Crystal structures of hydrates of simple inorganic salts. I. Water-rich magnesium halide hydrates MgCl₂·8H₂O, MgCl₂·12H₂O, MgBr₂·6H₂O, MgBr₂·9H₂O, MgI₂·8H₂O and MgI₂·9H₂O

The previously reported structures of the hydrates of simple inorganic salts that crystallize at room temperature are generally well determined. This is not true for water-rich hydrates, which crystallize at temperatures below 273 K. In this series, investigations of the crystal structures of water-rich hydrates crystallized from aqueous solutions at low temperatures are presented. Reported herein are the structures of a set of magnesium salts. Crystals of MgCl₂·8H₂O (magnesium dichloride octa­hydrate), MgCl₂·12H₂O (magnesium dichloride dodeca­hydrate), MgBr₂·6H₂O (magnesium dibromide hexa­hydrate), MgBr₂·9H₂O (magnesium dibromide nona­hydrate), MgI₂·8H₂O (magnesium diiodide octa­hydrate) and MgI₂·9H₂O (magnesium diiodide nona­hydrate) were grown from their aqueous solutions at temperatures below 298 K according to the solid-liquid phase diagrams. All structures are built up from Mg(H₂O)₆ octa­hedra. Dimensions and angles in the hexa­aqua cation complexes are very similar and variation is not systematic. The anions are incorporated into a specific network of O-H...X hydrogen bonds.

Computing details

Data collection: X-AREA (Stoe & Cie, 2009) for MgCl2_12H2O, MgBr2_9H2O, MgI2_9H2O, MgI2_8H2O, MgBr2_6H2O; APEX2 (Bruker, 2006) for MgCl2_8H2O. Cell refinement: X-AREA (Stoe & Cie, 2009) for MgCl2_12H2O, MgBr2_9H2O, MgI2_9H2O, MgI2_8H2O, MgBr2_6H2O; SAINT (Bruker, 2006) for MgCl2_8H2O. Data reduction: X-RED (Stoe & Cie, 2009) for MgCl2_12H2O, MgBr2_9H2O, MgI2_9H2O, MgI2_8H2O, MgBr2_6H2O; SAINT (Bruker, 2006) for MgCl2_8H2O. For all compounds, program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2012 (Sheldrick, 2008). Molecular graphics: DIAMOND (Brandenburg, 2006) for MgCl2_12H2O, MgBr2_9H2O, MgI2_9H2O, MgI2_8H2O, MgBr2_6H2O; SHELXTL (Sheldrick, 2008) for MgCl2_8H2O. Software used to prepare material for publication: publCIF (Westrip, 2010) for MgCl2_12H2O, MgBr2_9H2O, MgI2_9H2O, MgI2_8H2O, MgBr2_6H2O; SHELXTL (Sheldrick, 2008) for MgCl2_8H2O.

(MgCl2_12H2O) Magnesium chloride dodecahydrate

Crystal data

MgCl2·12H2O	F(000) = 332
Mr = 311.40	Dx = 1.241 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 7.3496 (16) Å	Cell parameters from 1803 reflections
b = 14.419 (3) Å	θ = 2.9–29.5°
c = 8.570 (3) Å	µ = 0.46 mm^−1
β = 113.44 (2)°	T = 150 K
V = 833.2 (4) Å^3	0.98 × 0.76 × 0.53 mm
Z = 2

Data collection

Stoe IPDS 2T diffractometer	1649 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.128
Absorption correction: integration (Coppens, 1970)	θmax = 27.5°, θmin = 2.8°
Tmin = 0.664, Tmax = 0.782	h = −9→10
1918 measured reflections	k = −19→16
1916 independent reflections	l = −11→1

Refinement

Refinement on F^2	Hydrogen site location: difference Fourier map
Least-squares matrix: full	All H-atom parameters refined
R[F^2 > 2σ(F^2)] = 0.048	w = 1/[σ^2(Fo^2) + (0.1155P)^2] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.141	(Δ/σ)max < 0.001
S = 1.04	Δρmax = 0.98 e Å^−3
1916 reflections	Δρmin = −0.62 e Å^−3
119 parameters	Extinction correction: SHELXL2012 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
18 restraints	Extinction coefficient: 0.072 (11)

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.

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

	x	y	z	Uiso*/Ueq
Cl1	0.24946 (6)	0.19019 (3)	0.01260 (6)	0.0273 (2)
Mg1	0.0000	0.0000	0.5000	0.0204 (3)
O5	0.3377 (2)	0.98878 (10)	0.19001 (19)	0.0287 (3)
O3	0.8420 (2)	0.29031 (12)	0.9073 (2)	0.0323 (4)
O2	−0.1147 (2)	0.12266 (10)	0.37546 (17)	0.0299 (4)
O4	0.6795 (2)	0.15162 (11)	0.03240 (19)	0.0312 (4)
O1	−0.0221 (2)	0.04993 (11)	0.71709 (18)	0.0304 (4)
O6	0.2781 (2)	0.05679 (10)	0.57454 (18)	0.0294 (4)
H1B	−0.115 (4)	0.037 (2)	0.747 (4)	0.049 (8)*
H4A	0.724 (5)	0.1927 (18)	−0.012 (4)	0.055 (11)*
H4B	0.566 (2)	0.1625 (19)	0.030 (4)	0.032 (7)*
H5B	0.325 (5)	0.951 (2)	0.112 (3)	0.059 (10)*
H3A	0.959 (2)	0.271 (2)	0.941 (4)	0.049 (8)*
H6B	0.305 (5)	0.1014 (15)	0.524 (4)	0.044 (8)*
H2B	−0.152 (5)	0.1647 (18)	0.424 (4)	0.053 (9)*
H5A	0.313 (5)	1.0418 (12)	0.145 (4)	0.049 (9)*
H1A	0.056 (4)	0.0846 (19)	0.792 (3)	0.043 (8)*
H6A	0.385 (3)	0.034 (2)	0.642 (3)	0.048 (8)*
H3B	0.796 (8)	0.292 (4)	0.8004 (13)	0.100 (17)*
H2A	−0.177 (5)	0.127 (3)	0.2699 (14)	0.069 (11)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0247 (3)	0.0254 (3)	0.0284 (3)	−0.00034 (15)	0.0071 (2)	0.00013 (15)
Mg1	0.0190 (4)	0.0206 (5)	0.0193 (4)	−0.0011 (3)	0.0051 (3)	−0.0012 (3)
O5	0.0277 (7)	0.0276 (7)	0.0285 (7)	0.0017 (5)	0.0088 (6)	0.0016 (6)
O3	0.0305 (8)	0.0340 (8)	0.0323 (8)	0.0085 (6)	0.0122 (6)	0.0027 (6)
O2	0.0366 (8)	0.0247 (7)	0.0244 (7)	0.0059 (6)	0.0080 (5)	0.0013 (5)
O4	0.0274 (7)	0.0347 (8)	0.0312 (7)	0.0058 (6)	0.0112 (6)	0.0042 (6)
O1	0.0284 (7)	0.0374 (8)	0.0268 (7)	−0.0093 (6)	0.0123 (5)	−0.0117 (6)
O6	0.0201 (6)	0.0311 (8)	0.0306 (7)	−0.0052 (5)	0.0033 (5)	0.0042 (6)

