research communications\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 77| Part 7| July 2021| Pages 703-707
https://doi.org/10.1107/S2056989021005594

Synthesis and crystal structure of a one-dimensional chain-like strontium(II) coordination polymer built of N-methyldi­ethano­lamine and isobutyrate ligands

crossmark logo
Maximilian Seiss,a Sebastian Schmitz,a Martin Börnera and Kirill Yu. Monakhova*

aLeibniz Institute of Surface Engineering (IOM), Permoserstr. 15, 04318 Leipzig, Germany
*Correspondence e-mail: kirill.monakhov@iom-leipzig.de

Edited by G. Díaz de Delgado, Universidad de Los Andes, Venezuela (Received 18 February 2021; accepted 31 May 2021; online 11 June 2021)

The one-dimensional coordination polymer (I) [Sr(ib)2(H2mda)]n (Hib = isobutyric acid, C4H8O2, and H2mda = N-methyldi­ethano­lamine, C5H13NO2), namely, catena-poly[[(N-methyldi­ethano­lamine-κ3O,N,O′)strontium(II)]-di-μ2-isobutyrato-κ3O,O′:O;κ3O:O,O′], was prepared by the one-pot aerobic reaction of [Zr6O4(OH)4(ib)12(H2O)]·3Hib with Sr(NO3)2 and H2mda in the presence of MnCl2 and Et3N in aceto­nitrile. The use of MnCl2 is key to the isolation of I as high-quality colorless crystals in good yield. The mol­ecular solid-state structure of I was determined by single-crystal X-ray diffraction. Compound I crystallizes in the monoclinic space group P21/c and shows a one-dimensional polymeric chain structure. Each monomeric unit of this coordination polymer consists of a central SrII ion in the NO8 coordination environment of two deprotonated ib− ligands and one fully protonated H2mda ligand. The C and O atoms of the H2mda ligand were refined as disordered over two sets of sites with site occupancies of 0.619 (3) and 0.381 (3). Compound I shows thermal stability up to 130°C in air.

CCDC reference: 2087088

Similar articles

1. Chemical context

Simple metal isobutyrate salts such as TM(ib)2 (e.g. TM = Mn, Co and Ni; Hib = isobutyric acid) and AM(ib) (e.g. AM = Na and K) are known to act as precursor materials for the synthesis of a wide variety of polynuclear coordination com­plexes, e.g. [MnII4MnIII2(ib)8(Hbda)2(bda)2] (H2bda = N-but­yl­diethano­lamine), [MnII4CoIII2(ib)8(Hmda)2(mda)2] (Malae­stean et al., 2010[Malaestean, I. L., Speldrich, M., Ellern, A., Baca, S. G. & Kögerler, P. (2010). Polyhedron, 29, 1990-1997.]), [CoII3CoIII2(Hbda)2(bda)2(ib)6]·2MeCN and [NiII4(Hbda)3(ib)5(MeCN)] (Schmitz et al., 2016[Schmitz, S., Monakhov, K. Yu., van Leusen, J., Izarova, N. V., Hess, V. & Kögerler, P. (2016). RSC Adv. 6, 100664-100669.]), [GdIII4MII8(OH)8(Lig)8(ib)8](ClO4)4 (M = ZnII or CuII, HLig = 2-(hy­droxy­meth­yl)pyridine); Hooper et al., 2012[Hooper, T. N., Schnack, J., Piligkos, S., Evangelisti, M. & Brechin, E. K. (2012). Angew. Chem. Int. Ed. 51, 4633-4636.]) and [Cr3O(ib)6(H2O)3](NO3) (Parsons et al., 2000[Parsons, S., Smith, A. A. & Winpenny, R. E. P. (2000). Chem. Commun. pp. 579-580.]). The formation of these polynuclear homo- and heterometallic complexes was enabled by the introduction of flexible amino alcohol ligands into the reaction mixtures (Schmitz et al., 2016[Schmitz, S., Monakhov, K. Yu., van Leusen, J., Izarova, N. V., Hess, V. & Kögerler, P. (2016). RSC Adv. 6, 100664-100669.]; Malaestean et al., 2010[Malaestean, I. L., Speldrich, M., Ellern, A., Baca, S. G. & Kögerler, P. (2010). Polyhedron, 29, 1990-1997.]). We describe here the first example of a coordination polymer composed of monomeric SrII units that are supported by both isobutyrate and amino alcohol ligands. This makes the synthesized compound [Sr(ib)2(H2mda)]n (I) an appealing precursor for reactions with transition metal and lanthanide complexes. In addition, I can find application in solvothermal reactions as it is described, e.g. for the transformation of [CoII3CoIII2(Hbda)2(bda)2(ib)6] to [CoII10(OH)2(bda)6(ib)6] (Schmitz et al., 2018[Schmitz, S., Secker, T., Batool, M., van Leusen, J., Nadeem, M. A. & Kögerler, P. (2018). Inorg. Chim. Acta, 482, 522-525.]). Herein compound I was isolated as colorless crystals from an aerobic reaction, characterized by infrared (IR) spectroscopy, thermogravimetric analysis (TGA) and single-crystal X-ray diffraction. Compound I represents a rare class of alkaline earth metal–isobutyrate complexes with a 1D polymeric structure (cf. {[Mg(ib)2(H2O)3]·H2O}n (Malaestean et al., 2013[Malaestean, I. L., Schmitz, S., Ellern, A. & Kögerler, P. (2013). Acta Cryst. C69, 1144-1146.])). Remarkably, MnCl2 is crucial in the synthesis of I for the formation of high-quality single crystals (in 36% yield) suitable for X-ray diffraction. When the reaction is carried out without MnCl2, poor quality crystalline material is formed in lower yield within several days. For the syntheses of homometallic coordination complexes it is common to use an additional metal salt, which yields a heterometallic reaction mixture, from which the homometallic complex can be obtained selectively as a solid product (Ako et al., 2007[Ako, A. M., Waldmann, O., Mereacre, V., Klöwer, F., Hewitt, I. J., Anson, C. E., Güdel, H. U. & Powell, A. K. (2007). Inorg. Chem. 46, 756-766.]; Liu et al., 2018[Liu, X., Gao, P. & Hu, M. (2018). Polyhedron, 144, 119-124.]). In 2007, Ako and co-workers described two hepta­nuclear iron(III) complexes [FeIII7O3(bda)3(piv)9(H2O)3] and [FeIII7O3(phda)3(piv)9(H2O)3] (H2phda = N-phenyldi­ethano­lamine and Hpiv = pivalic acid), which were obtained by the reaction of [Fe3O(piv)6]piv, nickel(II) acetate tetra­hydrate (Ni(OAc)2·4H2O) and H2bda or H2phda in a molar ratio of 1:1:2 using MeCN as solvent (Ako et al., 2007[Ako, A. M., Waldmann, O., Mereacre, V., Klöwer, F., Hewitt, I. J., Anson, C. E., Güdel, H. U. & Powell, A. K. (2007). Inorg. Chem. 46, 756-766.]). Although Ni(OAc)2·4H2O was used in an equimolar ratio with the iron(III) precursor, nickel did not incorporate into the final product. Similar to this, Liu et al. (2018[Liu, X., Gao, P. & Hu, M. (2018). Polyhedron, 144, 119-124.]) synthesized a hexa­nuclear [Zn6(Lig)6(OOCH)6] complex (HLig = 4′-(4-carb­oxy­phen­yl)-2,2′:6′,2′′-terpyridine) by the reaction of zinc(II) acetate, Zn(OAc)2, with HLig in the presence of praseodymium(III) nitrate hexa­hydrate, Pr(NO3)3·6H2O, using a 2:2:1 molar ratio. The reaction was performed solvothermally in DMF and praseodymium did not incorporate into the final [Zn6(Lig)6(OOCH)6] complex, which was isolated as a pure product by filtration (Liu et al., 2018[Liu, X., Gao, P. & Hu, M. (2018). Polyhedron, 144, 119-124.]). Here [Sr(ib)2(H2mda)]n was also isolated as a pure product by filtration, which indicates that the additional metal salts (here MnCl2) remain in the mother liquor.

