Strontium D-glutamate hexa­hydrate and strontium di(hydrogen L-glutamate) penta­hydrate

[Sr(C₅H₇NO₄)]·6H₂O, (I), and [Sr(C₅H₈NO₄)₂]·5H₂O, (II), both crystallize with similar strontium-glutamate-water layers. In (I), the neutral layers are connected through hydrogen bonds by water mol­ecules, while in (II), the positively charged layers are connected through hydrogen bonds and electrostatic inter­actions by inter­leaving layers of hydrogen glutamate anions and water mol­ecules.

S1. Comment

In recent years, it has been found that Sr has a significant influence on the development and growth of bone, and the effect of dose on bone structure has been investigated in great detail (Schrooten et al., 2003). These investigations have led to a growing interest in strontium(II) salts, and in synthetic methods that may provide products of high yield and purity. The present paper presents the structural investigations of two new strontium(II) salts, viz. the title compounds Sr(C₅H₇NO₄)·6H₂O, (I), and Sr(C₅H₈NO₄)₂·5H₂O, (II).

The crystal structure of (I) is in full agreement with the structure of strontium(II) L-glutamate hexahydrate (Schmidbaur et al., 1989). Compounds (I) and (II) are built from the same type of layers; the strontium ions are nine-coordinated to three water and six carboxylic O atoms to form distorted mono-capped quadratic antiprisms. The α-carboxylates bridge two adjacent Sr-coordination complexes, with the polyhedra sharing edges to form zigzagging polyhedral chains in the a and b directions in (I) and (II), respectively. The chelating α- and γ-carboxylates are connected to different Sr polyedral chains, thus cross-linking them to form layers in the ab planes (cf. Figs. 3 and 4). Despite the difference in charge due to the protonated glutamate in (II), these layers are very similar as reflected in the unit-cell dimensions [a(I) = 7.3244 (4) Å, b_(II) = 7.2450 (4) Å and a_(II) = 8.7087 (5) Å, b_(I) = 8.7417 (5) Å]. The difference between the structures lies in the stacking of the layers. The neutral Sr–glutamate–water layers in (I) are linked by hydrogen bonding to the three water molecules not involved in Sr coordination (Fig. 3 and Table 3). In (II), the positively charged Sr–hydrogen glutamate–water layers are interleaved by negatively charged layers of the hydrogen glutamate and the two water molecules not involved in Sr coordination. These layers are then linked by hydrogen-bonding and electrostatic interactions (Fig. 4 and Table 6). The conformations of the three glutamate ions are very similar, as seen from their torsion angles (Table 5). The difference between the Sr-coordinated glutamates (I) and (II:1) is due to the difference in absolute configuration, and the difference between the two L-glutamates (II:1) and (II:2) is essentially in the rotation of the carboxylic groups in order to optimize hydrogen bonding.

A zigzagging chain of Sr polyhedra is a common structural element in Sr^II dicarboxylic acid structures, seen in, for example, Sr^II maleate (Diaz de Delgade et al., 1995), Sr^II oxalate (Sterling, 1965), Sr^II phthalate (Bats et al., 1978) and Sr^II aspartate (Derrisen et al., 1968). By contrast, the two forms of Sr^II tartrate, the tri- (Ambady, 1968) and tetrahydrates (Starynowicz & Meyer, 2000), form isolated Sr^II polyhedra. The cross-linking of the Sr chains into layers as in the glutamates is also seen in Sr^II aspartate and Sr^II maleate. In Sr^II oxalate, on the other hand, the oxalates form three-dimensional connections through strontium coordination, and in Sr^II phthalate the Sr polyhedra chains are connected through hydrogen bonds into layers and by van der Waals bonds between layers. Obviously, the layer formations as in the glutamate, aspartate and maleate salts require a certain carbon chain length to allow for the layer formation.

S2. Experimental

The synthesis of strontium(II) compounds was performed according to a novel method of high-temperature synthesis that readily provided high-quality crystals that were well suited for analysis by single-crystal X-ray analysis (Price et al., 1999). Briefly, the crystal were obtained by synthesis in an autoclave at temperatures between 393–413 K over a period of 15 min. The crystals of strontium(II) D-glutamate were obtained by reacting strontium(II) hydroxide octahydrate with D-glutamic acid in a molar ratio of 1:2, while crystals of strontium(II) di(hydrogen L-glutamate) were obtained by reacting equimolar amounts of strontium(II) chloride hexahydrate with disodium L-glutamate (Price et al. 1999).

