Crystal structure of rubidium peroxide ammonia disolvate

Grassl, T.; Korber, N.

doi:10.1107/S2056989017000354

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Volume 73| Part 2| February 2017| Pages 200-202

https://doi.org/10.1107/S2056989017000354

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Crystal structure of rubidium peroxide ammonia disolvate

Tobias Grassl ^a and Nikolaus Korber ^a ^*

^aInstitut für Anorganische Chemie, Universität Regensburg, Universitätsstrasse 31, 93053 Regensburg, Germany
^*Correspondence e-mail: nikolaus.korber@chemie.uni-regensburg.de

Edited by T. J. Prior, University of Hull, England (Received 6 December 2016; accepted 9 January 2017; online 17 January 2017)

The title compound, Rb₂O₂·2NH₃, has been obtained as a reaction product of rubidium metal dissolved in liquid ammonia and glucuronic acid. As a result of the low-temperature crystallization, a disolvate was formed. To our knowledge, only one other solvate of an alkali metal peroxide is known: Na₂O₂·8H₂O has been reported by Grehl et al. [Acta Cryst. (1995), C51, 1038–1040]. We determined the peroxide bond length to be 1.530 (11) Å, which is in accordance with the length reported by Bremm & Jansen [Z. Anorg. Allg. Chem. (1992), 610, 64–66]. One of the ammonia solvate molecules is disordered relative to a mirror plane, with 0.5 occupancy for the corresponding nitrogen atom.

Keywords: crystal structure; rubidium; peroxide; ammonia disolvate.

CCDC reference: 1526250

1. Chemical context

The crystal structure of the title compound was determined in the course of investigations regarding the reactivity of carbohydrates towards alkali metals and NH₃ in solutions where liquid ammonia itself is used as solvent. The source of the peroxide anion could not be explicitly traced back but it seems to have its origin in oxygen gas from intruding atmosphere due to undetected leakage in the reaction vessel.

2. Structural commentary

The asymmetric unit contains one peroxide anion, two charge-compensating rubidium cations and two ammonia molecules (Fig. 1). Except for one nitrogen atom (N1, showing half-occupancy) and one hydrogen atom (H2B), all other atoms are located on mirror planes. The anion is surrounded by four rubidium cations located around the girth of the peroxide ion (Fig. 2). This unit forms one-dimensional infinite strands by sharing one common edge of a distorted plane of four Rb ions (Fig. 3). This structural motif can also be observed in potassium acetylide K₂C₂ (Hamberger et al., 2012 ). The peroxide bond length was determined to be 1.530 (11) Å. The anion–cation contacts range between 2.790 (5) Å and 2.917 (6) Å. The coordination number of the cations is 8.

Figure 1
The asymmetric unit of the title compound, with the atom labeling and displacement ellipsoids drawn at the 50% probability level.

Figure 2
The environment of the peroxide anion. Displacement ellipsoids are drawn at the 50% probability level. [Symmetry code: (i) −1 + x, y, z.]

Figure 3
One-dimensional infinite strands formed by peroxide anions and rubidium cations. Displacement ellipsoids are drawn at the 50% probability level.

The O—O bond length of the peroxide anion is longer than the value found in the literature based on the work of Föppl which is approximately 1.49 Å. In Fig. 4, a comparative view of bond lengths is presented based on the work of Bremm & Jansen (1992 ), Föppl (1954 , 1955 , 1957 ) and Grehl et al. (1995 ).

Figure 4
Comparison of peroxide bond lengths in different compounds. The vertical line shows the peroxide bond length commonly used in the literature. Each data point is shown with its standard uncertainties.

3. Supramolecular features

Despite the low ammonia content, numerous hydrogen bonds can be observed and the NH₃ molecules bridge the peroxide anions. The peroxide anion shows five contacts to ammonia molecules, forming a three-dimensional network in the packing. The distances between donor and acceptor atoms ranges from 2.926(15) Angstrom to 3.597(16) Angstrom, which is commonly observed in ammoniates. Numerical details of the hydrogen-bonding interactions are given in Table 1.