[Scheme 1]

2. Structural commentary

The crystal structure consists of a SrII monomer unit (Fig. 1[link]) extending along the a-axis direction. The asymmetric unit contains one central SrII ion, which is coordinated by a disordered, tridentate and fully protonated H2mda and two deprotonated isobutyrate ligands. In other words, SrII is nine-coordinated by six O atoms (O1, O3, O1i, O3ii, O2i, and O4ii; see Table 1[link] for geometric parameters and symmetry codes) from four different carboxyl­ate groups, two O atoms (O5 and O6 or O5A and O6A) and one N atom (N1) from the N-methyldi­ethano­lamine ligand. The resulting coordination environment of the strontium center is NO8. The polyhedral shape of Sr was evaluated using the SHAPE software version 2.1 (Llunell et al., 2013[Llunell, M., Casanova, D., Cirera, A., Alemany, A. & Alvarez, S. (2013). SHAPE. University of Barcelona, Barcelona, Spain.]) and can be described as an in-between a distorted spherical capped square anti­prism and a distorted spherical tricapped trigonal prism (Fig. 2[link]). The values of the deviation from the ideal geometry are listed in Table 2[link]. The Sr—Oib bond lengths of the bridging O atoms are between 2.5377 (10) and 2.7563 (10) Å, whereas the non-bridging Sr—Oib bond lengths range from 2.6270 (11) to 2.6364 (11) Å. The non-bonding Sr⋯Sr distances are 4.2869 (3) and 4.2982 (3) Å with Sr—O—Sr angles of 108.50 (4) and 108.84 (5)°. The Sr—OH2mda bond lengths range between 2.582 (20) and 2.731 (11) Å, and Sr—N bond length is 2.8495 (13) Å.

Table 1
Selected geometric parameters (Å, °)

Sr1—O1i 2.7563 (10) Sr1—O5 2.731 (11)
Sr1—O3ii 2.7244 (11) Sr1—O6 2.66 (3)
Sr1—O1 2.5377 (10) Sr1—N1 2.8495 (13)
Sr1—O3 2.5444 (10) Sr1⋯Sr1i 4.2981 (3)
Sr1—O2i 2.6270 (11) Sr1⋯Sr1ii 4.2868 (3)
Sr1—O4ii 2.6364 (11)    
       
Sr1—O1—Sr1i 108.50 (4) Sr1—O1—Sr1ii 108.84 (5)
Symmetry codes: (i) [-x+2, -y+1, -z+1]; (ii) [-x+1, -y+1, -z+1].

Table 2
Selected Continuous Shapes Measures (CShM) values for the geometry about the nine-coordinate SrII ions of I

Shape Capped square anti­prism (C4v, J10) Spherical capped square anti­prism (C4v) Tricapped trigonal prism (D3h, J51) Spherical tricapped trigonal prism (D3h) Muffin (Cs)
Sri 4.349 3.765 5.892 3.696 3.732
Srii 4.026 3.346 5.575 3.423 3.358
Symmetry codes: (i) [-x+2, -y+1, -z+1]; (ii) [-x+1, -y+1, -z+1].
[Figure 1]
Figure 1
Ellipsoid plot of the monomeric unit of I with displacement ellipsoids at the 30% probability level for all non-H atoms. H atoms are omitted for clarity. Color code: Sr teal, C gray, N blue, O red. Disordered atoms are omitted for clarity. Symmetry codes: (i) 2 − x, 1 − y, 1 − z; (ii) 1 − x, 1 − y, 1 − z.
[Figure 2]
Figure 2
Representation of a polyhedron around a central Sr ion spanned by the NO8 coordination environment. Color code: Sr teal, N blue, O red, polyhedron borders black and polyhedron faces transparent.

3. Supra­molecular features

The crystal packing reveals the existence of 1D polymeric zigzag chains running along the a-axis direction (Figs. 3[link] and 4[link]), in which monomeric SrII units are inter­linked by one O atom of each isobutyrate ligand, which are all coordinated in a chelating, bridging μ2-η2:η1 mode. The H2mda ligands coord­inate in the chelating μ1-η1: η1: η1 mode to the Sr centers of I. The edge-sharing SrNO8 polyhedra are linked by the isobutyrate O1 and O1ii atoms on the one side and O3 and O3i atoms on the other side. Intra­molecular hydrogen bonding is present along the chains via O5—H5⋯O2, O6—H6⋯O4 and O6A—H6A⋯O4 contacts (Fig. 3[link], Table 3[link]).

