Dirubidium hexa­aqua­cobalt(II) tetra­kis­(hydrogen phthalate) tetra­hydrate and coordination modes of the hydrogen phthalate anion

The title compound, Rb₂[Co(H₂O)₆](C₈H₅O₄)₄·4H₂O, consists of nearly regular octa­hedral [Co(H₂O)₆]²⁺ cations with the Co^II cations on the inversion centre (special position 2a), Rb⁺ cations, hydrogen phthalate (Hpht^-) anions and disordered water mol­ecules. The Rb⁺ cation is surrounded by nine O atoms from Hpht^- anions and water mol­ecules, with a strongly deformed penta­gonal-bipyramidal geometry and one apex split into three positions. The crystal packing is governed by numerous hydrogen bonds involving all water mol­ecules and Hpht^- anions. In this way, layers parallel to the ab plane are formed, with the aromatic rings of the Hpht^- anions esentially directed along the c axis. While Hpht^- anions form the outer part of the layers, disordered water mol­ecules and Rb⁺ cations alternate with [Co(H₂O)₆]²⁺ cations in the inner parts. The only inter­actions between the layers are van der Waals forces between the atoms of the aromatic rings. A search of the Cambridge Structural Database for coordination modes and types of hydrogen-bonding inter­action of the Hpht^- anion showed that, when uncoordinated Hpht^- anions are present, compounds with inter­molecular hydrogen bonds are more numerous than compounds with intra­molecular hydrogen bonds. For coordinated Hpht^- anions, chelating and bridging anions are almost equally common, while monodentate anions are relatively scarce. The same coordination modes appear for Hpht^- anions with or without intra­molecular hydrogen bonds, although intra­molecular hydrogen bonds are less common.

S1. Experimental

Crystal data, data collection and structure refinement details are summarized in Table 1.

S1.1. Synthesis and crystallization

The compounds were crystallized from a dilute (~0.1 M) aqueous solution containing Co²⁺, pht^2- and Rb⁺/Cs⁺ ions in the molar ratio 1:2:2. The initial pH of the solution was 4.5. Suitable single crystals were obtained by slow evaporation under ambient conditions after approximately five months. The IR spectra confirmed the presence of Hpht anions and a great similarity between (I), (II) and (V).

S1.2. Refinement

C-bound H atoms were positioned geometrically and refined as riding, with C—H = 0.93 Å and U_iso(H) = 1.2U_eq(C). The initial positions of the remaining H atoms were calculated using the program HYDROGEN (Nardelli, 1999) and then refined with O—H restrained to 0.85 (1) Å. The exceptions were the H atoms of the disordered water molecules (O12 and O13), which were added to the structural model in the final cycles of refinement with fixed coordinates and U_iso(H) = 1.5U_eq(O).

S2. Comment

The title compound, hexa­aqua­cobalt(II) dirubidium tetra­kis(hydrogen phthalate) tetra­hydrate, (I), belongs to the rare class of complexes containing hydrogen phthalate anions (Hpht) and a combination of two metal cations, i.e. an alkali metal cation and a transition metal cation. Actually, the first such complex, K₂[Ni(H₂O)₆](Hpht)₄.4H₂O, (II), was reported several years ago (Biagini Cingi et al., 1984), and it was recently described again by Wu et al. (2009), who appeared to be unaware of the previous publication. Meanwhile, structures of two very similar complexes, K₂[Co(H₂O)₆](Hpht)₄.4H₂O, (III) (Furmanova et al., 2000), and K₂[Co_0.76Ni_0.24(H₂O)₆](Hpht)₄.4H₂O, (IV) (Muthu et al., 2012a), were described. Thus, (II), (III) and (IV), together with Rb₂[Co(H₂O)₆](Hpht)₄.4H₂O, (I), and the caesium analogue Cs₂[Co(H₂O)₆](Hpht)₄.4H₂O, (V), presented here, make a short series of five heterocation complexes with identical general formula and the same crystal structure. These types of complex show good transparency for visible light and have recently been mentioned as potential nonlinear optic and electro-optic materials (Muthu et al., 2012a,b).

In the report of Biagini Cingi et al. (1984), one uncoordinated water molecule is split over two close positions, while another has an extremely high displacement parameter [B = 13.2 (2) Ų]. Later, both solvent water molecules were described as disordered (Furmanova et al., 2000; Muthu et al., 2012a). Therefore, although (I) was obtained unintentionally during attempts to prepare a mixed-cation complex with pht^2- and not Hpht^- anions, we decided to perform the crystal structure analysis in order to resolve ambiguity about uncoordinated water molecules and to test the influence of increasing alkali cation size on the structure and properties. Since crystals of Cs₂[Co(H₂O)₆](Hpht)₄.4H₂O, (V), were of poor quality, only the space group and unit-cell parameters were determined in a preliminary experiment: P2₁/c, a = 10.05 (4), b = 6.78 (6) and c = 30.69 (9) Å, β = 96.09 (19)° and V = 2080 (17) ų. These data suggested isostructurality with (I)–(IV), although an unexpected slightly smaller unit-cell volume with respect to (I) was observed.

The general structural characteristics of (I) (Figs. 1 and 2) are in accordance with previous descriptions (Biagini Cingi et al., 1984; Furmanova et al., 2000; Muthu et al., 2012a). Atom Co1 is located on the inversion centre (special position 2a) and the o­cta­hedral [Co(H₂O)₆]²⁺ cation is close to regular, with minor orthorhombic deformations (Table 1).