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1A⋯O2	1.05 (14)	1.98 (15)	2.941 (16)	151 (8)
N1—H1B⋯O2ⁱ	0.97 (13)	2.04 (15)	2.926 (15)	151 (8)
N1—H1C⋯O1ⁱⁱ	0.82 (14)	3.07 (16)	3.597 (16)	125 (11)
N2—H2A⋯N2ⁱⁱⁱ	0.74 (16)	3.03 (12)	3.57 (2)	131 (6)
N2—H2A⋯N2^iv	0.74 (16)	3.03 (12)	3.57 (2)	131 (6)
N2—H2A⋯N2^v	0.74 (16)	3.03 (12)	3.57 (2)	131 (6)
N2—H2B⋯O1ⁱⁱ	1.01 (11)	1.95 (11)	2.955 (10)	173 (8)
Symmetry codes: (i) $[x+{\script{1\over 2}}, -y+{\script{3\over 2}}, -z+{\script{1\over 2}}]$ ; (ii) x+1, y, z; (iii) -x+1, -y+1, -z+1; (iv) $[-x+1, y-{\script{1\over 2}}, -z+1]$ ; (v) $[-x+1, y+{\script{1\over 2}}, -z+1]$ .

4. Synthesis and crystallization

500 mg (2.58 mmol) D-glucuronic acid and 880 mg (10.29 mmol) rubidium were placed under an argon atmosphere in a reaction vessel and 25 ml of dry liquid ammonia were condensed. The mixture was stored at 237 K for five days. The flask was then stored at 161 K for several months. After that period, clear needle-shaped colorless crystals of the title compound could be found at the wall of the flask.

5. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2. The nitrogen atom N1 is disordered with 0.5 as the site occupation factor. All hydrogen atoms could be located in difference map and and their positions were refined freely with a common U_iso(H) parameter. The isotropic displacement parameters were fixed to 0.025.

Table 2
Experimental details

Crystal data
Chemical formula	Rb₂O₂·2NH₃
M_r	237.01
Crystal system, space group	Orthorhombic, Pnma
Temperature (K)	123
a, b, c (Å)	7.3957 (7), 4.0932 (6), 18.1873 (17)
V (Å³)	550.57 (11)
Z	4
Radiation type	Mo Kα
μ (mm⁻¹)	17.66
Crystal size (mm)	0.24 × 0.09 × 0.08

Data collection
Diffractometer	Agilent SuperNova Dual Source diffractometer with an Eos detector
Absorption correction	Analytical [CrysAlis PRO (Agilent, 2012 ), based on expressions derived by Clark & Reid (1995 )]
T_min, T_max	0.064, 0.354
No. of measured, independent and observed [I > 2σ(I)] reflections	2921, 641, 570
R_int	0.057
(sin θ/λ)_max (Å⁻¹)	0.625

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.050, 0.118, 1.35
No. of reflections	641
No. of parameters	51
H-atom treatment	Only H-atom coordinates refined
Δρ_max, Δρ_min (e Å⁻³)	1.12, −1.79
Computer programs: CrysAlis PRO (Agilent, 2012), olex2.solve (Bourhis et al., 2015 ), SHELXL2014 (Sheldrick, 2015 ), DIAMOND (Brandenburg & Putz, 2012 ) and OLEX2 (Dolomanov et al., 2009 ).

Supporting information

CCDC reference: 1526250

Crystal structure: contains datablock I. DOI: https://doi.org/10.1107/S2056989017000354/pj2039sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989017000354/pj2039Isup2.hkl

checkCIF report

Computing details top

Data collection: CrysAlis PRO (Agilent, 2012); cell refinement: CrysAlis PRO (Agilent, 2012); data reduction: CrysAlis PRO (Agilent, 2012); program(s) used to solve structure: olex2.solve (Bourhis et al., 2015); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: DIAMOND (Brandenburg & Putz, 2012); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009).