S3. Refinement

All H-atom parameters were initially refined freely. In the final cycles, H atoms of CH₂ and CH groups were placed in calculated positions, with C—H = 0.97 and 0.98 Å, respectively, and refined as riding atoms. For the water molecules, the O—H distances were restrained to 0.84 (2) Å, and the N—H distances were restrained to 0.89 (2) Å. The displacement parameters were set to 1.2 (CH and NH) or 1.5 (OH) times U_eq of the corresponding C, N or O atoms.

Computing details

For both compounds, data collection: SMART (Bruker, 1999); cell refinement: SAINT-Plus (Bruker, 1999); data reduction: SAINT-Plus and SADABS (Sheldrick, 2002); program(s) used to solve structure: SHELXTL (Sheldrick, 2000); program(s) used to refine structure: SHELXTL; molecular graphics: ORTEP-3 (Farrugia, 1997) and ATOMS (Dowty, 2000); software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. The asymmetric unit of (I), showing 75% probability displacement ellipsoids and the atomic numbering. H atoms are represented by circles of arbitrary size. O1*, O2*, O3* and O4* are added to complete the Sr coordination sphere. [Atoms labelled with an asterisk (*) are at the symmetry positions indicated in Table 1.]
	Fig. 2. The asymmetric unit of (II), showing 75% probability displacement ellipsoids and the atomic numbering. H atoms are represented by circles of arbitrary size.
	Fig. 3. The crystal packing of (I), viewed down the a axis. The Sr nine-coordination is shown as polyhedra. H-atom positions have been omitted for clarity.
	Fig. 4. The crystal packing of (II), viewed along the b axis. The Sr nine-coordination is shown as polyhedra. H-atom positions have been omitted for clarity.

(I) Strontium D-glutamate hexahydrate

Crystal data

Sr(C5H7NO4)·6H2O	F(000) = 696
Mr = 340.83	Dx = 1.760 Mg m^−3
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 3509 reflections
a = 7.3244 (4) Å	θ = 2.5–28.0°
b = 8.7417 (5) Å	µ = 4.23 mm^−1
c = 20.0952 (12) Å	T = 120 K
V = 1286.65 (13) Å^3	Plate, colourless
Z = 4	0.30 × 0.10 × 0.03 mm

Data collection

Bruker SMART APEX diffractometer	3098 independent reflections
Radiation source: fine-focus sealed tube	2812 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.039
ω scans, frame data integration	θmax = 28.0°, θmin = 2.0°
Absorption correction: multi-scan (SADABS; Sheldrick, 2002)	h = −9→9
Tmin = 0.64, Tmax = 0.88	k = −11→11
9203 measured reflections	l = −26→25

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.028	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.051	w = 1/[σ^2(Fo^2)]
S = 0.89	(Δ/σ)max = 0.002
3098 reflections	Δρmax = 0.83 e Å^−3
196 parameters	Δρmin = −0.44 e Å^−3
14 restraints	Absolute structure: Flack (1983),1293 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.003 (6)