Geometric parameters (Å, º)

Mg1—O6	2.0533 (14)	Mg1—O1^i	2.0605 (15)
Mg1—O6^i	2.0533 (14)	Mg1—O2	2.0644 (15)
Mg1—O1	2.0605 (15)	Mg1—O2^i	2.0644 (15)
O6—Mg1—O6^i	180.0	O1—Mg1—O2	90.28 (6)
O6—Mg1—O1	90.33 (6)	O1^i—Mg1—O2	89.72 (6)
O6^i—Mg1—O1	89.67 (6)	O6—Mg1—O2^i	91.70 (6)
O6—Mg1—O1^i	89.66 (6)	O6^i—Mg1—O2^i	88.30 (6)
O6^i—Mg1—O1^i	90.33 (6)	O1—Mg1—O2^i	89.72 (6)
O1—Mg1—O1^i	180.0	O1^i—Mg1—O2^i	90.28 (6)
O6—Mg1—O2	88.30 (6)	O2—Mg1—O2^i	180.0
O6^i—Mg1—O2	91.70 (6)

Symmetry code: (i) −x, −y, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2A···O4^ii	0.84 (1)	1.92 (1)	2.751 (2)	173 (4)
O3—H3B···Cl1^iii	0.84 (1)	2.37 (2)	3.186 (2)	165 (5)
O6—H6A···O5^iv	0.83 (1)	2.00 (1)	2.818 (2)	167 (3)
O1—H1A···Cl1^v	0.84 (1)	2.40 (1)	3.2349 (16)	173 (3)
O5—H5A···Cl1^vi	0.84 (1)	2.38 (1)	3.2220 (16)	178 (3)
O2—H2B···Cl1^vii	0.84 (1)	2.43 (1)	3.2548 (16)	166 (3)
O6—H6B···O3^viii	0.84 (1)	1.93 (1)	2.770 (2)	174 (3)
O3—H3A···Cl1^ix	0.84 (1)	2.29 (1)	3.1173 (17)	169 (3)
O5—H5B···O4^x	0.84 (1)	1.92 (1)	2.749 (2)	169 (4)
O4—H4B···Cl1	0.84 (1)	2.31 (1)	3.1468 (17)	178 (3)
O4—H4A···O3^xi	0.84 (1)	1.92 (1)	2.755 (2)	175 (4)
O1—H1B···O5^xii	0.84 (1)	1.95 (1)	2.792 (2)	178 (4)
O2—H2A···O4^ii	0.84 (1)	1.92 (1)	2.751 (2)	173 (4)
O3—H3B···Cl1^iii	0.84 (1)	2.37 (2)	3.186 (2)	165 (5)
O6—H6A···O5^iv	0.83 (1)	2.00 (1)	2.818 (2)	167 (3)
O1—H1A···Cl1^v	0.84 (1)	2.40 (1)	3.2349 (16)	173 (3)
O5—H5A···Cl1^vi	0.84 (1)	2.38 (1)	3.2220 (16)	178 (3)
O2—H2B···Cl1^vii	0.84 (1)	2.43 (1)	3.2548 (16)	166 (3)
O6—H6B···O3^viii	0.84 (1)	1.93 (1)	2.770 (2)	174 (3)
O3—H3A···Cl1^ix	0.84 (1)	2.29 (1)	3.1173 (17)	169 (3)
O5—H5B···O4^x	0.84 (1)	1.92 (1)	2.749 (2)	169 (4)
O4—H4B···Cl1	0.84 (1)	2.31 (1)	3.1468 (17)	178 (3)
O4—H4A···O3^xi	0.84 (1)	1.92 (1)	2.755 (2)	175 (4)
O1—H1B···O5^xii	0.84 (1)	1.95 (1)	2.792 (2)	178 (4)
O1—H1B···O5^xii	0.84 (1)	1.95 (1)	2.792 (2)	178 (4)
O4—H4A···O3^xi	0.84 (1)	1.92 (1)	2.755 (2)	175 (4)
O4—H4B···Cl1	0.84 (1)	2.31 (1)	3.1468 (17)	178 (3)
O5—H5B···O4^x	0.84 (1)	1.92 (1)	2.749 (2)	169 (4)
O3—H3A···Cl1^ix	0.84 (1)	2.29 (1)	3.1173 (17)	169 (3)
O6—H6B···O3^viii	0.84 (1)	1.93 (1)	2.770 (2)	174 (3)
O2—H2B···Cl1^vii	0.84 (1)	2.43 (1)	3.2548 (16)	166 (3)
O5—H5A···Cl1^vi	0.84 (1)	2.38 (1)	3.2220 (16)	178 (3)
O1—H1A···Cl1^v	0.84 (1)	2.40 (1)	3.2349 (16)	173 (3)
O6—H6A···O5^iv	0.83 (1)	2.00 (1)	2.818 (2)	167 (3)
O3—H3B···Cl1^iii	0.84 (1)	2.37 (2)	3.186 (2)	165 (5)
O2—H2A···O4^ii	0.84 (1)	1.92 (1)	2.751 (2)	173 (4)

Symmetry codes: (ii) x−1, y, z; (iii) x+1/2, −y+1/2, z+1/2; (iv) −x+1, −y+1, −z+1; (v) x, y, z+1; (vi) x, y+1, z; (vii) x−1/2, −y+1/2, z+1/2; (viii) x−1/2, −y+1/2, z−1/2; (ix) x+1, y, z+1; (x) −x+1, −y+1, −z; (xi) x, y, z−1; (xii) −x, −y+1, −z+1.

(MgBr2_9H2O) Magnesium dibromide nonahydrate

Crystal data

MgBr2·9H2O	F(000) = 688
Mr = 346.25	Dx = 1.855 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 11.835 (4) Å	Cell parameters from 12091 reflections
b = 6.4341 (14) Å	θ = 2.4–29.6°
c = 16.290 (4) Å	µ = 6.61 mm^−1
β = 92.04 (3)°	T = 200 K
V = 1239.7 (6) Å^3	, colourless
Z = 4	0.39 × 0.32 × 0.25 mm

Data collection

Stoe IPDS 2 diffractometer	1088 independent reflections
Radiation source: fine-focus sealed tube	938 reflections with I > 2σ(I)
Detector resolution: 6.67 pixels mm^-1	Rint = 0.087
rotation method scans	θmax = 25.0°, θmin = 2.5°
Absorption correction: integration (Coppens, 1970)	h = −14→14
Tmin = 0.093, Tmax = 0.194	k = −7→7
1088 measured reflections	l = −19→19

Refinement

Refinement on F^2	Hydrogen site location: difference Fourier map
Least-squares matrix: full	Only H-atom coordinates refined
R[F^2 > 2σ(F^2)] = 0.029	w = 1/[σ^2(Fo^2) + (0.0547P)^2] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.072	(Δ/σ)max < 0.001
S = 1.04	Δρmax = 0.64 e Å^−3
1088 reflections	Δρmin = −0.96 e Å^−3
85 parameters	Extinction correction: SHELXL2012 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
13 restraints	Extinction coefficient: 0.0030 (4)

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.