Table 3
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A D⋯A D—H⋯A
O6A—H6A⋯O4iii 0.84 1.83 2.61 (5) 153
O6—H6B⋯O4iii 0.84 1.95 2.75 (3) 160
O5—H5⋯O2iv 0.84 1.87 2.680 (12) 163
Symmetry codes: (iii) x+1, y, z; (iv) [x-1, y, z].
[Figure 3]
Figure 3
Representation of a segment of the polymeric structure of [Sr(ib)2(H2mda)]n (I) along the crystallographic c axis. Color code: Sr teal, C gray, N blue, O red, bridging O spheres red and H atoms white. Hydrogen bonds are shown as dashed black lines. Disordered fragments are omitted for clarity.
[Figure 4]
Figure 4
Packing diagram of I, viewed down the a axis (left) and the c axis (right). Color code: Sr teal, C (ib) gray, C (H2mda) green, N blue, O red. H atoms and disordered fragments are omitted for clarity.

4. Database survey

A search of the Cambridge Structural Database (CSD, version 5.42, update of November 2020; Groom et al., 2016[Groom, C. R., Bruno, I. J., Lightfoot, M. P. & Ward, S. C. (2016). Acta Cryst. B72, 171-179.]) resulted in 34 hits for metal complexes ligated by isobutyrate and N-alkyl­diethano­lamine. To the best of our knowledge, there are no alkaline earth complexes as well as coordination polymers incorporating both ligands. There are four polymeric structures solely containing group two elements and isobutyrate anions: the magnesium complex catena-poly[[tri­aqua­(isobutyrato)-κO)magnesium]-μ-isobutyrato-κ2O:O′] monohydrate, refcode VIQTOG (Malaestean et al., 2013[Malaestean, I. L., Schmitz, S., Ellern, A. & Kögerler, P. (2013). Acta Cryst. C69, 1144-1146.]), catena-poly[[μ-aqua-di­aqua­(μ3-2-methyl­propano­ato-κ4O:O,O′:O′)calcium] 2-methyl­propano­ate dihydrate], refcode JUWMEW (Samolová & Fábry, 2020[Samolová, E. & Fábry, J. (2020). Acta Cryst. E76, 1684-1688.]), as well as the isostructural strontium complex, refcode JUWMIA (Samolová & Fábry, 2020[Samolová, E. & Fábry, J. (2020). Acta Cryst. E76, 1684-1688.]) and the mixed calcium/strontium complex catena-poly[[μ-aqua-di­aqua­(μ3-2-methyl­propano­ato-κ4O:O,O′:O′)calcium/strontium] 2-methyl­propano­ate dihydrate], refcode JUWMOG (Samolová & Fábry, 2020[Samolová, E. & Fábry, J. (2020). Acta Cryst. E76, 1684-1688.]).

5. Synthesis and crystallization

The one-pot reaction of freshly prepared hexa­nuclear zirconium complex [Zr6O4(OH)4(ib)12(H2O)]·3Hib (Kogler et al., 2004[Kogler, F. R., Jupa, M., Puchberger, M. & Schubert, U. (2004). J. Mater. Chem. 14, 3133-3138.], abbreviated as {Zr6}) with strontium(II) nitrate and manganese(II) chloride in a 1.0:2.2:2.2, molar ratio was performed in aceto­nitrile under aerobic conditions, involving 11.1 eq. of N-methyldi­ethano­lamine as a co-ligand and 4.0 eq. of tri­ethyl­amine as a base (see Fig. 5[link]). The polymeric coord­ination complex [Sr(ib)2(H2mda)]n (I) was isolated as colorless crystals. By-products could not be identified. The IR spectrum of I is characterized by the asymmetric O–C–O vibration bands at 1556 cm−1 and the symmetric O–C–O ones in the range of 1366–1426 cm−1.

[Figure 5]
Figure 5
Synthesis of compound I.

The TGA curve (Fig. 6[link]) shows that the thermal decomposition of I occurs between 130 and 440°C with a mass loss of C12H27NO3 per monomer unit (Δmtotal = 60.00% vs Δmcalcd. = 61.25%), and it yields SrCO3. Overall, the thermal stability of I up to 130°C in air is similar to that determined for isobutyrate di­ethano­lamine complexes of cobalt (140°C) and nickel (130°C) (Schmitz et al., 2016[Schmitz, S., Monakhov, K. Yu., van Leusen, J., Izarova, N. V., Hess, V. & Kögerler, P. (2016). RSC Adv. 6, 100664-100669.]).

[Figure 6]
Figure 6
Thermogravimetric analysis for I.

6. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 4[link]. The structure was solved using dual space methods and refined by full-matrix least-squares minimization on F2. The coordinates of all non-hydrogen atoms were refined with anisotropic thermal parameters. All H atoms were placed in geometrically idealized positions and refined using a rigid model and included as riding atoms, with methyl C—H = 0.98 Å, methyl­ene C—H = 0.99 Å, methine C—H = 1.00 Å and O—H = 0.84 Å. Isotropic displacement parameters were set to Uiso(H) = 1.2Ueq for the parent atom (1.5 for methyl and hy­droxy groups). The hy­droxy groups and the idealized methyl group were refined as rotating. Atoms C9, C10, C11, C12, C13, O5 and O6 of the H2mda ligand were refined as disordered over two sets of sites with site occupancies of 0.619 (3) and 0.381 (3). As a result of the short distance between the disordered atoms C11, C13, O5, O6 and their corresponding counterparts, EADP constraints were applied to equalize the displacement ellipsoids of the atom pairs.

