A new three-dimensional coordination polymer of Sr^II based on dipicolinic acid, with different coordination environments for Sr^II

A three-dimensional coordination polymer of Sr^II based on dipicolinic acid (pydcH₂) has been synthesized and characterized, namely poly[[di­aqua­bis­([mu]₃-6-carb­oxy­pyridine-2-car­box­yl­ato)bis­([mu]₄-pyridine-2,6-di­carboxyl­ato)tri­strontium(II)] di­hydrate], {[Sr₃(C₇H₃NO₄)₂(C₇H₄NO₄)₂(H₂O)₂]·2H₂O}_n. The asymmetric unit consists of two unique Sr^II centres (one of them situated on an inversion centre), two independent pydc^2- ligands, and one coordinated and one uncoordinated water mol­ecule. The two independent Sr^II cations are surrounded by water and dipicolinate mol­ecules in distorted square-anti­prism and distorted tricapped trigonal prismatic geometries. The dipicolinate ligands adopt [mu]₃- and [mu]₄-bridging modes, linking the alkaline earth metal centres into a three-dimensional coordination framework. One dipicolin­ate ligand is doubly deprotonated, while the other is singly deprotonated.

S1. Introduction

There is continuing inter­est in the design and construction of coordination polymers, not only for their potential applications in gas adsorption, magnetism, luminescence and catalysis technologies and their photophysical and porous properties, but also for their charming architecture and topologies (Wang et al., 2012; Bu et al., 2004; Carlucci et al., 2003).

The construction of coordination polymers (CPs) is mainly dependent on the metal centres and organic ligands used (Liang et al., 2009; Martin et al., 2008; Kumar et al., 2007). The coordination features of the organic ligand, including the coordination mode and orientation of the donor groups, play an important role in controlling CP structures. Many reports demonstrate that aromatic di­carb­oxy­lic acids acting as organic linkers have been extensively utilized in the preparation of coordination polymers (Roesky & Andruh, 2003; Barnett & Champness, 2003; Dalai et al., 2002). Against this background, we present here the crystal structure of the title complex, (I), of Sr with dipicolinic acid (pydcH₂), {[Sr₂(pydc)(pydcH)(H₂O)₂].2H₂O}_n.

S2. Experimental

S2.1. Synthesis and crystallization

A mixture of pyridine-2,6-di­carb­oxy­lic acid (30 mg, 0.19 mmol), 2,9-di­methyl­phenanthroline (80 mg, 0.38 mmol) and Sr(NO₃)₂ (40 mg, 0.19 mmol) in water (10 ml) was stirred and heated to 353 K for 1 h. Colourless crystals of the title compound, (I), were obtained by slow evaporation of the solution at room temperature over a period of two months. Analysis, calculated for C₁₄H₁₀N₂O₁₀Sr_1.50: C 33.75, H 2.01, N 5.63%; found: C 33.63, H 2.06, N 5.64%. Spectroscopic analysis: IR (KBr disc, ν, cm^-1): 3598 (s), 3477 (s), 1610 (s), 1581 (s), 1566 (s), 1402 (s), 1381 (s), 908 (s), 823 (s), 766 (s), 655 (s).

S2.2. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1. The water and carboxyl­ate H atoms were initially observed in a Fourier difference map and included with O—H bond lengths set at 0.85 Å. The C-bound H atoms were included in geometrically calculated positions and treated as riding atoms, with C—H = 0.93 Å. All H atoms were refined, with U_iso(H) = 1.2U_eq(C,O).

S3. Results and discussion

As depicted in Fig. 1, the asymmetric unit of (I) consists of two unique Sr^II centres (one situated on an inversion centre), one doubly deprotonated pydc^2- ligand, one singly deprotonated pydcH^- ligand, and one coordinated and one uncoordinated water molecule.

In the synthesis of (I), we used dipicolinic acoid (pydcH₂) and 2,9-di­methyl­phenanthroline (dmp) so as to form a coordination polymer containing the dmp fragment as an auxiliary ligand. However, the results show that only pydc^2-/pydcH^- contributes to the network of (I), forming a three-dimensional coordination polymer, as shown in Fig. 2.

There are two independent Sr^II cations in the structure of (I). Atom Sr1 is coordinated by one N atom, seven O atoms from the dipicolinate ligands and one O atom of a water molecule (Fig. 3). Thus, the coordination geometry around atom Sr1 is a distorted tricapped trigonal prism. Atom Sr2 is o­cta­coordinated by two N atoms (N1 and N1B) and six O atoms (O1, O1B, O4, O4B, O8A and O8AA) from the carboxyl­ate groups of pydcH^- ligands (see Fig. 3 for symmetry codes). However, the coordination geometry around Sr2 is a distorted square anti­prism (Fig. 3). The two pydcH^- ligands that bond to Sr2 are coplanar (the mean? deviation from the mean plane of the ring is 0.0087 Å and the angle between the plane of the rings is 0.0°).

Inter­estingly, there are two types of dipicolinate ligand in (I) which bridge several alkaline earth metal ions. One of the dipicolinate ligands bridges four Sr^II cations and the other bridges three Sr^II cations, creating a three-dimensional network from Sr1 and Sr2 units.

The Sr1—N2 bond distance is shorter than the Sr2—-N1 distance. The Sr1—O and Sr2—O bond lengths range from 2.470 (14) to 2.824 (15) Å. The range of bond distances for Sr2—O is smaller than that for Sr1—O, owing to a lowering of the steric hindrance in the Sr2 building blocks (coordination number = 8) compared with Sr1 (coordination number = 9).

Two types of four-membered Sr₂O₂ ring exist, with Sr···Sr distances of 4.281 (4) Å for two symmetry-related Sr1 atoms bridged by two symmetry-related O7 atoms, and 4.388 (3) Å for Sr1 and Sr2 bridged by O1 and O4 atoms (Fig. 3). The binuclear units comprised of Sr1 atoms are connected by Sr2 atoms to form the final framework.

This network is different from that of a previously reported Sr^II complex (Soleimannejad et al., 2007), which was composed of an anionic [Sr₂(pydc)₂(H₂O)₃]^2- complex, a protonated 4,4'-bi­pyridine as counterion and three uncoordinated water molecules.

