrate, C₁₁H₉N₅·3H₂O·[+solvent], I, and its hydrate hydro­chloride salt 2-[6-(1H-imidazol-2-yl)pyridin-2-yl]-1H-imidazol-3-ium chlo­ride trihydrate, C₁₁H₁₀N₅⁺·Cl⁻·3H₂O, II, are reported and analysed in detail, along with potentiometric and spectrophotometric titrations for evaluation of the acid–base equilibria and proton-coupled electron-transfer reactions. Compound I crystallizes in the high-symmetry trigonal space group P3₂21 with an atypical formation of solvent-accessible voids, as a consequence of the 3₂ screw axis in the crystallographic c-axis direction, which are probably occupied by uncharacterized disordered solvent mol­ecules. Additionally, the trihydrated chloride salt crystallizes in the conventional monoclinic space group P2₁/c without the formation of solvent-accessible voids. The acid–base equilibria of H₂dimpy were studied by potentiometric and spectrophotometric titrations, and the results suggest the formation of H₃dimpy⁺ (pK_a1 = 5.40) and H₄dimpy²⁺ (pK_a2 = 3.98), with the electrochemical behaviour of these species showing two consecutive irreversible proton-coupled electron-transfer reactions. Density functional theory (DFT) calculations corroborate the inter­pretation of the experimental results and support the assignment of the electrochemical behaviour.

Computing details

For both structures, data collection: APEX3 (Bruker, 2010); cell refinement: SAINT (Bruker, 2010); data reduction: SAINT (Bruker, 2010); program(s) used to solve structure: SHELXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2018 (Sheldrick, 2015b); molecular graphics: OLEX2 (Dolomanov et al., 2009) and ORTEP-3 (Farrugia, 2012); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009) and Mercury (Macrae et al., 2008).

2,6-Bis(1H-imidazol-2-yl)pyridine trihydrate (H2dimpyI)

Crystal data

C11H9N5·3H2O·[+solvent]	Dx = 1.127 Mg m^−3
Mr = 265.28	Cu Kα radiation, λ = 1.54178 Å
Trigonal, P3221	Cell parameters from 3604 reflections
a = 18.6043 (5) Å	θ = 2.7–68.5°
c = 3.9112 (1) Å	µ = 0.71 mm^−1
V = 1172.38 (7) Å^3	T = 150 K
Z = 3	Needle, colourless
F(000) = 420	0.42 × 0.07 × 0.06 mm

Data collection

Bruker APEX CCD detector diffractometer	1416 independent reflections
Radiation source: fine-focus sealed tube	1375 reflections with I > 2σ(I)
Detector resolution: 8.3333 pixels mm^-1	Rint = 0.035
φ and ω scans	θmax = 68.5°, θmin = 2.7°
Absorption correction: multi-scan (SADABS; Bruker, 2010)	h = −22→22
Tmin = 0.589, Tmax = 0.753	k = −21→11
4574 measured reflections	l = −4→4

Refinement

Refinement on F^2	Hydrogen site location: mixed
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.038	w = 1/[σ^2(Fo^2) + (0.0717P)^2 + 0.0039P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.095	(Δ/σ)max < 0.001
S = 1.12	Δρmax = 0.19 e Å^−3
1416 reflections	Δρmin = −0.18 e Å^−3
107 parameters	Absolute structure: Flack x determined using 610 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons et al., 2013)
13 restraints	Absolute structure parameter: −0.06 (13)
Primary atom site location: dual