Table 4
Experimental details

Crystal data
Chemical formula [Sr(C4H7O2)2(C5H13NO2)]
Mr 380.97
Crystal system, space group Monoclinic, P21/c
Temperature (K) 180
a, b, c (Å) 8.1516 (2), 19.1921 (6), 11.4288 (3)
β (°) 99.295 (2)
V (Å3) 1764.52 (8)
Z 4
Radiation type Cu Kα
μ (mm−1) 4.46
Crystal size (mm) 0.28 × 0.21 × 0.13
 
Data collection
Diffractometer Stoe Stadivari
Absorption correction Multi-scan (X-AREA LANA; Stoe, 2019[Stoe (2019). X-AREA. Stoe & Cie, Darmstadt, Germany.])
Tmin, Tmax 0.178, 0.458
No. of measured, independent and observed [I > 2σ(I)] reflections 15496, 3300, 3009
Rint 0.014
(sin θ/λ)max (Å−1) 0.611
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.018, 0.046, 1.06
No. of reflections 3300
No. of parameters 240
H-atom treatment H-atom parameters constrained
Δρmax, Δρmin (e Å−3) 0.39, −0.19
Computer programs: X-AREA Pilatus3_SV, Recipe and Integrate (Stoe, 2019[Stoe (2019). X-AREA. Stoe & Cie, Darmstadt, Germany.]), olex2.solve (Bourhis et al., 2015[Bourhis, L. J., Dolomanov, O. V., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2015). Acta Cryst. A71, 59-75.]), SHELXL2018/3 (Sheldrick, 2015[Sheldrick, G. M. (2015). Acta Cryst. C71, 3-8.]) and OLEX2 (Dolomanov et al., 2009[Dolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339-341.]).

Supporting information

CCDC reference: 2087088

Crystal structure: contains datablock I. DOI: https://doi.org/10.1107/S2056989021005594/dj2022sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989021005594/dj2022Isup3.hkl

Supporting information file. DOI: https://doi.org/10.1107/S2056989021005594/dj2022sup4.zip

checkCIF report


Computing details top

Data collection: X-AREA Pilatus3_SV (Stoe, 2019); cell refinement: X-AREA Recipe (Stoe, 2019); data reduction: X-AREA Integrate (Stoe, 2019); program(s) used to solve structure: olex2.solve (Bourhis et al., 2015); program(s) used to refine structure: SHELXL2018/3 (Sheldrick, 2015); molecular graphics: Olex2 1.3 (Dolomanov et al., 2009); software used to prepare material for publication: X-AREA (Stoe, 2019).

catena-Poly[[(N-methyldiethanolamine-κ3O,N,O')strontium(II)]-di-µ2-isobutyrato-κ3O,O':O;κ3O:O,O'] top
Crystal data top
[Sr(C4H7O2)2(C5H13NO2)]F(000) = 792
Mr = 380.97Dx = 1.434 Mg m−3
Monoclinic, P21/cCu Kα radiation, λ = 1.54186 Å
a = 8.1516 (2) ÅCell parameters from 16191 reflections
b = 19.1921 (6) Åθ = 4.5–70.9°
c = 11.4288 (3) ŵ = 4.46 mm−1
β = 99.295 (2)°T = 180 K
V = 1764.52 (8) Å3Block, light yellow
Z = 40.28 × 0.21 × 0.13 mm
Data collection top
Stoe Stadivari
diffractometer		3300 independent reflections
Radiation source: GeniX 3D HF Cu3009 reflections with I > 2σ(I)
Graded multilayer mirror monochromatorRint = 0.014
Detector resolution: 5.81 pixels mm-1θmax = 70.5°, θmin = 4.6°
rotation method, ω scansh = −6→9
Absorption correction: multi-scan
(XAREA LANA; Stoe, 2019)		k = −23→22
Tmin = 0.178, Tmax = 0.458l = −13→13
15496 measured reflections
Refinement top
Refinement on F2Primary atom site location: iterative
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.018H-atom parameters constrained
wR(F2) = 0.046 w = 1/[σ2(Fo2) + (0.031P)2 + 0.1664P]
where P = (Fo2 + 2Fc2)/3
S = 1.06(Δ/σ)max = 0.002
3300 reflectionsΔρmax = 0.39 e Å−3
240 parametersΔρmin = −0.19 e Å−3
0 restraints
Special details top