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

	x	y	z	Uiso*/Ueq
Br1	0.18095 (3)	0.01876 (5)	0.32410 (2)	0.02809 (18)
Mg1	1.0000	0.5000	0.5000	0.0175 (3)
O1	0.9988 (2)	0.2099 (3)	0.55139 (14)	0.0300 (5)
O2	0.8290 (2)	0.5058 (4)	0.49641 (15)	0.0332 (6)
O3	1.0056 (2)	0.6292 (3)	0.61873 (13)	0.0265 (5)
O4	0.6769 (2)	0.4782 (4)	0.61754 (16)	0.0336 (6)
O5	1.0000	0.3546 (5)	0.7500	0.0344 (8)
H2A	0.786 (3)	0.508 (6)	0.5357 (18)	0.041*
H2B	0.790 (3)	0.513 (6)	0.4528 (16)	0.041*
H4A	0.691 (4)	0.521 (6)	0.6654 (11)	0.041*
H3A	1.015 (4)	0.549 (5)	0.6598 (16)	0.041*
H1B	1.058 (2)	0.157 (6)	0.573 (2)	0.041*
H3B	0.956 (3)	0.712 (5)	0.636 (2)	0.041*
H5A	0.943 (2)	0.284 (5)	0.734 (2)	0.041*
H1A	0.942 (2)	0.162 (6)	0.575 (2)	0.041*
H4B	0.646 (3)	0.362 (3)	0.623 (2)	0.041*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.0313 (2)	0.0315 (2)	0.0215 (2)	0.00111 (13)	0.00122 (14)	−0.00132 (12)
Mg1	0.0208 (7)	0.0167 (7)	0.0150 (7)	0.0006 (5)	0.0019 (5)	0.0008 (5)
O1	0.0374 (13)	0.0216 (12)	0.0315 (14)	0.0020 (9)	0.0054 (10)	0.0060 (9)
O2	0.0210 (12)	0.0562 (17)	0.0227 (13)	0.0023 (10)	0.0026 (9)	0.0002 (10)
O3	0.0395 (13)	0.0235 (12)	0.0168 (11)	0.0067 (9)	0.0028 (9)	0.0001 (8)
O4	0.0423 (15)	0.0348 (14)	0.0241 (12)	0.0051 (11)	0.0064 (11)	0.0027 (10)
O5	0.051 (2)	0.0258 (18)	0.0262 (18)	0.000	−0.0040 (16)	0.000

Geometric parameters (Å, º)

Mg1—O2	2.023 (3)	Mg1—O1	2.046 (2)
Mg1—O2^i	2.023 (3)	Mg1—O3	2.104 (2)
Mg1—O1^i	2.046 (2)	Mg1—O3^i	2.104 (2)
O2—Mg1—O2^i	180.0	O1^i—Mg1—O3	90.88 (9)
O2—Mg1—O1^i	89.59 (10)	O1—Mg1—O3	89.12 (9)
O2^i—Mg1—O1^i	90.41 (10)	O2—Mg1—O3^i	88.97 (10)
O2—Mg1—O1	90.41 (10)	O2^i—Mg1—O3^i	91.03 (10)
O2^i—Mg1—O1	89.58 (10)	O1^i—Mg1—O3^i	89.12 (9)
O1^i—Mg1—O1	180.0	O1—Mg1—O3^i	90.88 (9)
O2—Mg1—O3	91.03 (10)	O3—Mg1—O3^i	180.0
O2^i—Mg1—O3	88.97 (10)

Symmetry code: (i) −x+2, −y+1, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O4—H4B···O3^ii	0.84 (1)	2.24 (2)	3.026 (4)	157 (4)
O1—H1A···Br1^iii	0.84 (1)	2.52 (2)	3.334 (2)	162 (4)
O5—H5A···Br1^iii	0.85 (1)	2.60 (2)	3.410 (2)	162 (4)
O3—H3B···Br1^iv	0.85 (1)	2.48 (1)	3.319 (2)	174 (4)
O1—H1B···O4^v	0.85 (1)	1.94 (1)	2.769 (4)	167 (4)
O3—H3A···O5	0.85 (1)	1.94 (1)	2.776 (3)	167 (4)
O4—H4A···Br1^vi	0.84 (1)	2.61 (2)	3.364 (3)	151 (4)
O2—H2B···Br1^vii	0.84 (1)	2.42 (1)	3.256 (3)	177 (4)
O2—H2A···O4	0.84 (1)	1.89 (1)	2.723 (4)	171 (4)
O4—H4B···O3^ii	0.84 (1)	2.24 (2)	3.026 (4)	157 (4)
O1—H1A···Br1^iii	0.84 (1)	2.52 (2)	3.334 (2)	162 (4)
O5—H5A···Br1^iii	0.85 (1)	2.60 (2)	3.410 (2)	162 (4)
O3—H3B···Br1^iv	0.85 (1)	2.48 (1)	3.319 (2)	174 (4)
O1—H1B···O4^v	0.85 (1)	1.94 (1)	2.769 (4)	167 (4)
O3—H3A···O5	0.85 (1)	1.94 (1)	2.776 (3)	167 (4)
O4—H4A···Br1^vi	0.84 (1)	2.61 (2)	3.364 (3)	151 (4)
O2—H2B···Br1^vii	0.84 (1)	2.42 (1)	3.256 (3)	177 (4)
O2—H2A···O4	0.84 (1)	1.89 (1)	2.723 (4)	171 (4)
O4—H4B···O3^ii	0.84 (1)	2.24 (2)	3.026 (4)	157 (4)
O1—H1A···Br1^iii	0.84 (1)	2.52 (2)	3.334 (2)	162 (4)
O5—H5A···Br1^iii	0.85 (1)	2.60 (2)	3.410 (2)	162 (4)
O3—H3B···Br1^iv	0.85 (1)	2.48 (1)	3.319 (2)	174 (4)
O1—H1B···O4^v	0.85 (1)	1.94 (1)	2.769 (4)	167 (4)
O3—H3A···O5	0.85 (1)	1.94 (1)	2.776 (3)	167 (4)
O4—H4A···Br1^vi	0.84 (1)	2.61 (2)	3.364 (3)	151 (4)
O2—H2B···Br1^vii	0.84 (1)	2.42 (1)	3.256 (3)	177 (4)
O2—H2A···O4	0.84 (1)	1.89 (1)	2.723 (4)	171 (4)
O2—H2A···O4	0.84 (1)	1.89 (1)	2.723 (4)	171 (4)
O2—H2B···Br1^vii	0.84 (1)	2.42 (1)	3.256 (3)	177 (4)
O4—H4A···Br1^vi	0.84 (1)	2.61 (2)	3.364 (3)	151 (4)
O3—H3A···O5	0.85 (1)	1.94 (1)	2.776 (3)	167 (4)
O1—H1B···O4^v	0.85 (1)	1.94 (1)	2.769 (4)	167 (4)
O3—H3B···Br1^iv	0.85 (1)	2.48 (1)	3.319 (2)	174 (4)
O5—H5A···Br1^iii	0.85 (1)	2.60 (2)	3.410 (2)	162 (4)
O1—H1A···Br1^iii	0.84 (1)	2.52 (2)	3.334 (2)	162 (4)
O4—H4B···O3^ii	0.84 (1)	2.24 (2)	3.026 (4)	157 (4)
O2—H2A···O4	0.84 (1)	1.89 (1)	2.723 (4)	171 (4)
O2—H2B···Br1^vii	0.84 (1)	2.42 (1)	3.256 (3)	177 (4)
O4—H4A···Br1^vi	0.84 (1)	2.61 (2)	3.364 (3)	151 (4)
O3—H3A···O5	0.85 (1)	1.94 (1)	2.776 (3)	167 (4)
O1—H1B···O4^v	0.85 (1)	1.94 (1)	2.769 (4)	167 (4)
O3—H3B···Br1^iv	0.85 (1)	2.48 (1)	3.319 (2)	174 (4)
O5—H5A···Br1^iii	0.85 (1)	2.60 (2)	3.410 (2)	162 (4)
O1—H1A···Br1^iii	0.84 (1)	2.52 (2)	3.334 (2)	162 (4)
O4—H4B···O3^ii	0.84 (1)	2.24 (2)	3.026 (4)	157 (4)
O2—H2A···O4	0.84 (1)	1.89 (1)	2.723 (4)	171 (4)
O2—H2B···Br1^vii	0.84 (1)	2.42 (1)	3.256 (3)	177 (4)
O4—H4A···Br1^vi	0.84 (1)	2.61 (2)	3.364 (3)	151 (4)
O3—H3A···O5	0.85 (1)	1.94 (1)	2.776 (3)	167 (4)
O1—H1B···O4^v	0.85 (1)	1.94 (1)	2.769 (4)	167 (4)
O3—H3B···Br1^iv	0.85 (1)	2.48 (1)	3.319 (2)	174 (4)
O5—H5A···Br1^iii	0.85 (1)	2.60 (2)	3.410 (2)	162 (4)
O1—H1A···Br1^iii	0.84 (1)	2.52 (2)	3.334 (2)	162 (4)
O4—H4B···O3^ii	0.84 (1)	2.24 (2)	3.026 (4)	157 (4)
O2—H2A···O4	0.84 (1)	1.89 (1)	2.723 (4)	171 (4)
O2—H2B···Br1^vii	0.84 (1)	2.42 (1)	3.256 (3)	177 (4)
O4—H4A···Br1^vi	0.84 (1)	2.61 (2)	3.364 (3)	151 (4)
O3—H3A···O5	0.85 (1)	1.94 (1)	2.776 (3)	167 (4)
O1—H1B···O4^v	0.85 (1)	1.94 (1)	2.769 (4)	167 (4)
O3—H3B···Br1^iv	0.85 (1)	2.48 (1)	3.319 (2)	174 (4)
O5—H5A···Br1^iii	0.85 (1)	2.60 (2)	3.410 (2)	162 (4)
O1—H1A···Br1^iii	0.84 (1)	2.52 (2)	3.334 (2)	162 (4)
O4—H4B···O3^ii	0.84 (1)	2.24 (2)	3.026 (4)	157 (4)