Inter- and intra­molecular O—H···O hydrogen-bond inter­actions between O atoms of the carboxyl­ate groups and water molecules support the three-dimensional structure of (I). An intra­molecular O—H···O hydrogen-bonding inter­action between atoms H9B and O3 of a carboxyl­ate group of the pydcH^- ligand results in the formation of an R(8) ring [see Bernstein et al. (1995) for details of graph-set analysis]. The other H atom of the coordinated water molecule (H9A) forms an O—H···O hydrogen bond to atom O2 of the free water molecule. The two H atoms of this water molecule also contribute to the hydrogen bonding. One of the H atoms (H2B) forms a typical O—H···O hydrogen bond with atom O3 of one of the pydcH^- ligands. The second H atom (H2A) forms bifurcated O—H···O hydrogen bonds to atoms O6 and O5 of two different pydc^2- ligands (Table 2). Lastly, carb­oxy­lic acid atom O2 forms a strong hydrogen bond to carboxyl­ate atom O5 of a neighbouring independent pydc^2- ligand.

Related literature

For related literature, see: Barnett & Champness (2003); Bernstein et al. (1995); Bu et al. (2004); Carlucci et al. (2003); Dalai et al. (2002); Kumar et al. (2007); Liang et al. (2009); Martin et al. (2008); Roesky & Andruh (2003); Soleimannejad et al. (2007); Wang et al. (2012).

Computing details

Data collection: SMART (Bruker, 2007); cell refinement: SMART (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

Fig. 1. The asymmetric unit of (I), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.

Fig. 2. Representations of the three-dimensional structure of (I), (a) along the a axis and (b) along the b axis.

Fig. 3. The different coordination polyhedra around atoms Sr1 and Sr2 in (I). [Symmetry codes: (A) x - 1, y, z; (B) -x, -y, -z; (AA) -x + 1, -y, -z; (C) -x + 1, y - 1/2, -z + 1/2.]

Fig. 4. The four-membered Sr₂O₂ units of (I), each formed by two Sr atoms. The units formed by Sr1 atoms are shown in yellow and those formed by one Sr1 and one Sr2 atom are shown in violet.

Poly[[diaquabis(µ₃-2-carboxypyridine-2-carboxylato)bis(µ₄-pyridine-2,6-dicarboxylato)tristrontium(II)] dihydrate]

Crystal data

[Sr3(C7H3NO4)2(C7H4NO4)2(H2O)2]·2H2O	F(000) = 984
Mr = 997.36	Dx = 1.947 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P2ybc	Cell parameters from 9958 reflections
a = 10.3733 (5) Å	θ = 2.5–27.5°
b = 9.1936 (4) Å	µ = 4.78 mm^−1
c = 18.4182 (8) Å	T = 296 K
β = 104.469 (1)°	Block, colourless
V = 1700.79 (13) Å^3	0.43 × 0.38 × 0.36 mm
Z = 2

Data collection

Bruker SMART CCD area-detector diffractometer	3839 independent reflections
Radiation source: fine-focus sealed tube	3572 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.032
ϕ and ω scans	θmax = 27.5°, θmin = 2.3°
Absorption correction: multi-scan (SADABS; Sheldrick, 2005)	h = −13→13
Tmin = 0.233, Tmax = 0.278	k = −11→11
21356 measured reflections	l = −22→22

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: mixed
R[F^2 > 2σ(F^2)] = 0.023	H-atom parameters constrained
wR(F^2) = 0.057	w = 1/[σ^2(Fo^2) + (0.0302P)^2 + 1.4191P] where P = (Fo^2 + 2Fc^2)/3
S = 1.06	(Δ/σ)max < 0.001
3839 reflections	Δρmax = 0.87 e Å^−3
251 parameters	Δρmin = −0.40 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0174 (5)