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 (Å2) top
xyzUiso*/UeqOcc. (<1)
Sr10.74277 (2)0.53023 (2)0.46969 (2)0.02003 (5)
O11.03404 (12)0.57713 (5)0.53587 (9)0.0276 (2)
N10.71783 (17)0.65620 (7)0.33604 (12)0.0315 (3)
C11.14299 (18)0.61161 (8)0.60142 (13)0.0248 (3)
O21.29545 (13)0.59817 (6)0.60970 (11)0.0350 (3)
C21.0907 (2)0.66959 (9)0.67912 (16)0.0333 (4)
H20.9673930.6755840.6600220.040*
O30.44290 (13)0.51634 (6)0.36832 (9)0.0277 (2)
C31.1366 (3)0.64916 (12)0.80933 (18)0.0564 (6)
H3A1.0798800.6057210.8236500.085*
H3B1.1024010.6862030.8592610.085*
H3C1.2571470.6424390.8286950.085*
O40.18685 (13)0.48389 (7)0.29816 (10)0.0360 (3)
C41.1738 (3)0.73767 (10)0.6536 (2)0.0579 (6)
H4A1.2945850.7312630.6657160.087*
H4B1.1454480.7739730.7072150.087*
H4C1.1347320.7516260.5712880.087*
O5A0.577 (3)0.6350 (9)0.5311 (11)0.0265 (9)0.381 (3)
H5A0.6090720.6366610.6046610.040*0.381 (3)
C50.33403 (18)0.49642 (8)0.28442 (13)0.0248 (3)
O6A0.882 (6)0.530 (3)0.273 (5)0.0294 (17)0.381 (3)
H6A0.9643260.5046790.2675290.044*0.381 (3)
C60.3829 (2)0.48362 (10)0.16298 (15)0.0350 (4)
H60.5020600.4970400.1663440.042*
C70.2768 (3)0.52822 (12)0.06894 (18)0.0542 (6)
H7A0.1594150.5158430.0650630.081*
H7B0.3104970.519856−0.0083770.081*
H7C0.2924950.5775680.0898220.081*
C80.3644 (3)0.40680 (11)0.13232 (17)0.0484 (5)
H8A0.4323870.3792900.1942900.073*
H8B0.4014590.3983220.0561460.073*
H8C0.2475700.3931700.1267310.073*
C9A0.5616 (6)0.6538 (3)0.2356 (5)0.0484 (14)0.381 (3)
H9AA0.4628610.6418320.2702310.073*0.381 (3)
H9AB0.5787480.6186260.1766470.073*0.381 (3)
H9AC0.5457470.6995580.1972780.073*0.381 (3)
C10A0.6919 (7)0.7102 (2)0.4143 (5)0.0447 (13)0.381 (3)
H10A0.6589940.7526260.3671580.054*0.381 (3)
H10B0.7988020.7202090.4660680.054*0.381 (3)
C11A0.5675 (15)0.6966 (8)0.4890 (14)0.0384 (12)0.381 (3)
H11A0.5816080.7303920.5553140.046*0.381 (3)
H11B0.4556280.7037090.4421460.046*0.381 (3)
C12A0.8593 (6)0.6604 (2)0.2824 (4)0.0372 (12)0.381 (3)
H12A0.9570840.6671640.3450230.045*0.381 (3)
H12B0.8496870.7021210.2308770.045*0.381 (3)
C13A0.893 (4)0.5941 (18)0.205 (3)0.0431 (8)0.381 (3)
H13A0.8095100.5927420.1312100.052*0.381 (3)
H13B1.0044600.5977450.1817220.052*0.381 (3)
O60.866 (3)0.5342 (16)0.268 (3)0.0294 (17)0.619 (3)
H6B0.9601280.5171840.2943660.044*0.619 (3)
O50.5875 (15)0.6406 (5)0.5558 (6)0.0265 (9)0.619 (3)
H50.5059030.6192090.5749900.040*0.619 (3)
C90.8519 (4)0.70964 (15)0.3830 (3)0.0411 (7)0.619 (3)
H9A0.9616380.6908030.3760320.062*0.619 (3)
H9B0.8469630.7196380.4664900.062*0.619 (3)
H9C0.8329100.7526780.3366860.062*0.619 (3)
C110.5250 (7)0.6997 (5)0.4694 (8)0.0384 (12)0.619 (3)
H11C0.4038610.7055980.4670520.046*0.619 (3)
H11D0.5800420.7437360.4986830.046*0.619 (3)
C120.7389 (4)0.63928 (16)0.2165 (2)0.0404 (8)0.619 (3)
H12C0.7470000.6830900.1721080.048*0.619 (3)
H12D0.6390440.6139610.1774950.048*0.619 (3)
C130.887 (2)0.5965 (11)0.2096 (17)0.0431 (8)0.619 (3)
H13C0.8967810.5873660.1257680.052*0.619 (3)
H13D0.9884420.6208320.2479820.052*0.619 (3)
C100.5591 (3)0.68558 (14)0.3441 (3)0.0372 (7)0.619 (3)
H10C0.4722200.6536330.3043690.045*0.619 (3)
H10D0.5481790.7300280.2995560.045*0.619 (3)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Sr10.01411 (8)0.02466 (8)0.02156 (8)−0.00039 (4)0.00361 (5)−0.00108 (5)
O10.0218 (5)0.0283 (5)0.0319 (6)−0.0029 (4)0.0016 (4)−0.0046 (4)
N10.0321 (8)0.0296 (7)0.0338 (7)0.0040 (5)0.0082 (6)0.0048 (6)
C10.0201 (7)0.0262 (7)0.0287 (7)−0.0014 (5)0.0059 (5)−0.0009 (6)
O20.0176 (6)0.0348 (6)0.0537 (7)−0.0017 (4)0.0092 (5)−0.0128 (5)
C20.0233 (8)0.0343 (8)0.0418 (9)0.0036 (6)0.0040 (6)−0.0114 (7)
O30.0203 (5)0.0360 (6)0.0259 (5)−0.0021 (4)0.0010 (4)−0.0006 (4)
C30.0662 (14)0.0652 (14)0.0378 (11)0.0156 (11)0.0084 (9)−0.0165 (10)
O40.0177 (6)0.0627 (8)0.0276 (6)−0.0007 (5)0.0043 (4)0.0012 (5)
C40.0619 (14)0.0340 (10)0.0818 (16)−0.0043 (9)0.0239 (11)−0.0198 (10)
O5A0.0273 (17)0.0322 (16)0.021 (3)−0.0033 (11)0.008 (3)−0.0085 (19)
C50.0200 (8)0.0308 (8)0.0235 (7)0.0022 (6)0.0031 (5)0.0009 (6)
O6A0.023 (4)0.035 (3)0.031 (2)0.007 (3)0.007 (3)0.0037 (18)