Special details

Experimental. Oxford Cryosystem liquid nitrogen cryostream cooler

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 > 2σ(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
Sr1	0.59172 (4)	0.29952 (3)	0.942985 (12)	0.00864 (6)
O1	0.7410 (3)	0.1447 (2)	1.04626 (9)	0.0116 (4)
O2	0.4388 (3)	0.1327 (2)	1.03924 (9)	0.0123 (5)
O3	0.5981 (3)	−0.5032 (2)	1.04399 (8)	0.0130 (4)
O4	0.5819 (3)	−0.39746 (19)	0.94409 (9)	0.0129 (4)
O5	0.6344 (3)	0.3971 (3)	0.82041 (10)	0.0179 (5)
O6	0.3875 (3)	0.0953 (2)	0.87571 (10)	0.0145 (5)
O7	0.7930 (3)	0.0837 (2)	0.88795 (10)	0.0143 (5)
O8	0.5885 (4)	−0.1647 (2)	0.85517 (9)	0.0164 (5)
O9	0.8906 (3)	0.2018 (3)	0.76530 (9)	0.0193 (5)
O10	0.2660 (3)	0.1808 (3)	0.74915 (10)	0.0217 (5)
N1	0.7484 (3)	−0.0371 (3)	1.16126 (12)	0.0145 (5)
C1	0.5884 (5)	0.0934 (3)	1.06514 (12)	0.0100 (5)
C2	0.5814 (4)	−0.0261 (3)	1.12097 (12)	0.0117 (6)
C3	0.5328 (4)	−0.1824 (3)	1.09245 (12)	0.0111 (6)
C4	0.6588 (4)	−0.2339 (3)	1.03601 (14)	0.0175 (7)
C5	0.6087 (4)	−0.3870 (3)	1.00622 (13)	0.0119 (6)
H1	0.4821	0.0035	1.1510	0.014*
H2	0.779 (4)	0.052 (2)	1.1790 (13)	0.017*
H3	0.840 (3)	−0.069 (3)	1.1351 (12)	0.017*
H4	0.4083	−0.1793	1.0760	0.013*
H5	0.5377	−0.2576	1.1279	0.013*
H6	0.6563	−0.1572	1.0011	0.021*
H7	0.7828	−0.2394	1.0528	0.021*
H8	0.706 (4)	0.346 (3)	0.7962 (14)	0.027*
H9	0.654 (5)	0.482 (2)	0.8057 (16)	0.027*
H10	0.422 (5)	0.011 (2)	0.8672 (14)	0.022*
H11	0.308 (4)	0.079 (4)	0.9006 (13)	0.022*
H12	0.883 (3)	0.057 (3)	0.9087 (13)	0.021*
H13	0.742 (4)	0.001 (3)	0.8795 (15)	0.021*
H14	0.625 (4)	−0.203 (4)	0.8225 (11)	0.025*
H15	0.581 (5)	−0.233 (3)	0.8820 (12)	0.025*
H16	0.869 (5)	0.151 (3)	0.7971 (12)	0.029*
H17	0.845 (4)	0.152 (3)	0.7356 (12)	0.029*
H18	0.157 (3)	0.196 (5)	0.7539 (15)	0.033*
H19	0.301 (5)	0.155 (4)	0.7851 (11)	0.033*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Sr1	0.00822 (11)	0.00753 (10)	0.01018 (10)	0.00026 (13)	0.00026 (13)	−0.00005 (11)
O1	0.0101 (11)	0.0116 (9)	0.0131 (10)	−0.0011 (8)	0.0002 (9)	0.0027 (8)
O2	0.0088 (12)	0.0130 (10)	0.0150 (10)	0.0016 (8)	0.0001 (9)	0.0025 (8)
O3	0.0127 (10)	0.0107 (9)	0.0154 (10)	−0.0004 (10)	0.0015 (10)	0.0009 (8)
O4	0.0138 (9)	0.0113 (9)	0.0136 (8)	0.0000 (9)	−0.0005 (12)	0.0002 (8)
O5	0.0224 (14)	0.0150 (11)	0.0163 (11)	0.0020 (10)	0.0058 (9)	0.0011 (9)
O6	0.0140 (13)	0.0120 (10)	0.0176 (10)	0.0016 (10)	0.0035 (10)	−0.0009 (9)
O7	0.0121 (12)	0.0122 (11)	0.0186 (11)	0.0009 (9)	−0.0041 (9)	−0.0014 (10)
O8	0.0228 (12)	0.0104 (11)	0.0161 (10)	−0.0004 (11)	0.0039 (13)	0.0005 (8)
O9	0.0231 (12)	0.0207 (11)	0.0140 (10)	−0.0040 (14)	0.0015 (11)	−0.0023 (11)
O10	0.0212 (13)	0.0268 (14)	0.0172 (11)	−0.0016 (12)	−0.0003 (10)	0.0041 (11)
N1	0.0139 (14)	0.0149 (13)	0.0145 (13)	−0.0005 (11)	−0.0026 (11)	−0.0020 (11)
C1	0.0132 (13)	0.0058 (11)	0.0110 (13)	−0.0009 (13)	0.0020 (15)	−0.0043 (11)
C2	0.0134 (14)	0.0124 (13)	0.0092 (12)	0.0012 (14)	−0.0007 (14)	−0.0001 (10)
C3	0.0132 (14)	0.0093 (15)	0.0109 (13)	−0.0017 (12)	−0.0008 (11)	0.0023 (12)
C4	0.0209 (17)	0.0127 (16)	0.0188 (15)	−0.0052 (12)	0.0028 (13)	−0.0020 (12)
C5	0.0066 (15)	0.0120 (14)	0.0170 (14)	0.0002 (13)	0.0053 (13)	−0.0001 (11)

Geometric parameters (Å, º)