Rubidium peroxide ammonia disolvate top

Crystal data top

Rb₂O₂·2NH₃	D_x = 2.859 Mg m⁻³
M_r = 237.01	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pnma	Cell parameters from 1711 reflections
a = 7.3957 (7) Å	θ = 3.4–28.3°
b = 4.0932 (6) Å	µ = 17.66 mm⁻¹
c = 18.1873 (17) Å	T = 123 K
V = 550.57 (11) Å³	Block, clear colourless
Z = 4	0.24 × 0.09 × 0.08 mm
F(000) = 440

Data collection top

Agilent SuperNova Dual Source diffractometer with an Eos detector	641 independent reflections
Mirror monochromator	570 reflections with I > 2σ(I)
Detector resolution: 7.9851 pixels mm^-1	R_int = 0.057
phi and ω scans	θ_max = 26.4°, θ_min = 3.6°
Absorption correction: analytical [CrysAlis PRO (Agilent, 2012), based on expressions derived by Clark & Reid (1995)]	h = −9→9
T_min = 0.064, T_max = 0.354	k = −5→4
2921 measured reflections	l = −22→22

Refinement top

Refinement on F²	0 restraints
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F² > 2σ(F²)] = 0.050	Only H-atom coordinates refined
wR(F²) = 0.118	w = 1/[σ²(F_o²) + (0.0361P)² + 7.6682P] where P = (F_o² + 2F_c²)/3
S = 1.35	(Δ/σ)_max < 0.001
641 reflections	Δρ_max = 1.12 e Å⁻³
51 parameters	Δρ_min = −1.79 e Å⁻³

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

	x	y	z	U_iso*/U_eq	Occ. (<1)
Rb1	0.11196 (14)	0.2500	0.42075 (5)	0.0164 (4)
Rb2	−0.25614 (15)	1.2500	0.28803 (5)	0.0182 (4)
O1	−0.1266 (11)	0.7500	0.3825 (4)	0.019 (2)
O2	0.0133 (11)	0.7500	0.3206 (4)	0.022 (2)
N2	0.6843 (16)	0.2500	0.4710 (6)	0.020 (3)
N1	0.4060 (18)	0.650 (4)	0.3327 (7)	0.017 (4)	0.5
H1A	0.28 (2)	0.7500	0.340 (8)	0.025*
H1B	0.42 (2)	0.7500	0.285 (8)	0.025*
H1C	0.46 (2)	0.7500	0.364 (8)	0.025*
H2A	0.58 (2)	0.2500	0.472 (8)	0.025*
H2B	0.739 (13)	0.43 (3)	0.441 (5)	0.025*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Rb1	0.0107 (5)	0.0268 (8)	0.0116 (5)	0.000	−0.0022 (4)	0.000
Rb2	0.0088 (5)	0.0345 (8)	0.0113 (5)	0.000	0.0003 (4)	0.000
O1	0.012 (4)	0.027 (6)	0.020 (4)	0.000	0.003 (3)	0.000
O2	0.011 (4)	0.040 (7)	0.014 (4)	0.000	0.000 (3)	0.000
N2	0.017 (5)	0.025 (7)	0.018 (5)	0.000	0.000 (4)	0.000
N1	0.016 (6)	0.019 (12)	0.016 (6)	−0.007 (6)	−0.002 (5)	0.000 (6)