As shown in Fig. 2, in the crystal packing of (I) there are `sandwich' layers parallel to (001). Rb⁺ and [Co(H₂O)₆]²⁺ cations, together with uncoordinated water molecules, are concentrated in the inner layer, while Hpht anions make up the outer part of the layers. Thus, between the layers only weak van der Waals inter­actions exist and perfect crystal cleavage could be expected.

There are two different Hpht anions (A and B; Fig. 1). In anion A, the angle between the aromatic ring and the –COO^- group is 69.5 (2)°, while the angle between the aromatic ring and the –COOH group is 23.8 (2)°; in anion B, the corresponding angles are 74.1 (2) and 24.4 (3)°, respectively. Hpht anions are connected in columns parallel to the b axis (Fig. 2) by relatively short hydrogen bonds (Table 2). All these findings are quite common when there are inter­molecular hydrogen bonds present between Hpht anions (Langkilde et al., 2004; Biagini Cingi et al., 1984).

Atom Rb1 is surrounded by nine O atoms, five from Hpht anions and four from water molecules, with Rb—O distances ranging from 2.783 (9) to 3.391 (3) Å (Table 1). The corresponding polyhedron can be described as a deformed penta­gonal bipyramid, with atoms O4, O5, O10ⁱⁱ, O12B and O13B in the equatorial plane, and one apex split into three positions occupied by atoms O8, O12Bⁱ and O13Aⁱ (symmetry codes are given in Fig. 1). A bond-valence calculation (Wills, 2011) yielded a quite acceptable sum value of 1.07 valence units. The coordination number (CN) of the Rb atom in (I) is higher than in other Rb-containing Hpht compounds, viz. RbHpht (Smith, 1975b) and Rb[H(Hpht)₂].2H₂O (Küppers, 1977) have CN = 7 and 8, respectively.

However, since water molecules O12 and O13 are statistically disordered over two positions in an approximate 1/3:2/3 ratio for O atoms labelled A and B, respectively (Fig. 1), an alternative view of the Rb coordination polyhedra could be given. If the water molecules are classified as bridging (darker shading in Fig. 1) and terminal (lighter in Fig. 1), then two thirds of the centrosymmetrically related Rb cations are bridged by water molecules to form Rb₂(H₂O)₄ units; these Rb cations are surrounded by nine O atoms. The remaining one third of the Rb cations have only seven nearest neighbours, involving terminal water molecules O12A and O13A. In this manner, the real structure would be a combination of these two extremes, and the depiction obtained by X-ray diffraction is just an average of them.

As expected, the Rb—O distances in (I) are longer than the K—O distances in complexes (II)–(IV), which range between about 2.64 and 3.31 Å. However, the CN for K⁺ is only 8, while the ninth O atom is at 3.5 Å. This distinction can be easily explained by the different radii of K⁺ and Rb⁺ cations (Shannon, 1976). It is remarkable that, with increasing ionic radius, the distance between pairs of disordered water molecules decreases; they are about 0.85 and 1.30 Å in (III) and (IV), but only 0.700 (19) Å for O12A···O12B and 0.915 (13) Å for O13A···O13B in (I).

As mentioned at the beginning, disorder of water molecules is common for this group of complexes and it was simply not completely resolved in the case of (II) (Biagini Cingi et al., 1984). In (I), the two Rb polyhedra described above alternate with [Co(H₂O)₆]²⁺ o­cta­hedra in the inner part of the layers (Fig. 2), where there are also numerous hydrogen bonds (Table 2). A great similarity in unit-cell dimensions and crystal packing between (I)–(V) and [Co(H₂O)₆](Hpht)₂ (Adiwidjaja et al., 1978) should be emphasized. For example, the unit-cell volumes of [Co(H₂O)₆](Hpht)₂ and (I) are nearly identical [2014.1 (5) and 2115.16 (18) ų, respectively [Difference of 100 so not very close?]]. This is because every second Co o­cta­hedron in [Co(H₂O)₆](Hpht)₂ is simply replaced by two Rb polyhedra in (I). The Rb···Rb distance in (I) is 4.4218 (7) Å, which is comparable with the K···K distances (about 4.45 Å) in (III) (Furmanova et al., 2000) and (IV) (Muthu et al., 2012a).

With respect to other hydrogen benzene­dicarboxyl­ate anions, as hydrogen iso- and terephthalate, the Hpht anion with its –COO^- and –COOH groups in the ortho positions is special because intra­molecular hydrogen bonding is possible. As a consequence, compounds containing Hpht anions can be classified into two main groups, viz. with or without intra­molecular hydrogen bonds. In the latter case, Hpht anions are usually connected in infinite chains, as also found in (I). In both cases, the hydrogen bonds are short and strong, but typically shorter if they are intra­molecular (2.35–2.40 versus 2.50–2.60 Å). These are the main conclusions from a recent study by Langkilde et al. (2004). However, that study was limited, in a way, focusing only on the classification of the hydrogen bonds and the geometry of the Hpht anions.

Therefore, we also did a search of Cambridge Structural Database (CSD, Version 5.33; Allen, 2002), concentrating on the coordination modes of Hpht anions in addition to the type of hydrogen bonding. The search involved alkali and alkaline earth metal (AM) salts, and transition and inner transition metal (TM) complexes. Two compounds containing NH₄⁺ and (CH₃)₄N⁺ cations and one Tl⁺ salt were also included, due to their expected similarity with AM cations.