Sr1—O1^i	2.623 (2)	C3—H5	0.9700
Sr1—O5	2.625 (2)	C4—C5	1.512 (4)
Sr1—O2^ii	2.635 (2)	C4—H6	0.9700
Sr1—O7	2.637 (2)	C4—H7	0.9700
Sr1—O4^iii	2.6501 (17)	C5—O4	1.267 (3)
Sr1—O3^iii	2.6639 (17)	C5—O3	1.270 (3)
Sr1—O2	2.6687 (18)	O5—H8	0.841 (18)
Sr1—O6	2.693 (2)	O5—H9	0.811 (18)
Sr1—O1	2.7083 (19)	O6—H10	0.802 (17)
O1—C1	1.263 (3)	O6—H11	0.778 (17)
O2—C1	1.261 (4)	O7—H12	0.812 (18)
C1—C2	1.534 (4)	O7—H13	0.829 (18)
C2—N1	1.470 (4)	O8—H14	0.783 (17)
C2—C3	1.524 (4)	O8—H15	0.803 (17)
C2—H1	0.9800	O9—H16	0.797 (17)
N1—H2	0.883 (17)	O9—H17	0.810 (17)
N1—H3	0.897 (17)	O10—H18	0.814 (17)
C3—C4	1.530 (4)	O10—H19	0.799 (18)
C3—H4	0.9700
O1^i—Sr1—O5	97.67 (6)	O2—Sr1—O1	48.78 (5)
O1^i—Sr1—O2^ii	153.09 (6)	O6—Sr1—O1	106.12 (6)
O5—Sr1—O2^ii	86.51 (6)	O2—C1—O1	123.2 (2)
O1^i—Sr1—O7	135.63 (7)	O2—C1—C2	117.3 (3)
O5—Sr1—O7	76.85 (7)	O1—C1—C2	119.4 (3)
O2^ii—Sr1—O7	71.24 (6)	N1—C2—C3	110.1 (2)
O1^i—Sr1—O4^iii	77.69 (6)	N1—C2—C1	114.8 (3)
O5—Sr1—O4^iii	71.71 (6)	C3—C2—C1	110.1 (2)
O2^ii—Sr1—O4^iii	78.48 (6)	N1—C2—H1	107.2
O7—Sr1—O4^iii	137.20 (7)	C3—C2—H1	107.2
O1^i—Sr1—O3^iii	80.45 (7)	C1—C2—H1	107.2
O5—Sr1—O3^iii	120.15 (6)	C2—N1—H2	112 (2)
O2^ii—Sr1—O3^iii	74.58 (6)	C2—N1—H3	108.7 (19)
O7—Sr1—O3^iii	140.60 (7)	H2—N1—H3	109 (3)
O4^iii—Sr1—O3^iii	49.23 (5)	C2—C3—C4	113.7 (2)
O1^i—Sr1—O2	68.34 (6)	C2—C3—H4	108.8
O5—Sr1—O2	155.17 (6)	C4—C3—H4	108.8
O2^ii—Sr1—O2	115.44 (4)	C2—C3—H5	108.8
O7—Sr1—O2	98.49 (6)	C4—C3—H5	108.8
O4^iii—Sr1—O2	121.92 (6)	H4—C3—H5	107.7
O3^iii—Sr1—O2	78.98 (6)	C5—C4—C3	114.1 (3)
O1^i—Sr1—O6	67.72 (7)	C5—C4—H6	108.7
O5—Sr1—O6	79.08 (7)	C3—C4—H6	108.7
O2^ii—Sr1—O6	138.86 (7)	C5—C4—H7	108.7
O7—Sr1—O6	68.02 (6)	C3—C4—H7	108.7
O4^iii—Sr1—O6	130.68 (7)	H6—C4—H7	107.6
O3^iii—Sr1—O6	145.23 (7)	O4—C5—O3	121.4 (2)
O2—Sr1—O6	76.62 (6)	O4—C5—C4	119.5 (2)
O1^i—Sr1—O1	115.16 (5)	O3—C5—C4	119.1 (2)
O5—Sr1—O1	146.43 (6)	H8—O5—H9	99 (3)
O2^ii—Sr1—O1	67.59 (5)	H10—O6—H11	102 (3)
O7—Sr1—O1	74.82 (6)	H12—O7—H13	103 (3)
O7—Sr1—O1	74.82 (6)	H14—O8—H15	106 (3)
O4^iii—Sr1—O1	120.27 (6)	H16—O9—H17	102 (3)
O3^iii—Sr1—O1	74.49 (6)	H18—O10—H19	105 (3)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H2···O5^ii	0.88 (2)	2.64 (3)	3.102 (3)	114 (2)
N1—H3···O4^iv	0.90 (2)	2.40 (2)	3.283 (3)	169 (3)
O5—H8···O9	0.84 (2)	1.95 (2)	2.768 (3)	163 (3)
O5—H9···O10^v	0.81 (2)	2.14 (2)	2.939 (3)	168 (3)
O6—H10···O8	0.80 (2)	1.97 (2)	2.740 (3)	160 (4)
O6—H11···O3^vi	0.78 (2)	2.01 (2)	2.783 (3)	170 (4)
O7—H12···O3^iv	0.81 (2)	1.90 (2)	2.713 (3)	177 (3)
O7—H13···O8	0.83 (2)	1.90 (2)	2.719 (3)	170 (3)
O8—H14···O10^vii	0.78 (2)	1.94 (2)	2.711 (3)	171 (3)
O8—H15···O4	0.80 (2)	1.91 (2)	2.708 (3)	176 (4)
O9—H16···O7	0.80 (2)	2.00 (2)	2.766 (3)	163 (3)
O9—H17···N1^viii	0.81 (2)	1.93 (2)	2.735 (3)	176 (3)
O10—H18···O9^ix	0.81 (2)	1.97 (2)	2.775 (3)	172 (4)
O10—H19···O6	0.80 (2)	2.00 (2)	2.796 (3)	178 (4)