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

(MgI2_9H2O) Magnesium diiodide nonahydrate

Crystal data

MgI2·9H2O	F(000) = 832
Mr = 440.25	Dx = 2.137 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 15.0768 (13) Å	Cell parameters from 40178 reflections
b = 6.6334 (3) Å	θ = 1.8–29.6°
c = 16.7964 (15) Å	µ = 4.66 mm^−1
β = 125.447 (6)°	T = 200 K
V = 1368.5 (2) Å^3	, colourless
Z = 4	0.32 × 0.21 × 0.11 mm

Data collection

Stoe IPDS 2 diffractometer	3766 independent reflections
Radiation source: fine-focus sealed tube	2970 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.092
Detector resolution: 6.67 pixels mm^-1	θmax = 29.4°, θmin = 1.7°
rotation method scans	h = −20→20
Absorption correction: integration (Coppens, 1970)	k = −9→9
Tmin = 0.316, Tmax = 0.602	l = −20→20
3766 measured reflections

Refinement

Refinement on F^2	27 restraints
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.029	All H-atom parameters refined
wR(F^2) = 0.100	w = 1/[σ^2(Fo^2) + (0.0653P)^2 + 1.518P] where P = (Fo^2 + 2Fc^2)/3
S = 1.02	(Δ/σ)max = 0.001
3673 reflections	Δρmax = 0.80 e Å^−3
181 parameters	Δρmin = −1.74 e Å^−3

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.

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

	x	y	z	Uiso*/Ueq
Mg1	0.25042 (9)	0.26358 (14)	0.37605 (7)	0.0171 (2)
I1	0.43196 (2)	0.77324 (3)	0.28956 (2)	0.02624 (9)
I2	0.06797 (2)	0.76276 (3)	0.45929 (2)	0.02680 (9)
O4	0.2591 (2)	−0.0190 (4)	0.42848 (18)	0.0284 (5)
O5	0.2568 (2)	0.3903 (4)	0.49418 (16)	0.0273 (4)
O1	0.24242 (19)	0.1333 (4)	0.25825 (16)	0.0267 (4)
O6	0.4160 (2)	0.2757 (4)	0.4585 (2)	0.0337 (6)
O7	0.0760 (3)	0.7795 (4)	0.1764 (2)	0.0331 (6)
O3	0.0844 (2)	0.2529 (4)	0.2943 (2)	0.0333 (6)
O9	0.5757 (3)	0.2660 (4)	0.4278 (2)	0.0320 (6)
O8	0.2567 (2)	0.3630 (4)	0.12752 (17)	0.0337 (5)
O2	0.2434 (2)	0.5451 (4)	0.32340 (18)	0.0298 (5)
H6A	0.437 (4)	0.255 (6)	0.5152 (14)	0.032 (13)*
H3A	0.065 (4)	0.245 (7)	0.2374 (16)	0.044 (16)*
H2A	0.188 (2)	0.579 (11)	0.271 (3)	0.12 (3)*
H3B	0.029 (3)	0.269 (9)	0.292 (4)	0.08 (3)*
H6B	0.470 (3)	0.270 (10)	0.457 (4)	0.09 (3)*
H4B	0.316 (2)	−0.070 (10)	0.474 (4)	0.12 (3)*
H5B	0.274 (4)	0.314 (6)	0.539 (3)	0.061 (17)*
H1B	0.289 (3)	0.049 (5)	0.272 (3)	0.056 (15)*
H2B	0.295 (2)	0.598 (7)	0.327 (3)	0.055 (15)*
H4A	0.209 (2)	−0.067 (7)	0.429 (3)	0.048 (13)*
H5A	0.209 (3)	0.466 (7)	0.486 (4)	0.072 (18)*
H1A	0.237 (4)	0.208 (6)	0.217 (3)	0.048 (15)*
H9A	0.557 (6)	0.226 (7)	0.374 (2)	0.060 (19)*
H8A	0.210 (3)	0.442 (6)	0.088 (3)	0.08 (2)*
H7A	0.056 (5)	0.737 (6)	0.122 (2)	0.047 (17)*
H7B	0.100 (5)	0.893 (4)	0.182 (4)	0.09 (2)*
H8B	0.311 (3)	0.427 (7)	0.168 (3)	0.10 (3)*
H9B	0.608 (7)	0.373 (7)	0.438 (5)	0.15 (4)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Mg1	0.0156 (5)	0.0218 (5)	0.0176 (5)	0.0018 (3)	0.0117 (4)	0.0021 (3)
I1	0.02866 (15)	0.03045 (13)	0.02467 (14)	0.00168 (7)	0.01836 (12)	0.00029 (7)
I2	0.02861 (16)	0.03133 (13)	0.02533 (15)	−0.00173 (7)	0.01843 (13)	−0.00265 (7)
O4	0.0305 (11)	0.0256 (10)	0.0355 (12)	0.0041 (9)	0.0229 (10)	0.0095 (9)
O5	0.0363 (12)	0.0278 (11)	0.0258 (10)	0.0068 (9)	0.0227 (10)	0.0043 (8)
O1	0.0366 (12)	0.0270 (11)	0.0260 (10)	0.0086 (9)	0.0236 (10)	0.0054 (8)
O6	0.0195 (13)	0.0593 (17)	0.0247 (12)	0.0010 (10)	0.0142 (11)	0.0034 (10)
O7	0.0371 (16)	0.0369 (14)	0.0366 (15)	0.0090 (10)	0.0278 (13)	0.0094 (10)
O3	0.0198 (14)	0.0584 (18)	0.0266 (13)	0.0025 (9)	0.0163 (12)	0.0014 (9)
O9	0.0331 (15)	0.0387 (14)	0.0345 (15)	0.0083 (9)	0.0256 (13)	0.0074 (9)
O8	0.0478 (15)	0.0293 (12)	0.0267 (11)	0.0000 (11)	0.0232 (11)	0.0020 (9)
O2	0.0318 (12)	0.0262 (11)	0.0371 (12)	0.0037 (9)	0.0233 (11)	0.0098 (9)