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
Sr1	0.429169 (15)	0.052192 (18)	0.096509 (9)	0.00757 (7)
Sr2	0.0000	0.0000	0.0000	0.00860 (8)
N1	−0.05890 (15)	0.27558 (17)	0.03896 (9)	0.0103 (3)
N2	0.66963 (15)	0.14008 (18)	0.17779 (9)	0.0095 (3)
C1	0.16033 (18)	0.2930 (2)	0.11886 (11)	0.0133 (4)
C2	0.02716 (18)	0.3615 (2)	0.08591 (11)	0.0116 (4)
C3	−0.0028 (2)	0.5018 (2)	0.10372 (12)	0.0160 (4)
H3	0.0609	0.5589	0.1358	0.019*
C4	−0.1297 (2)	0.5555 (2)	0.07275 (13)	0.0178 (4)
H4	−0.1526	0.6496	0.0832	0.021*
C5	−0.2218 (2)	0.4658 (2)	0.02592 (12)	0.0153 (4)
H5	−0.3085	0.4974	0.0056	0.018*
C6	−0.18184 (18)	0.3282 (2)	0.00999 (11)	0.0105 (4)
C7	−0.27438 (18)	0.2230 (2)	−0.04103 (10)	0.0099 (4)
C8	0.75994 (18)	−0.0145 (2)	0.09605 (11)	0.0100 (4)
C9	0.78041 (18)	0.0903 (2)	0.16165 (10)	0.0099 (3)
C10	0.90676 (18)	0.1398 (2)	0.19866 (11)	0.0132 (4)
H10	0.9823	0.1004	0.1877	0.016*
C11	0.91831 (19)	0.2481 (2)	0.25183 (11)	0.0150 (4)
H11	1.0014	0.2847	0.2762	0.018*
C12	0.80362 (19)	0.3013 (2)	0.26836 (11)	0.0136 (4)
H12	0.8082	0.3746	0.3037	0.016*
C13	0.68158 (18)	0.2424 (2)	0.23068 (10)	0.0101 (4)
C77	0.55270 (18)	0.2977 (2)	0.24504 (10)	0.0097 (4)
O1	0.18794 (13)	0.17345 (15)	0.09723 (8)	0.0150 (3)
O2	0.23705 (14)	0.36889 (17)	0.17132 (9)	0.0236 (4)
H2	0.3159	0.3364	0.1862	0.028*
O3	−0.39752 (12)	0.24446 (16)	−0.05602 (8)	0.0136 (3)
O4	−0.22098 (12)	0.11491 (15)	−0.06335 (8)	0.0113 (3)
O5	0.44715 (12)	0.23118 (15)	0.21000 (8)	0.0134 (3)
O6	0.55610 (13)	0.40241 (16)	0.28713 (8)	0.0156 (3)
O7	0.64358 (13)	−0.02905 (15)	0.05541 (8)	0.0117 (3)
O8	0.86292 (13)	−0.07439 (15)	0.08574 (8)	0.0131 (3)
O9	0.46618 (14)	0.30997 (16)	0.05084 (8)	0.0157 (3)
H9B	0.5163	0.3069	0.0207	0.019*
H9A	0.5063	0.3758	0.0804	0.019*
O2S	0.57078 (18)	0.55022 (17)	0.14218 (9)	0.0277 (4)
H2B	0.5242	0.6216	0.1210	0.033*
H2A	0.5784	0.5635	0.1887	0.033*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Sr1	0.01112 (9)	0.00716 (11)	0.00555 (11)	−0.00024 (6)	0.00421 (6)	−0.00065 (6)
Sr2	0.01046 (11)	0.00764 (14)	0.00920 (13)	0.00101 (8)	0.00523 (9)	−0.00166 (9)
N1	0.0138 (7)	0.0086 (8)	0.0104 (8)	−0.0004 (6)	0.0064 (6)	−0.0017 (6)
N2	0.0146 (7)	0.0083 (8)	0.0062 (8)	0.0003 (6)	0.0037 (6)	0.0008 (6)
C1	0.0152 (8)	0.0126 (10)	0.0136 (10)	−0.0008 (7)	0.0063 (7)	−0.0037 (7)
C2	0.0141 (8)	0.0111 (10)	0.0110 (10)	−0.0004 (7)	0.0055 (7)	−0.0013 (7)
C3	0.0180 (9)	0.0127 (10)	0.0176 (11)	−0.0015 (7)	0.0048 (8)	−0.0045 (8)
C4	0.0219 (10)	0.0089 (10)	0.0233 (12)	0.0032 (7)	0.0066 (8)	−0.0038 (8)
C5	0.0164 (9)	0.0117 (10)	0.0180 (11)	0.0026 (7)	0.0047 (8)	0.0000 (8)
C6	0.0143 (8)	0.0089 (9)	0.0096 (9)	−0.0010 (7)	0.0054 (7)	0.0007 (7)
C7	0.0159 (8)	0.0074 (9)	0.0076 (9)	−0.0005 (7)	0.0054 (7)	0.0025 (7)
C8	0.0163 (8)	0.0080 (9)	0.0083 (9)	0.0007 (7)	0.0076 (7)	0.0032 (7)
C9	0.0155 (8)	0.0091 (9)	0.0063 (9)	0.0000 (7)	0.0053 (7)	0.0020 (7)
C10	0.0134 (8)	0.0161 (10)	0.0110 (10)	0.0012 (7)	0.0051 (7)	0.0024 (7)
C11	0.0151 (8)	0.0195 (11)	0.0099 (10)	−0.0038 (7)	0.0022 (7)	−0.0002 (8)
C12	0.0207 (9)	0.0119 (10)	0.0087 (10)	−0.0023 (7)	0.0045 (7)	−0.0019 (7)
C13	0.0163 (8)	0.0093 (9)	0.0056 (9)	0.0004 (7)	0.0046 (7)	0.0017 (7)
C77	0.0157 (8)	0.0101 (9)	0.0034 (9)	0.0016 (7)	0.0028 (7)	0.0022 (7)
O1	0.0148 (6)	0.0125 (7)	0.0175 (8)	0.0020 (5)	0.0038 (5)	−0.0068 (6)
O2	0.0165 (7)	0.0208 (9)	0.0286 (9)	0.0050 (6)	−0.0035 (6)	−0.0156 (7)
O3	0.0133 (6)	0.0137 (7)	0.0141 (7)	0.0012 (5)	0.0041 (5)	−0.0010 (5)
O4	0.0144 (6)	0.0083 (7)	0.0117 (7)	0.0009 (5)	0.0039 (5)	−0.0023 (5)
O5	0.0141 (6)	0.0142 (7)	0.0125 (7)	0.0008 (5)	0.0045 (5)	−0.0044 (5)
O6	0.0213 (7)	0.0146 (7)	0.0113 (7)	0.0026 (6)	0.0051 (5)	−0.0060 (6)
O7	0.0149 (6)	0.0126 (7)	0.0090 (7)	−0.0002 (5)	0.0055 (5)	−0.0021 (5)
O8	0.0162 (6)	0.0124 (7)	0.0138 (7)	0.0025 (5)	0.0093 (5)	0.0006 (5)
O9	0.0235 (7)	0.0134 (7)	0.0124 (7)	0.0011 (6)	0.0089 (6)	0.0009 (6)
O2S	0.0483 (10)	0.0182 (9)	0.0167 (9)	0.0110 (7)	0.0084 (7)	0.0025 (6)

Geometric parameters (Å, º)