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

(II) Strontium di(hydrogen-L-glutamate) pentahydrate

Crystal data

Sr(C5H8NO4)2·5H2O	F(000) = 484
Mr = 469.95	Dx = 1.725 Mg m^−3
Monoclinic, P21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2yb	Cell parameters from 4782 reflections
a = 8.7097 (5) Å	θ = 2.4–30.0°
b = 7.2450 (4) Å	µ = 3.05 mm^−1
c = 14.5854 (8) Å	T = 117 K
β = 100.521 (1)°	Plate, colourless
V = 904.89 (9) Å^3	0.46 × 0.15 × 0.04 mm
Z = 2

Data collection

Bruker SMART APEX diffractometer	4586 independent reflections
Radiation source: fine-focus sealed tube	4179 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.021
ω scans, frame data integration	θmax = 30.0°, θmin = 2.4°
Absorption correction: multi-scan (SADABS; Sheldrick, 2002)	h = −11→12
Tmin = 0.633, Tmax = 0.883	k = −9→10
7102 measured reflections	l = −20→18

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.026	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.054	w = 1/[σ^2(Fo^2)]
S = 0.79	(Δ/σ)max = 0.001
4586 reflections	Δρmax = 0.74 e Å^−3
283 parameters	Δρmin = −0.33 e Å^−3
17 restraints	Absolute structure: Flack (1983), 1850 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.010 (5)