C60.0265 (9)0.0539 (10)0.0260 (8)−0.0021 (7)0.0088 (6)−0.0036 (7)
C70.0684 (15)0.0683 (14)0.0276 (9)0.0088 (11)0.0131 (9)0.0082 (9)
C80.0536 (12)0.0571 (12)0.0346 (10)0.0073 (9)0.0073 (8)−0.0139 (9)
C9A0.037 (3)0.052 (3)0.052 (3)−0.001 (2)−0.005 (2)0.017 (2)
C10A0.057 (3)0.026 (2)0.056 (3)−0.003 (2)0.022 (2)−0.002 (2)
C11A0.030 (3)0.0315 (12)0.056 (3)0.017 (2)0.015 (3)0.0070 (18)
C12A0.039 (3)0.034 (2)0.042 (3)0.0017 (18)0.015 (2)0.015 (2)
C13A0.0521 (15)0.0471 (17)0.0352 (18)0.0102 (11)0.0227 (11)0.0109 (12)
O60.023 (4)0.035 (3)0.031 (2)0.007 (3)0.007 (3)0.0037 (18)
O50.0273 (17)0.0322 (16)0.021 (3)−0.0033 (11)0.008 (3)−0.0085 (19)
C90.0362 (16)0.0362 (15)0.0495 (18)−0.0081 (12)0.0024 (12)0.0055 (13)
C110.030 (3)0.0315 (12)0.056 (3)0.017 (2)0.015 (3)0.0070 (18)
C120.051 (2)0.0420 (16)0.0275 (14)0.0089 (13)0.0056 (12)0.0089 (12)
C130.0521 (15)0.0471 (17)0.0352 (18)0.0102 (11)0.0227 (11)0.0109 (12)
C100.0311 (15)0.0330 (14)0.0478 (17)0.0068 (11)0.0076 (12)0.0106 (12)
Geometric parameters (Å, º) top
Sr1—O1i2.7563 (10)C6—H61.0000
Sr1—O3ii2.7244 (11)C6—C71.528 (3)
Sr1—O12.5377 (10)C6—C81.517 (3)
Sr1—O32.5444 (10)C7—H7A0.9800
Sr1—O2i2.6270 (11)C7—H7B0.9800
Sr1—O4ii2.6364 (11)C7—H7C0.9800
Sr1—O52.731 (11)C8—H8A0.9800
Sr1—O62.66 (3)C8—H8B0.9800
Sr1—N12.8495 (13)C8—H8C0.9800
Sr1—Sr1i4.2981 (3)C9A—H9AA0.9800
Sr1—Sr1ii4.2868 (3)C9A—H9AB0.9800
Sr1—O5A2.58 (2)C9A—H9AC0.9800
Sr1—C5ii3.0199 (15)C10A—H10A0.9900
Sr1—O6A2.68 (6)C10A—H10B0.9900
O1—C11.2541 (18)C10A—C11A1.450 (16)
N1—C9A1.571 (5)C11A—H11A0.9900
N1—C10A1.407 (5)C11A—H11B0.9900
N1—C12A1.393 (5)C12A—H12A0.9900
N1—C91.531 (3)C12A—H12B0.9900
N1—C121.441 (3)C12A—C13A1.60 (3)
N1—C101.428 (3)C13A—H13A0.9900
C1—O21.2578 (19)C13A—H13B0.9900
C1—C21.527 (2)O6—H6B0.8400
C2—H21.0000O6—C131.39 (4)
C2—C31.526 (3)O5—H50.8400
C2—C41.521 (3)O5—C111.537 (12)
O3—C51.2563 (18)C9—H9A0.9800
C3—H3A0.9800C9—H9B0.9800
C3—H3B0.9800C9—H9C0.9800
C3—H3C0.9800C11—H11C0.9900
O4—C51.2581 (19)C11—H11D0.9900
C4—H4A0.9800C11—C101.526 (10)
C4—H4B0.9800C12—H12C0.9900
C4—H4C0.9800C12—H12D0.9900
O5A—H5A0.8400C12—C131.471 (18)
O5A—C11A1.27 (2)C13—H13C0.9900
C5—C61.524 (2)C13—H13D0.9900
O6A—H6A0.8400C10—H10C0.9900
O6A—C13A1.46 (6)C10—H10D0.9900
O1—Sr1—O1i71.51 (4)H4A—C4—H4C109.5
O1—Sr1—N180.86 (4)H4B—C4—H4C109.5
O1i—Sr1—N1127.74 (4)Sr1—O5A—H5A102.1
O1—Sr1—O2i119.26 (3)C11A—O5A—Sr1128.5 (14)
O1—Sr1—O3163.08 (4)C11A—O5A—H5A109.5
O1—Sr1—O3ii120.63 (3)O3—C5—Sr1ii64.42 (8)
O1—Sr1—O4ii72.27 (3)O3—C5—O4122.22 (14)
O1—Sr1—O5A98.5 (4)O3—C5—C6119.20 (14)
O1i—Sr1—C5ii97.57 (4)O4—C5—Sr1ii60.41 (8)
O1—Sr1—C5ii96.16 (4)O4—C5—C6118.51 (13)
O1—Sr1—O6A75.4 (11)C6—C5—Sr1ii160.72 (11)
O1—Sr1—O677.3 (6)Sr1—O6A—H6A120.7
O1—Sr1—O594.8 (2)C13A—O6A—Sr1121 (3)
N1—Sr1—C5ii129.42 (4)C13A—O6A—H6A109.5
O2i—Sr1—O1i48.14 (3)C5—C6—H6108.6
O2i—Sr1—N1128.06 (4)C5—C6—C7110.42 (15)
O2i—Sr1—O3ii83.06 (4)C7—C6—H6108.6
O2i—Sr1—O4ii104.22 (4)C8—C6—C5109.65 (15)
O2i—Sr1—C5ii97.57 (4)C8—C6—H6108.6
O2i—Sr1—O6A75.6 (12)C8—C6—C7110.99 (16)
O2i—Sr1—O676.6 (7)C6—C7—H7A109.5
O2i—Sr1—O5144.7 (2)C6—C7—H7B109.5
O3—Sr1—O1i120.02 (3)C6—C7—H7C109.5
O3ii—Sr1—O1i102.22 (3)H7A—C7—H7B109.5
O3—Sr1—N182.22 (4)H7A—C7—H7C109.5
O3ii—Sr1—N1130.04 (4)H7B—C7—H7C109.5
O3—Sr1—O2i72.11 (3)C6—C8—H8A109.5
O3—Sr1—O3ii71.14 (4)C6—C8—H8B109.5
O3—Sr1—O4ii118.97 (3)C6—C8—H8C109.5
O3—Sr1—O5A72.5 (4)H8A—C8—H8B109.5
O3—Sr1—C5ii94.46 (4)H8A—C8—H8C109.5
O3ii—Sr1—C5ii24.58 (4)H8B—C8—H8C109.5
O3—Sr1—O6A97.1 (10)N1—C9A—H9AA109.5
O3—Sr1—O694.5 (6)N1—C9A—H9AB109.5
O3ii—Sr1—O570.7 (2)N1—C9A—H9AC109.5
O3—Sr1—O577.2 (2)H9AA—C9A—H9AB109.5
O4ii—Sr1—O1i84.80 (3)H9AA—C9A—H9AC109.5
O4ii—Sr1—N1127.72 (4)H9AB—C9A—H9AC109.5
O4ii—Sr1—O3ii48.46 (3)N1—C10A—H10A108.4
O4ii—Sr1—C5ii24.52 (4)N1—C10A—H10B108.4
O4ii—Sr1—O6A142.4 (9)N1—C10A—C11A115.7 (8)
O4ii—Sr1—O6145.4 (6)H10A—C10A—H10B107.4
O4ii—Sr1—O575.82 (16)C11A—C10A—H10A108.4
O5A—Sr1—N159.3 (4)C11A—C10A—H10B108.4
O5A—Sr1—C5ii71.5 (4)O5A—C11A—C10A112.5 (14)
O5A—Sr1—O6A122.7 (11)O5A—C11A—H11A109.1
O6A—Sr1—N163.5 (10)O5A—C11A—H11B109.1