Sr1—O6^i	2.5197 (14)	C4—C5	1.387 (3)
Sr1—O9	2.5754 (14)	C4—H4	0.9300
Sr1—O4^ii	2.5958 (13)	C5—C6	1.385 (3)
Sr1—O5	2.6301 (14)	C5—H5	0.9300
Sr1—O7	2.6304 (13)	C6—C7	1.513 (3)
Sr1—N2	2.6926 (15)	C7—O3	1.253 (2)
Sr1—O7^iii	2.7183 (14)	C7—O4	1.256 (2)
Sr1—O1	2.7425 (13)	C7—Sr1^ii	3.0337 (19)
Sr1—O3^ii	2.8248 (14)	C8—O8	1.257 (2)
Sr1—C7^ii	3.0337 (19)	C8—O7	1.258 (2)
Sr1—Sr1^iii	4.2813 (4)	C8—C9	1.518 (3)
Sr1—Sr2	4.3880 (3)	C8—Sr2^v	3.3985 (18)
Sr2—O8^iii	2.4710 (13)	C9—C10	1.394 (3)
Sr2—O8^iv	2.4710 (13)	C10—C11	1.381 (3)
Sr2—O4^ii	2.5289 (13)	C10—H10	0.9300
Sr2—O4	2.5289 (13)	C11—C12	1.389 (3)
Sr2—N1	2.7434 (16)	C11—H11	0.9300
Sr2—N1^ii	2.7434 (16)	C12—C13	1.392 (3)
Sr2—O1	2.7939 (13)	C12—H12	0.9300
Sr2—O1^ii	2.7939 (13)	C13—C77	1.514 (2)
Sr2—C8^iv	3.3985 (18)	C77—O6	1.231 (2)
Sr2—C8^iii	3.3985 (18)	C77—O5	1.279 (2)
Sr2—Sr1^ii	4.3880 (2)	O2—H2	0.8500
N1—C2	1.336 (2)	O3—Sr1^ii	2.8248 (14)
N1—C6	1.343 (2)	O4—Sr1^ii	2.5958 (13)
N2—C9	1.338 (2)	O6—Sr1^vi	2.5197 (14)
N2—C13	1.338 (2)	O7—Sr1^iii	2.7183 (14)
C1—O1	1.227 (2)	O8—Sr2^v	2.4710 (13)
C1—O2	1.292 (2)	O9—H9B	0.8500
C1—C2	1.502 (3)	O9—H9A	0.8500
C2—C3	1.385 (3)	O2S—H2B	0.8500
C3—C4	1.389 (3)	O2S—H2A	0.8500
C3—H3	0.9300
O6^i—Sr1—O9	142.98 (5)	O8^iii—Sr2—C8^iii	16.85 (5)
O6^i—Sr1—O4^ii	75.33 (4)	O8^iv—Sr2—C8^iii	163.15 (5)
O9—Sr1—O4^ii	130.61 (4)	O4^ii—Sr2—C8^iii	63.83 (4)
O6^i—Sr1—O5	71.86 (5)	O4—Sr2—C8^iii	116.17 (4)
O9—Sr1—O5	72.37 (4)	N1—Sr2—C8^iii	109.87 (4)
O4^ii—Sr1—O5	116.54 (4)	N1^ii—Sr2—C8^iii	70.13 (4)
O6^i—Sr1—O7	102.34 (4)	O1—Sr2—C8^iii	80.01 (4)
O9—Sr1—O7	87.80 (4)	O1^ii—Sr2—C8^iii	99.99 (4)
O4^ii—Sr1—O7	118.55 (4)	C8^iv—Sr2—C8^iii	180.00 (5)
O5—Sr1—O7	120.61 (4)	O8^iii—Sr2—Sr1	62.68 (3)
O6^i—Sr1—N2	80.80 (5)	O8^iv—Sr2—Sr1	117.32 (3)
O9—Sr1—N2	73.29 (5)	O4^ii—Sr2—Sr1	31.56 (3)
O4^ii—Sr1—N2	155.38 (5)	O4—Sr2—Sr1	148.44 (3)
O5—Sr1—N2	59.90 (4)	N1—Sr2—Sr1	93.60 (3)
O7—Sr1—N2	60.84 (4)	N1^ii—Sr2—Sr1	86.40 (3)
O6^i—Sr1—O7^iii	140.81 (4)	O1—Sr2—Sr1	37.17 (3)
O9—Sr1—O7^iii	76.20 (4)	O1^ii—Sr2—Sr1	142.83 (3)
O4^ii—Sr1—O7^iii	73.19 (4)	C8^iv—Sr2—Sr1	126.49 (3)
O5—Sr1—O7^iii	144.43 (4)	C8^iii—Sr2—Sr1	53.51 (3)
O7—Sr1—O7^iii	73.67 (5)	O8^iii—Sr2—Sr1^ii	117.32 (3)
N2—Sr1—O7^iii	125.18 (4)	O8^iv—Sr2—Sr1^ii	62.68 (3)
O6^i—Sr1—O1	94.56 (4)	O4^ii—Sr2—Sr1^ii	148.44 (3)
O9—Sr1—O1	80.69 (4)	O4—Sr2—Sr1^ii	31.55 (3)
O4^ii—Sr1—O1	62.30 (4)	N1—Sr2—Sr1^ii	86.40 (3)
O5—Sr1—O1	68.00 (4)	N1^ii—Sr2—Sr1^ii	93.60 (3)
O7—Sr1—O1	162.74 (4)	O1—Sr2—Sr1^ii	142.83 (3)
N2—Sr1—O1	126.51 (4)	O1^ii—Sr2—Sr1^ii	37.17 (3)
O7^iii—Sr1—O1	91.02 (4)	C8^iv—Sr2—Sr1^ii	53.51 (3)
O6^i—Sr1—O3^ii	71.05 (4)	C8^iii—Sr2—Sr1^ii	126.49 (3)
O9—Sr1—O3^ii	145.00 (4)	Sr1—Sr2—Sr1^ii	180.0
O4^ii—Sr1—O3^ii	48.05 (4)	C2—N1—C6	117.31 (16)
O5—Sr1—O3^ii	142.60 (4)	C2—N1—Sr2	124.01 (12)
O7—Sr1—O3^ii	72.59 (4)	C6—N1—Sr2	118.68 (12)
N2—Sr1—O3^ii	117.83 (4)	C9—N2—C13	118.30 (16)
O7^iii—Sr1—O3^ii	70.65 (4)	C9—N2—Sr1	120.11 (12)
O1—Sr1—O3^ii	110.35 (4)	C13—N2—Sr1	121.36 (11)
O6^i—Sr1—C7^ii	75.24 (5)	O1—C1—O2	125.19 (18)