The CSD survey resulted in 64 unique compounds with 90 Hpht anions overall. As in (I)–(V), some compounds contain two crystallographically and/or chemically different Hpht anions. They could be all uncoordinated, like in (I)–(V), coordinated and uncoordinated, as in [Mn₂(Hpht)₂(phen)₄](Hpht)₂.2H₂O (phen is 1,10-phenanthroline; Ma et al., 2004) and [Mn₂(Hpht)₂(phen)₄](Hpht)₂.6H₂O (Yang et al., 2005), or coordinated in different ways, as in [Zn(Hpht)₂(4,4'-bpy)] (4,4'-bipy is 4,4'-bi­pyridine; Tang et al., 2004). All types of hydrogen bonds can be further classified as symmetrical, as in [Co(H₂O)₆](Hpht)₂ (Küppers, 1990) and [Cd(Hpht)₂(4,4'-bpy)]_n (Wang et al., 2005), or asymmetrical, which is observed more frequently. These two types were not treated separately due to the well known uncertainty in the H-atom coordinates in most cases. When uncoordinated Hpht anions with intra­molecular hydrogen bonds are present, sometimes inter­esting Hpht···H₂O···Hpht chains can be found, instead of Hpht···Hpht chains, as in [M(1-MeIm)₆](Hpht)₂.2H₂O (M = Co or Ni; 1-MeIm is 1-methyl­imidazole; Baca et al., 2004).

The results of the CSD search are summarized in Fig. 3. The compounds containing AM, ammonium or Tl⁺ cations are regarded as ionic salts. When uncoordinated Hpht anions are considered, those with inter­molecular hydrogen bonds are more numerous, regardless of the cations present. Previously, Langkilde et al. (2004) found a nearly equal distribution of the two bond types, but the present survey is more reliable since it involves a greater number of compounds with duplicated structures excluded. Also, it can be concluded that the presence of different AM or TM cations has no significant influence on the type of hydrogen bonds. A good example is [Co(H₂O)₆](Hpht)₂, which appears as three polymorphs, two of them (Adiwidjaja et al., 1978; Kariuki & Jones, 1993) with inter- and one (Küppers, 1990) with intra­molecular hydrogen bonds. This suggests that the stabilities of the different Hpht conformations are similar. Two special cases are K[H(Hpht)₂].2H₂O (Benedict et al., 2004) and Rb[H(Hpht)₂].2H₂O (Küppers, 1977) containing the so-called hydrogen diphthalate anion (Fig. 3, Type 1 III), which can be described as a proton-bound hydrogen phthalate dimer.

If compounds containing TM cations are compared, coordinated Hpht anions are slightly more common than uncoordinated ones. Thus, the presence of the –COOH group has no strong influence on the coordination ability of Hpht anions. Fig. 3 also shows a somewhat unexpected diversity of coordination modes of Hpht anions, which could be from mono- to tetra­dentate, and also bridging or chelating. Extreme examples are one of Hpht anions in [Ag₂(cnpy)₂(Hpht)₂] (cnpy is 4-cyano­pyridine; Sun et al., 2011) and the Hpht anion in {[Cu(Hpht)(N₃)].H₂O}_n (Escuer et al., 1997), where only protonated O atoms are uncoordinated and Hpht acts as an endo–exo (i.e. 1,2,4) and a mono-endo-exo (i.e. 1,1,3,4) bridge, respectively. Chelating and bridging Hpht anions are almost equally common, while monodentate Hpht anions are relatively scarce. The same coordination modes appear for Hpht anions with or without intra­molecular hydrogen bonds, although those with intra­molecular ones are generally less common (compare the corresponding Type I and II modes in Fig. 3), as was concluded for uncoordinated Hpht anions.

Finally, some inter­esting hydrogen-bond motifs should be mentioned. In [Mn₂(Hpht)₂(phen)₄](ClO₄)₂.2H₂O (Ma et al., 2004), dimeric complex units make pseudo-chains due to inter­molecular hydrogen bonds in the form of centrosymmetric R₂²(8) pseudo-rings (Bernstein et al., 1995) characteristic of carb­oxy­lic acids. In [Ag(cnpy)₂(Hpht)] (cnpy = 4–cyano­pyridine; Sun et al., 2011), the complex units also form pseudo-dimers, but in this case much larger R₂²(14) pseudo-rings exist (Fig. 3, Type 2.1 III).

Related literature

For related literature, see: Adiwidjaja et al. (1978); Allen (2002); Baca et al. (2004); Benedict et al. (2004); Bernstein et al. (1995); Biagini Cingi, Manotti Lanfredi & Tiripicchio (1984); Escuer et al. (1997); Furmanova et al. (2000); Küppers (1977, 1990); Kariuki & Jones (1993); Langkilde et al. (2004); Ma et al. (2004); Muthu et al. (2012a, 2012b); Nardelli (1999); Shannon (1976); Smith (1975b); Sun et al. (2011); Tang et al. (2004); Wang et al. (2005); Wills (2011); Wu et al. (2009); Yang et al. (2005).

Computing details

Data collection: CrysAlis PRO (Oxford Diffraction, 2010); cell refinement: CrysAlis PRO (Oxford Diffraction, 2010); data reduction: CrysAlis PRO (Oxford Diffraction, 2010); program(s) used to solve structure: SIR2004 (Burla et al., 2005); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008) and WinGX (Farrugia, 2012); molecular graphics: Mercury (Macrae et al., 2008) and ATOMS (Dowty, 2006); software used to prepare material for publication: publCIF (Westrip, 2010) and PARST (Nardelli, 1995).