Special details

Experimental. Oxford Cryosystem liquid nitrogen cryostream cooler

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 > 2σ(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
Sr1	0.932020 (19)	0.16270 (5)	0.417546 (11)	0.00873 (5)
O5	1.1124 (3)	0.3690 (3)	0.33635 (17)	0.0187 (5)
O6	1.1111 (3)	−0.0453 (3)	0.33451 (16)	0.0146 (5)
O7	0.78680 (18)	0.1907 (3)	0.24323 (11)	0.0143 (4)
O8	0.35864 (19)	0.1455 (4)	0.28977 (12)	0.0218 (4)
O9	1.0634 (2)	0.2480 (3)	0.80663 (13)	0.0206 (4)
O11	0.1279 (2)	0.3170 (3)	0.55534 (14)	0.0120 (4)
O12	0.1458 (2)	0.0119 (3)	0.56695 (14)	0.0133 (4)
O13	0.77427 (14)	0.1673 (4)	0.55646 (9)	0.0122 (3)
O14	0.63131 (15)	0.1599 (4)	0.41515 (9)	0.0133 (3)
O21	0.8866 (2)	−0.0449 (3)	0.84618 (12)	0.0233 (4)
O22	1.01166 (17)	−0.3115 (3)	0.88272 (10)	0.0172 (4)
O23	0.57147 (17)	−0.8159 (3)	0.87965 (10)	0.0153 (4)
O24	0.42711 (19)	−0.5604 (2)	0.86319 (12)	0.0145 (3)
N11	0.3188 (2)	0.0846 (3)	0.75108 (14)	0.0120 (4)
N21	0.7758 (2)	−0.0354 (3)	1.00541 (14)	0.0123 (4)
C11	0.19157 (19)	0.1710 (5)	0.59123 (12)	0.0095 (3)
C12	0.3377 (2)	0.1920 (4)	0.66696 (14)	0.0101 (5)
C13	0.4835 (2)	0.1268 (3)	0.63076 (15)	0.0120 (5)
C14	0.4996 (3)	0.2275 (3)	0.54154 (16)	0.0151 (5)
C15	0.6434 (2)	0.1803 (5)	0.50156 (14)	0.0110 (4)
C21	0.9153 (3)	−0.1877 (3)	0.89410 (16)	0.0118 (4)
C22	0.8221 (3)	−0.2185 (3)	0.97207 (15)	0.0109 (4)
C23	0.6730 (2)	−0.3311 (6)	0.93811 (13)	0.0140 (4)
C24	0.7032 (3)	−0.5316 (3)	0.91896 (17)	0.0147 (5)
C25	0.5559 (3)	−0.6423 (3)	0.88471 (15)	0.0113 (4)
H1	1.149 (4)	0.454 (4)	0.368 (3)	0.028*
H2	1.090 (4)	0.407 (4)	0.2820 (14)	0.028*
H3	1.148 (4)	−0.126 (4)	0.371 (2)	0.022*
H4	1.183 (3)	0.002 (4)	0.3135 (19)	0.022*
H5	0.850 (3)	0.202 (4)	0.2093 (15)	0.021*
H6	0.713 (2)	0.132 (4)	0.2185 (16)	0.021*
H7	0.440 (2)	0.148 (6)	0.3264 (16)	0.033*
H8	0.308 (3)	0.240 (3)	0.296 (2)	0.033*
H9	1.014 (3)	0.157 (4)	0.8198 (19)	0.031*
H10	1.009 (3)	0.323 (4)	0.7754 (19)	0.031*
H11	0.3506	0.3227	0.6840	0.012*
H12	0.232 (2)	0.126 (4)	0.7688 (16)	0.014*
H13	0.309 (3)	−0.034 (2)	0.7405 (18)	0.014*
H14	0.401 (2)	0.090 (4)	0.7961 (14)	0.014*
H15	0.5755	0.1492	0.6779	0.014*
H16	0.4762	−0.0050	0.6189	0.014*
H17	0.4080	0.2008	0.4947	0.018*
H18	0.5001	0.3592	0.5536	0.018*