Geometric parameters (Å, º)

Mg1—O6	2.036 (3)	Mg1—O4	2.043 (2)
Mg1—O3	2.042 (3)	Mg1—O1	2.097 (2)
Mg1—O2	2.042 (2)	Mg1—O5	2.105 (2)
O6—Mg1—O3	179.49 (12)	O2—Mg1—O1	90.46 (10)
O6—Mg1—O2	89.62 (11)	O4—Mg1—O1	89.03 (10)
O3—Mg1—O2	90.29 (11)	O6—Mg1—O5	88.61 (11)
O6—Mg1—O4	89.81 (11)	O3—Mg1—O5	90.88 (11)
O3—Mg1—O4	90.27 (11)	O2—Mg1—O5	90.33 (10)
O2—Mg1—O4	179.23 (10)	O4—Mg1—O5	90.19 (10)
O6—Mg1—O1	91.99 (11)	O1—Mg1—O5	179.01 (10)
O3—Mg1—O1	88.51 (11)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O9—H9B···O5^i	0.82 (1)	2.28 (3)	3.075 (4)	162 (8)
O8—H8B···I1	0.82 (1)	2.91 (3)	3.668 (3)	156 (5)
O7—H7B···O1^ii	0.82 (1)	2.36 (3)	3.113 (4)	152 (6)
O7—H7B···I2^iii	0.82 (1)	3.33 (6)	3.800 (3)	120 (5)
O7—H7A···I2^iv	0.82 (1)	2.85 (3)	3.589 (3)	151 (5)
O8—H8A···I2^iv	0.82 (1)	2.78 (1)	3.594 (3)	175 (5)
O9—H9A···I1^v	0.82 (1)	2.87 (3)	3.586 (3)	148 (5)
O1—H1A···O8	0.82 (1)	1.98 (2)	2.781 (3)	167 (5)
O5—H5A···I2	0.82 (1)	2.74 (1)	3.552 (2)	172 (5)
O4—H4A···I2^vi	0.82 (1)	2.71 (1)	3.520 (2)	171 (4)
O2—H2B···I1	0.82 (1)	2.75 (2)	3.545 (2)	165 (4)
O1—H1B···I1^vi	0.82 (1)	2.71 (1)	3.522 (2)	172 (4)
O5—H5B···O8^vii	0.82 (1)	2.02 (2)	2.800 (3)	159 (5)
O4—H4B···O9^viii	0.82 (1)	1.99 (2)	2.782 (4)	163 (6)
O6—H6B···O9	0.82 (1)	1.93 (1)	2.739 (4)	169 (5)
O3—H3B···O7^ix	0.82 (1)	1.94 (2)	2.739 (4)	163 (6)
O2—H2A···O7	0.82 (1)	2.01 (4)	2.767 (4)	154 (8)
O3—H3A···I2^ix	0.82 (1)	2.70 (2)	3.475 (3)	158 (5)
O6—H6A···I1^i	0.82 (1)	2.68 (2)	3.467 (3)	161 (5)
O6—H6A···I1^i	0.82 (1)	2.68 (2)	3.467 (3)	161 (5)
O3—H3A···I2^ix	0.82 (1)	2.70 (2)	3.475 (3)	158 (5)
O2—H2A···O7	0.82 (1)	2.01 (4)	2.767 (4)	154 (8)
O3—H3B···O7^ix	0.82 (1)	1.94 (2)	2.739 (4)	163 (6)
O6—H6B···O9	0.82 (1)	1.93 (1)	2.739 (4)	169 (5)
O4—H4B···O9^viii	0.82 (1)	1.99 (2)	2.782 (4)	163 (6)
O5—H5B···O8^vii	0.82 (1)	2.02 (2)	2.800 (3)	159 (5)
O1—H1B···I1^vi	0.82 (1)	2.71 (1)	3.522 (2)	172 (4)
O2—H2B···I1	0.82 (1)	2.75 (2)	3.545 (2)	165 (4)
O4—H4A···I2^vi	0.82 (1)	2.71 (1)	3.520 (2)	171 (4)
O5—H5A···I2	0.82 (1)	2.74 (1)	3.552 (2)	172 (5)
O1—H1A···O8	0.82 (1)	1.98 (2)	2.781 (3)	167 (5)
O9—H9A···I1^v	0.82 (1)	2.87 (3)	3.586 (3)	148 (5)
O8—H8A···I2^iv	0.82 (1)	2.78 (1)	3.594 (3)	175 (5)
O7—H7A···I2^iv	0.82 (1)	2.85 (3)	3.589 (3)	151 (5)
O7—H7B···I2^iii	0.82 (1)	3.33 (6)	3.800 (3)	120 (5)
O7—H7B···O1^ii	0.82 (1)	2.36 (3)	3.113 (4)	152 (6)
O8—H8B···I1	0.82 (1)	2.91 (3)	3.668 (3)	156 (5)
O9—H9B···O5^i	0.82 (1)	2.28 (3)	3.075 (4)	162 (8)

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

(MgCl2_8H2O) Magnesium dichloride octahydrate

Crystal data

MgCl2·8H2O	F(000) = 504.0
Mr = 239.34	Dx = 1.453 Mg m^−3
Orthorhombic, Pcab	Mo Kα radiation, λ = 0.71073 Å
a = 11.9153 (3) Å	Cell parameters from 4627 reflections
b = 6.7482 (4) Å	θ = 3.0–34.5°
c = 13.6052 (5) Å	µ = 0.66 mm^−1
V = 1093.95 (7) Å^3	T = 230 K
Z = 4	0.67 × 0.56 × 0.44 mm

