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Crystal structures of catena-poly[[μ-aqua-di­aqua(μ3-2-methyl­propano­ato-κ4O:O,O′:O′)calcium] 2-methyl­propano­ate dihydrate], catena-poly[[μ-aqua-di­aqua­(μ3-2-methyl­propano­ato-κ4O:O,O′:O′)strontium] 2-methyl­propano­ate dihydrate] and catena-poly[[μ-aqua-di­aqua­(μ3-2-methyl­propano­ato-κ4O:O,O′:O′)(calcium/strontium)] 2-methyl­propano­ate dihydrate]

CROSSMARK_Color_square_no_text.svg

aInst. of Physics of the Czech Academy of Sciences, Na Slovance 2, 182 21 Praha 8, Czech Republic
*Correspondence e-mail: fabry@fzu.cz

Edited by M. Weil, Vienna University of Technology, Austria (Received 28 August 2020; accepted 21 September 2020; online 25 September 2020)

The crystal structures of catena-poly[[μ-aqua-di­aqua­(μ3-2-methyl­propano­ato-κ4O:O,O′:O′)calcium] 2-methyl­propano­ate dihydrate], {[Ca(C4H7O2)(H2O)3](C4H7O2)·2H2O}n, (I), catena-poly[[μ-aqua-di­aqua­(μ3-2-methyl­propano­ato-κ4O:O,O′:O′)strontium] 2-methyl­propano­ate dihydrate], {[Sr(C4H7O2)(H2O)3](C4H7O2)·2H2O}n, (II), and catena-poly[[μ-aqua-di­aqua­(μ3-2-methyl­propano­ato-κ4O:O,O′:O′)(calcium/strontium)] 2-methyl­propano­ate dihydrate], {[(Ca,Sr)(C4H7O2)(H2O)3](C4H7O2)·2H2O}n, (III), are related. (III) can be considered as an Sr-containing solid solution of (I), with Ca2+ and Sr2+ occupationally disordered in the ratio 0.7936 (16):0.2064 (16). (I)/(III) and (II) are homeotypic with different space groups of Pbca and Cmce, respectively. All the title crystal structures are composed of hydro­philic sheets containing the cations, carboxyl­ate groups as well as water mol­ecules. The hydro­phobic layers, which consist of 2-methyl­propano­ate chains, surround the hydro­philic sheets from both sides, thus forming a sandwich-like structure extending parallel to (001). The cohesion forces within these sheets are the cation–oxygen bonds and O—H⋯O hydrogen bonds of moderate strength. Stacking of these sandwiches along [001] is consolidated by van der Waals forces. The structures contain columns defined by the cation–oxygen inter­actions in which just one symmetry-independent 2-methyl­propano­ate anion is included, together with three water mol­ecules. These mol­ecules participate in an irregular coordination polyhedron composed of eight O atoms around the cation. Additional water mol­ecules as well as the second 2-methyl­propano­ate anion are not part of the coordination sphere. These mol­ecules are connected to the above-mentioned columns by O—H⋯O hydrogen bonds of moderate strength. In (II), the Sr2+ cation, two of the coordinating water mol­ecules and both anions are situated on a mirror plane with a concomitant positional disorder of the 2-methyl­propyl groups; the non-coordinating water mol­ecule also shows positional disorder of its hydrogen atom.

1. Chemical context

A search of the Cambridge Structural Database (Groom et al., 2016[Groom, C. R., Bruno, I. J., Lightfoot, M. P. & Ward, S. C. (2016). Acta Cryst. B72, 171-179.]; version 5.41 with updates until August 2020) for crystal structures containing solely alkaline earth cations and 2-methyl­propano­ate (or isobutyrate) anions revealed hexa­kis­[bis­(μ2-2-methyl­propano­ato)(2-methyl­propanoic acid)mag­nes­ium], refcode NAGQUI (Coker et al., 2004[Coker, E. N., Boyle, T. J., Rodríguez, M. A. & Alam, T. M. (2004). Polyhedron, 23, 1739-1747.]) and catena-poly[[tri­aqua­(isobutyrato-kO)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.]). Although limited to these two examples, some basic structural features of these compounds can be inferred from other simple carboxyl­ate salts. These features, among others, are illustrated by the series of structures determined by Coker et al. (2004[Coker, E. N., Boyle, T. J., Rodríguez, M. A. & Alam, T. M. (2004). Polyhedron, 23, 1739-1747.]), in which the number of carbon atoms in the carboxyl­ate anions gradually increases.

[Scheme 1]
[Scheme 2]
[Scheme 3]

In the crystal structure of catena-[tetra­kis­(μ2-formato)tetra­aqua­dimagnesium], MGFORD03 (Coker et al., 2004[Coker, E. N., Boyle, T. J., Rodríguez, M. A. & Alam, T. M. (2004). Polyhedron, 23, 1739-1747.]), no hydro­phobic organic chain is present. In the other member of this series, bis­(μ2-acetato-O,O,O′)-tetra­kis­(μ2-acetato-O,O′)bis­(acetic acid)di­aqua­trimagnesium acetic acid solvate, NAGQOC [Coker et al. (2004[Coker, E. N., Boyle, T. J., Rodríguez, M. A. & Alam, T. M. (2004). Polyhedron, 23, 1739-1747.]), see also the redetermination of this structure by Scheurell et al. (2012[Scheurell, K., König, R., Troyanov, S. I. & Kemnitz, E. (2012). Z. Anorg. Allg. Chem. 638, 1265-1273.]), NAGQOC02], there are sheets within the structure separated into hydro­philic parts (composed of the cations and oxygen atoms) and hydro­phobic parts (composed of methyl groups). The remaining free acetic acid mol­ecules are bound by Oacetic—H⋯O hydrogen bonds between the layers. NAGQUI is an example of a structure where the hydro­philic part is surrounded by a hydro­phobic layer. The same holds for hexa­kis­[bis­(μ2-3,3-di­methyl­butanato)(3,3-di­methyl­butanoic acid)magnesium], NAGRET (Coker et al., 2004[Coker, E. N., Boyle, T. J., Rodríguez, M. A. & Alam, T. M. (2004). Polyhedron, 23, 1739-1747.]), as well as for bis­(pivalato)tetra­kis­(pivalic acid)magnesium, VAMCUI01 [Coker et al. (2004[Coker, E. N., Boyle, T. J., Rodríguez, M. A. & Alam, T. M. (2004). Polyhedron, 23, 1739-1747.]), see also VAMCUI determined by Troyanov et al. (2002[Troyanov, S. I., Kiseleva, E. A., Rykov, A. N. & Korenev, Yu. M. (2002). Zh. Neorg. Khim. 47, 1667-1671.])]. Thus, the longer the organic chain, the more important the van der Waals forces become for mol­ecular cohesion in structures with carboxyl­ate anions. The different cohesion forces in the hydro­philic and the hydro­phobic parts are the reason for the formation of layer-like structures or structures where an organic part completely surrounds a hydro­philic metal–oxygen sheet or a hydro­philic cluster. Likewise, the longer the hydro­phobic chains, the larger is the probability of inclusion of non-coordinating water mol­ecules into the structure because the latter can provide binding bridges between the carboxyl­ate anions, which would otherwise be isolated. Such a situation is realised in VIQTOG where the water mol­ecules complete a column substructure that is defined by the cation–oxygen bonds stemming from the carboxyl­ate groups and water mol­ecules. The growing complexity of water substructures with a growing number of carbon atoms in carboxyl­ate anions has also been observed in the salts of the first five di­carb­oxy­lic acids with 4,6-di­amino­pyrimidine (Matulková et al., 2017[Matulková, I., Andreoni, R., Císařová, I., Němec, I. & Fábry, J. (2017). Z. Kristallogr. 232, 471-484.]).

The present study was undertaken to prepare dicalcium strontium hexa­kis­(2-methyl­propano­ate) with the intention that the resulting crystal structure might be related to dicalcium strontium hexa­kis­(propionate) (CASRPP06; Mishima, 1984[Mishima, N. (1984). J. Phys. Soc. Jpn, 53, 1062-1070.]), which exhibits inter­esting structural and physical properties (e.g. Itoh, 1992[Itoh, K. (1992). Ferroelectrics, 135, 291-302.]). However, the synthesis attempt resulted in one of the title structures, catena-poly[[μ-aqua-di­aqua­(μ3-2-methyl­propano­ato-κ4O:O,O′:O′)(calcium/stront­ium)] 2-methyl­propano­ate dihydrate], (III)[link]. We then also prepared the pure Ca and Sr compounds, i.e. (I)[link] and (II)[link], the crystal structures of which are also reported here.

2. Structural commentary

The structures have the same features and are composed of the respective cation, two carboxyl­ate mol­ecules and additional water mol­ecules. One of the carboxyl­ate anions and three water mol­ecules coordinate to the cation, the remaining mol­ecules form a substructure inter­connected by hydrogen bonds only. Compound (III)[link] is an Sr-containing solid solution of (I)[link], and the two structures are crystal-chemically isotypic. The refined ratio of the occupationally disordered cation site is Ca:Sr = 0.7936 (16):0.2064 (16). The crystal structures of (I)/(III) and (II)[link] are homeotypic (Lima-de-Faria et al., 1990[Lima-de-Faria, J., Hellner, E., Liebau, F., Makovicky, E. & Parthé, E. (1990). Acta Cryst. A46, 1-11.]), with similar lattice parameters and crystal-chemical features, but different space-group types.