O6A—Sr1—C5ii164.0 (9)C10A—C11A—H11A109.1
O6—Sr1—O1i70.0 (6)C10A—C11A—H11B109.1
O6—Sr1—N161.0 (6)H11A—C11A—H11B107.8
O6—Sr1—O3ii158.1 (7)N1—C12A—H12A108.5
O6—Sr1—C5ii167.2 (5)N1—C12A—H12B108.5
O6—Sr1—O5123.5 (7)N1—C12A—C13A115.2 (12)
O5—Sr1—O1i159.08 (16)H12A—C12A—H12B107.5
O5—Sr1—N162.5 (2)C13A—C12A—H12A108.5
O5—Sr1—C5ii67.5 (2)C13A—C12A—H12B108.5
Sr1—O1—Sr1i108.50 (4)O6A—C13A—C12A110 (3)
Sr1—O1—Sr1ii108.84 (5)O6A—C13A—H13A109.7
C1—O1—Sr1154.61 (10)O6A—C13A—H13B109.7
C1—O1—Sr1i90.10 (9)C12A—C13A—H13A109.7
C9A—N1—Sr1110.3 (2)C12A—C13A—H13B109.7
C10A—N1—Sr1106.8 (2)H13A—C13A—H13B108.2
C10A—N1—C9A107.4 (3)Sr1—O6—H6B97.5
C12A—N1—Sr1106.99 (19)C13—O6—Sr1122 (2)
C12A—N1—C9A108.1 (3)C13—O6—H6B109.5
C12A—N1—C10A117.2 (3)Sr1—O5—H598.5
C9—N1—Sr1113.27 (13)C11—O5—Sr1117.7 (5)
C12—N1—Sr1107.93 (14)C11—O5—H5109.5
C12—N1—C9107.2 (2)N1—C9—H9A109.5
C10—N1—Sr1106.71 (13)N1—C9—H9B109.5
C10—N1—C9108.39 (19)N1—C9—H9C109.5
C10—N1—C12113.45 (19)H9A—C9—H9B109.5
O1—C1—Sr1i65.45 (8)H9A—C9—H9C109.5
O1—C1—O2122.18 (14)H9B—C9—H9C109.5
O1—C1—C2119.64 (13)O5—C11—H11C109.1
O2—C1—Sr1i59.55 (8)O5—C11—H11D109.1
O2—C1—C2118.10 (13)H11C—C11—H11D107.9
C2—C1—Sr1i159.64 (11)C10—C11—O5112.4 (6)
C1—O2—Sr1i96.07 (9)C10—C11—H11C109.1
C1—C2—H2108.8C10—C11—H11D109.1
C3—C2—C1109.41 (14)N1—C12—H12C108.8
C3—C2—H2108.8N1—C12—H12D108.8
C4—C2—C1109.84 (15)N1—C12—C13113.6 (8)
C4—C2—H2108.8H12C—C12—H12D107.7
C4—C2—C3111.17 (17)C13—C12—H12C108.8
Sr1—O3—Sr1ii108.86 (4)C13—C12—H12D108.8
C5—O3—Sr1ii91.00 (9)O6—C13—C12106.9 (17)
C5—O3—Sr1152.58 (10)O6—C13—H13C110.3
C2—C3—H3A109.5O6—C13—H13D110.3
C2—C3—H3B109.5C12—C13—H13C110.3
C2—C3—H3C109.5C12—C13—H13D110.3
H3A—C3—H3B109.5H13C—C13—H13D108.6
H3A—C3—H3C109.5N1—C10—C11115.8 (3)
H3B—C3—H3C109.5N1—C10—H10C108.3
C5—O4—Sr1ii95.07 (9)N1—C10—H10D108.3
C2—C4—H4A109.5C11—C10—H10C108.3
C2—C4—H4B109.5C11—C10—H10D108.3
C2—C4—H4C109.5H10C—C10—H10D107.4
H4A—C4—H4B109.5
Sr1—O1—C1—Sr1i138.0 (2)Sr1—O5—C11—C101.0 (9)
Sr1i—O1—C1—O218.98 (15)O1—C1—O2—Sr1i−20.07 (16)
Sr1—O1—C1—O2157.02 (16)O1—C1—C2—C3113.07 (18)
Sr1i—O1—C1—C2−157.82 (13)O1—C1—C2—C4−124.64 (17)
Sr1—O1—C1—C2−19.8 (3)N1—C10A—C11A—O5A42.3 (14)
Sr1—N1—C10A—C11A−46.2 (7)N1—C12A—C13A—O6A−49 (3)
Sr1—N1—C12A—C13A54.3 (13)N1—C12—C13—O661.3 (18)
Sr1—N1—C12—C13−50.4 (9)O2—C1—C2—C3−63.9 (2)
Sr1—N1—C10—C1157.0 (5)O2—C1—C2—C458.4 (2)
Sr1i—C1—C2—C313.9 (4)C2—C1—O2—Sr1i156.78 (12)
Sr1i—C1—C2—C4136.2 (3)O3—C5—C6—C7−123.02 (18)
Sr1—O3—C5—Sr1ii137.4 (2)O3—C5—C6—C8114.37 (17)
Sr1ii—O3—C5—O418.43 (16)O4—C5—C6—C759.8 (2)
Sr1—O3—C5—O4155.79 (15)O4—C5—C6—C8−62.8 (2)
Sr1ii—O3—C5—C6−158.64 (13)C9A—N1—C10A—C11A72.0 (7)
Sr1—O3—C5—C6−21.3 (3)C9A—N1—C12A—C13A−64.4 (13)
Sr1ii—O4—C5—O3−19.14 (16)C10A—N1—C12A—C13A174.1 (13)
Sr1ii—O4—C5—C6157.94 (13)C12A—N1—C10A—C11A−166.1 (6)
Sr1—O5A—C11A—C10A−12.8 (19)O5—C11—C10—N1−41.3 (8)
Sr1ii—C5—C6—C7141.2 (3)C9—N1—C12—C1372.0 (9)
Sr1ii—C5—C6—C818.6 (4)C9—N1—C10—C11−65.3 (5)
Sr1—O6A—C13A—C12A15 (4)C12—N1—C10—C11175.7 (5)
Sr1—O6—C13—C12−41 (2)C10—N1—C12—C13−168.4 (9)
Symmetry codes: (i) −x+2, −y+1, −z+1; (ii) −x+1, −y+1, −z+1.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O6A—H6A···O4iii0.841.832.61 (5)153
O6—H6B···O4iii0.841.952.75 (3)160
O5—H5···O2iv0.841.872.680 (12)163
Symmetry codes: (iii) x+1, y, z; (iv) x−1, y, z.
Selected Continuous Shapes Measures (CShM) values for the geometry about the nine-coordinate SrII ions of I top
ShapeCapped square antiprism (C4v, J10)Spherical capped square antiprism (C4v)Tricapped trigonal prism (D3h, J51)Spherical tricapped trigonal prism (D3h)Muffin (Cs)
Sri4.3493.7655.8923.6963.732
Srii4.0263.3465.5753.4233.358
Symmetry codes: (i) 2 - x, 1 - y, 1 - z; (ii) 1 - x, 1 - y, 1 - z.
Selected bond lengths (Å) and angles (°). top
Sr1 – O1i2.7568 (13)Sr1 – O62.655 (4)
Sr1 – O3ii2.7251 (14)Sr1 – N12.8516 (16)
Sr1 – O12.5370 (12)Sr1 ··· Sr1i4.2981 (3)
Sr1 – O32.5441 (13)Sr1 ··· Sr1ii4.2868 (3)
Sr1 – O2i2.6273 (14)Sr1 – O1 – Sr1i108.50 (4)
Sr1 – O4ii2.6367 (14)Sr1 – O1 – Sr1ii108.84 (5)
Sr1 – O52.678 (4)
Symmetry codes: (i) 2 – x, 1 – y, 1 – z; (ii) 1 – x, 1 – y, 1 – z.