Special details

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

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
C1	0.82009 (12)	0.40541 (14)	0.3290 (4)	0.0424 (5)
H1	0.810118	0.449603	0.278080	0.051*
C2	0.77089 (11)	0.32375 (13)	0.2485 (4)	0.0439 (5)
H2	0.719764	0.301261	0.128372	0.053*
C3	0.87644 (11)	0.33371 (12)	0.5186 (4)	0.0376 (4)
C4	0.93872 (11)	0.31921 (12)	0.6842 (4)	0.0393 (5)
C5	0.93498 (13)	0.24231 (13)	0.6823 (5)	0.0488 (5)
H5	0.889499	0.195000	0.581093	0.059*
C6	1.000000	0.23727 (18)	0.833333	0.0563 (7)
H6	1.000000	0.186204	0.833331	0.068*
N1	0.88686 (9)	0.41061 (10)	0.4985 (3)	0.0371 (4)
H1A	0.929205	0.456226	0.580214	0.045*
N2	0.80616 (10)	0.27824 (10)	0.3670 (4)	0.0434 (4)
N3	1.000000	0.38611 (12)	0.833333	0.0357 (5)
O1	1.000000	0.56592 (11)	0.833333	0.0498 (5)
H1B	0.984190	0.590942	0.977527	0.075*
O2B	0.7265 (2)	0.1091 (2)	0.420 (4)	0.126 (4)	0.710 (16)
H2BA	0.753917	0.088908	0.317271	0.189*	0.710 (16)
H2BB	0.762778	0.161343	0.450509	0.189*	0.710 (16)
O2A	0.7301 (4)	0.1159 (4)	0.160 (3)	0.059 (3)	0.290 (16)
H2AA	0.735540	0.091151	−0.018624	0.089*	0.290 (16)
H2AB	0.770014	0.167082	0.141571	0.089*	0.290 (16)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0340 (9)	0.0561 (12)	0.0319 (7)	0.0187 (9)	0.0036 (6)	0.0041 (7)
C2	0.0340 (9)	0.0572 (12)	0.0333 (8)	0.0175 (8)	0.0007 (6)	−0.0024 (7)
C3	0.0302 (8)	0.0444 (9)	0.0303 (8)	0.0126 (7)	0.0070 (6)	−0.0016 (6)
C4	0.0334 (9)	0.0448 (10)	0.0336 (8)	0.0150 (8)	0.0094 (7)	0.0010 (7)
C5	0.0433 (12)	0.0431 (10)	0.0536 (11)	0.0167 (9)	0.0053 (9)	−0.0019 (8)
C6	0.0581 (18)	0.0482 (11)	0.0658 (17)	0.0291 (9)	0.0001 (14)	0.0001 (7)
N1	0.0275 (7)	0.0437 (8)	0.0320 (6)	0.0117 (6)	0.0047 (5)	0.0009 (6)
N2	0.0343 (7)	0.0484 (9)	0.0364 (7)	0.0122 (7)	0.0029 (5)	−0.0061 (6)
N3	0.0298 (10)	0.0420 (9)	0.0312 (9)	0.0149 (5)	0.0072 (7)	0.0036 (3)
O1	0.0377 (10)	0.0433 (8)	0.0665 (13)	0.0189 (5)	−0.0007 (8)	−0.0004 (4)
O2B	0.0570 (19)	0.0463 (17)	0.261 (13)	0.0153 (14)	−0.052 (4)	−0.027 (3)
O2A	0.049 (3)	0.040 (3)	0.084 (6)	0.019 (2)	−0.024 (3)	−0.014 (3)

Geometric parameters (Å, º)