There are three main cohesion forces present in the title structures: The first cohesion force regards the cation–oxygen inter­actions. For each of the crystal structures, there are eight oxygen atoms in the coordination sphere, defined by one carboxyl­ate mol­ecule in a bidentate bridging mode. (In VIQTOG there are two carboxyl­ate anions coordinating in a monodentate mode and bridging to other Mg2+ cations.) In the title structures, the cation-coordinating atoms are symmetry-equivalent atoms O1 in (II)[link], and O1 and O2 in (I)[link] and (III)[link], respectively. Other coordinating O atoms are the water O atoms O2, O3 and O4 in (II)[link], and the water O atoms O3, O4 and O5 in (I)[link] and (III)[link]. [The Sr2+ cation in (II)[link] is located on a mirror plane (Wyckoff position 8f)]. Numerical values of the cation–oxygen bonds are listed in Tables 1[link], 2[link] and 3[link] for structures (I)[link], (II)[link] and (III)[link], respectively. The coordination polyhedra form columns oriented parallel to the a axis. Because of the similarity of the three structures, (III)[link] was chosen as a representative (Fig. 1[link]a,b).

Table 1
Selected bond lengths (Å) for (I)[link]

Ca1—O3 2.3479 (12) Ca1—O2 2.4993 (11)
Ca1—O2i 2.3653 (10) Ca1—O1 2.5308 (11)
Ca1—O1ii 2.3938 (10) Ca1—O4ii 2.5446 (11)
Ca1—O5 2.4085 (12) Ca1—O4 2.6019 (11)
Symmetry codes: (i) [x+{\script{1\over 2}}, y, -z+{\script{1\over 2}}]; (ii) [x-{\script{1\over 2}}, y, -z+{\script{1\over 2}}].

Table 2
Selected bond lengths (Å) for (II)[link]

Sr1—O1i 2.4788 (10) Sr1—O1 2.6561 (11)
Sr1—O1ii 2.4788 (10) Sr1—O1iii 2.6561 (11)
Sr1—O3 2.4899 (16) Sr1—O2 2.6796 (11)
Sr1—O4 2.5593 (18) Sr1—O2ii 2.6796 (11)
Symmetry codes: (i) [-x+{\script{3\over 2}}, y, -z+{\script{1\over 2}}]; (ii) [x-{\script{1\over 2}}, y, -z+{\script{1\over 2}}]; (iii) -x+1, y, z.

Table 3
Selected bond lengths (Å) for (III)[link]

Ca1—O3 2.3719 (10) Ca1—O2 2.5457 (9)
Ca1—O2i 2.3845 (9) Ca1—O1 2.5714 (9)
Ca1—O1ii 2.4091 (8) Ca1—O4ii 2.5747 (9)
Ca1—O5 2.4209 (10) Ca1—O4 2.6271 (9)
Symmetry codes: (i) [x+{\script{1\over 2}}, y, -z+{\script{1\over 2}}]; (ii) [x-{\script{1\over 2}}, y, -z+{\script{1\over 2}}].
[Figure 1]
Figure 1
(a) View of the columns along the a axis in the crystal structure of (III)[link]. The columns depicted are formed by (Ca1/Sr1) (green) and O atoms (red); the latter are also depicted with bonds to carbon C atoms (grey) and H atoms (light-grey spheres of arbitrary radius). Displacement ellipsoids are shown at the 30% probability level. (b) Perspective view of the columns in (III)[link].

The second type of a cohesion force in the title structures originates from O—H⋯O hydrogen bonds of moderate strength (Gilli & Gilli, 2009[Gilli, G. & Gilli, P. (2009). The Nature of the Hydrogen Bond, p. 61. New York: Oxford University Press Inc.]) that link the above mentioned columns into hydro­philic sheets parallel to (001) (Fig. 2[link]a,b). Within a sheet, the coordinating water mol­ecules are solely engaged as donor groups whereas the non-coordinating water mol­ecules (Ow1 and Ow2 in (I)[link] and (III)[link], and Ow1 in (II)) have the functions both as donor and acceptor groups. The carboxyl­ate acceptor atoms O6 and O7 in the structure of (I)[link] and (III)[link] and the pair of equivalent atoms O5 (x, y, z and 1 − x, y, z) in the structure of (II)[link] stem from the second, non-coord­inating carboxyl­ate anion. Each of these carboxyl­ate oxygen atoms is an acceptor of three hydrogen bonds that are donated by two coordinating and by one non-coordinating water mol­ecules. Numerical values of these inter­actions are collated in Tables 4[link], 5[link] and 6[link] for structures (I)[link], (II)[link] and (III)), respectively. Fig. 3[link]a,b depict the hydrogen-bonded substructures in (II)[link] and (III)[link]. The graph-set motifs are R55(10) (Etter et al., 1990[Etter, M. C., MacDonald, J. C. & Bernstein, J. (1990). Acta Cryst. B46, 256-262.]), which include these atoms: Ow1–Ow1xiii(−x + [{1\over 2}], y, −z + [{1\over 2}])–Ow1xiv(x + [{1\over 2}], y, −z + [{1\over 2}])–Ow1iii(−x + 1, y, z)–O3xv(−x + 1, y + [{1\over 2}], −z + [{1\over 2}]) for (II)[link] and Ow1–Ow2v(−x − [{1\over 2}], y, −z + [{1\over 2}])–Ow1ii(x + [{1\over 2}], y, −z + [{1\over 2}])–Ow2–O3vi(−x + 1, y + [{1\over 2}], −z + [{1\over 2}]) for (III)[link], respectively. Note the disorder of the hydrogen atoms H2ow1 and H3ow1 bound to Ow1 in the structure of (II)[link].

Table 4
Hydrogen-bond geometry (Å, °) for (I)[link]

D—H⋯A D—H H⋯A DA D—H⋯A
O3—H1o3⋯Ow2iii 0.840 (13) 2.063 (15) 2.8754 (16) 162.5 (15)
O3—H2o3⋯Ow1iii 0.840 (14) 1.954 (15) 2.7829 (17) 168.8 (15)
O4—H1o4⋯O6 0.840 (13) 1.936 (13) 2.7560 (15) 165.1 (14)
O4—H2o4⋯O7i 0.840 (14) 1.925 (13) 2.7431 (15) 164.4 (14)
O5—H1o5⋯O6ii 0.840 (13) 1.966 (13) 2.7805 (15) 163.0 (18)
O5—H2o5⋯O7i 0.840 (13) 1.935 (13) 2.7597 (15) 166.9 (18)
Ow1—H1ow1⋯Ow2iv 0.840 (5) 1.882 (4) 2.7192 (17) 174 (2)
Ow1—H2ow1⋯O7 0.840 (13) 1.960 (13) 2.7872 (17) 168.0 (18)
Ow2—H1ow2⋯O6 0.840 (13) 1.969 (13) 2.8070 (17) 175.1 (17)
Ow2—H2ow2⋯Ow1i 0.840 (7) 1.886 (7) 2.7242 (18) 175 (2)
Symmetry codes: (i) [x+{\script{1\over 2}}, y, -z+{\script{1\over 2}}]; (ii) [x-{\script{1\over 2}}, y, -z+{\script{1\over 2}}]; (iii) [-x+1, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]; (iv) x-1, y, z.

Table 5
Hydrogen-bond geometry (Å, °) for (II)[link]

D—H⋯A D—H H⋯A DA D—H⋯A
O2—H1o2⋯O5 0.820 (16) 1.936 (15) 2.7465 (14) 169.3 (17)
O3—H1o3⋯Ow1iv 0.827 (17) 2.022 (17) 2.8339 (18) 167.1 (18)
O4—H1o4⋯O5i 0.844 (18) 1.964 (17) 2.7887 (16) 165.3 (19)
Ow1—H1ow1⋯O5iii 0.818 (18) 1.976 (19) 2.7913 (18) 174 (2)
Ow1—H2ow1⋯Ow1v 0.82 (2) 1.92 (3) 2.736 (2) 176 (5)
Ow1—H3ow1⋯Ow1vi 0.803 (17) 1.946 (17) 2.747 (2) 176 (5)
Symmetry codes: (i) [-x+{\script{3\over 2}}, y, -z+{\script{1\over 2}}]; (iii) -x+1, y, z; (iv) [-x+1, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]; (v) [-x+{\script{1\over 2}}, y, -z+{\script{1\over 2}}]; (vi) -x, y, z.