Figures

	Fig. 1. Part of the crystal structure of (I), showing the atomic numbering scheme. Displacement ellipsoids are plotted at the 50% probability level. The two crystallographically independent Hpht anions are labelled A and B. H atoms have been omitted for clarity. [Symmetry codes: (i) x + 1, -y, -z + 1; (ii) -x + 2, -y, -z + 1; (iii) -x + 2, -y + 1, -z + 1; (iv) x - 1, y, z.]
	Fig. 2. A projection of (I), along the b axis, showing the crystal packing and the hydrogen bonding between Hpht anions (dashed lines). For emphasis, [Co(H2O)6]^2+ octahedra are also shown.
	Fig. 3. Coordination modes of Hpht anions, with numbers showing the appearance of each coordination mode (AM = alkali and alkaline earth metals, TM = transition metals). (a) AM: Askarinejad & Morsali (2006); Bats, Schuckmann & Fuess (1978); Hu et al. (2004); Jessen (1990); Kariuki & Jones (1989); Li et al. (2003); Okaya (1965); Smith (1975a,b,c, 1977). TM: Adiwidjaja et al. (1978); Babb et al. (2003); Baca et al. (2003); Biagini Cingi et al. (1984); Furmanova et al. (2000); Kariuki & Jones (1993); Muthu et al. (2012a); Tomić et al. (1996); Zhao et al. (2002). Complexes (I) and (V) described in this study are also accounted for. (b) AM: Gonschorek & Küppers (1975); Kariuki & Jones (1989 OR 1993 ?); Küppers (1978); Küppers et al. (1981); Langkilde et al. (2004). TM: Baca et al. (2005); Cingi et al. (1977); Küppers (1990); Ma et al. (2004); Poleti et al. (1999); Sharma et al. (2005); Yang et al. (2005); Zhu et al. (2010). (c) Benedict et al. (2004); Küppers (1977). (d) Adiwidjaja & Küppers (1976); Babb et al. (2003); Bermejo et al. (1999); Tang et al. (2004). (e) Marsh (2009). (f) Sun et al. (2011). (g) Gerbeleu et al. (1999); Tang et al. (2004). (h) Bartl & Küppers (1980). (i) Baca et al. (2003, 2005). (j) Chen et al. (2001); Li et al. (2000); Ma et al. (2004); Poleti et al. (1999); Yang et al. (2005). (k) Escuer et al. (1997). (l) Bats, Kallel & Fuess (1978); Rodrigues et al. (1999). (m) Bermejo et al. (1999); Wang et al. (2005). (n) Sun et al. (2011). (o) Escuer et al. (1997).

Dirubidium hexaaquacobalt(II) tetrakis(hydrogen phthalate) tetrahydrate

Crystal data

Rb2[Co(H2O)6](C8H5O4)4·4H2O	F(000) = 1082
Mr = 1070.51	Dx = 1.681 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 3513 reflections
a = 10.3408 (5) Å	θ = 3.0–28.9°
b = 6.8658 (3) Å	µ = 2.78 mm^−1
c = 30.0660 (17) Å	T = 295 K
β = 97.743 (5)°	Prismatic, pink
V = 2115.16 (18) Å^3	0.48 × 0.23 × 0.15 mm
Z = 2

Data collection

Oxford Gemini S diffractometer	4326 independent reflections
Radiation source: fine-focus sealed tube	3305 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.033
Detector resolution: 16.3280 pixels mm^-1	θmax = 26.4°, θmin = 3.3°
ϕ and ω scans	h = −8→12
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2010)	k = −8→6
Tmin = 0.690, Tmax = 1.000	l = −37→32
9648 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.056	Hydrogen site location: difference Fourier map
wR(F^2) = 0.115	H atoms treated by a mixture of independent and constrained refinement
S = 1.07	w = 1/[σ^2(Fo^2) + (0.0392P)^2 + 2.5644P] where P = (Fo^2 + 2Fc^2)/3
4326 reflections	(Δ/σ)max = 0.001
317 parameters	Δρmax = 0.54 e Å^−3
8 restraints	Δρmin = −0.67 e Å^−3

Special details

Experimental. Absorption correction: CrysAlisPro (Oxford Diffraction, 2010). (Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.)

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.