C1—H1	0.9500	C5—H5	0.9500
C1—C2	1.362 (3)	C5—C6	1.391 (3)
C1—N1	1.368 (3)	C6—H6	0.9500
C2—H2	0.9500	N1—H1A	0.8800
C2—N2	1.385 (3)	O1—H1B^i	0.87
C3—C4	1.465 (3)	O1—H1B	0.8708
C3—N1	1.347 (3)	O2B—H2BA	0.8693
C3—N2	1.333 (3)	O2B—H2BB	0.8699
C4—C5	1.397 (3)	O2A—H2AA	0.8711
C4—N3	1.330 (2)	O2A—H2AB	0.8700
C2—C1—H1	127.1	C6—C5—C4	117.8 (2)
C2—C1—N1	105.72 (18)	C6—C5—H5	121.1
N1—C1—H1	127.1	C5^i—C6—C5	119.7 (3)
C1—C2—H2	124.9	C5^i—C6—H6	120.2
C1—C2—N2	110.18 (16)	C5—C6—H6	120.2
N2—C2—H2	124.9	C1—N1—H1A	126.0
N1—C3—C4	120.95 (17)	C3—N1—C1	108.06 (16)
N2—C3—C4	127.88 (18)	C3—N1—H1A	126.0
N2—C3—N1	111.15 (18)	C3—N2—C2	104.88 (16)
C5—C4—C3	123.15 (18)	C4—N3—C4^i	119.1 (2)
N3—C4—C3	114.09 (18)	H1B—O1—H1B^i	90.6
N3—C4—C5	122.75 (18)	H2BA—O2B—H2BB	104.6
C4—C5—H5	121.1	H2AA—O2A—H2AB	104.4
C1—C2—N2—C3	0.12 (19)	N1—C1—C2—N2	0.22 (19)
C2—C1—N1—C3	−0.47 (17)	N1—C3—C4—C5	−173.49 (15)
C3—C4—C5—C6	176.78 (13)	N1—C3—C4—N3	5.7 (2)
C3—C4—N3—C4^i	−177.97 (15)	N1—C3—N2—C2	−0.43 (17)
C4—C3—N1—C1	179.33 (14)	N2—C3—C4—C5	5.0 (3)
C4—C3—N2—C2	−179.08 (15)	N2—C3—C4—N3	−175.81 (13)
C4—C5—C6—C5^i	1.07 (11)	N2—C3—N1—C1	0.58 (17)
C5—C4—N3—C4^i	1.18 (12)	N3—C4—C5—C6	−2.3 (2)

Symmetry code: (i) −x+2, −x+y+1, −z+5/3.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O1	0.88	2.05	2.900 (2)	163
O1—H1B···O2B^ii	0.87	2.07	2.823 (5)	144
O1—H1B···O2A^ii	0.87	2.19	2.719 (7)	119
O2B—H2BB···N2	0.87	1.93	2.734 (4)	153
O2A—H2AB···N2	0.87	2.03	2.740 (7)	138

Symmetry code: (ii) −y+1, x−y, z+2/3.

2-[6-(1H-Imidazol-2-yl)pyridin-2-yl]-1H-imidazol-3-ium chloride trihydrate (II)

Crystal data

C11H10N5^+·Cl^−·3H2O	F(000) = 632
Mr = 301.74	Dx = 1.404 Mg m^−3
Monoclinic, P21/c	Cu Kα radiation, λ = 1.54178 Å
a = 6.6577 (5) Å	Cell parameters from 51 reflections
b = 22.6308 (16) Å	θ = 2.4–19.1°
c = 9.7566 (7) Å	µ = 2.53 mm^−1
β = 103.845 (3)°	T = 150 K
V = 1427.31 (18) Å^3	Needle, colorless
Z = 4	0.21 × 0.12 × 0.06 mm

Data collection

Bruker APEX CCD detector diffractometer	2337 reflections with I > 2σ(I)
Detector resolution: 8.3333 pixels mm^-1	Rint = 0.037
phi and ω scans	θmax = 66.6°, θmin = 3.9°
Absorption correction: multi-scan (SADABS; Bruker, 2010)	h = −7→7
Tmin = 0.541, Tmax = 0.753	k = −26→26
12948 measured reflections	l = −10→11
2501 independent reflections

Refinement

Refinement on F^2	Primary atom site location: dual
Least-squares matrix: full	Hydrogen site location: mixed
R[F^2 > 2σ(F^2)] = 0.030	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.083	w = 1/[σ^2(Fo^2) + (0.0446P)^2 + 0.3908P] where P = (Fo^2 + 2Fc^2)/3
S = 1.08	(Δ/σ)max < 0.001
2501 reflections	Δρmax = 0.19 e Å^−3
208 parameters	Δρmin = −0.25 e Å^−3
0 restraints