Table 6
Hydrogen-bond geometry (Å, °) for (III)[link]

D—H⋯A D—H H⋯A DA D—H⋯A
O3—H1o3⋯Ow2iii 0.840 (11) 2.061 (12) 2.8767 (14) 163.6 (13)
O3—H2o3⋯Ow1iii 0.840 (12) 1.953 (12) 2.7842 (14) 169.8 (13)
O4—H1o4⋯O6 0.840 (11) 1.932 (10) 2.7498 (13) 164.2 (11)
O4—H2o4⋯O7i 0.840 (11) 1.920 (10) 2.7382 (13) 164.2 (11)
O5—H1o5⋯O6ii 0.840 (11) 1.964 (11) 2.7831 (13) 164.9 (15)
O5—H2o5⋯O7i 0.840 (11) 1.944 (11) 2.7636 (13) 165.0 (14)
Ow1—H1ow1⋯Ow2iv 0.840 (4) 1.888 (3) 2.7233 (14) 172.8 (16)
Ow1—H2ow1⋯O7 0.840 (10) 1.951 (11) 2.7836 (14) 170.7 (15)
Ow2—H1ow2⋯O6 0.840 (10) 1.967 (10) 2.8050 (14) 175.3 (15)
Ow2—H2ow2⋯Ow1i 0.840 (5) 1.887 (5) 2.7248 (15) 175.2 (17)
Symmetry codes: (i) [x+{\script{1\over 2}}, y, -z+{\script{1\over 2}}]; (ii) [x-{\script{1\over 2}}, y, -z+{\script{1\over 2}}]; (iii) [-x+1, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]; (iv) x-1, y, z.
[Figure 2]
Figure 2
View of the unit-cell content of (a) (II)[link] and (b) (III)[link]. Hydrogen bonds are shown as yellow dashed lines; colour code as in Fig. 1[link]. The substructures with the hydro­philic sheets and hydrogen-bonded system, which connects the columns and water mol­ecules, are clearly discernible from the hydro­phobic part of the structure composed of 2-methyl­ethyl chains.
[Figure 3]
Figure 3
View of the hydrogen-bonded substructures in (a) (II)[link] and (b) (III)[link]. The symmetry codes correspond to those given in Tables 5[link] and 6[link], respectively. Colour code is as in Fig. 1[link].

The third type of cohesion force is related to van der Waals inter­actions between the hydro­phobic parts of the layers involving the methyl­ene and methyl groups. The shortest C⋯C distances observed in (I)[link] and (III)[link] are C4⋯C7(x + [{1\over 2}], −y, z + [{1\over 2}]), which are 3.762 (2) and 3.746 (2) Å, respectively. The shortest C⋯C inter­actions in (II)[link] for C3b⋯C6 (x + [{1\over 2}], −y + [{1\over 2}], −z) and C3b⋯C7 (−x + [{3\over 2}], −y + [{1\over 2}], −z) are 3.569 (4) and 3.146 (5) Å, respectively. These comparatively shorter distances indicate positional disorder (see Refinement section). As a general rule, it can be inferred that the shorter the C⋯C distances between adjacent groups, the greater is the probability for the occurrence of positional disorder of the 1-methyl­ethyl group. See also the discussion regarding the observed disorder in barium dicalcium hexa­kis­(propano­ate) (CABAPN) by Stadnicka & Glazer (1980[Stadnicka, K. & Glazer, A. M. (1980). Acta Cryst. B36, 2977-2985.]) where, however, the methyl carbons get as close as 4.05 (2) Å.

3. Synthesis and crystallization

For (III)[link], two molar equivalents of CaCO3 and one molar equivalent of SrCO3 were neutralized by six molar equivalents of 2-methyl­propionic acid (using 0.76 g of CaCO3, 0.56 g of SrCO3 and about 2.50 g of 2-methyl­propionic acid). The solution was heated at 343 K, an excess of the acid was then added until the pH was between 5 and 6. The solution was filtered and then heated at 313 K until needle-like colourless crystals appeared. The pure Ca compound, (I)[link], and the pure Sr compound, (II)[link], were prepared for the sake of comparison. 0.85 g of CaCO3 were neutralized by 1.5 g of 2-methyl­propionic acid and 1.26 g of SrCO3 were neutralized by 1.5 g of 2-methyl­propionic acid, respectively; in each case these values correspond to the molar ratio of 1:2. The solutions were heated at 343 K, an excess of the acid was then added until the pH was between 5 and 6. The solutions were filtered and then heated at 313 K until needle-like colourless crystals appeared.

We have also tried to prepare magnesium 2-methyl­propano­ate and barium 2-methyl­propano­ate in a similar way as for (I)–(III). However, it turned out that the obtained crystals of the former compound correspond to VIQTOG, while the crystal structure of the latter compound is modulated and is being solved at present. Provided that we obtain a satisfactory model, the results will be published elsewhere.

4. Structure determination and refinement

Crystal data, data collection and structure refinement details are summarized in Table 7[link]. In all structures, the methane­triyl hydrogen atoms were placed in calculated positions and refined with Cmethane­tri­yl—Hmethane­tri­yl = 1.00 Å, Uiso(Hmethane­tri­yl) = 1.2Ueq(Cmethane­tri­yl). Methyl hydrogen atoms were discernible in difference electron-density maps and were refined with Cmeth­yl—Hmeth­yl = 0.98 Å, Uiso(Hmeth­yl) = 1.5Ueq(Cmeth­yl). Finally, difference electron density maps revealed the water hydrogen atoms, which were refined with restraints of Owater—Hwater = 0.840 (1) Å.

Table 7
Experimental details

  (I) (II) (III)
Crystal data
Chemical formula [Ca(C4H7O2)(H2O)3]·C4H7O2·2H2O [Sr(C4H7O2)(H2O)3]·C4H7O2·2H2O [Ca0.794Sr0.206(C4H7O2)(H2O)3]·C4H7O2·2H2O
Mr 304.4 351.9 314.2
Crystal system, space group Orthorhombic, Pbca Orthorhombic, Cmce Orthorhombic, Pbca
Temperature (K) 120 120 120
a, b, c (Å) 6.6662 (2), 19.5903 (7), 23.4286 (8) 6.8801 (3), 19.7520 (11), 23.2734 (13) 6.7153 (3), 19.6061 (10), 23.3498 (11)
V3) 3059.61 (18) 3162.8 (3) 3074.3 (3)
Z 8 8 8
Radiation type Mo Kα Mo Kα Mo Kα
μ (mm−1) 0.44 3.44 1.08
Crystal size (mm) 0.27 × 0.17 × 0.05 0.24 × 0.12 × 0.08 0.59 × 0.18 × 0.08
 
Data collection
Diffractometer Bruker D8 VENTURE Kappa Duo PHOTON 100 CMOS Bruker D8 VENTURE Kappa Duo PHOTON 100 CMOS Bruker D8 VENTURE Kappa Duo PHOTON 100 CMOS
Absorption correction Multi-scan (SADABS; Bruker, 2017[Bruker (2017). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Multi-scan (SADABS; Bruker, 2017[Bruker (2017). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Multi-scan (SADABS; Bruker, 2017[Bruker (2017). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.])
Tmin, Tmax 0.889, 0.980 0.491, 0.770 0.573, 0.917
No. of measured, independent and observed [I > 3σ(I)] reflections 25865, 3511, 2955 21213, 1965, 1762 25462, 3533, 2787
Rint 0.033 0.032 0.030
(sin θ/λ)max−1) 0.649 0.649 0.651
 
Refinement
R[F > 3σ(F)], wR(F), S 0.039, 0.081, 1.99 0.021, 0.055, 1.79 0.026, 0.062, 1.54
No. of reflections 3511 1965 3533
No. of parameters 193 126 195
No. of restraints 10 9 10
H-atom treatment H atoms treated by a mixture of independent and constrained refinement H atoms treated by a mixture of independent and constrained refinement H atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å−3) 0.31, −0.38 0.37, −0.30 0.27, −0.25
Computer programs: APEX2 and SAINT (Bruker, 2017[Bruker (2017). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]), SUPERFLIP (Palatinus & Chapuis, 2007[Palatinus, L. & Chapuis, G. (2007). J. Appl. Cryst. 40, 786-790.]), SHELXT (Sheldrick, 2015[Sheldrick, G. M. (2015). Acta Cryst. A71, 3-8.]), JANA2006 (Petříček et al., 2014[Petříček, V., Dušek, M. & Palatinus, L. (2014). Z. Kristallogr. 229, 345-352.]), DIAMOND (Brandenburg, 2015[Brandenburg, K. (2015). DIAMOND. Crystal Impact, Bonn, Germany.]) and publCIF (Westrip, 2010[Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.]).

For (II)[link], difference electron-density maps revealed positional disorder of the 2-methyl­propyl entity in both anions. This positional disorder affects the non-oxygen atoms that are not situated on the mirror plane (Wyckoff position 8f). In addition, methyl atoms C3a and C3b with their attached hydrogen atoms were first subjected to a trial refinement of their occupancies, which resulted in 0.510 (5) and 0.490 (5) for C3a and C3b and the attached hydrogen atoms, respectively. In the final model, the occupancies were fixed at 0.50 for these groups. Ow1 is situated in a general position like its hydrogen atoms. As a result of the local environment, H1ow1 was assumed to be fully occupied while H2ow1 and H3ow1 were supposed to be equally disordered over two positions. This assumption turned out to be in agreement with a trial refinement of their occupational parameters despite the very low scattering power of the hydrogen atoms.