Data collection

Bruker APEXII CCD area-detector diffractometer	2131 independent reflections
Radiation source: sealed tube	1713 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.027
Detector resolution: 6.67 pixels mm^-1	θmax = 35.3°, θmin = 3.0°
φ and ω scans	h = −19→10
Absorption correction: multi-scan (Coppens, 1970)	k = −7→10
Tmin = 0.65, Tmax = 0.75	l = −21→16
9636 measured reflections

Refinement

Refinement on F^2	Hydrogen site location: difference Fourier map
Least-squares matrix: full	All H-atom parameters refined
R[F^2 > 2σ(F^2)] = 0.025	w = 1/[σ^2(Fo^2) + (0.0239P)^2 + 0.0665P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.055	(Δ/σ)max = 0.001
S = 1.02	Δρmax = 0.27 e Å^−3
2131 reflections	Δρmin = −0.20 e Å^−3
85 parameters	Extinction correction: SHELXL2012 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
0 restraints	Extinction coefficient: 0.0345 (14)

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
Mg2	0.0000	1.0000	0.0000	0.01649 (9)
O2	0.16933 (6)	1.00842 (10)	0.01898 (5)	0.03047 (16)
O1	−0.01884 (5)	0.85060 (9)	0.13410 (4)	0.02412 (13)
O3	0.01343 (6)	0.73610 (9)	−0.07187 (5)	0.02850 (15)
O4	0.32080 (6)	0.96977 (10)	0.87158 (5)	0.02792 (14)
H1A	0.0352 (9)	0.7786 (19)	0.1531 (9)	0.050 (3)*
H2A	0.2077 (12)	1.0116 (17)	0.0736 (11)	0.060 (4)*
H3A	−0.0351 (9)	0.6852 (17)	−0.0973 (9)	0.042 (3)*
H2B	0.2123 (11)	0.9957 (15)	−0.0217 (9)	0.043 (4)*
H3B	0.0693 (9)	0.6773 (18)	−0.0865 (8)	0.046 (3)*
H4A	0.2843 (12)	0.9708 (17)	0.8168 (10)	0.057 (4)*
H4B	0.3574 (10)	0.872 (2)	0.8725 (10)	0.062 (4)*
H1B	−0.0402 (10)	0.9062 (19)	0.1791 (9)	0.044 (3)*
Cl1	0.15438 (2)	0.96936 (3)	0.69229 (2)	0.02372 (7)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Mg2	0.01482 (18)	0.01872 (17)	0.01594 (17)	0.00075 (12)	−0.00094 (13)	−0.00139 (12)
O2	0.0156 (3)	0.0539 (4)	0.0219 (3)	0.0011 (2)	−0.0021 (2)	−0.0024 (3)
O1	0.0274 (3)	0.0268 (3)	0.0182 (3)	0.0070 (2)	0.0023 (2)	0.0007 (2)
O3	0.0243 (3)	0.0251 (3)	0.0361 (4)	0.0019 (3)	−0.0019 (3)	−0.0125 (3)
O4	0.0226 (3)	0.0330 (3)	0.0281 (3)	0.0030 (2)	−0.0031 (3)	−0.0045 (3)
Cl1	0.01976 (11)	0.03071 (12)	0.02068 (10)	−0.00023 (7)	0.00099 (7)	−0.00140 (7)

Geometric parameters (Å, º)

Mg2—O2	2.0349 (7)	Mg2—O3	2.0379 (6)
Mg2—O2^i	2.0349 (7)	Mg2—O1	2.0965 (6)
Mg2—O3^i	2.0379 (6)	Mg2—O1^i	2.0965 (6)
O2—Mg2—O2^i	180.0	O3^i—Mg2—O1	89.67 (3)
O2—Mg2—O3^i	89.57 (3)	O3—Mg2—O1	90.33 (3)
O2^i—Mg2—O3^i	90.43 (3)	O2—Mg2—O1^i	89.47 (3)
O2—Mg2—O3	90.43 (3)	O2^i—Mg2—O1^i	90.53 (3)
O2^i—Mg2—O3	89.57 (3)	O3^i—Mg2—O1^i	90.33 (3)
O3^i—Mg2—O3	180.0	O3—Mg2—O1^i	89.67 (3)
O2—Mg2—O1	90.53 (3)	O1—Mg2—O1^i	180.0
O2^i—Mg2—O1	89.47 (3)