Special details

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

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.12492 (5)	0.11289 (2)	0.19035 (3)	0.02985 (13)
N1	0.23324 (18)	0.15345 (5)	0.50852 (13)	0.0242 (3)
H1	0.209 (3)	0.1367 (8)	0.4320 (19)	0.029*
N2	0.32601 (18)	0.16788 (5)	0.73294 (13)	0.0238 (3)
H2	0.363 (2)	0.1621 (8)	0.8221 (19)	0.029*
N3	0.25814 (16)	0.03224 (5)	0.52905 (12)	0.0207 (2)
N4	0.16978 (18)	−0.02797 (6)	0.27592 (13)	0.0264 (3)
H4	0.164 (3)	0.0095 (8)	0.2606 (19)	0.032*
N5	0.21873 (18)	−0.11532 (5)	0.38022 (14)	0.0284 (3)
C1	0.2362 (2)	0.21322 (6)	0.52931 (16)	0.0301 (3)
H1A	0.202959	0.242704	0.458158	0.036*
C2	0.2952 (2)	0.22247 (6)	0.66969 (16)	0.0292 (3)
H2A	0.312323	0.259679	0.716116	0.035*
C3	0.28748 (19)	0.12627 (6)	0.63302 (14)	0.0211 (3)
C4	0.29992 (18)	0.06222 (6)	0.65134 (14)	0.0203 (3)
C5	0.3499 (2)	0.03559 (6)	0.78353 (15)	0.0253 (3)
H5	0.377869	0.058487	0.867563	0.030*
C6	0.3575 (2)	−0.02556 (6)	0.78827 (16)	0.0293 (3)
H6	0.390061	−0.045476	0.876542	0.035*
C7	0.3175 (2)	−0.05737 (6)	0.66416 (15)	0.0271 (3)
H7	0.324146	−0.099307	0.665627	0.032*
C8	0.26720 (19)	−0.02676 (6)	0.53637 (15)	0.0217 (3)
C9	0.21986 (19)	−0.05725 (6)	0.40025 (15)	0.0231 (3)
C10	0.1339 (2)	−0.06927 (7)	0.17056 (16)	0.0316 (3)
H10	0.095412	−0.062150	0.071766	0.038*
C11	0.1645 (2)	−0.12247 (7)	0.23613 (17)	0.0326 (4)
H11	0.150535	−0.159532	0.189061	0.039*
O1	0.70136 (19)	0.21532 (5)	0.43975 (13)	0.0386 (3)
H1B	0.726 (3)	0.2432 (10)	0.503 (2)	0.058*
H1C	0.728 (3)	0.1862 (10)	0.494 (2)	0.058*
O2	0.4310 (2)	0.14867 (5)	0.01164 (11)	0.0345 (3)
H2B	0.344 (3)	0.1399 (9)	0.064 (2)	0.052*