For (III)[link], the Ca/Sr occupation was refined [ratio 0.7936 (16):0.2064 (16)] under the assumption of the same position and the same displacement parameters for Ca and Sr and a fully occupied site. A B-C type 1 Lorentzian isotropic (Becker & Coppens, 1974[Becker, P. J. & Coppens, P. (1974). Acta Cryst. A30, 129-147.]) extinction correction was applied.

Supporting information


Computing details top

For all structures, data collection: APEX2 (Bruker, 2017); cell refinement: SAINT (Bruker, 2017); data reduction: SAINT (Bruker, 2017). Program(s) used to solve structure: SUPERFLIP (Palatinus & Chapuis, 2007) for (I), (III); SHELXT (Sheldrick, 2015) for (II). For all structures, program(s) used to refine structure: JANA2006 (Petříček et al., 2014); molecular graphics: DIAMOND (Brandenburg, 2015); software used to prepare material for publication: publCIF (Westrip, 2010).

\ catena-Poly[[µ-aqua-diaqua(µ3-2-methylpropanoato-\ κ4O:O,O':O')calcium] 2-methylpropanoate dihydrate] (I) top
Crystal data top
[Ca(C4H7O2)(H2O)3]·C4H7O2·2H2OThere have been used diffractions with I/σ(I)>20 for the unit cell determination.
Mr = 304.4Dx = 1.321 Mg m3
Orthorhombic, PbcaMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2abCell parameters from 9916 reflections
a = 6.6662 (2) Åθ = 2.3–27.5°
b = 19.5903 (7) ŵ = 0.44 mm1
c = 23.4286 (8) ÅT = 120 K
V = 3059.61 (18) Å3Prism, colourless
Z = 80.27 × 0.17 × 0.05 mm
F(000) = 1312
Data collection top
Bruker D8 VENTURE Kappa Duo PHOTON 100 CMOS
diffractometer
3511 independent reflections
Radiation source: X-ray tube2955 reflections with I > 3σ(I)
Quazar Mo multilayer optic monochromatorRint = 0.033
φ and ω scansθmax = 27.5°, θmin = 2.1°
Absorption correction: multi-scan
(SADABS; Bruker, 2017)
h = 88
Tmin = 0.889, Tmax = 0.980k = 2425
25865 measured reflectionsl = 3030
Refinement top
Refinement on F266 constraints
R[F > 3σ(F)] = 0.039Primary atom site location: charge flipping
wR(F) = 0.081H atoms treated by a mixture of independent and constrained refinement
S = 1.99Weighting scheme based on measured s.u.'s w = 1/(σ2(I) + 0.0004I2)
3511 reflections(Δ/σ)max = 0.015
193 parametersΔρmax = 0.31 e Å3
10 restraintsΔρmin = 0.38 e Å3
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Ca10.51243 (4)0.148107 (15)0.283542 (12)0.01153 (9)
O10.67506 (14)0.12357 (6)0.18811 (5)0.0155 (3)
O20.34606 (14)0.12092 (6)0.19069 (4)0.0161 (3)
C10.5086 (2)0.11831 (8)0.16303 (6)0.0129 (4)
C20.4989 (2)0.10975 (8)0.09862 (7)0.0165 (4)
H1c20.4464180.1538680.0832080.0198*
C30.3552 (3)0.05243 (10)0.08221 (7)0.0284 (6)
H1c30.3492270.0485920.0405360.0426*
H2c30.4030260.0092710.0984190.0426*
H3c30.2211790.062580.0971190.0426*
C40.7039 (2)0.09872 (10)0.07130 (7)0.0238 (5)
H1c40.6892120.0969320.0297010.0357*
H2c40.7931350.1364970.0816340.0357*
H3c40.7610630.0556380.0849790.0357*
O30.49949 (16)0.03175 (6)0.30728 (6)0.0229 (4)
H1o30.3920 (16)0.0098 (9)0.3109 (8)0.0343*
H2o30.594 (2)0.0035 (8)0.3078 (8)0.0343*
O40.76674 (16)0.23978 (6)0.24860 (5)0.0156 (3)
H1o40.737 (3)0.2657 (8)0.2213 (5)0.0233*
H2o40.804 (3)0.2649 (8)0.2756 (5)0.0233*
O50.52665 (15)0.22166 (6)0.36582 (5)0.0168 (3)
H1o50.4273 (17)0.2477 (8)0.3694 (8)0.0252*
H2o50.6286 (17)0.2468 (8)0.3667 (8)0.0252*
O60.69414 (15)0.30599 (6)0.14688 (4)0.0181 (3)
O70.36106 (15)0.30246 (6)0.15020 (5)0.0180 (3)
C50.5238 (2)0.31076 (8)0.12347 (6)0.0137 (4)
C60.5131 (2)0.33159 (9)0.06102 (7)0.0179 (4)
H1c60.3796230.3176050.0454540.0215*
C70.5390 (3)0.40883 (9)0.05774 (7)0.0268 (5)
H1c70.5306880.423530.0178240.0403*
H2c70.4327690.4311020.0798680.0403*
H3c70.6700910.4215070.0734090.0403*
C80.6681 (3)0.29543 (10)0.02414 (7)0.0295 (6)
H1c80.6517250.3095880.0157040.0443*
H2c80.8031430.3074660.0372730.0443*
H3c80.6493090.2459410.027110.0443*
Ow10.22518 (17)0.42507 (7)0.19654 (5)0.0225 (4)
H1ow10.1005 (5)0.4296 (11)0.1931 (8)0.0337*
H2ow10.253 (3)0.3889 (6)0.1790 (8)0.0337*
Ow20.81843 (18)0.43259 (7)0.19043 (5)0.0229 (4)
H1ow20.782 (3)0.3957 (5)0.1754 (8)0.0344*
H2ow20.791 (3)0.4276 (11)0.2252 (2)0.0344*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Ca10.00793 (14)0.01282 (15)0.01385 (16)0.00014 (12)0.00009 (12)0.00034 (11)
O10.0097 (5)0.0190 (6)0.0176 (6)0.0006 (4)0.0018 (4)0.0019 (5)
O20.0099 (5)0.0213 (6)0.0173 (6)0.0007 (5)0.0010 (4)0.0039 (5)
C10.0124 (7)0.0089 (7)0.0175 (7)0.0007 (6)0.0003 (6)0.0006 (6)
C20.0153 (7)0.0187 (8)0.0154 (7)0.0004 (7)0.0001 (6)0.0011 (6)
C30.0300 (10)0.0383 (12)0.0169 (9)0.0148 (9)0.0002 (7)0.0072 (8)
C40.0217 (8)0.0315 (11)0.0182 (9)0.0031 (8)0.0042 (7)0.0065 (8)
O30.0121 (5)0.0141 (6)0.0424 (7)0.0006 (5)0.0006 (5)0.0027 (5)
O40.0172 (5)0.0150 (6)0.0145 (6)0.0002 (5)0.0009 (4)0.0004 (5)
O50.0114 (5)0.0183 (6)0.0207 (6)0.0007 (4)0.0009 (5)0.0028 (5)
O60.0151 (5)0.0217 (7)0.0175 (6)0.0018 (5)0.0029 (4)0.0010 (5)
O70.0142 (5)0.0200 (6)0.0198 (6)0.0016 (5)0.0029 (4)0.0009 (5)
C50.0160 (7)0.0078 (7)0.0173 (7)0.0001 (6)0.0002 (6)0.0013 (6)