Symmetry code: (i) −x, −y+2, −z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1B···Cl1^ii	0.762 (13)	2.370 (13)	3.1085 (6)	163.7 (12)
O4—H4B···O1^iii	0.791 (14)	2.106 (14)	2.8863 (9)	168.5 (13)
O4—H4A···Cl1	0.862 (15)	2.296 (15)	3.1436 (7)	167.8 (13)
O3—H3B···O4^iv	0.800 (12)	2.000 (12)	2.7792 (9)	164.4 (11)
O2—H2B···O4^v	0.758 (13)	1.953 (13)	2.7105 (10)	178.2 (12)
O3—H3A···Cl1^vi	0.757 (11)	2.410 (12)	3.1499 (7)	166.0 (11)
O2—H2A···Cl1^vii	0.873 (14)	2.308 (15)	3.1615 (7)	166.0 (13)
O1—H1A···Cl1^viii	0.847 (12)	2.258 (12)	3.0901 (7)	167.2 (11)
O1—H1B···Cl1^ii	0.762 (13)	2.370 (13)	3.1085 (6)	163.7 (12)
O4—H4B···O1^iii	0.791 (14)	2.106 (14)	2.8863 (9)	168.5 (13)
O4—H4A···Cl1	0.862 (15)	2.296 (15)	3.1436 (7)	167.8 (13)
O3—H3B···O4^iv	0.800 (12)	2.000 (12)	2.7792 (9)	164.4 (11)
O2—H2B···O4^v	0.758 (13)	1.953 (13)	2.7105 (10)	178.2 (12)
O3—H3A···Cl1^vi	0.757 (11)	2.410 (12)	3.1499 (7)	166.0 (11)
O2—H2A···Cl1^vii	0.873 (14)	2.308 (15)	3.1615 (7)	166.0 (13)
O1—H1A···Cl1^viii	0.847 (12)	2.258 (12)	3.0901 (7)	167.2 (11)
O1—H1B···Cl1^ii	0.762 (13)	2.370 (13)	3.1085 (6)	163.7 (12)
O4—H4B···O1^iii	0.791 (14)	2.106 (14)	2.8863 (9)	168.5 (13)
O4—H4A···Cl1	0.862 (15)	2.296 (15)	3.1436 (7)	167.8 (13)
O3—H3B···O4^iv	0.800 (12)	2.000 (12)	2.7792 (9)	164.4 (11)
O2—H2B···O4^v	0.758 (13)	1.953 (13)	2.7105 (10)	178.2 (12)
O3—H3A···Cl1^vi	0.757 (11)	2.410 (12)	3.1499 (7)	166.0 (11)
O2—H2A···Cl1^vii	0.873 (14)	2.308 (15)	3.1615 (7)	166.0 (13)
O1—H1A···Cl1^viii	0.847 (12)	2.258 (12)	3.0901 (7)	167.2 (11)
O1—H1B···Cl1^ii	0.762 (13)	2.370 (13)	3.1085 (6)	163.7 (12)
O4—H4B···O1^iii	0.791 (14)	2.106 (14)	2.8863 (9)	168.5 (13)
O4—H4A···Cl1	0.862 (15)	2.296 (15)	3.1436 (7)	167.8 (13)
O3—H3B···O4^iv	0.800 (12)	2.000 (12)	2.7792 (9)	164.4 (11)
O2—H2B···O4^v	0.758 (13)	1.953 (13)	2.7105 (10)	178.2 (12)
O3—H3A···Cl1^vi	0.757 (11)	2.410 (12)	3.1499 (7)	166.0 (11)
O2—H2A···Cl1^vii	0.873 (14)	2.308 (15)	3.1615 (7)	166.0 (13)
O1—H1A···Cl1^viii	0.847 (12)	2.258 (12)	3.0901 (7)	167.2 (11)
O1—H1A···Cl1^viii	0.847 (12)	2.258 (12)	3.0901 (7)	167.2 (11)
O2—H2A···Cl1^vii	0.873 (14)	2.308 (15)	3.1615 (7)	166.0 (13)
O3—H3A···Cl1^vi	0.757 (11)	2.410 (12)	3.1499 (7)	166.0 (11)
O2—H2B···O4^v	0.758 (13)	1.953 (13)	2.7105 (10)	178.2 (12)
O3—H3B···O4^iv	0.800 (12)	2.000 (12)	2.7792 (9)	164.4 (11)
O4—H4A···Cl1	0.862 (15)	2.296 (15)	3.1436 (7)	167.8 (13)
O4—H4B···O1^iii	0.791 (14)	2.106 (14)	2.8863 (9)	168.5 (13)
O1—H1B···Cl1^ii	0.762 (13)	2.370 (13)	3.1085 (6)	163.7 (12)
O1—H1A···Cl1^viii	0.847 (12)	2.258 (12)	3.0901 (7)	167.2 (11)
O2—H2A···Cl1^vii	0.873 (14)	2.308 (15)	3.1615 (7)	166.0 (13)
O3—H3A···Cl1^vi	0.757 (11)	2.410 (12)	3.1499 (7)	166.0 (11)
O2—H2B···O4^v	0.758 (13)	1.953 (13)	2.7105 (10)	178.2 (12)
O3—H3B···O4^iv	0.800 (12)	2.000 (12)	2.7792 (9)	164.4 (11)
O4—H4A···Cl1	0.862 (15)	2.296 (15)	3.1436 (7)	167.8 (13)
O4—H4B···O1^iii	0.791 (14)	2.106 (14)	2.8863 (9)	168.5 (13)
O1—H1B···Cl1^ii	0.762 (13)	2.370 (13)	3.1085 (6)	163.7 (12)
O1—H1A···Cl1^viii	0.847 (12)	2.258 (12)	3.0901 (7)	167.2 (11)
O2—H2A···Cl1^vii	0.873 (14)	2.308 (15)	3.1615 (7)	166.0 (13)
O3—H3A···Cl1^vi	0.757 (11)	2.410 (12)	3.1499 (7)	166.0 (11)
O2—H2B···O4^v	0.758 (13)	1.953 (13)	2.7105 (10)	178.2 (12)
O3—H3B···O4^iv	0.800 (12)	2.000 (12)	2.7792 (9)	164.4 (11)
O4—H4A···Cl1	0.862 (15)	2.296 (15)	3.1436 (7)	167.8 (13)
O4—H4B···O1^iii	0.791 (14)	2.106 (14)	2.8863 (9)	168.5 (13)
O1—H1B···Cl1^ii	0.762 (13)	2.370 (13)	3.1085 (6)	163.7 (12)
O1—H1A···Cl1^viii	0.847 (12)	2.258 (12)	3.0901 (7)	167.2 (11)
O2—H2A···Cl1^vii	0.873 (14)	2.308 (15)	3.1615 (7)	166.0 (13)
O3—H3A···Cl1^vi	0.757 (11)	2.410 (12)	3.1499 (7)	166.0 (11)
O2—H2B···O4^v	0.758 (13)	1.953 (13)	2.7105 (10)	178.2 (12)
O3—H3B···O4^iv	0.800 (12)	2.000 (12)	2.7792 (9)	164.4 (11)
O4—H4A···Cl1	0.862 (15)	2.296 (15)	3.1436 (7)	167.8 (13)
O4—H4B···O1^iii	0.791 (14)	2.106 (14)	2.8863 (9)	168.5 (13)
O1—H1B···Cl1^ii	0.762 (13)	2.370 (13)	3.1085 (6)	163.7 (12)

Symmetry codes: (ii) −x, −y+2, −z+1; (iii) −x+1/2, y+3/2, −z+1; (iv) x+1/2, −y−1/2, z−1; (v) x, y, z−1; (vi) x+1/2, −y−1, −z+1/2; (vii) −x, −y+5/2, z−1/2; (viii) −x−1/2, y+2, z−1/2.

(MgI2_8H2O) Magnesium diiodide octahydrate

Crystal data

MgI2·8H2O	F(000) = 792
Mr = 422.24	Dx = 2.124 Mg m^−3
Orthorhombic, Cmca	Mo Kα radiation, λ = 0.71073 Å
a = 8.5256 (7) Å	Cell parameters from 5956 reflections
b = 15.6980 (17) Å	θ = 2.1–29.5°
c = 9.8671 (12) Å	µ = 4.82 mm^−1
V = 1320.6 (2) Å^3	T = 200 K
Z = 4

Data collection

Stoe IPDS 2 diffractometer	840 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.000
Graphite monochromator	θmax = 29.1°, θmin = 2.6°
Detector resolution: 6.67 pixels mm^-1	h = 0→11
rotation method scans	k = 0→21
951 measured reflections	l = 0→13
950 independent reflections

Refinement

Refinement on F^2	Hydrogen site location: difference Fourier map
Least-squares matrix: full	All H-atom parameters refined
R[F^2 > 2σ(F^2)] = 0.022	w = 1/[σ^2(Fo^2) + (0.0414P)^2] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.053	(Δ/σ)max < 0.001
S = 1.02	Δρmax = 0.80 e Å^−3
950 reflections	Δρmin = −0.78 e Å^−3
52 parameters	Extinction correction: SHELXL2012 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
6 restraints	Extinction coefficient: 0.0015 (2)

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.