H2C	0.531 (3)	0.1656 (10)	0.063 (2)	0.052*
O3	0.76769 (18)	0.20389 (5)	0.17490 (12)	0.0348 (3)
H3A	0.868 (3)	0.1834 (10)	0.182 (2)	0.052*
H3B	0.756 (3)	0.2116 (9)	0.259 (2)	0.052*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0355 (2)	0.0303 (2)	0.0229 (2)	0.00122 (13)	0.00543 (15)	0.00105 (13)
N1	0.0294 (6)	0.0225 (6)	0.0205 (6)	−0.0018 (5)	0.0054 (5)	−0.0005 (5)
N2	0.0294 (6)	0.0204 (6)	0.0220 (6)	−0.0016 (4)	0.0067 (5)	−0.0017 (5)
N3	0.0171 (5)	0.0209 (6)	0.0236 (6)	−0.0005 (4)	0.0040 (4)	−0.0009 (4)
N4	0.0261 (6)	0.0254 (6)	0.0267 (6)	−0.0006 (5)	0.0042 (5)	−0.0039 (5)
N5	0.0262 (6)	0.0233 (6)	0.0360 (7)	−0.0026 (4)	0.0076 (5)	−0.0072 (5)
C1	0.0390 (8)	0.0205 (7)	0.0318 (8)	−0.0010 (6)	0.0107 (6)	0.0046 (6)
C2	0.0387 (8)	0.0181 (7)	0.0329 (8)	−0.0027 (6)	0.0128 (6)	−0.0016 (6)
C3	0.0180 (6)	0.0233 (7)	0.0224 (7)	−0.0008 (5)	0.0055 (5)	−0.0009 (5)
C4	0.0155 (6)	0.0215 (7)	0.0235 (7)	−0.0002 (5)	0.0041 (5)	−0.0016 (5)
C5	0.0258 (7)	0.0257 (7)	0.0227 (7)	0.0008 (5)	0.0026 (5)	−0.0009 (6)
C6	0.0341 (8)	0.0262 (7)	0.0258 (7)	0.0018 (6)	0.0035 (6)	0.0054 (6)
C7	0.0286 (7)	0.0198 (6)	0.0312 (8)	0.0008 (5)	0.0042 (6)	0.0012 (6)
C8	0.0151 (6)	0.0219 (7)	0.0280 (7)	−0.0009 (5)	0.0050 (5)	−0.0022 (5)
C9	0.0177 (6)	0.0228 (6)	0.0284 (7)	−0.0015 (5)	0.0049 (5)	−0.0025 (6)
C10	0.0289 (8)	0.0388 (9)	0.0264 (8)	−0.0030 (6)	0.0051 (6)	−0.0106 (6)
C11	0.0284 (7)	0.0308 (8)	0.0381 (9)	−0.0041 (6)	0.0071 (7)	−0.0148 (7)
O1	0.0539 (7)	0.0298 (6)	0.0310 (6)	0.0030 (5)	0.0083 (5)	−0.0031 (5)
O2	0.0469 (7)	0.0338 (6)	0.0238 (5)	−0.0080 (5)	0.0101 (5)	−0.0031 (4)
O3	0.0395 (6)	0.0338 (6)	0.0305 (6)	0.0071 (5)	0.0073 (5)	0.0053 (5)