C60.0149 (7)0.0217 (8)0.0170 (8)0.0021 (7)0.0017 (6)0.0014 (6)
C70.0380 (10)0.0210 (9)0.0215 (9)0.0040 (8)0.0008 (8)0.0061 (7)
C80.0419 (11)0.0276 (11)0.0191 (9)0.0059 (9)0.0078 (8)0.0003 (8)
Ow10.0164 (6)0.0178 (7)0.0333 (7)0.0000 (5)0.0021 (5)0.0035 (5)
Ow20.0213 (6)0.0194 (7)0.0280 (7)0.0000 (5)0.0028 (5)0.0035 (6)
Geometric parameters (Å, º) top
Ca1—O32.3479 (12)C8—H1c80.98
Ca1—O2i2.3653 (10)C8—H2c80.98
Ca1—O1ii2.3938 (10)C8—H3c80.98
Ca1—O52.4085 (12)O3—H1o30.840 (13)
Ca1—O22.4993 (11)O3—H2o30.840 (14)
Ca1—O12.5308 (11)O4—H1o40.840 (13)
Ca1—O4ii2.5446 (11)O4—H2o40.840 (14)
Ca1—O42.6019 (11)O5—H1o50.840 (13)
O1—C11.2597 (17)O5—H2o50.840 (13)
O2—C11.2637 (17)Ow1—H1ow10.840 (5)
C1—C21.520 (2)Ow1—H2ow10.840 (13)
C2—H1c21Ow2—H1ow20.840 (13)
C2—C31.525 (2)Ow2—H2ow20.840 (7)
C2—C41.524 (2)C2—C64.435 (2)
C3—H1c30.98C2—C84.189 (2)
C3—H2c30.98C2—C8iii4.073 (2)
C3—H3c30.98C3—C4iv4.443 (2)
C4—H1c40.98C3—C7iii3.971 (2)
C4—H2c40.98C3—C7v3.892 (3)
C4—H3c40.98C3—C8iii4.080 (3)
O6—C51.2643 (18)C4—C6vi3.965 (2)
O7—C51.2634 (18)C4—C7vi3.762 (2)
C5—C61.520 (2)C4—C7vii4.108 (3)
C6—H1c61C4—C84.016 (3)
C6—C71.525 (2)C4—C8vi4.345 (2)
C6—C81.522 (2)C6—C8iii3.932 (2)
C7—H1c70.98C8—C8iii3.944 (3)
C7—H2c70.98C8—C8vi3.944 (3)
C7—H3c70.98
O1—Ca1—O1ii127.55 (4)H1c2—C2—C4106.53
O1—Ca1—O251.73 (3)C3—C2—C4110.65 (14)
O1—Ca1—O2i77.29 (3)C2—C3—H1c3109.47
O1—Ca1—O392.33 (4)C2—C3—H2c3109.47
O1—Ca1—O464.79 (4)C2—C3—H3c3109.47
O1—Ca1—O4ii98.53 (4)H1c3—C3—H2c3109.47
O1—Ca1—O5143.49 (4)H1c3—C3—H3c3109.47
O1ii—Ca1—O277.40 (3)H2c3—C3—H3c3109.47
O1ii—Ca1—O2i140.12 (4)C2—C4—H1c4109.47
O1ii—Ca1—O372.83 (4)C2—C4—H2c4109.47
O1ii—Ca1—O4146.94 (4)C2—C4—H3c4109.47
O1ii—Ca1—O4ii67.61 (4)H1c4—C4—H2c4109.47
O1ii—Ca1—O586.28 (4)H1c4—C4—H3c4109.47
O2—Ca1—O2i126.26 (4)H2c4—C4—H3c4109.47
O2—Ca1—O389.03 (4)C5—C6—H1c6108.62
O2—Ca1—O499.34 (4)C5—C6—C7108.04 (13)
O2—Ca1—O4ii66.87 (4)C5—C6—C8112.92 (13)
O2—Ca1—O5147.31 (4)H1c6—C6—C7110.74
O2i—Ca1—O375.85 (4)H1c6—C6—C8105.64
O2i—Ca1—O467.86 (4)C7—C6—C8110.89 (14)
O2i—Ca1—O4ii147.11 (4)C6—C7—H1c7109.47
O2i—Ca1—O583.88 (4)C6—C7—H2c7109.47
O3—Ca1—O4140.23 (4)C6—C7—H3c7109.47
O3—Ca1—O4ii137.03 (4)H1c7—C7—H2c7109.47
O3—Ca1—O5113.12 (4)H1c7—C7—H3c7109.47
O4—Ca1—O4ii80.74 (3)H2c7—C7—H3c7109.47
O4—Ca1—O579.23 (4)C6—C8—H1c8109.47
O4ii—Ca1—O580.79 (4)C6—C8—H2c8109.47
Ca1—O1—Ca1i96.85 (4)C6—C8—H3c8109.47
Ca1—O2—Ca1ii98.46 (4)H1c8—C8—H2c8109.47
Ca1—O4—Ca1i91.45 (4)H1c8—C8—H3c8109.47
O1—C1—O2120.85 (13)H2c8—C8—H3c8109.47
O1—C1—C2120.64 (12)H1o3—O3—H2o3107.6 (15)
O2—C1—C2118.50 (12)H1o4—O4—H2o4106.8 (14)
C1—C2—H1c2106.15H1o5—O5—H2o5106.3 (14)
C1—C2—C3111.00 (13)H1ow1—Ow1—H2ow1105 (2)
C1—C2—C4113.24 (12)H1ow2—Ow2—H2ow2104.1 (19)
H1c2—C2—C3108.99
Symmetry codes: (i) x+1/2, y, z+1/2; (ii) x1/2, y, z+1/2; (iii) x1/2, y+1/2, z; (iv) x1, y, z; (v) x+1/2, y1/2, z; (vi) x+1/2, y+1/2, z; (vii) x+3/2, y1/2, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O3—H1o3···Ow2viii0.840 (13)2.063 (15)2.8754 (16)162.5 (15)
O3—H2o3···Ow1viii0.840 (14)1.954 (15)2.7829 (17)168.8 (15)
O4—H1o4···O60.840 (13)1.936 (13)2.7560 (15)165.1 (14)
O4—H2o4···O7i0.840 (14)1.925 (13)2.7431 (15)164.4 (14)
O5—H1o5···O6ii0.840 (13)1.966 (13)2.7805 (15)163.0 (18)
O5—H2o5···O7i0.840 (13)1.935 (13)2.7597 (15)166.9 (18)
Ow1—H1ow1···Ow2iv0.840 (5)1.882 (4)2.7192 (17)174 (2)
Ow1—H2ow1···O70.840 (13)1.960 (13)2.7872 (17)168.0 (18)
Ow2—H1ow2···O60.840 (13)1.969 (13)2.8070 (17)175.1 (17)
Ow2—H2ow2···Ow1i0.840 (7)1.886 (7)2.7242 (18)175 (2)
Symmetry codes: (i) x+1/2, y, z+1/2; (ii) x1/2, y, z+1/2; (iv) x1, y, z; (viii) x+1, y1/2, z+1/2.
catena-Poly[[µ-aqua-diaqua(µ3-2-methylpropanoato-\ κ4O:O,O':O')strontium] 2-methylpropanoate dihydrate] (II) top
Crystal data top
[Sr(C4H7O2)(H2O)3]·C4H7O2·2H2OThere have been used diffractions with I/σ(I)>20 for the unit cell determination.
Mr = 351.9Dx = 1.478 Mg m3
Orthorhombic, CmceMo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2bc 2Cell parameters from 9972 reflections
a = 6.8801 (3) Åθ = 2.2–27.5°
b = 19.7520 (11) ŵ = 3.44 mm1
c = 23.2734 (13) ÅT = 120 K
V = 3162.8 (3) Å3Prism, colourless
Z = 80.24 × 0.12 × 0.08 mm
F(000) = 1456
Data collection top
Bruker D8 VENTURE Kappa Duo PHOTON 100 CMOS
diffractometer
1965 independent reflections
Radiation source: X-ray tube1762 reflections with I > 3σ(I)
Quazar Mo multilayer optic monochromatorRint = 0.032
φ and ω scansθmax = 27.5°, θmin = 2.2°
Absorption correction: multi-scan
(SADABS; Bruker, 2017)
h = 88
Tmin = 0.491, Tmax = 0.770k = 2525
21213 measured reflectionsl = 3027
Refinement top
Refinement on F262 constraints
R[F > 3σ(F)] = 0.021Primary atom site location: dual-space method
wR(F) = 0.055H atoms treated by a mixture of independent and constrained refinement
S = 1.79Weighting scheme based on measured s.u.'s w = 1/(σ2(I) + 0.0004I2)
1965 reflections(Δ/σ)max = 0.050
126 parametersΔρmax = 0.37 e Å3
9 restraintsΔρmin = 0.30 e Å3
Special details top