Geometric parameters (Å, º) top

Rb1—Rb2ⁱ	3.6383 (15)	Rb2—N1^x	3.507 (15)
Rb1—O1	2.790 (5)	Rb2—N1^xiii	2.988 (14)
Rb1—O1ⁱⁱ	3.579 (8)	Rb2—N1^ix	2.988 (14)
Rb1—O1ⁱ	2.790 (6)	O1—Rb1ⁱⁱ	3.579 (8)
Rb1—O2	2.836 (5)	O1—Rb1^viii	2.790 (5)
Rb1—O2ⁱ	2.836 (5)	O1—Rb2ⁱ	2.839 (6)
Rb1—N2ⁱⁱⁱ	3.292 (12)	O1—O2	1.530 (11)
Rb1—N2^iv	3.215 (8)	O2—Rb1^viii	2.836 (5)
Rb1—N2^v	3.215 (8)	O2—Rb2^xiv	3.316 (6)
Rb1—N2^vi	3.215 (8)	O2—Rb2^xv	3.316 (6)
Rb1—N1^vii	3.157 (14)	O2—Rb2ⁱ	2.917 (6)
Rb1—N1	3.157 (14)	N2—Rb1^iv	3.215 (8)
Rb2—O1	2.839 (6)	N2—Rb1^xvi	3.292 (12)
Rb2—O1^viii	2.839 (6)	N2—Rb1^xvii	3.215 (8)
Rb2—O2^viii	2.917 (6)	N2—Rb2^xviii	3.356 (11)
Rb2—O2^ix	3.316 (6)	N1—Rb1^viii	3.652 (15)
Rb2—O2	2.917 (6)	N1—Rb2^xiv	2.988 (14)
Rb2—O2^x	3.316 (6)	N1—Rb2^xv	3.507 (15)
Rb2—N2^xi	3.356 (11)	N1—Rb2^xvi	3.598 (14)
Rb2—N1^xi	3.095 (15)	N1—Rb2^xviii	3.095 (15)
Rb2—N1^xii	3.095 (15)	N1—N1^xix	0.82 (3)