Geometric parameters (Å, º)

N1—H1	0.818 (18)	C4—C5	1.3899 (19)
N1—C1	1.3672 (18)	C5—H5	0.9500
N1—C3	1.3321 (18)	C5—C6	1.385 (2)
N2—H2	0.856 (18)	C6—H6	0.9500
N2—C2	1.3742 (19)	C6—C7	1.379 (2)
N2—C3	1.3354 (18)	C7—H7	0.9500
N3—C4	1.3426 (17)	C7—C8	1.395 (2)
N3—C8	1.3376 (17)	C8—C9	1.4625 (19)
N4—H4	0.861 (19)	C10—H10	0.9500
N4—C9	1.3521 (19)	C10—C11	1.356 (2)
N4—C10	1.3674 (19)	C11—H11	0.9500
N5—C9	1.3286 (18)	O1—H1B	0.87 (2)
N5—C11	1.375 (2)	O1—H1C	0.84 (2)
C1—H1A	0.9500	O2—H2B	0.88 (2)
C1—C2	1.348 (2)	O2—H2C	0.82 (2)
C2—H2A	0.9500	O3—H3A	0.80 (2)
C3—C4	1.4604 (18)	O3—H3B	0.86 (2)
C1—N1—H1	125.9 (12)	C6—C5—C4	117.58 (13)
C3—N1—H1	124.8 (12)	C6—C5—H5	121.2
C3—N1—C1	109.29 (12)	C5—C6—H6	120.2
C2—N2—H2	124.7 (12)	C7—C6—C5	119.63 (13)
C3—N2—H2	126.3 (12)	C7—C6—H6	120.2
C3—N2—C2	108.91 (12)	C6—C7—H7	120.7
C8—N3—C4	117.38 (12)	C6—C7—C8	118.69 (13)
C9—N4—H4	129.1 (12)	C8—C7—H7	120.7
C9—N4—C10	107.50 (13)	N3—C8—C7	122.78 (13)
C10—N4—H4	123.4 (12)	N3—C8—C9	115.17 (12)
C9—N5—C11	104.94 (12)	C7—C8—C9	122.05 (12)
N1—C1—H1A	126.4	N4—C9—C8	122.47 (12)
C2—C1—N1	107.14 (13)	N5—C9—N4	111.18 (12)
C2—C1—H1A	126.4	N5—C9—C8	126.35 (13)
N2—C2—H2A	126.5	N4—C10—H10	127.1
C1—C2—N2	107.02 (12)	C11—C10—N4	105.83 (14)
C1—C2—H2A	126.5	C11—C10—H10	127.1
N1—C3—N2	107.63 (12)	N5—C11—H11	124.7
N1—C3—C4	124.40 (12)	C10—C11—N5	110.55 (13)
N2—C3—C4	127.97 (12)	C10—C11—H11	124.7
N3—C4—C3	113.53 (12)	H1B—O1—H1C	99 (2)
N3—C4—C5	123.93 (12)	H2B—O2—H2C	107 (2)
C5—C4—C3	122.54 (12)	H3A—O3—H3B	107 (2)
C4—C5—H5	121.2
N1—C1—C2—N2	−0.46 (17)	C4—N3—C8—C7	0.00 (19)
N1—C3—C4—N3	2.26 (18)	C4—N3—C8—C9	179.85 (11)
N1—C3—C4—C5	−177.58 (12)	C4—C5—C6—C7	0.5 (2)
N2—C3—C4—N3	−177.85 (12)	C5—C6—C7—C8	−0.9 (2)
N2—C3—C4—C5	2.3 (2)	C6—C7—C8—N3	0.7 (2)
N3—C4—C5—C6	0.3 (2)	C6—C7—C8—C9	−179.12 (12)
N3—C8—C9—N4	−0.23 (18)	C7—C8—C9—N4	179.61 (13)
N3—C8—C9—N5	179.97 (12)	C7—C8—C9—N5	−0.2 (2)
N4—C10—C11—N5	0.03 (16)	C8—N3—C4—C3	179.65 (11)
C1—N1—C3—N2	−0.29 (15)	C8—N3—C4—C5	−0.51 (18)
C1—N1—C3—C4	179.62 (12)	C9—N4—C10—C11	−0.15 (15)
C2—N2—C3—N1	0.00 (15)	C9—N5—C11—C10	0.10 (16)
C2—N2—C3—C4	−179.91 (13)	C10—N4—C9—N5	0.22 (15)
C3—N1—C1—C2	0.48 (17)	C10—N4—C9—C8	−179.60 (12)
C3—N2—C2—C1	0.29 (16)	C11—N5—C9—N4	−0.20 (15)
C3—C4—C5—C6	−179.91 (12)	C11—N5—C9—C8	179.62 (13)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···Cl1	0.82 (2)	2.35 (2)	3.1508 (13)	166 (2)
N2—H2···O2^i	0.86 (2)	1.82 (2)	2.6762 (17)	178 (2)
N4—H4···Cl1	0.86 (2)	2.43 (2)	3.2907 (13)	174 (2)
O1—H1B···O3^ii	0.87 (2)	2.03 (2)	2.8839 (16)	169 (2)
O1—H1C···N5^iii	0.84 (2)	2.00 (2)	2.8359 (18)	178 (2)
O2—H2B···Cl1	0.88 (2)	2.21 (2)	3.0900 (13)	177 (2)
O2—H2C···O3	0.82 (2)	1.90 (2)	2.7230 (17)	177 (2)
O3—H3A···Cl1^iv	0.80 (2)	2.33 (2)	3.1223 (12)	171 (2)
O3—H3B···O1	0.86 (2)	1.89 (2)	2.7359 (17)	169 (2)

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