Refinement. The positions of the methyl hydrogen atoms s H1C6, H2C6 and H3C6 were restrained by the angle restraints 56.250?(1) ° for the angles H1c6—C6—H2c6iii, H2c6—C6—H2c6iii, H2c6—C6—H2c6iii, H3c6—C6—H3c6iii ((iii) x + 1, y, z).

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/UeqOcc. (<1)
Sr10.50.145526 (9)0.287511 (8)0.01228 (6)
O10.65991 (15)0.11785 (5)0.18632 (5)0.0166 (3)
C10.50.11399 (10)0.15989 (9)0.0130 (6)
C20.50.10609 (11)0.09535 (10)0.0163 (6)
H1c20.446230.1493670.0797110.0196*0.5
C3a0.3722 (5)0.04613 (19)0.07858 (15)0.0299 (11)0.5
H1c3a0.4292810.0042340.0935480.0448*0.5
H2c3a0.2418960.0522140.0948060.0448*0.5
H3c3a0.3632330.0434190.0366180.0448*0.5
C3b0.7010 (5)0.09931 (18)0.06811 (14)0.0233 (10)0.5
H1c3b0.7782280.1396820.0768910.035*0.5
H2c3b0.7662180.0591550.083590.035*0.5
H3c3b0.6873850.0947330.0263760.035*0.5
O20.750.23969 (8)0.250.0159 (4)
H1o20.717 (3)0.2627 (9)0.2223 (6)0.0238*
O30.50.02368 (8)0.31496 (8)0.0218 (5)
H1o30.599 (2)0.0003 (10)0.3152 (9)0.0328*
O40.50.22986 (9)0.37100 (8)0.0276 (6)
H1o40.597 (2)0.2558 (10)0.3707 (9)0.0414*
O50.66149 (19)0.30397 (6)0.14868 (5)0.0267 (4)
C40.50.31058 (11)0.12363 (10)0.0204 (7)
C50.50.33102 (9)0.06050 (8)0.0185 (6)
H1c50.3781860.3145690.0416720.0222*0.5
C60.50.40764 (9)0.05703 (8)0.0570 (13)
H1c60.3657060.4241530.0562820.0855*0.5
H2c60.567150.4263130.0906130.0855*0.5
H3c60.5671430.4219940.0219480.0855*0.5
C70.6601 (5)0.2941 (2)0.02353 (15)0.0302 (12)0.5
H1c70.7880410.3131740.0324790.0452*0.5
H2c70.6596770.2456070.0325290.0452*0.5
H3c70.6321220.3004850.0173980.0452*0.5
Ow10.1996 (2)0.42598 (7)0.19314 (6)0.0323 (4)
H1ow10.233 (3)0.3890 (8)0.1810 (10)0.0484*
H2ow10.228 (8)0.424 (2)0.2273 (9)0.0484*0.5
H3ow10.083 (2)0.424 (2)0.1927 (19)0.0484*0.5
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Sr10.01072 (11)0.01255 (11)0.01357 (12)000.00006 (8)
O10.0105 (5)0.0232 (6)0.0160 (6)0.0002 (4)0.0021 (4)0.0048 (5)
C10.0139 (10)0.0088 (9)0.0163 (11)000.0014 (8)
C20.0160 (11)0.0193 (11)0.0137 (11)000.0003 (9)
C3a0.0282 (19)0.044 (2)0.0176 (17)0.0197 (17)0.0033 (15)0.0109 (16)
C3b0.0209 (16)0.0328 (19)0.0164 (16)0.0053 (14)0.0062 (13)0.0033 (14)
O20.0209 (8)0.0128 (7)0.0140 (8)00.0028 (7)0
O30.0114 (8)0.0127 (8)0.0415 (11)000.0013 (7)
O40.0419 (12)0.0215 (9)0.0194 (9)000.0014 (7)
O50.0430 (8)0.0199 (6)0.0172 (6)0.0072 (6)0.0088 (5)0.0004 (5)
C40.0384 (14)0.0081 (9)0.0145 (11)000.0002 (8)
C50.0226 (12)0.0198 (11)0.0132 (11)000.0012 (9)
C60.128 (3)0.0216 (14)0.0217 (15)000.0094 (12)
C70.041 (2)0.034 (2)0.0162 (17)0.0110 (17)0.0050 (16)0.0005 (15)
Ow10.0426 (8)0.0220 (7)0.0322 (7)0.0113 (6)0.0130 (7)0.0072 (6
Geometric parameters (Å, º) top
Sr1—O1i2.4788 (10)C5—C7iii1.577 (4)
Sr1—O1ii2.4788 (10)C6—H1c60.98
Sr1—O32.4899 (16)C6—H1c6iii0.98
Sr1—O42.5593 (18)C6—H2c60.98
Sr1—O12.6561 (11)C6—H2c6iii0.98
Sr1—O1iii2.6561 (11)C6—H3c60.98
Sr1—O22.6796 (11)C6—H3c6iii0.98
Sr1—O2ii2.6796 (11)C7—H1c70.98
O1—C11.2629 (15)C7—H2c70.98
C1—C21.510 (3)C7—H3c70.98
C2—H1c21Ow1—H1ow10.818 (18)
C2—H1c2iii1Ow1—H2ow10.82 (2)
C2—C3a1.526 (4)Ow1—H3ow10.803 (17)
C2—C3aiii1.526 (4)C2—C74.217 (4)
C2—C3b1.527 (3)C2—C7iv4.124 (4)
C2—C3biii1.527 (3)C2—C7v4.124 (4)
C3a—H1c3a0.98C2—C7iii4.217 (4)
C3a—H2c3a0.98C3a—C3avi4.087 (5)
C3a—H3c3a0.98C3a—C3avii4.449 (5)
C3b—H1c3b0.98C3a—C3bvii4.491 (5)
C3b—H2c3b0.98C3a—C6viii3.781 (4)
C3b—H3c3b0.98C3a—C6iv4.166 (4)
O2—H1o20.820 (16)C3a—C7iv4.212 (5)
O2—H1o2i0.820 (16)C3b—C3bix4.115 (5)
O3—H1o30.827 (17)C3b—C5x3.884 (4)
O3—H1o3iii0.827 (17)C3b—C6xi4.317 (4)
O4—H1o40.844 (18)C3b—C6x3.569 (4)
O4—H1o4iii0.844 (18)C3b—C73.993 (5)
O5—C41.2615 (16)C3b—C7x4.356 (5)
C4—C51.524 (3)C3b—C7v3.146 (5)
C5—H1c51C5—C7iv3.923 (4)
C5—H1c5iii1C5—C7v3.923 (4)
C5—C61.516 (3)C7—C7iv4.007 (5)
C5—C71.577 (4)C7—C7x4.007 (5)
O1—Sr1—O1i77.38 (3)C2—C3a—H3c3a109.47
O1—Sr1—O1ii124.29 (3)H1c3a—C3a—H2c3a109.47
O1—Sr1—O1iii48.94 (3)H1c3a—C3a—H3c3a109.47
O1—Sr1—O265.67 (3)H1c3aiii—C3a—H3c3a103.72
O1—Sr1—O2ii96.88 (2)H2c3a—C3a—H3c3a109.47
O1—Sr1—O391.64 (5)C2—C3b—H1c3b109.47
O1—Sr1—O4143.81 (4)C2—C3b—H2c3b109.47
O1i—Sr1—O1ii141.45 (4)C2—C3b—H3c3b109.47
O1i—Sr1—O1iii124.29 (3)H1c3b—C3b—H2c3b109.47
O1i—Sr1—O268.11 (3)H1c3b—C3b—H3c3b109.47
O1i—Sr1—O2ii147.04 (3)H2c3b—C3b—H3c3b109.47
O1i—Sr1—O373.97 (3)H1o2—O2—H1o2i112.6 (16)
O1i—Sr1—O487.54 (3)H1o3—O3—H1o3iii110.2 (17)
O1ii—Sr1—O1iii77.38 (3)H1o4—O4—H1o4iii105.2 (18)
O1ii—Sr1—O2147.04 (3)O5—C4—O5iii123.46 (19)
O1ii—Sr1—O2ii68.11 (3)O5—C4—C5118.23 (10)
O1ii—Sr1—O373.97 (3)O5iii—C4—C5118.23 (10)
O1ii—Sr1—O487.54 (3)C4—C5—H1c5109.66
O1iii—Sr1—O296.88 (2)C4—C5—H1c5iii109.66
O1iii—Sr1—O2ii65.67 (3)C4—C5—C6108.42 (15)
O1iii—Sr1—O391.64 (5)C4—C5—C7113.80 (17)
O1iii—Sr1—O4143.81 (4)C4—C5—C7iii113.80 (17)
O2—Sr1—O2ii79.87 (3)H1c5—C5—H1c5iii113.88
O2—Sr1—O3138.98 (2)H1c5—C5—C6107.52
O2—Sr1—O478.21 (3)C5—C6—H1c6109.47
O2ii—Sr1—O3138.98 (2)C5—C6—H1c6iii109.47
O2ii—Sr1—O478.21 (3)C5—C6—H2c6109.47
O3—Sr1—O4115.74 (6)C5—C6—H2c6iii109.47
Sr1—O1—Sr1i97.34 (4)C5—C6—H3c6109.47
Sr1—O2—Sr1i92.08 (5)C5—C6—H3c6iii109.47
O1—C1—O1iii121.20 (18)H1c6—C6—H2c6109.47
O1—C1—C2119.39 (10)H1c6—C6—H3c6109.47
O1iii—C1—C2119.39 (10)H1c6iii—C6—H2c6iii109.47
C1—C2—H1c2105.88H1c6iii—C6—H3c6iii109.47
C1—C2—H1c2iii105.88H2c6—C6—H3c6109.47