Acknowledgements

The authors are grateful to Professor H. Krautscheid (Leipzig University) for access to the single-crystal X-ray diffraction equipment.

Funding information

Funding for this research was provided by: the Leibniz Association through the Leibniz Collaborative Excellence funding program (iMolKit).

References

First citationAko, A. M., Waldmann, O., Mereacre, V., Klöwer, F., Hewitt, I. J., Anson, C. E., Güdel, H. U. & Powell, A. K. (2007). Inorg. Chem. 46, 756–766.  Web of Science CSD CrossRef PubMed CAS Google Scholar
 First citationBourhis, L. J., Dolomanov, O. V., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2015). Acta Cryst. A71, 59–75.  Web of Science CrossRef IUCr Journals Google Scholar
 First citationDolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339–341.  Web of Science CrossRef CAS IUCr Journals Google Scholar
 First citationGroom, C. R., Bruno, I. J., Lightfoot, M. P. & Ward, S. C. (2016). Acta Cryst. B72, 171–179.  Web of Science CrossRef IUCr Journals Google Scholar
 First citationHooper, T. N., Schnack, J., Piligkos, S., Evangelisti, M. & Brechin, E. K. (2012). Angew. Chem. Int. Ed. 51, 4633–4636.  Web of Science CSD CrossRef CAS Google Scholar
 First citationKogler, F. R., Jupa, M., Puchberger, M. & Schubert, U. (2004). J. Mater. Chem. 14, 3133–3138.  Web of Science CSD CrossRef CAS Google Scholar
 First citationLiu, X., Gao, P. & Hu, M. (2018). Polyhedron, 144, 119–124.  Web of Science CSD CrossRef CAS Google Scholar
 First citationLlunell, M., Casanova, D., Cirera, A., Alemany, A. & Alvarez, S. (2013). SHAPE. University of Barcelona, Barcelona, Spain.  Google Scholar
 First citationMalaestean, I. L., Schmitz, S., Ellern, A. & Kögerler, P. (2013). Acta Cryst. C69, 1144–1146.  Web of Science CSD CrossRef IUCr Journals Google Scholar
 First citationMalaestean, I. L., Speldrich, M., Ellern, A., Baca, S. G. & Kögerler, P. (2010). Polyhedron, 29, 1990–1997.  Web of Science CSD CrossRef CAS Google Scholar
 First citationParsons, S., Smith, A. A. & Winpenny, R. E. P. (2000). Chem. Commun. pp. 579–580.  Web of Science CSD CrossRef Google Scholar
 First citationSamolová, E. & Fábry, J. (2020). Acta Cryst. E76, 1684–1688.  Web of Science CSD CrossRef IUCr Journals Google Scholar
 First citationSchmitz, S., Monakhov, K. Yu., van Leusen, J., Izarova, N. V., Hess, V. & Kögerler, P. (2016). RSC Adv. 6, 100664–100669.  Web of Science CSD CrossRef CAS Google Scholar
 First citationSchmitz, S., Secker, T., Batool, M., van Leusen, J., Nadeem, M. A. & Kögerler, P. (2018). Inorg. Chim. Acta, 482, 522–525.  Web of Science CSD CrossRef CAS Google Scholar
 First citationSheldrick, G. M. (2015). Acta Cryst. C71, 3–8.  Web of Science CrossRef IUCr Journals Google Scholar
 First citationStoe (2019). X-AREA. Stoe & Cie, Darmstadt, Germany.  Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 77| Part 7| July 2021| Pages 703-707
https://doi.org/10.1107/S2056989021005594
Follow Acta Cryst. E
Sign up for e-alerts
E-alerts
Follow Acta Cryst. on Twitter
Twitter
Follow us on facebook
Facebook
Sign up for RSS feeds
RSS