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 > 2sigma(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	Occ. (<1)
Rb1	0.70477 (5)	0.07012 (8)	0.526253 (17)	0.05489 (18)
Co1	1.0000	0.5000	0.5000	0.02361 (18)
O1	0.3207 (3)	0.4692 (4)	0.57659 (12)	0.0534 (9)
O2	0.4706 (3)	0.6683 (4)	0.60988 (11)	0.0475 (8)
O3	0.7458 (3)	0.2296 (5)	0.66615 (11)	0.0413 (7)
H31	0.799 (4)	0.210 (8)	0.6474 (13)	0.067 (18)*
O4	0.6229 (3)	0.2997 (5)	0.60154 (11)	0.0541 (9)
O5	0.9166 (3)	0.1852 (4)	0.61220 (11)	0.0437 (8)
O6	1.0280 (3)	−0.0132 (4)	0.57429 (11)	0.0462 (8)
O7	0.6827 (3)	−0.2776 (5)	0.66221 (11)	0.0435 (8)
H7	0.613 (4)	−0.300 (11)	0.644 (2)	0.14 (3)*
O8	0.7559 (3)	−0.2007 (5)	0.59878 (11)	0.0583 (10)
O9	0.8666 (3)	0.3014 (4)	0.46741 (11)	0.0357 (7)
H9A	0.807 (3)	0.352 (7)	0.4490 (14)	0.063 (16)*
H9B	0.902 (4)	0.222 (5)	0.4510 (13)	0.051 (15)*
O10	1.1222 (3)	0.2642 (4)	0.52420 (10)	0.0335 (7)
H10A	1.087 (3)	0.185 (4)	0.5405 (11)	0.025 (11)*
H10B	1.190 (3)	0.300 (6)	0.5409 (13)	0.049 (14)*
O11	0.8950 (3)	0.4867 (5)	0.55360 (12)	0.0449 (8)
H11A	0.853 (4)	0.576 (6)	0.5646 (18)	0.08 (2)*
H11B	0.913 (4)	0.405 (5)	0.5746 (11)	0.053 (15)*
O12A	0.637 (2)	−0.007 (3)	0.4301 (8)	0.066 (3)	0.31 (2)
H12A	0.6341	0.0735	0.4081	0.098*	0.31 (2)
H12B	0.5847	−0.0984	0.4219	0.098*	0.31 (2)
O12B	0.5804 (14)	−0.0157 (13)	0.4406 (3)	0.066 (3)	0.69 (2)
H12C	0.5715	0.0836	0.4228	0.098*	0.69 (2)
H12D	0.5360	−0.1079	0.4263	0.098*	0.69 (2)
O13A	0.3783 (14)	0.372 (2)	0.4754 (5)	0.085 (2)	0.396 (8)
H13A	0.3606	0.3612	0.4464	0.128*	0.396 (8)
H13B	0.3148	0.4307	0.4842	0.128*	0.396 (8)
O13B	0.4544 (9)	0.3176 (13)	0.4869 (3)	0.085 (2)	0.604 (8)
H13C	0.4771	0.2756	0.4617	0.128*	0.604 (8)
H13D	0.4702	0.4392	0.4795	0.128*	0.604 (8)
C1	0.4021 (3)	0.5172 (6)	0.60887 (16)	0.0339 (10)
C2	0.4124 (3)	0.3957 (5)	0.65109 (14)	0.0281 (9)
C3	0.3075 (4)	0.3985 (6)	0.67544 (18)	0.0445 (12)
H3	0.2321	0.4664	0.6644	0.053*
C4	0.3142 (5)	0.3015 (7)	0.71577 (19)	0.0546 (14)
H4	0.2445	0.3092	0.7322	0.065*
C5	0.4213 (5)	0.1945 (7)	0.73197 (17)	0.0517 (13)
H5	0.4242	0.1280	0.7590	0.062*
C6	0.5254 (4)	0.1861 (6)	0.70768 (15)	0.0380 (10)
H6	0.5980	0.1112	0.7182	0.046*
C7	0.5230 (3)	0.2875 (5)	0.66797 (14)	0.0266 (8)
C8	0.6344 (4)	0.2747 (6)	0.64164 (14)	0.0309 (9)
C9	0.9787 (3)	0.0312 (5)	0.60875 (14)	0.0284 (9)
C10	1.0038 (3)	−0.0996 (5)	0.64939 (13)	0.0255 (8)
C11	1.1276 (4)	−0.0960 (6)	0.67410 (16)	0.0383 (11)
H11	1.1936	−0.0244	0.6636	0.046*
C12	1.1536 (4)	−0.1968 (6)	0.71377 (16)	0.0442 (12)
H12	1.2360	−0.1887	0.7304	0.053*
C13	1.0603 (4)	−0.3080 (7)	0.72892 (16)	0.0459 (12)