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

	x	y	z	Uiso*/Ueq
I1	0.5000	0.17679 (2)	0.06211 (2)	0.03450 (11)
O1	0.5000	0.11795 (17)	0.4101 (3)	0.0408 (6)
O2	0.2500	0.15995 (18)	0.7500	0.0454 (6)
O3	0.7425 (3)	0.0000	0.5000	0.0418 (6)
Mg1	0.5000	0.0000	0.5000	0.0278 (3)
O4	0.5000	0.05475 (16)	0.6877 (3)	0.0380 (5)
H1A	0.5000	0.126 (3)	0.3260 (13)	0.068 (16)*
H1B	0.5000	0.1673 (11)	0.443 (3)	0.029 (11)*
H4A	0.577 (3)	0.0843 (19)	0.711 (4)	0.072 (13)*
H2A	0.260 (7)	0.195 (2)	0.813 (3)	0.11 (2)*
H3A	0.792 (5)	0.042 (2)	0.470 (5)	0.102 (16)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
I1	0.04525 (15)	0.02265 (13)	0.03559 (14)	0.000	0.000	0.00064 (7)
O1	0.0634 (16)	0.0211 (10)	0.0378 (12)	0.000	0.000	0.0019 (9)
O2	0.0491 (14)	0.0363 (13)	0.0508 (14)	0.000	0.0174 (13)	0.000
O3	0.0277 (10)	0.0293 (11)	0.0685 (18)	0.000	0.000	0.0055 (11)
Mg1	0.0285 (6)	0.0198 (6)	0.0351 (8)	0.000	0.000	0.0002 (5)
O4	0.0358 (12)	0.0373 (12)	0.0407 (12)	0.000	0.000	−0.0061 (10)

Geometric parameters (Å, º)

O1—Mg1	2.053 (3)	Mg1—O4^i	2.042 (3)
O3—Mg1	2.067 (2)	Mg1—O1^i	2.053 (3)
Mg1—O4	2.042 (3)	Mg1—O3^i	2.067 (2)
O4—Mg1—O4^i	180.0	O1^i—Mg1—O3	90.0
O4—Mg1—O1^i	89.31 (10)	O1—Mg1—O3	90.0
O4^i—Mg1—O1^i	90.69 (10)	O4—Mg1—O3^i	90.0
O4—Mg1—O1	90.69 (10)	O4^i—Mg1—O3^i	90.0
O4^i—Mg1—O1	89.31 (10)	O1^i—Mg1—O3^i	90.0
O1^i—Mg1—O1	180.0	O1—Mg1—O3^i	90.0
O4—Mg1—O3	90.0	O3—Mg1—O3^i	180.0
O4^i—Mg1—O3	90.0

Symmetry code: (i) −x+1, −y, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3A···I1^ii	0.84 (1)	2.78 (2)	3.5913 (15)	164 (5)
O2—H2A···I1^iii	0.84 (1)	3.24 (5)	3.8142 (19)	128 (5)
O2—H2A···I1^iv	0.84 (1)	3.21 (5)	3.7546 (4)	125 (4)
O4—H4A···O2^v	0.84 (1)	1.93 (1)	2.766 (2)	174 (4)
O1—H1B···I1^vi	0.84 (1)	2.72 (1)	3.554 (3)	177 (3)
O1—H1A···I1	0.84 (1)	2.73 (1)	3.556 (3)	171 (5)

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

(MgBr2_6H2O) Magnesium dibromide hexahydrate

Crystal data

MgBr2·6H2O	F(000) = 284.0
Mr = 292.21	Dx = 2.110 Mg m^−3
Monoclinic, C2/m	Mo Kα radiation, λ = 0.71073 Å
a = 10.2299 (16) Å	Cell parameters from 4549 reflections
b = 7.2642 (9) Å	θ = 2.8–29.6°
c = 6.1964 (9) Å	µ = 8.86 mm^−1
β = 93.025 (12)°	T = 150 K
V = 459.83 (11) Å^3	, colourless
Z = 2	0.6 × 0.47 × 0.36 mm

Data collection

Stoe IPDS 2 diffractometer	557 independent reflections
Radiation source: fine-focus sealed tube	550 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.084
Detector resolution: 6.67 pixels mm^-1	θmax = 27.5°, θmin = 3.3°
rotation method scans	h = −13→14
Absorption correction: integration (Coppens, 1970)	k = −10→10
Tmin = 0.010, Tmax = 0.043	l = −8→8
575 measured reflections

Refinement

Refinement on F^2	Hydrogen site location: difference Fourier map
Least-squares matrix: full	All H-atom parameters refined
R[F^2 > 2σ(F^2)] = 0.038	w = 1/[σ^2(Fo^2) + (0.1P)^2 + 0.1814P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.119	(Δ/σ)max < 0.001
S = 1.16	Δρmax = 1.38 e Å^−3
667 reflections	Δρmin = −1.10 e Å^−3
41 parameters	Extinction correction: SHELXL2012 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
6 restraints	Extinction coefficient: 0.075 (13)

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
Br1	0.18235 (3)	0.0000	0.38865 (4)	0.0162 (3)
Mg1	1.0000	0.5000	1.0000	0.0136 (4)
O1	0.8063 (3)	0.5000	0.8951 (5)	0.0280 (7)
O2	1.0432 (3)	0.2975 (4)	0.7832 (4)	0.0327 (7)
H1A	0.771 (10)	0.5000	0.769 (7)	0.09 (4)*
H2A	0.990 (4)	0.214 (5)	0.744 (8)	0.030 (11)*
H2B	1.096 (4)	0.306 (7)	0.684 (6)	0.040 (13)*
H1B	0.751 (8)	0.5000	0.992 (12)	0.05 (2)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.0118 (4)	0.0195 (4)	0.0173 (4)	0.000	0.00174 (19)	0.000
Mg1	0.0097 (9)	0.0177 (9)	0.0134 (8)	0.000	0.0011 (6)	0.000
O1	0.0104 (14)	0.057 (2)	0.0170 (14)	0.000	0.0004 (10)	0.000
O2	0.0272 (13)	0.0331 (14)	0.0398 (12)	−0.0149 (10)	0.0189 (10)	−0.0221 (11)

Geometric parameters (Å, º)

Mg1—O1	2.050 (3)	Mg1—O2^ii	2.055 (2)
Mg1—O1^i	2.050 (3)	Mg1—O2^iii	2.055 (2)
Mg1—O2^i	2.055 (2)	Mg1—O2	2.055 (2)
O1—Mg1—O1^i	180.0	O2^i—Mg1—O2^iii	91.38 (16)
O1—Mg1—O2^i	88.24 (10)	O2^ii—Mg1—O2^iii	180.0
O1^i—Mg1—O2^i	91.76 (10)	O1—Mg1—O2	91.76 (10)
O1—Mg1—O2^ii	91.76 (10)	O1^i—Mg1—O2	88.24 (10)
O1^i—Mg1—O2^ii	88.24 (10)	O2^i—Mg1—O2	180.0
O2^i—Mg1—O2^ii	88.62 (16)	O2^ii—Mg1—O2	91.38 (16)
O1—Mg1—O2^iii	88.24 (10)	O2^iii—Mg1—O2	88.62 (16)
O1^i—Mg1—O2^iii	91.76 (10)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1A···Br1^iv	0.84 (1)	2.48 (1)	3.318 (3)	176 (11)
O2—H2A···Br1^v	0.84 (1)	2.46 (1)	3.295 (2)	173 (5)
O2—H2B···Br1^vi	0.84 (1)	3.04 (4)	3.609 (2)	127 (4)
O2—H2B···Br1^vii	0.84 (1)	2.73 (3)	3.387 (2)	137 (4)
O1—H1B···Br1^viii	0.84 (1)	2.59 (5)	3.369 (3)	154 (9)

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