C1—C2—C3a109.54 (19)H2c6iii—C6—H3c6iii109.47
C1—C2—C3aiii109.54 (19)H1c7—C7—H2c7109.47
C1—C2—C3b114.96 (14)H1c7—C7—H3c7109.47
C1—C2—C3biii114.96 (14)H2c7—C7—H3c7109.47
H1c2—C2—C3a110.93H1c7—H3c7—H2c760
H1c2—C2—C3b105.01H1ow1—Ow1—H2ow1103 (4)
H1c2iii—C2—C3aiii110.93H1ow1—Ow1—H3ow1104 (4)
C2—C3a—H1c3a109.47H2ow1—Ow1—H3ow1104 (5)
C2—C3a—H2c3a109.47
Symmetry codes: (i) x+3/2, y, z+1/2; (ii) x1/2, y, z+1/2; (iii) x+1, y, z; (iv) x1/2, y+1/2, z; (v) x+3/2, y+1/2, z; (vi) x, y, z; (vii) x+1, y, z; (viii) x1/2, y1/2, z; (ix) x+2, y, z; (x) x+1/2, y+1/2, z; (xi) x+1/2, y1/2, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O2—H1o2···O50.820 (16)1.936 (15)2.7465 (14)169.3 (17)
O3—H1o3···Ow1xii0.827 (17)2.022 (17)2.8339 (18)167.1 (18)
O4—H1o4···O5i0.844 (18)1.964 (17)2.7887 (16)165.3 (19)
Ow1—H1ow1···O5iii0.818 (18)1.976 (19)2.7913 (18)174 (2)
Ow1—H2ow1···Ow1xiii0.82 (2)1.92 (3)2.736 (2)176 (5)
Ow1—H3ow1···Ow1xiv0.803 (17)1.946 (17)2.747 (2)176 (5)
Symmetry codes: (i) x+3/2, y, z+1/2; (iii) x+1, y, z; (xii) x+1, y1/2, z+1/2; (xiii) x+1/2, y, z+1/2; (xiv) x, y, z.
catena-Poly[[µ-aqua-diaqua(µ3-2-methylpropanoato-\ κ4O:O,O':O')(calcium/strontium)] 2-methylpropanoate dihydrate] (III) top
Crystal data top
[Ca0.794Sr0.206(C4H7O2)(H2O)3]·C4H7O2·2H2OThere have been used diffractions with I/σ(I)>20 for the unit cell determination.
Mr = 314.2Dx = 1.358 Mg m3
Orthorhombic, PbcaMo Kα radiation, λ = 0.71073 Å
Hall symbol: –P 2ac 2abCell parameters from 9952 reflections
a = 6.7153 (3) Åθ = 2.3–27.5°
b = 19.6061 (10) ŵ = 1.08 mm1
c = 23.3498 (11) ÅT = 120 K
V = 3074.3 (3) Å3Prism, colourless
Z = 80.59 × 0.18 × 0.08 mm
F(000) = 1342
Data collection top
Bruker D8 VENTURE Kappa Duo PHOTON 100 CMOS
diffractometer
3533 independent reflections
Radiation source: X-ray tube2787 reflections with I > 3σ(I)
Quazar Mo multilayer optic monochromatorRint = 0.030
φ and ω scansθmax = 27.5°, θmin = 2.1°
Absorption correction: multi-scan
(SADABS; Bruker, 2017)
h = 88
Tmin = 0.573, Tmax = 0.917k = 2524
25462 measured reflectionsl = 3030
Refinement top
Refinement on F2Primary atom site location: charge flipping
R[F > 3σ(F)] = 0.026H atoms treated by a mixture of independent and constrained refinement
wR(F) = 0.062Weighting scheme based on measured s.u.'s w = 1/(σ2(I) + 0.0004I2)
S = 1.54(Δ/σ)max = 0.041
3533 reflectionsΔρmax = 0.27 e Å3
195 parametersΔρmin = 0.25 e Å3
10 restraintsExtinction correction: B-C type 1 Lorentzian isotropic (Becker & Coppens, 1974)
75 constraintsExtinction coefficient: 3100 (900)
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/UeqOcc. (<1)
Ca10.51172 (3)0.147275 (10)0.285280 (8)0.01318 (7)0.7936 (16)
Sr10.51172 (3)0.147275 (10)0.285280 (8)0.01318 (7)0.2064 (16)
O10.67331 (12)0.12224 (5)0.18768 (4)0.0183 (3)
O20.34659 (12)0.11963 (5)0.18993 (4)0.0193 (3)
C10.50850 (17)0.11708 (6)0.16238 (5)0.0157 (4)
C20.49970 (18)0.10867 (7)0.09788 (6)0.0197 (4)
H1c20.4460050.1525710.0824990.0236*
C30.3591 (2)0.05083 (8)0.08122 (6)0.0329 (5)
H1c30.3504640.0479780.0393910.0494*
H2c30.4101190.007650.0964560.0494*
H3c30.226580.0597080.0971060.0494*
C40.7032 (2)0.09886 (8)0.07048 (6)0.0271 (5)
H1c40.6884530.0965530.028770.0407*
H2c40.7895040.1373440.0805350.0407*
H3c40.7626680.0563760.0844810.0407*
O30.49864 (13)0.02977 (5)0.30914 (5)0.0278 (3)
H1o30.3934 (13)0.0071 (7)0.3132 (7)0.0417*
H2o30.5919 (16)0.0012 (6)0.3097 (7)0.0417*
O40.76561 (13)0.23946 (5)0.24874 (4)0.0186 (3)
H1o40.734 (2)0.2655 (6)0.2217 (4)0.0279*
H2o40.807 (2)0.2641 (6)0.2757 (4)0.0279*
O50.52603 (13)0.22321 (5)0.36693 (4)0.0223 (3)
H1o50.4290 (15)0.2502 (6)0.3690 (7)0.0335*
H2o50.6251 (14)0.2493 (6)0.3680 (6)0.0335*
O60.69194 (12)0.30554 (5)0.14705 (4)0.0194 (3)
O70.36161 (13)0.30221 (5)0.15020 (4)0.0197 (3)
C50.52316 (17)0.31043 (6)0.12361 (5)0.0151 (3)
C60.51349 (18)0.33128 (7)0.06086 (5)0.0198 (4)
H1c60.3812570.3173760.0449960.0237*
C70.5386 (2)0.40842 (7)0.05757 (6)0.0296 (5)
H1c70.4345060.4305520.0803920.0444*
H2c70.6696690.4211150.0726120.0444*
H3c70.5276340.4232070.0176060.0444*
C80.6670 (2)0.29505 (8)0.02419 (6)0.0333 (5)
H1c80.6498390.3085330.0159230.05*
H2c80.8009740.3075830.0370630.05*
H3c80.6493180.2456080.0277320.05*
Ow10.22415 (14)0.42437 (5)0.19632 (5)0.0245 (3)
H1ow10.1006 (4)0.4288 (9)0.1920 (7)0.0368*
H2ow10.253 (2)0.3873 (4)0.1804 (6)0.0368*
Ow20.81968 (14)0.43158 (5)0.19043 (4)0.0247 (3)
H1ow20.787 (2)0.3938 (4)0.1763 (6)0.0371*
H2ow20.793 (2)0.4272 (9)0.22542 (17)0.0371*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Ca10.01013 (11)0.01378 (12)0.01565 (12)0.00007 (8)0.00019 (8)0.00028 (8)
Sr10.01013 (11)0.01378 (12)0.01565 (12)0.00007 (8)0.00019 (8)0.00028 (8)
O10.0151 (4)0.0226 (5)0.0172 (5)0.0002 (4)0.0021 (4)0.0025 (4)
O20.0155 (5)0.0251 (5)0.0174 (5)0.0001 (4)0.0011 (4)0.0033 (4)
C10.0187 (6)0.0096 (6)0.0190 (6)0.0001 (5)0.0004 (5)0.0004 (5)
C20.0224 (7)0.0211 (7)0.0155 (6)0.0011 (6)0.0007 (5)0.0007 (5)
C30.0371 (9)0.0443 (10)0.0173 (7)0.0170 (8)0.0002 (6)0.0081 (7)
C40.0282 (8)0.0356 (9)0.0174 (7)0.0058 (7)0.0041 (6)0.0059 (7)
O30.0155 (5)0.0175 (5)0.0504 (7)0.0009 (4)0.0001 (5)0.0016 (5)
O40.0240 (5)0.0167 (5)0.0151 (5)0.0007 (4)0.0006 (4)0.0003 (4)
O50.0154 (5)0.0276 (6)0.0240 (5)0.0002 (4)0.0007 (4)0.0028 (4)