H13	1.0793	−0.3775	0.7555	0.055*
C14	0.9368 (4)	−0.3179 (6)	0.70468 (14)	0.0358 (10)
H14	0.8733	−0.3958	0.7149	0.043*
C15	0.9070 (3)	−0.2122 (5)	0.66522 (13)	0.0261 (8)
C16	0.7752 (4)	−0.2279 (6)	0.63913 (14)	0.0308 (9)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Rb1	0.0660 (3)	0.0642 (3)	0.0325 (3)	−0.0145 (2)	−0.0004 (2)	0.0048 (2)
Co1	0.0247 (4)	0.0227 (4)	0.0233 (4)	0.0010 (3)	0.0027 (3)	0.0035 (3)
O1	0.0437 (18)	0.050 (2)	0.058 (2)	−0.0071 (14)	−0.0223 (16)	0.0062 (17)
O2	0.0456 (17)	0.0418 (18)	0.051 (2)	−0.0146 (14)	−0.0071 (15)	0.0159 (16)
O3	0.0311 (16)	0.062 (2)	0.0309 (19)	0.0117 (14)	0.0051 (13)	0.0060 (16)
O4	0.0433 (17)	0.093 (3)	0.0273 (19)	0.0283 (17)	0.0112 (14)	0.0100 (18)
O5	0.0452 (17)	0.0390 (17)	0.051 (2)	0.0204 (14)	0.0225 (15)	0.0219 (16)
O6	0.070 (2)	0.0322 (16)	0.042 (2)	0.0042 (14)	0.0259 (16)	0.0056 (15)
O7	0.0346 (17)	0.062 (2)	0.0359 (19)	−0.0149 (14)	0.0117 (14)	0.0027 (16)
O8	0.0382 (17)	0.094 (3)	0.040 (2)	−0.0186 (16)	−0.0051 (14)	0.030 (2)
O9	0.0360 (17)	0.0316 (17)	0.0374 (19)	0.0018 (13)	−0.0029 (14)	−0.0039 (15)
O10	0.0313 (16)	0.0298 (16)	0.0386 (19)	−0.0023 (12)	0.0022 (14)	0.0120 (14)
O11	0.064 (2)	0.0394 (19)	0.036 (2)	0.0152 (16)	0.0239 (16)	0.0121 (17)
O12A	0.084 (7)	0.057 (3)	0.050 (5)	−0.017 (5)	−0.013 (4)	0.008 (3)
O12B	0.084 (7)	0.057 (3)	0.050 (5)	−0.017 (5)	−0.013 (4)	0.008 (3)
O13A	0.079 (6)	0.105 (6)	0.071 (5)	−0.004 (5)	0.008 (4)	−0.007 (4)
O13B	0.079 (6)	0.105 (6)	0.071 (5)	−0.004 (5)	0.008 (4)	−0.007 (4)
C1	0.0238 (19)	0.031 (2)	0.046 (3)	0.0056 (17)	0.0028 (18)	0.001 (2)
C2	0.0277 (19)	0.023 (2)	0.035 (2)	−0.0026 (15)	0.0065 (16)	−0.0040 (18)
C3	0.032 (2)	0.038 (3)	0.067 (4)	−0.0032 (18)	0.019 (2)	−0.007 (3)
C4	0.059 (3)	0.050 (3)	0.064 (4)	−0.015 (2)	0.039 (3)	−0.011 (3)
C5	0.078 (3)	0.042 (3)	0.039 (3)	−0.013 (3)	0.025 (3)	0.003 (2)
C6	0.050 (3)	0.034 (2)	0.032 (3)	−0.0034 (19)	0.009 (2)	−0.001 (2)
C7	0.0294 (19)	0.025 (2)	0.026 (2)	−0.0045 (15)	0.0066 (16)	−0.0011 (17)
C8	0.034 (2)	0.030 (2)	0.028 (2)	0.0072 (16)	0.0033 (18)	0.0006 (18)
C9	0.0248 (19)	0.026 (2)	0.035 (2)	−0.0075 (15)	0.0058 (16)	0.0036 (18)
C10	0.0276 (19)	0.021 (2)	0.028 (2)	0.0031 (15)	0.0058 (16)	0.0028 (17)
C11	0.032 (2)	0.032 (2)	0.050 (3)	−0.0003 (17)	0.0002 (19)	−0.001 (2)
C12	0.041 (2)	0.038 (3)	0.048 (3)	0.010 (2)	−0.015 (2)	−0.003 (2)
C13	0.062 (3)	0.038 (3)	0.034 (3)	0.012 (2)	−0.007 (2)	0.005 (2)
C14	0.048 (2)	0.033 (2)	0.028 (2)	0.0032 (18)	0.0076 (19)	0.0021 (19)
C15	0.0313 (19)	0.025 (2)	0.023 (2)	0.0040 (15)	0.0057 (16)	−0.0003 (17)
C16	0.032 (2)	0.031 (2)	0.029 (2)	−0.0019 (16)	0.0048 (17)	0.0067 (19)