O9—Sr1—C7^ii	140.08 (5)	O1—C1—C2	120.69 (17)
O4^ii—Sr1—C7^ii	24.21 (4)	O2—C1—C2	114.10 (17)
O5—Sr1—C7^ii	135.72 (5)	N1—C2—C3	123.46 (17)
O7—Sr1—C7^ii	94.63 (5)	N1—C2—C1	114.34 (17)
N2—Sr1—C7^ii	140.93 (5)	C3—C2—C1	122.21 (17)
O7^iii—Sr1—C7^ii	66.46 (5)	C2—C3—C4	118.63 (19)
O1—Sr1—C7^ii	86.21 (5)	C2—C3—H3	120.7
O3^ii—Sr1—C7^ii	24.37 (4)	C4—C3—H3	120.7
O6^i—Sr1—Sr1^iii	128.56 (3)	C5—C4—C3	118.65 (19)
O9—Sr1—Sr1^iii	79.92 (3)	C5—C4—H4	120.7
O4^ii—Sr1—Sr1^iii	96.32 (3)	C3—C4—H4	120.7
O5—Sr1—Sr1^iii	146.03 (3)	C6—C5—C4	118.59 (18)
O7—Sr1—Sr1^iii	37.54 (3)	C6—C5—H5	120.7
N2—Sr1—Sr1^iii	93.81 (3)	C4—C5—H5	120.7
O7^iii—Sr1—Sr1^iii	36.13 (3)	N1—C6—C5	123.31 (18)
O1—Sr1—Sr1^iii	126.73 (3)	N1—C6—C7	114.11 (16)
O3^ii—Sr1—Sr1^iii	66.78 (3)	C5—C6—C7	122.57 (17)
C7^ii—Sr1—Sr1^iii	78.23 (3)	O3—C7—O4	124.13 (18)
O6^i—Sr1—Sr2	97.15 (3)	O3—C7—C6	119.32 (17)
O9—Sr1—Sr2	100.79 (3)	O4—C7—C6	116.48 (16)
O4^ii—Sr1—Sr2	30.65 (3)	O3—C7—Sr1^ii	68.44 (10)
O5—Sr1—Sr2	104.69 (3)	O4—C7—Sr1^ii	57.96 (9)
O7—Sr1—Sr2	134.24 (3)	C6—C7—Sr1^ii	160.48 (13)
N2—Sr1—Sr2	164.41 (3)	O8—C8—O7	126.06 (18)
O7^iii—Sr1—Sr2	65.28 (3)	O8—C8—C9	116.28 (17)
O1—Sr1—Sr2	37.98 (3)	O7—C8—C9	117.60 (16)
O3^ii—Sr1—Sr2	75.42 (3)	O8—C8—Sr2^v	34.72 (9)
C7^ii—Sr1—Sr2	51.27 (3)	O7—C8—Sr2^v	114.41 (12)
Sr1^iii—Sr1—Sr2	99.387 (6)	C9—C8—Sr2^v	114.48 (11)
O8^iii—Sr2—O8^iv	180.00 (8)	N2—C9—C10	122.33 (18)
O8^iii—Sr2—O4^ii	79.07 (4)	N2—C9—C8	115.91 (16)
O8^iv—Sr2—O4^ii	100.93 (4)	C10—C9—C8	121.58 (16)
O8^iii—Sr2—O4	100.93 (4)	C11—C10—C9	119.11 (17)
O8^iv—Sr2—O4	79.07 (4)	C11—C10—H10	120.4
O4^ii—Sr2—O4	180.00 (5)	C9—C10—H10	120.4
O8^iii—Sr2—N1	96.48 (5)	C10—C11—C12	118.85 (17)
O8^iv—Sr2—N1	83.52 (5)	C10—C11—H11	120.6
O4^ii—Sr2—N1	120.04 (4)	C12—C11—H11	120.6
O4—Sr2—N1	59.96 (4)	C11—C12—C13	118.39 (18)
O8^iii—Sr2—N1^ii	83.52 (5)	C11—C12—H12	120.8
O8^iv—Sr2—N1^ii	96.48 (5)	C13—C12—H12	120.8
O4^ii—Sr2—N1^ii	59.96 (4)	N2—C13—C12	122.95 (17)
O4—Sr2—N1^ii	120.04 (4)	N2—C13—C77	115.97 (16)
N1—Sr2—N1^ii	180.00 (6)	C12—C13—C77	121.01 (17)
O8^iii—Sr2—O1	80.26 (4)	O6—C77—O5	125.29 (17)
O8^iv—Sr2—O1	99.74 (4)	O6—C77—C13	118.99 (16)
O4^ii—Sr2—O1	62.34 (4)	O5—C77—C13	115.70 (16)
O4—Sr2—O1	117.66 (4)	C1—O1—Sr1	130.76 (12)
N1—Sr2—O1	58.03 (4)	C1—O1—Sr2	122.50 (12)
N1^ii—Sr2—O1	121.97 (4)	Sr1—O1—Sr2	104.85 (4)
O8^iii—Sr2—O1^ii	99.74 (4)	C1—O2—H2	114.5
O8^iv—Sr2—O1^ii	80.26 (4)	C7—O3—Sr1^ii	87.19 (11)
O4^ii—Sr2—O1^ii	117.66 (4)	C7—O4—Sr2	127.06 (12)
O4—Sr2—O1^ii	62.34 (4)	C7—O4—Sr1^ii	97.83 (10)
N1—Sr2—O1^ii	121.97 (4)	Sr2—O4—Sr1^ii	117.79 (5)
N1^ii—Sr2—O1^ii	58.03 (4)	C77—O5—Sr1	125.58 (11)
O1—Sr2—O1^ii	180.0	C77—O6—Sr1^vi	161.64 (13)
O8^iii—Sr2—C8^iv	163.15 (5)	C8—O7—Sr1	123.58 (12)
O8^iv—Sr2—C8^iv	16.85 (5)	C8—O7—Sr1^iii	126.79 (11)
O4^ii—Sr2—C8^iv	116.17 (4)	Sr1—O7—Sr1^iii	106.33 (5)
O4—Sr2—C8^iv	63.83 (4)	C8—O8—Sr2^v	128.43 (12)
N1—Sr2—C8^iv	70.13 (4)	Sr1—O9—H9B	110.4
N1^ii—Sr2—C8^iv	109.87 (4)	Sr1—O9—H9A	122.4
O1—Sr2—C8^iv	99.99 (4)	H9B—O9—H9A	99.1
O1^ii—Sr2—C8^iv	80.01 (4)	H2B—O2S—H2A	104.6