H21	0.8875	−0.2837	1.0238	0.013*
H22	0.715 (3)	−0.053 (4)	1.0498 (16)	0.015*
H23	0.725 (3)	0.026 (4)	0.9574 (14)	0.015*
H24	0.855 (2)	0.027 (3)	1.0391 (16)	0.015*
H25	0.6070	−0.3246	0.9849	0.017*
H26	0.6163	−0.2753	0.8815	0.017*
H27	0.7592	−0.5877	0.9757	0.018*
H28	0.7698	−0.5381	0.8726	0.018*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Sr1	0.00914 (8)	0.00785 (8)	0.00920 (8)	−0.00016 (12)	0.00164 (5)	0.00005 (13)
O5	0.0283 (14)	0.0137 (12)	0.0142 (12)	−0.0054 (10)	0.0043 (11)	−0.0024 (9)
O6	0.0144 (11)	0.0138 (11)	0.0164 (12)	0.0028 (9)	0.0051 (9)	0.0029 (9)
O7	0.0137 (7)	0.0177 (13)	0.0117 (7)	−0.0038 (7)	0.0031 (5)	−0.0022 (8)
O8	0.0171 (8)	0.0266 (13)	0.0206 (8)	0.0020 (10)	0.0000 (6)	−0.0007 (10)
O9	0.0176 (10)	0.0251 (10)	0.0186 (10)	0.0022 (7)	0.0022 (7)	0.0037 (8)
O11	0.0139 (10)	0.0080 (10)	0.0138 (10)	0.0023 (7)	0.0017 (8)	0.0002 (8)
O12	0.0132 (10)	0.0105 (10)	0.0149 (10)	−0.0016 (7)	−0.0007 (7)	−0.0023 (8)
O13	0.0117 (6)	0.0117 (6)	0.0132 (6)	0.0024 (11)	0.0020 (5)	0.0011 (11)
O14	0.0124 (6)	0.0149 (7)	0.0127 (6)	−0.0011 (10)	0.0031 (5)	−0.0028 (11)
O21	0.0362 (11)	0.0176 (9)	0.0199 (10)	0.0097 (8)	0.0155 (8)	0.0085 (8)
O22	0.0157 (7)	0.0210 (12)	0.0160 (7)	0.0070 (8)	0.0062 (6)	0.0041 (8)
O23	0.0154 (7)	0.0099 (10)	0.0191 (7)	−0.0004 (8)	−0.0004 (5)	−0.0010 (9)
O24	0.0123 (8)	0.0155 (9)	0.0161 (9)	0.0008 (6)	0.0038 (7)	−0.0001 (7)
N11	0.0129 (10)	0.0119 (9)	0.0106 (9)	−0.0009 (8)	0.0007 (7)	0.0001 (8)
N21	0.0128 (10)	0.0127 (10)	0.0121 (10)	−0.0027 (8)	0.0037 (8)	−0.0031 (8)
C11	0.0082 (8)	0.0121 (9)	0.0089 (8)	−0.0026 (14)	0.0040 (6)	−0.0049 (14)
C12	0.0096 (9)	0.0098 (15)	0.0104 (9)	−0.0004 (8)	0.0008 (7)	0.0021 (9)
C13	0.0101 (10)	0.0119 (16)	0.0142 (10)	0.0017 (7)	0.0027 (8)	0.0001 (8)
C14	0.0124 (11)	0.0198 (12)	0.0139 (11)	0.0050 (8)	0.0042 (9)	0.0035 (9)
C15	0.0127 (9)	0.0041 (11)	0.0170 (9)	−0.0009 (11)	0.0047 (7)	0.0017 (12)
C21	0.0104 (11)	0.0135 (12)	0.0109 (11)	−0.0019 (8)	0.0007 (8)	−0.0017 (9)
C22	0.0130 (11)	0.0106 (11)	0.0095 (10)	0.0007 (8)	0.0031 (8)	0.0005 (8)
C23	0.0126 (8)	0.0139 (9)	0.0161 (9)	−0.0011 (15)	0.0040 (7)	−0.0018 (16)
C24	0.0123 (11)	0.0134 (12)	0.0181 (12)	0.0004 (9)	0.0020 (9)	−0.0004 (10)
C25	0.0140 (11)	0.0141 (12)	0.0064 (10)	−0.0014 (8)	0.0035 (8)	−0.0001 (8)