Geometric parameters (Å, º)

Rb1—O12B	2.783 (9)	O12A—H12A	0.86 (2)
Rb1—O8	2.860 (3)	O12A—H12B	0.84 (2)
Rb1—O12A	2.93 (2)	O12B—H12C	0.865 (9)
Rb1—O4	2.973 (3)	O12B—H12D	0.861 (9)
Rb1—O9	3.041 (3)	O13A—O13B	0.898 (12)
Rb1—O13B^i	3.127 (9)	O13A—H13A	0.868 (14)
Rb1—O13A^i	3.155 (14)	O13A—H13B	0.842 (15)
Rb1—O13B	3.189 (10)	O13B—H13C	0.872 (8)
Rb1—O5	3.252 (3)	O13B—H13D	0.885 (9)
Rb1—O12B^i	3.259 (16)	C1—C2	1.510 (6)
Rb1—O10^ii	3.391 (3)	C1—Rb1^iv	4.954 (4)
Co1—O11	2.063 (3)	C2—C3	1.388 (6)
Co1—O11^iii	2.063 (3)	C2—C7	1.400 (5)
Co1—O9^iii	2.088 (3)	C3—C4	1.377 (7)
Co1—O9	2.088 (3)	C3—H3	0.93
Co1—O10^iii	2.121 (3)	C4—C5	1.363 (7)
Co1—O10	2.121 (3)	C4—H4	0.93
O1—C1	1.241 (5)	C5—C6	1.381 (6)
O2—C1	1.254 (5)	C5—H5	0.93
O3—C8	1.318 (5)	C6—C7	1.380 (6)
O3—H31	0.849 (10)	C6—H6	0.93
O4—C8	1.208 (5)	C7—C8	1.486 (5)
O5—C9	1.249 (5)	C9—C10	1.510 (5)
O6—C9	1.253 (5)	C10—C11	1.391 (5)
O7—C16	1.301 (5)	C10—C15	1.398 (5)
O7—H7	0.851 (10)	C11—C12	1.374 (6)
O8—C16	1.217 (5)	C11—H11	0.93
O9—H9A	0.846 (10)	C12—C13	1.356 (7)
O9—H9B	0.850 (10)	C12—H12	0.93
O10—H10A	0.847 (10)	C13—C14	1.384 (6)
O10—H10B	0.841 (10)	C13—H13	0.93
O11—H11A	0.842 (10)	C14—C15	1.389 (5)
O11—H11B	0.847 (10)	C14—H14	0.93
O12A—O12B	0.704 (19)	C15—C16	1.482 (5)
O12B—Rb1—O8	125.7 (2)	O9—Rb1—O12A^i	146.8 (3)
O12B—Rb1—O12A	13.8 (3)	O13B^i—Rb1—O12A^i	58.0 (4)
O8—Rb1—O12A	129.1 (5)	O13A^i—Rb1—O12A^i	69.2 (4)
O12B—Rb1—O4	132.3 (3)	O13B—Rb1—O12A^i	57.7 (4)
O8—Rb1—O4	78.85 (10)	O5—Rb1—O12A^i	107.4 (3)
O12A—Rb1—O4	142.4 (5)	O12B^i—Rb1—O12A^i	1.6 (4)
O12B—Rb1—O9	78.1 (3)	O10^ii—Rb1—O12A^i	128.5 (3)
O8—Rb1—O9	136.31 (8)	O6—Rb1—O12A^i	133.6 (3)
O12A—Rb1—O9	66.2 (5)	O11—Rb1—O12A^i	120.7 (3)
O4—Rb1—O9	113.67 (9)	O13A^iv—Rb1—O12A^i	84.7 (4)
O12B—Rb1—O13B^i	62.2 (3)	O12B—Rb1—O13A	60.3 (3)
O8—Rb1—O13B^i	65.34 (18)	O8—Rb1—O13A	132.5 (2)
O12A—Rb1—O13B^i	70.8 (5)	O12A—Rb1—O13A	69.2 (5)
O4—Rb1—O13B^i	110.39 (18)	O4—Rb1—O13A	73.1 (2)
O9—Rb1—O13B^i	133.84 (17)	O9—Rb1—O13A	90.5 (2)
O12B—Rb1—O13A^i	72.0 (3)	O13B^i—Rb1—O13A	89.5 (2)
O8—Rb1—O13A^i	53.7 (3)	O13A^i—Rb1—O13A	105.9 (3)
O12A—Rb1—O13A^i	77.5 (5)	O5—Rb1—O13A	127.5 (2)
O4—Rb1—O13A^i	114.7 (3)	O12B^i—Rb1—O13A	55.7 (3)
O9—Rb1—O13A^i	131.6 (3)	O10^ii—Rb1—O13A	129.5 (2)
O12B—Rb1—O13B	61.2 (3)	O6—Rb1—O13A	158.8 (2)
O8—Rb1—O13B	133.40 (17)	O11—Rb1—O13A	94.8 (2)
O12A—Rb1—O13B	69.8 (5)	O13A^iv—Rb1—O13A	48.0 (4)
O4—Rb1—O13B	72.54 (16)	O12A^i—Rb1—O13A	56.6 (4)
O9—Rb1—O13B	89.35 (17)	O12B—Rb1—O3	158.3 (3)
O13B^i—Rb1—O13B	91.1 (2)	O8—Rb1—O3	55.77 (9)
O13A^i—Rb1—O13B	107.6 (3)	O12A—Rb1—O3	170.9 (5)
O12B—Rb1—O5	164.8 (3)	O9—Rb1—O3	116.45 (7)
O8—Rb1—O5	61.09 (8)	O13B^i—Rb1—O3	108.67 (16)
O12A—Rb1—O5	150.9 (5)	O13A^i—Rb1—O3	104.5 (3)
O4—Rb1—O5	59.77 (7)	O13B—Rb1—O3	101.26 (15)
O9—Rb1—O5	88.33 (8)	O12B^i—Rb1—O3	72.83 (16)
O13B^i—Rb1—O5	126.43 (17)	O10^ii—Rb1—O3	128.30 (6)
O13A^i—Rb1—O5	113.5 (3)	O6—Rb1—O3	71.12 (7)
O13B—Rb1—O5	126.29 (16)	O11—Rb1—O3	65.52 (7)
O12B—Rb1—O12B^i	86.2 (4)	O13A^iv—Rb1—O3	75.9 (2)
O8—Rb1—O12B^i	76.96 (17)	O12A^i—Rb1—O3	71.3 (3)
O12A—Rb1—O12B^i	100.1 (6)	O13A—Rb1—O3	101.80 (19)
O4—Rb1—O12B^i	57.71 (17)	O11—Co1—O11^iii	180.000 (1)
O9—Rb1—O12B^i	146.02 (16)	O11—Co1—O9^iii	92.65 (14)
O13B^i—Rb1—O12B^i	57.2 (2)	O11^iii—Co1—O9^iii	87.35 (14)