O6^i—Sr1—Sr2—O8^iii	−160.26 (5)	O1—C1—C2—C3	−173.7 (2)
O9—Sr1—Sr2—O8^iii	52.27 (5)	O2—C1—C2—C3	8.0 (3)
O4^ii—Sr1—Sr2—O8^iii	−115.70 (7)	N1—C2—C3—C4	1.6 (3)
O5—Sr1—Sr2—O8^iii	126.68 (5)	C1—C2—C3—C4	−177.87 (19)
O7—Sr1—Sr2—O8^iii	−45.25 (6)	C2—C3—C4—C5	0.7 (3)
N2—Sr1—Sr2—O8^iii	118.33 (13)	C3—C4—C5—C6	−2.2 (3)
O7^iii—Sr1—Sr2—O8^iii	−16.93 (5)	C2—N1—C6—C5	0.7 (3)
O1—Sr1—Sr2—O8^iii	111.49 (6)	Sr2—N1—C6—C5	−179.93 (15)
O3^ii—Sr1—Sr2—O8^iii	−92.03 (5)	C2—N1—C6—C7	−178.51 (16)
C7^ii—Sr1—Sr2—O8^iii	−95.72 (6)	Sr2—N1—C6—C7	0.9 (2)
Sr1^iii—Sr1—Sr2—O8^iii	−29.15 (4)	C4—C5—C6—N1	1.5 (3)
O6^i—Sr1—Sr2—O8^iv	19.74 (5)	C4—C5—C6—C7	−179.36 (19)
O9—Sr1—Sr2—O8^iv	−127.73 (5)	N1—C6—C7—O3	162.32 (17)
O4^ii—Sr1—Sr2—O8^iv	64.30 (7)	C5—C6—C7—O3	−16.9 (3)
O5—Sr1—Sr2—O8^iv	−53.32 (5)	N1—C6—C7—O4	−14.9 (2)
O7—Sr1—Sr2—O8^iv	134.75 (6)	C5—C6—C7—O4	165.93 (18)
N2—Sr1—Sr2—O8^iv	−61.67 (13)	N1—C6—C7—Sr1^ii	53.5 (4)
O7^iii—Sr1—Sr2—O8^iv	163.07 (5)	C5—C6—C7—Sr1^ii	−125.7 (3)
O1—Sr1—Sr2—O8^iv	−68.51 (6)	C13—N2—C9—C10	1.0 (3)
O3^ii—Sr1—Sr2—O8^iv	87.97 (5)	Sr1—N2—C9—C10	175.57 (14)
C7^ii—Sr1—Sr2—O8^iv	84.28 (6)	C13—N2—C9—C8	−174.17 (16)
Sr1^iii—Sr1—Sr2—O8^iv	150.85 (4)	Sr1—N2—C9—C8	0.5 (2)
O6^i—Sr1—Sr2—O4^ii	−44.57 (7)	O8—C8—C9—N2	−172.30 (17)
O9—Sr1—Sr2—O4^ii	167.97 (7)	O7—C8—C9—N2	10.6 (3)
O5—Sr1—Sr2—O4^ii	−117.62 (7)	Sr2^v—C8—C9—N2	149.19 (13)
O7—Sr1—Sr2—O4^ii	70.44 (7)	O8—C8—C9—C10	12.5 (3)
N2—Sr1—Sr2—O4^ii	−125.97 (14)	O7—C8—C9—C10	−164.59 (18)
O7^iii—Sr1—Sr2—O4^ii	98.76 (7)	Sr2^v—C8—C9—C10	−26.0 (2)
O1—Sr1—Sr2—O4^ii	−132.82 (8)	N2—C9—C10—C11	−2.6 (3)
O3^ii—Sr1—Sr2—O4^ii	23.67 (6)	C8—C9—C10—C11	172.24 (18)
C7^ii—Sr1—Sr2—O4^ii	19.97 (7)	C9—C10—C11—C12	1.9 (3)
Sr1^iii—Sr1—Sr2—O4^ii	86.54 (6)	C10—C11—C12—C13	0.3 (3)
O6^i—Sr1—Sr2—O4	135.43 (7)	C9—N2—C13—C12	1.4 (3)
O9—Sr1—Sr2—O4	−12.03 (7)	Sr1—N2—C13—C12	−173.15 (14)
O4^ii—Sr1—Sr2—O4	180.0	C9—N2—C13—C77	178.35 (16)
O5—Sr1—Sr2—O4	62.37 (7)	Sr1—N2—C13—C77	3.8 (2)
O7—Sr1—Sr2—O4	−109.56 (7)	C11—C12—C13—N2	−2.0 (3)
N2—Sr1—Sr2—O4	54.02 (14)	C11—C12—C13—C77	−178.84 (18)
O7^iii—Sr1—Sr2—O4	−81.24 (7)	N2—C13—C77—O6	−172.34 (17)
O1—Sr1—Sr2—O4	47.18 (8)	C12—C13—C77—O6	4.7 (3)
O3^ii—Sr1—Sr2—O4	−156.33 (6)	N2—C13—C77—O5	6.2 (2)
C7^ii—Sr1—Sr2—O4	−160.03 (7)	C12—C13—C77—O5	−176.83 (17)
Sr1^iii—Sr1—Sr2—O4	−93.46 (6)	O2—C1—O1—Sr1	−28.2 (3)
O6^i—Sr1—Sr2—N1	104.30 (5)	C2—C1—O1—Sr1	153.67 (13)
O9—Sr1—Sr2—N1	−43.17 (5)	O2—C1—O1—Sr2	169.93 (15)
O4^ii—Sr1—Sr2—N1	148.86 (7)	C2—C1—O1—Sr2	−8.2 (3)
O5—Sr1—Sr2—N1	31.24 (5)	O6^i—Sr1—O1—C1	99.98 (18)
O7—Sr1—Sr2—N1	−140.69 (5)	O9—Sr1—O1—C1	−43.01 (18)
N2—Sr1—Sr2—N1	22.89 (13)	O4^ii—Sr1—O1—C1	170.78 (19)
O7^iii—Sr1—Sr2—N1	−112.37 (5)	O5—Sr1—O1—C1	31.63 (17)
O1—Sr1—Sr2—N1	16.05 (6)	O7—Sr1—O1—C1	−91.8 (2)
O3^ii—Sr1—Sr2—N1	172.53 (4)	N2—Sr1—O1—C1	18.0 (2)
C7^ii—Sr1—Sr2—N1	168.84 (6)	O7^iii—Sr1—O1—C1	−118.85 (18)
Sr1^iii—Sr1—Sr2—N1	−124.59 (3)	O3^ii—Sr1—O1—C1	171.45 (17)
O6^i—Sr1—Sr2—N1^ii	−75.70 (5)	C7^ii—Sr1—O1—C1	174.82 (18)
O9—Sr1—Sr2—N1^ii	136.83 (5)	Sr1^iii—Sr1—O1—C1	−112.91 (17)