O60.0168 (4)0.0239 (5)0.0176 (5)0.0003 (4)0.0022 (4)0.0013 (4)
O70.0174 (5)0.0223 (5)0.0194 (5)0.0011 (4)0.0029 (4)0.0017 (4)
C50.0179 (6)0.0107 (6)0.0167 (6)0.0006 (5)0.0000 (5)0.0013 (5)
C60.0187 (6)0.0247 (7)0.0159 (6)0.0023 (6)0.0016 (5)0.0012 (5)
C70.0421 (9)0.0257 (8)0.0210 (7)0.0039 (7)0.0007 (6)0.0075 (6)
C80.0479 (9)0.0339 (9)0.0181 (7)0.0067 (8)0.0086 (7)0.0007 (7)
Ow10.0189 (5)0.0206 (6)0.0341 (6)0.0002 (4)0.0022 (4)0.0031 (5)
Ow20.0237 (5)0.0235 (6)0.0269 (6)0.0002 (4)0.0025 (4)0.0035 (5)
Geometric parameters (Å, º) top
Ca1—Sr10C6—C71.524 (2)
Ca1—O32.3719 (10)C6—C81.517 (2)
Ca1—O2i2.3845 (9)C7—H1c70.98
Ca1—O1ii2.4091 (8)C7—H2c70.98
Ca1—O52.4209 (10)C7—H3c70.98
Ca1—O22.5457 (9)C8—H1c80.98
Ca1—O12.5714 (9)C8—H2c80.98
Ca1—O4ii2.5747 (9)C8—H3c80.98
Ca1—O42.6271 (9)O3—H1o30.840 (11)
Sr1—O12.5714 (9)O3—H2o30.840 (12)
Sr1—O1ii2.4091 (8)O4—H1o40.840 (11)
Sr1—O22.5457 (9)O4—H2o40.840 (11)
Sr1—O2i2.3845 (9)O5—H1o50.840 (11)
Sr1—O32.3719 (10)O5—H2o50.840 (11)
Sr1—O42.6271 (9)Ow1—H1ow10.840 (4)
Sr1—O4ii2.5747 (9)Ow1—H2ow10.840 (10)
Sr1—O52.4209 (10)Ow2—H1ow20.840 (10)
O1—C11.2587 (14)Ow2—H2ow20.840 (5)
O2—C11.2644 (15)C2—C64.450 (2)
C1—C21.5160 (18)C2—C84.192 (2)
C2—H1c21C2—C8iii4.084 (2)
C2—C31.526 (2)C3—C7iii3.972 (2)
C2—C41.5210 (18)C3—C7iv3.903 (2)
C3—H1c30.98C3—C8iii4.105 (2)
C3—H2c30.98C4—C6v3.9526 (19)
C3—H3c30.98C4—C7v3.746 (2)
C4—H1c40.98C4—C7vi4.128 (2)
C4—H2c40.98C4—C84.003 (2)
C4—H3c40.98C4—C8v4.349 (2)
O6—C51.2624 (14)C6—C8iii3.936 (2)
O7—C51.2603 (15)C8—C8iii3.959 (2)
C5—C61.5225 (18)C8—C8v3.959 (2)
C6—H1c61
O1—Ca1—O1ii126.26 (3)Ca1—O2—Ca1ii98.63 (3)
O1—Ca1—O250.81 (3)Ca1—O2—Sr1ii98.63 (3)
O1—Ca1—O2i76.93 (3)Ca1ii—O2—Sr198.63 (3)
O1—Ca1—O392.20 (3)Ca1ii—O2—O1160.57 (5)
O1—Ca1—O464.51 (3)Ca1ii—O2—O1ii54.25 (2)
O1—Ca1—O4ii97.55 (3)Ca1ii—O2—O3ii51.84 (3)
O1—Ca1—O5143.00 (3)Ca1ii—O2—O4ii60.18 (3)
O1ii—Ca1—O276.99 (3)Ca1ii—O2—O5ii48.02 (2)
O1ii—Ca1—O2i141.23 (3)Sr1—O2—Sr1ii98.63 (3)
O1ii—Ca1—O372.88 (3)Ca1—O4—Ca1i91.94 (3)
O1ii—Ca1—O4146.87 (3)Ca1—O4—Sr1i91.94 (3)
O1ii—Ca1—O4ii67.56 (3)Ca1i—O4—Sr191.94 (3)
O1ii—Ca1—O587.50 (3)Sr1—O4—Sr1i91.94 (3)
O2—Ca1—O2i125.08 (3)O1—C1—O2120.94 (11)
O2—Ca1—O389.00 (3)O1—C1—C2120.62 (11)
O2—Ca1—O498.35 (3)O2—C1—C2118.44 (10)
O2—Ca1—O4ii66.42 (3)C1—C2—H1c2106.1
O2—Ca1—O5146.83 (3)C1—C2—C3110.99 (11)
O2i—Ca1—O375.94 (3)C1—C2—C4113.37 (10)
O2i—Ca1—O467.86 (3)H1c2—C2—C3108.97
O2i—Ca1—O4ii147.12 (3)H1c2—C2—C4106.36
O2i—Ca1—O584.90 (3)C3—C2—C4110.76 (11)
O3—Ca1—O4140.23 (3)C2—C3—H1c3109.47
O3—Ca1—O4ii136.93 (3)C2—C3—H2c3109.47
O3—Ca1—O5114.44 (4)C2—C3—H3c3109.47
O4—Ca1—O4ii80.41 (3)H1c3—C3—H2c3109.47
O4—Ca1—O578.87 (3)H1c3—C3—H3c3109.47
O4ii—Ca1—O580.60 (3)H2c3—C3—H3c3109.47
O1—Sr1—O1ii126.26 (3)C2—C4—H1c4109.47
O1—Sr1—O250.81 (3)C2—C4—H2c4109.47
O1—Sr1—O2i76.93 (3)C2—C4—H3c4109.47
O1—Sr1—O392.20 (3)H1c4—C4—H2c4109.47
O1—Sr1—O464.51 (3)H1c4—C4—H3c4109.47
O1—Sr1—O4ii97.55 (3)H2c4—C4—H3c4109.47
O1—Sr1—O5143.00 (3)O6—C5—O7123.33 (11)
O1ii—Sr1—O276.99 (3)O6—C5—C6118.43 (10)
O1ii—Sr1—O2i141.23 (3)O7—C5—C6118.14 (10)
O1ii—Sr1—O372.88 (3)C5—C6—H1c6108.73
O1ii—Sr1—O4146.87 (3)C5—C6—C7108.08 (11)
O1ii—Sr1—O4ii67.56 (3)C5—C6—C8112.86 (11)
O1ii—Sr1—O587.50 (3)H1c6—C6—C7110.49
O2—Sr1—O2i125.08 (3)H1c6—C6—C8105.47
O2—Sr1—O389.00 (3)C7—C6—C8111.19 (11)
O2—Sr1—O498.35 (3)C6—C7—H1c7109.47
O2—Sr1—O4ii66.42 (3)C6—C7—H2c7109.47
O2—Sr1—O5146.83 (3)C6—C7—H3c7109.47
O2i—Sr1—O375.94 (3)H1c7—C7—H2c7109.47
O2i—Sr1—O467.86 (3)H1c7—C7—H3c7109.47
O2i—Sr1—O4ii147.12 (3)H2c7—C7—H3c7109.47
O2i—Sr1—O584.90 (3)C6—C8—H1c8109.47
O3—Sr1—O4140.23 (3)C6—C8—H2c8109.47
O3—Sr1—O4ii136.93 (3)C6—C8—H3c8109.47
O3—Sr1—O5114.44 (4)H1c8—C8—H2c8109.47
O4—Sr1—O4ii80.41 (3)H1c8—C8—H3c8109.47
O4—Sr1—O578.87 (3)H2c8—C8—H3c8109.47
O4ii—Sr1—O580.60 (3)H1o3—O3—H2o3105.9 (12)
Ca1—O1—Ca1i97.29 (3)H1o4—O4—H2o4107.3 (11)
Ca1—O1—Sr1i97.29 (3)H1o5—O5—H2o5103.2 (11)
Ca1i—O1—Sr197.29 (3)H1ow1—Ow1—H2ow1105.5 (15)
Ca1i—O1—O2160.27 (5)H1ow2—Ow2—H2ow2103.8 (15)
Sr1—O1—Sr1i97.29 (3)
Symmetry codes: (i) x+1/2, y, z+1/2; (ii) x1/2, y, z+1/2; (iii) x1/2, y+1/2, z; (iv) x+1/2, y1/2, z; (v) x+1/2, y+1/2, z; (vi) x+3/2, y1/2, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O3—H1o3···Ow2vii0.840 (11)2.061 (12)2.8767 (14)163.6 (13)
O3—H2o3···Ow1vii0.840 (12)1.953 (12)2.7842 (14)169.8 (13)
O4—H1o4···O60.840 (11)1.932 (10)2.7498 (13)164.2 (11)
O4—H2o4···O7i0.840 (11)1.920 (10)2.7382 (13)164.2 (11)
O5—H1o5···O6ii0.840 (11)1.964 (11)2.7831 (13)164.9 (15)
O5—H2o5···O7i0.840 (11)1.944 (11)2.7636 (13)165.0 (14)
Ow1—H1ow1···Ow2viii0.840 (4)1.888 (3)2.7233 (14)172.8 (16)
Ow1—H2ow1···O70.840 (10)1.951 (11)2.7836 (14)170.7 (15)
Ow2—H1ow2···O60.840 (10)1.967 (10)2.8050 (14)175.3 (15)
Ow2—H2ow2···Ow1i0.840 (5)1.887 (5)2.7248 (15)175.2 (17)
Symmetry codes: (i) x+1/2, y, z+1/2; (ii) x1/2, y, z+1/2; (vii) x+1, y1/2, z+1/2; (viii) x1, y, z.
 

Acknowledgements

Dr Ivana Císařová from the Faculty of Science is thanked for generous measurement of the samples.

Funding information

The authors express their gratitude for the support provided by Project NPU I–LO1603 of the Ministry of Education of the Czech Republic to the Institute of Physics of the Academy of Sciences of the Czech Republic.

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