O13A^i—Rb1—O12B^i	68.8 (3)	O11—Co1—O9	87.35 (14)
O13B—Rb1—O12B^i	56.8 (2)	O11^iii—Co1—O9	92.65 (14)
O5—Rb1—O12B^i	108.97 (16)	O9^iii—Co1—O9	180.0
O12B—Rb1—O10^ii	69.4 (3)	O11—Co1—O10^iii	87.11 (12)
O8—Rb1—O10^ii	81.17 (9)	O11^iii—Co1—O10^iii	92.89 (12)
O12A—Rb1—O10^ii	60.5 (5)	O9^iii—Co1—O10^iii	89.31 (11)
O4—Rb1—O10^ii	157.03 (8)	O9—Co1—O10^iii	90.69 (11)
O9—Rb1—O10^ii	74.24 (8)	O11—Co1—O10	92.89 (12)
O13B^i—Rb1—O10^ii	70.59 (17)	O11^iii—Co1—O10	87.11 (12)
O13A^i—Rb1—O10^ii	60.0 (3)	O9^iii—Co1—O10	90.69 (11)
O13B—Rb1—O10^ii	130.20 (16)	O9—Co1—O10	89.31 (11)
O5—Rb1—O10^ii	100.41 (7)	O10^iii—Co1—O10	180.00 (16)
O12B^i—Rb1—O10^ii	127.79 (17)	O1—C1—O2	124.0 (4)
O12B—Rb1—O6	130.0 (3)	O1—C1—C2	118.3 (4)
O8—Rb1—O6	60.77 (8)	O2—C1—C2	117.4 (4)
O12A—Rb1—O6	117.7 (5)	C3—C2—C7	118.3 (4)
O4—Rb1—O6	97.26 (8)	C3—C2—C1	117.6 (4)
O9—Rb1—O6	75.87 (7)	C7—C2—C1	124.0 (3)
O13B^i—Rb1—O6	111.69 (19)	C4—C3—C2	120.5 (4)
O13A^i—Rb1—O6	95.3 (3)	C5—C4—C3	121.2 (4)
O13B—Rb1—O6	157.16 (16)	C4—C5—C6	119.2 (5)
O12B^i—Rb1—O6	135.01 (16)	C7—C6—C5	120.8 (4)
O10^ii—Rb1—O6	62.78 (7)	C6—C7—C2	120.0 (4)
O12B—Rb1—O11	124.4 (2)	C6—C7—C8	120.4 (3)
O8—Rb1—O11	108.13 (9)	C2—C7—C8	119.5 (4)
O12A—Rb1—O11	115.5 (5)	O4—C8—O3	123.5 (4)
O4—Rb1—O11	66.24 (9)	O4—C8—C7	123.0 (3)
O9—Rb1—O11	51.33 (8)	O3—C8—C7	113.4 (4)
O13B^i—Rb1—O11	173.41 (17)	O5—C9—O6	123.1 (4)
O13A^i—Rb1—O11	158.7 (3)	O5—C9—C10	118.1 (4)
O13B—Rb1—O11	93.10 (16)	O6—C9—C10	118.7 (3)
O5—Rb1—O11	47.06 (7)	C11—C10—C15	118.5 (4)
O12B^i—Rb1—O11	121.60 (17)	C11—C10—C9	117.9 (3)
O10^ii—Rb1—O11	110.13 (7)	C15—C10—C9	123.4 (3)
O6—Rb1—O11	64.07 (7)	C12—C11—C10	120.9 (4)
O12B—Rb1—O13A^iv	97.0 (3)	C12—C11—H11	119.5
O8—Rb1—O13A^iv	131.4 (2)	C10—C11—H11	119.5
O12A—Rb1—O13A^iv	98.1 (5)	C13—C12—C11	120.7 (4)
O4—Rb1—O13A^iv	53.7 (2)	C13—C12—H12	119.7
O9—Rb1—O13A^iv	67.7 (2)	C11—C12—H12	119.7
O13B^i—Rb1—O13A^iv	136.0 (3)	C12—C13—C14	119.9 (4)
O13A^i—Rb1—O13A^iv	151.7 (5)	C12—C13—H13	120.1
O13B—Rb1—O13A^iv	46.4 (2)	C14—C13—H13	120.1
O5—Rb1—O13A^iv	84.0 (2)	C13—C14—C15	120.4 (4)
O12B^i—Rb1—O13A^iv	84.8 (3)	C13—C14—H14	119.8
O10^ii—Rb1—O13A^iv	141.5 (2)	C15—C14—H14	119.8
O6—Rb1—O13A^iv	111.1 (2)	C14—C15—C10	119.5 (3)
O11—Rb1—O13A^iv	47.3 (2)	C14—C15—C16	119.7 (4)
O12B—Rb1—O12A^i	87.8 (5)	C10—C15—C16	120.7 (3)
O8—Rb1—O12A^i	75.9 (3)	O8—C16—O7	122.6 (4)
O12A—Rb1—O12A^i	101.7 (6)	O8—C16—C15	122.1 (4)
O4—Rb1—O12A^i	56.4 (3)	O7—C16—C15	115.3 (4)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H31···O5	0.85 (4)	1.73 (4)	2.572 (5)	175 (5)
O7—H7···O2^v	0.85 (5)	1.70 (5)	2.548 (4)	177 (5)
O9—H9A···O1^iv	0.85 (4)	1.89 (4)	2.701 (4)	160 (4)
O9—H9B···O6^ii	0.85 (4)	1.82 (4)	2.654 (4)	167 (4)
O10—H10A···O6	0.85 (3)	1.85 (3)	2.691 (4)	171 (3)
O10—H10B···O1^vi	0.84 (3)	1.98 (4)	2.794 (4)	161 (3)
O11—H11A···O8^vii	0.84 (5)	2.17 (5)	3.008 (5)	175 (4)
O11—H11B···O5	0.85 (4)	1.88 (4)	2.708 (5)	164 (4)
O12A—H12A···O2^iv	0.86	2.11	2.78 (2)	134
O12A—H12B···O4^i	0.84	2.57	3.39 (2)	163
O12B—H12C···O2^iv	0.86	1.98	2.84 (1)	169
O12B—H12D···O4^i	0.86	2.18	3.02 (1)	163
O13A—H13A···O8^i	0.87	2.02	2.73 (1)	138
O13A—H13B···O11^iv	0.84	2.38	3.00 (2)	132
O13B—H13C···O2^iv	0.87	2.32	3.111 (9)	151
O13B—H13D···O13B^iv	0.88	2.05	2.75 (1)	136

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