O4^ii—Sr1—Sr2—N1^ii	−31.14 (7)	Sr2—Sr1—O1—C1	−164.2 (2)
O5—Sr1—Sr2—N1^ii	−148.76 (5)	O6^i—Sr1—O1—Sr2	−95.79 (5)
O7—Sr1—Sr2—N1^ii	39.31 (5)	O9—Sr1—O1—Sr2	121.22 (5)
N2—Sr1—Sr2—N1^ii	−157.11 (13)	O4^ii—Sr1—O1—Sr2	−24.98 (4)
O7^iii—Sr1—Sr2—N1^ii	67.63 (5)	O5—Sr1—O1—Sr2	−164.13 (6)
O1—Sr1—Sr2—N1^ii	−163.95 (6)	O7—Sr1—O1—Sr2	72.45 (15)
O3^ii—Sr1—Sr2—N1^ii	−7.47 (4)	N2—Sr1—O1—Sr2	−177.72 (5)
C7^ii—Sr1—Sr2—N1^ii	−11.16 (6)	O7^iii—Sr1—O1—Sr2	45.38 (5)
Sr1^iii—Sr1—Sr2—N1^ii	55.41 (3)	O3^ii—Sr1—O1—Sr2	−24.32 (6)
O6^i—Sr1—Sr2—O1	88.25 (6)	C7^ii—Sr1—O1—Sr2	−20.94 (5)
O9—Sr1—Sr2—O1	−59.21 (6)	Sr1^iii—Sr1—O1—Sr2	51.32 (6)
O4^ii—Sr1—Sr2—O1	132.82 (8)	O8^iii—Sr2—O1—C1	108.86 (16)
O5—Sr1—Sr2—O1	15.19 (6)	O8^iv—Sr2—O1—C1	−71.14 (16)
O7—Sr1—Sr2—O1	−156.74 (7)	O4^ii—Sr2—O1—C1	−168.44 (17)
N2—Sr1—Sr2—O1	6.84 (14)	O4—Sr2—O1—C1	11.56 (17)
O7^iii—Sr1—Sr2—O1	−128.42 (6)	N1—Sr2—O1—C1	4.85 (15)
O3^ii—Sr1—Sr2—O1	156.48 (6)	N1^ii—Sr2—O1—C1	−175.15 (15)
C7^ii—Sr1—Sr2—O1	152.79 (7)	C8^iv—Sr2—O1—C1	−54.03 (16)
Sr1^iii—Sr1—Sr2—O1	−140.64 (5)	C8^iii—Sr2—O1—C1	125.97 (16)
O6^i—Sr1—Sr2—O1^ii	−91.75 (6)	Sr1—Sr2—O1—C1	165.88 (18)
O9—Sr1—Sr2—O1^ii	120.79 (6)	Sr1^ii—Sr2—O1—C1	−14.12 (18)
O4^ii—Sr1—Sr2—O1^ii	−47.18 (8)	O8^iii—Sr2—O1—Sr1	−57.01 (5)
O5—Sr1—Sr2—O1^ii	−164.81 (6)	O8^iv—Sr2—O1—Sr1	122.99 (5)
O7—Sr1—Sr2—O1^ii	23.26 (7)	O4^ii—Sr2—O1—Sr1	25.68 (4)
N2—Sr1—Sr2—O1^ii	−173.16 (14)	O4—Sr2—O1—Sr1	−154.32 (4)
O7^iii—Sr1—Sr2—O1^ii	51.58 (6)	N1—Sr2—O1—Sr1	−161.02 (7)
O1—Sr1—Sr2—O1^ii	180.0	N1^ii—Sr2—O1—Sr1	18.98 (7)
O3^ii—Sr1—Sr2—O1^ii	−23.52 (6)	C8^iv—Sr2—O1—Sr1	140.09 (5)
C7^ii—Sr1—Sr2—O1^ii	−27.21 (7)	C8^iii—Sr2—O1—Sr1	−39.91 (5)
Sr1^iii—Sr1—Sr2—O1^ii	39.36 (5)	Sr1^ii—Sr2—O1—Sr1	180.0
O6^i—Sr1—Sr2—C8^iv	36.45 (5)	O4—C7—O3—Sr1^ii	16.85 (18)
O9—Sr1—Sr2—C8^iv	−111.02 (5)	C6—C7—O3—Sr1^ii	−160.13 (15)
O4^ii—Sr1—Sr2—C8^iv	81.01 (7)	O3—C7—O4—Sr2	−152.46 (14)
O5—Sr1—Sr2—C8^iv	−36.61 (5)	C6—C7—O4—Sr2	24.6 (2)
O7—Sr1—Sr2—C8^iv	151.46 (6)	Sr1^ii—C7—O4—Sr2	−133.92 (13)
N2—Sr1—Sr2—C8^iv	−44.96 (13)	O3—C7—O4—Sr1^ii	−18.5 (2)
O7^iii—Sr1—Sr2—C8^iv	179.78 (5)	C6—C7—O4—Sr1^ii	158.51 (13)
O1—Sr1—Sr2—C8^iv	−51.80 (6)	O8^iii—Sr2—O4—C7	−108.39 (14)
O3^ii—Sr1—Sr2—C8^iv	104.68 (5)	O8^iv—Sr2—O4—C7	71.61 (14)
C7^ii—Sr1—Sr2—C8^iv	100.99 (6)	N1—Sr2—O4—C7	−17.18 (14)
Sr1^iii—Sr1—Sr2—C8^iv	167.56 (4)	N1^ii—Sr2—O4—C7	162.82 (14)
O6^i—Sr1—Sr2—C8^iii	−143.55 (5)	O1—Sr2—O4—C7	−23.75 (16)
O9—Sr1—Sr2—C8^iii	68.98 (5)	O1^ii—Sr2—O4—C7	156.25 (16)
O4^ii—Sr1—Sr2—C8^iii	−98.99 (7)	C8^iv—Sr2—O4—C7	64.00 (14)
O5—Sr1—Sr2—C8^iii	143.39 (5)	C8^iii—Sr2—O4—C7	−116.00 (14)
O7—Sr1—Sr2—C8^iii	−28.54 (6)	Sr1—Sr2—O4—C7	−53.77 (17)
N2—Sr1—Sr2—C8^iii	135.04 (13)	Sr1^ii—Sr2—O4—C7	126.23 (17)
O7^iii—Sr1—Sr2—C8^iii	−0.22 (5)	O8^iii—Sr2—O4—Sr1^ii	125.38 (6)
O1—Sr1—Sr2—C8^iii	128.20 (6)	O8^iv—Sr2—O4—Sr1^ii	−54.62 (6)
O3^ii—Sr1—Sr2—C8^iii	−75.32 (5)	N1—Sr2—O4—Sr1^ii	−143.41 (7)
C7^ii—Sr1—Sr2—C8^iii	−79.01 (6)	N1^ii—Sr2—O4—Sr1^ii	36.59 (7)
Sr1^iii—Sr1—Sr2—C8^iii	−12.44 (4)	O1—Sr2—O4—Sr1^ii	−149.98 (5)