Geometric parameters (Å, º)

Sr1—O11^i	2.603 (2)	O22—C21	1.260 (3)
Sr1—O5	2.605 (2)	C21—C22	1.530 (3)
Sr1—O14	2.6130 (13)	C22—N21	1.494 (3)
Sr1—O6	2.619 (2)	C22—C23	1.537 (3)
Sr1—O7	2.6326 (16)	C22—H21	0.9800
Sr1—O11^ii	2.636 (2)	N21—H22	0.918 (16)
Sr1—O12^iii	2.639 (2)	N21—H23	0.879 (17)
Sr1—O13	2.6478 (12)	N21—H24	0.894 (17)
Sr1—O12^ii	2.816 (2)	C23—C24	1.511 (5)
O11—C11	1.263 (4)	C23—H25	0.9700
O12—C11	1.250 (4)	C23—H26	0.9700
C11—C12	1.533 (3)	C24—C25	1.519 (3)
C12—N11	1.487 (3)	C24—H27	0.9700
C12—C13	1.536 (3)	C24—H28	0.9700
C12—H11	0.9800	C25—O24	1.257 (3)
N11—H12	0.894 (16)	C25—O23	1.268 (3)
N11—H13	0.874 (17)	O5—H1	0.798 (18)
N11—H14	0.879 (17)	O5—H2	0.828 (17)
C13—C14	1.520 (3)	O6—H3	0.815 (18)
C13—H15	0.9700	O6—H4	0.825 (17)
C13—H16	0.9700	O7—H5	0.811 (16)
C14—C15	1.514 (3)	O7—H6	0.803 (17)
C14—H17	0.9700	O8—H7	0.808 (17)
C14—H18	0.9700	O8—H8	0.832 (18)
C15—O14	1.254 (2)	O9—H9	0.829 (19)
C15—O13	1.271 (2)	O9—H10	0.805 (18)
O21—C21	1.248 (3)
O11^i—Sr1—O5	140.85 (7)	C14—C13—C12	110.96 (18)
O11^i—Sr1—O14	76.48 (8)	C14—C13—H15	109.4
O5—Sr1—O14	133.21 (8)	C12—C13—H15	109.4
O11^i—Sr1—O6	70.71 (7)	C14—C13—H16	109.4
O5—Sr1—O6	70.15 (5)	C12—C13—H16	109.4
O14—Sr1—O6	132.02 (7)	H15—C13—H16	108.0
O11^i—Sr1—O7	98.43 (6)	C15—C14—C13	115.7 (2)
O5—Sr1—O7	74.93 (7)	C15—C14—H17	108.4
O14—Sr1—O7	71.58 (4)	C13—C14—H17	108.4
O6—Sr1—O7	79.60 (6)	C15—C14—H18	108.4
O11^i—Sr1—O11^ii	114.33 (5)	C13—C14—H18	108.4
O5—Sr1—O11^ii	75.11 (7)	H17—C14—H18	107.4
O14—Sr1—O11^ii	121.41 (6)	O14—C15—O13	121.66 (17)
O6—Sr1—O11^ii	103.85 (7)	O14—C15—C14	119.36 (18)
O7—Sr1—O11^ii	146.47 (6)	O13—C15—C14	118.95 (19)
O11^i—Sr1—O12^iii	147.92 (4)	O21—C21—O22	125.9 (2)
O5—Sr1—O12^iii	71.01 (7)	O21—C21—C22	117.3 (2)
O14—Sr1—O12^iii	74.70 (8)	O22—C21—C22	116.8 (2)
O6—Sr1—O12^iii	140.80 (7)	N21—C22—C21	108.90 (19)
O7—Sr1—O12^iii	85.60 (6)	N21—C22—C23	108.3 (2)
O11^ii—Sr1—O12^iii	70.66 (6)	C21—C22—C23	111.70 (18)
O11^i—Sr1—O13	75.48 (8)	N21—C22—H21	109.3
O5—Sr1—O13	141.36 (8)	C21—C22—H21	109.3
O14—Sr1—O13	49.57 (4)	C23—C22—H21	109.3
O6—Sr1—O13	142.85 (8)	C22—N21—H22	109.4 (18)
O7—Sr1—O13	120.87 (4)	C22—N21—H23	108.6 (18)
O11^ii—Sr1—O13	76.43 (6)	H22—N21—H23	111 (2)
O12^iii—Sr1—O13	75.24 (8)	C22—N21—H24	113.6 (17)
O11^i—Sr1—O12^ii	68.38 (6)	H22—N21—H24	100 (2)
O5—Sr1—O12^ii	101.90 (7)	H23—N21—H24	114 (3)
O14—Sr1—O12^ii	121.79 (6)	C24—C23—C22	113.87 (19)
O6—Sr1—O12^ii	76.65 (7)	C24—C23—H25	108.8
O7—Sr1—O12^ii	155.58 (6)	C22—C23—H25	108.8
O11^ii—Sr1—O12^ii	47.93 (4)	C24—C23—H26	108.8
O12^iii—Sr1—O12^ii	116.72 (5)	C22—C23—H26	108.8
O13—Sr1—O12^ii	76.99 (6)	H25—C23—H26	107.7
O12—C11—O11	124.21 (17)	C23—C24—C25	113.81 (19)
O12—C11—C12	118.4 (3)	C23—C24—H27	108.8
O11—C11—C12	117.3 (3)	C25—C24—H27	108.8
N11—C12—C11	109.90 (19)	C23—C24—H28	108.8
N11—C12—C13	110.19 (18)	C25—C24—H28	108.8
C11—C12—C13	110.58 (17)	H27—C24—H28	107.7
N11—C12—H11	108.7	O24—C25—O23	123.6 (2)
C11—C12—H11	108.7	O24—C25—C24	119.6 (2)
C13—C12—H11	108.7	O23—C25—C24	116.7 (2)
C12—N11—H12	106.9 (16)	H1—O5—H2	107 (4)
C12—N11—H13	113.0 (17)	H3—O6—H4	108 (3)
H12—N11—H13	109 (2)	H5—O7—H6	111 (3)
C12—N11—H14	113.5 (17)	H7—O8—H8	109 (4)
H12—N11—H14	113 (2)	H9—O9—H10	113 (3)
H13—N11—H14	102 (2)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N11—H12···O9^iv	0.89 (2)	1.88 (2)	2.769 (3)	171 (3)
N11—H13···O7^i	0.87 (2)	2.19 (2)	3.004 (3)	155 (2)
N11—H14···O23^v	0.88 (2)	1.87 (2)	2.715 (3)	161 (2)
N21—H22···O24^vi	0.92 (2)	1.93 (2)	2.840 (3)	173 (3)
N21—H23···O23^v	0.88 (2)	1.96 (2)	2.805 (3)	162 (2)
N21—H24···O22^vii	0.89 (2)	1.88 (2)	2.760 (3)	168 (2)
O5—H1···O13^viii	0.80 (2)	1.95 (2)	2.743 (3)	177 (4)
O5—H2···O21^viii	0.83 (2)	1.95 (2)	2.736 (3)	158 (3)
O6—H3···O13^ix	0.82 (2)	1.89 (2)	2.698 (3)	173 (4)
O6—H4···O8^ii	0.83 (2)	1.93 (2)	2.738 (3)	167 (3)
O7—H5···O22^viii	0.81 (2)	1.96 (2)	2.763 (2)	170 (3)
O7—H6···O24^iii	0.80 (2)	2.08 (2)	2.852 (2)	163 (3)
O8—H7···O14	0.81 (2)	1.91 (2)	2.722 (2)	178 (4)
O8—H8···O5^iv	0.83 (2)	2.11 (2)	2.866 (3)	150 (3)
O9—H9···O21	0.83 (2)	1.92 (2)	2.745 (3)	176 (3)
O9—H10···O6^viii	0.81 (2)	1.99 (2)	2.765 (3)	161 (3)

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