O8^iii—Sr2—N1—C2	−75.13 (15)	O1^ii—Sr2—O4—Sr1^ii	30.02 (5)
O8^iv—Sr2—N1—C2	104.87 (15)	C8^iv—Sr2—O4—Sr1^ii	−62.23 (6)
O4^ii—Sr2—N1—C2	5.98 (16)	C8^iii—Sr2—O4—Sr1^ii	117.77 (6)
O4—Sr2—N1—C2	−174.03 (16)	Sr1—Sr2—O4—Sr1^ii	180.0
O1—Sr2—N1—C2	−0.89 (13)	O6—C77—O5—Sr1	164.23 (14)
O1^ii—Sr2—N1—C2	179.11 (13)	C13—C77—O5—Sr1	−14.2 (2)
C8^iv—Sr2—N1—C2	115.41 (15)	O6^i—Sr1—O5—C77	101.25 (15)
C8^iii—Sr2—N1—C2	−64.59 (15)	O9—Sr1—O5—C77	−69.03 (14)
Sr1—Sr2—N1—C2	−12.24 (14)	O4^ii—Sr1—O5—C77	163.76 (14)
Sr1^ii—Sr2—N1—C2	167.76 (14)	O7—Sr1—O5—C77	7.38 (16)
O8^iii—Sr2—N1—C6	105.51 (14)	N2—Sr1—O5—C77	11.51 (14)
O8^iv—Sr2—N1—C6	−74.49 (14)	O7^iii—Sr1—O5—C77	−98.02 (15)
O4^ii—Sr2—N1—C6	−173.38 (12)	O1—Sr1—O5—C77	−155.89 (16)
O4—Sr2—N1—C6	6.62 (12)	O3^ii—Sr1—O5—C77	109.00 (15)
O1—Sr2—N1—C6	179.76 (15)	C7^ii—Sr1—O5—C77	145.20 (14)
O1^ii—Sr2—N1—C6	−0.24 (15)	Sr1^iii—Sr1—O5—C77	−32.20 (17)
C8^iv—Sr2—N1—C6	−63.95 (13)	Sr2—Sr1—O5—C77	−165.91 (14)
C8^iii—Sr2—N1—C6	116.05 (13)	O5—C77—O6—Sr1^vi	91.0 (4)
Sr1—Sr2—N1—C6	168.40 (13)	C13—C77—O6—Sr1^vi	−90.7 (4)
Sr1^ii—Sr2—N1—C6	−11.60 (13)	O8—C8—O7—Sr1	165.97 (14)
O6^i—Sr1—N2—C9	104.19 (14)	C9—C8—O7—Sr1	−17.2 (2)
O9—Sr1—N2—C9	−102.56 (14)	Sr2^v—C8—O7—Sr1	−155.85 (6)
O4^ii—Sr1—N2—C9	89.93 (17)	O8—C8—O7—Sr1^iii	−37.4 (3)
O5—Sr1—N2—C9	178.48 (15)	C9—C8—O7—Sr1^iii	139.42 (13)
O7—Sr1—N2—C9	−5.58 (13)	Sr2^v—C8—O7—Sr1^iii	0.78 (18)
O7^iii—Sr1—N2—C9	−43.64 (15)	O6^i—Sr1—O7—C8	−59.64 (15)
O1—Sr1—N2—C9	−166.94 (12)	O9—Sr1—O7—C8	84.40 (14)
O3^ii—Sr1—N2—C9	41.41 (15)	O4^ii—Sr1—O7—C8	−139.49 (14)
C7^ii—Sr1—N2—C9	51.70 (17)	O5—Sr1—O7—C8	16.43 (16)
Sr1^iii—Sr1—N2—C9	−24.28 (14)	N2—Sr1—O7—C8	12.34 (13)
Sr2—Sr1—N2—C9	−172.17 (10)	O7^iii—Sr1—O7—C8	160.67 (17)
O6^i—Sr1—N2—C13	−81.36 (14)	O1—Sr1—O7—C8	132.37 (16)
O9—Sr1—N2—C13	71.89 (14)	O3^ii—Sr1—O7—C8	−124.99 (15)
O4^ii—Sr1—N2—C13	−95.62 (17)	C7^ii—Sr1—O7—C8	−135.52 (14)
O5—Sr1—N2—C13	−7.06 (13)	Sr1^iii—Sr1—O7—C8	160.67 (17)
O7—Sr1—N2—C13	168.87 (15)	Sr2—Sr1—O7—C8	−172.65 (12)
O7^iii—Sr1—N2—C13	130.81 (13)	O6^i—Sr1—O7—Sr1^iii	139.69 (5)
O1—Sr1—N2—C13	7.52 (16)	O9—Sr1—O7—Sr1^iii	−76.27 (5)
O3^ii—Sr1—N2—C13	−144.14 (13)	O4^ii—Sr1—O7—Sr1^iii	59.84 (6)
C7^ii—Sr1—N2—C13	−133.85 (13)	O5—Sr1—O7—Sr1^iii	−144.24 (5)
Sr1^iii—Sr1—N2—C13	150.17 (13)	N2—Sr1—O7—Sr1^iii	−148.32 (7)
Sr2—Sr1—N2—C13	2.3 (2)	O7^iii—Sr1—O7—Sr1^iii	0.0
C6—N1—C2—C3	−2.3 (3)	O1—Sr1—O7—Sr1^iii	−28.30 (16)
Sr2—N1—C2—C3	178.36 (15)	O3^ii—Sr1—O7—Sr1^iii	74.34 (5)
C6—N1—C2—C1	177.24 (16)	C7^ii—Sr1—O7—Sr1^iii	63.82 (5)
Sr2—N1—C2—C1	−2.1 (2)	Sr2—Sr1—O7—Sr1^iii	26.69 (7)
O1—C1—C2—N1	6.8 (3)	O7—C8—O8—Sr2^v	81.2 (2)
O2—C1—C2—N1	−171.54 (17)	C9—C8—O8—Sr2^v	−95.67 (18)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···O5	0.85	1.64	2.4666 (19)	164
O9—H9B···O3^v	0.85	1.94	2.7615 (19)	163
O9—H9A···O2S	0.85	1.98	2.824 (2)	170
O2S—H2B···O3^vii	0.85	1.97	2.808 (2)	168
O2S—H2A···O5^vi	0.85	2.48	3.235 (2)	148
O2S—H2A···O6	0.85	2.40	3.033 (2)	132

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