O1ⁱⁱ—Rb1—Rb2ⁱ	133.30 (13)	O2—Rb2—N1^x	53.2 (3)
O1ⁱ—Rb1—Rb2ⁱ	50.32 (13)	O2—Rb2—N1^xi	150.4 (3)
O1—Rb1—Rb2ⁱ	50.32 (13)	O2—Rb2—N1^xii	97.3 (3)
O1ⁱ—Rb1—O1ⁱⁱ	105.56 (17)	O2^ix—Rb2—N1^x	103.6 (3)
O1—Rb1—O1ⁱ	94.4 (2)	O2^viii—Rb2—N1^ix	59.4 (3)
O1—Rb1—O1ⁱⁱ	105.56 (17)	O2^viii—Rb2—N1^x	112.7 (3)
O1ⁱ—Rb1—O2	101.92 (19)	O2^viii—Rb2—N1^xi	97.3 (3)
O1ⁱ—Rb1—O2ⁱ	31.5 (2)	O2^x—Rb2—N1^x	51.0 (3)
O1—Rb1—O2	31.5 (2)	O2—Rb2—N1^xiii	59.4 (3)
O1—Rb1—O2ⁱ	101.92 (19)	O2^viii—Rb2—N1^xiii	105.0 (3)
O1ⁱ—Rb1—N2^v	156.3 (3)	O2—Rb2—N1^ix	105.0 (3)
O1ⁱ—Rb1—N2ⁱⁱⁱ	57.42 (17)	N2^xi—Rb2—N1^x	131.7 (3)
O1ⁱ—Rb1—N2^iv	156.3 (3)	N1^xi—Rb2—O2^x	93.8 (3)
O1—Rb1—N2^v	89.0 (2)	N1^xi—Rb2—O2^ix	54.2 (3)
O1—Rb1—N2^iv	89.0 (2)	N1^ix—Rb2—O2^ix	55.3 (3)
O1—Rb1—N2^vi	156.3 (3)	N1^xii—Rb2—O2^ix	93.8 (3)
O1—Rb1—N2ⁱⁱⁱ	57.42 (17)	N1^xiii—Rb2—O2^x	55.3 (3)
O1ⁱ—Rb1—N2^vi	88.98 (19)	N1^xii—Rb2—O2^x	54.2 (3)
O1—Rb1—N1	85.9 (3)	N1^xiii—Rb2—O2^ix	96.1 (3)
O1ⁱ—Rb1—N1^vii	85.9 (3)	N1^ix—Rb2—O2^x	96.1 (3)
O1ⁱ—Rb1—N1	133.5 (3)	N1^xii—Rb2—N2^xi	68.5 (3)
O1—Rb1—N1^vii	133.5 (3)	N1^xiii—Rb2—N2^xi	141.3 (3)
O2ⁱ—Rb1—Rb2ⁱ	51.77 (13)	N1^xi—Rb2—N2^xi	68.5 (3)
O2—Rb1—Rb2ⁱ	51.77 (13)	N1^ix—Rb2—N2^xi	141.3 (3)
O2—Rb1—O1ⁱⁱ	130.55 (13)	N1^xii—Rb2—N1^xi	63.8 (6)
O2ⁱ—Rb1—O1ⁱⁱ	130.55 (13)	N1^ix—Rb2—N1^xi	103.1 (5)
O2—Rb1—O2ⁱ	92.4 (2)	N1^ix—Rb2—N1^xii	143.7 (3)
O2—Rb1—N2^v	93.14 (17)	N1^xiii—Rb2—N1^x	11.3 (4)
O2ⁱ—Rb1—N2^iv	166.8 (2)	N1^xiii—Rb2—N1^ix	66.4 (6)
O2ⁱ—Rb1—N2^vi	93.14 (17)	N1^ix—Rb2—N1^x	77.7 (3)
O2—Rb1—N2ⁱⁱⁱ	86.0 (2)	N1^xiii—Rb2—N1^xii	103.1 (5)
O2—Rb1—N2^iv	93.14 (17)	N1^xii—Rb2—N1^x	94.0 (2)
O2—Rb1—N2^vi	166.8 (2)	N1^xiii—Rb2—N1^xi	143.7 (3)
O2ⁱ—Rb1—N2^v	166.8 (2)	N1^xi—Rb2—N1^x	144.2 (4)
O2ⁱ—Rb1—N2ⁱⁱⁱ	86.0 (2)	Rb1^viii—O1—Rb1ⁱⁱ	74.44 (17)
O2—Rb1—N1	58.5 (3)	Rb1—O1—Rb1^viii	94.4 (2)
O2—Rb1—N1^vii	103.0 (3)	Rb1—O1—Rb1ⁱⁱ	74.44 (17)
O2ⁱ—Rb1—N1	103.0 (3)	Rb1—O1—Rb2ⁱ	80.53 (7)
O2ⁱ—Rb1—N1^vii	58.5 (3)	Rb1^viii—O1—Rb2	80.53 (7)
N2ⁱⁱⁱ—Rb1—Rb2ⁱ	57.66 (19)	Rb1^viii—O1—Rb2ⁱ	153.3 (3)
N2^vi—Rb1—Rb2ⁱ	139.21 (14)	Rb1—O1—Rb2	153.3 (3)
N2^iv—Rb1—Rb2ⁱ	139.21 (14)	Rb2—O1—Rb1ⁱⁱ	127.97 (15)
N2^v—Rb1—Rb2ⁱ	139.21 (14)	Rb2ⁱ—O1—Rb1ⁱⁱ	127.97 (15)
N2^iv—Rb1—O1ⁱⁱ	51.21 (19)	Rb2ⁱ—O1—Rb2	92.3 (2)
N2^v—Rb1—O1ⁱⁱ	51.21 (19)	O2—O1—Rb1ⁱⁱ	135.7 (5)
N2ⁱⁱⁱ—Rb1—O1ⁱⁱ	75.6 (2)	O2—O1—Rb1	75.9 (3)
N2^vi—Rb1—O1ⁱⁱ	51.21 (19)	O2—O1—Rb1^viii	75.9 (3)
N2^v—Rb1—N2ⁱⁱⁱ	106.3 (2)	O2—O1—Rb2	77.4 (3)
N2^vi—Rb1—N2ⁱⁱⁱ	106.3 (2)	O2—O1—Rb2ⁱ	77.4 (3)
N2^iv—Rb1—N2ⁱⁱⁱ	106.3 (2)	Rb1—O2—Rb1^viii	92.4 (2)
N2^v—Rb1—N2^vi	79.1 (2)	Rb1^viii—O2—Rb2	78.45 (8)
N2^v—Rb1—N2^iv	0.0 (5)	Rb1—O2—Rb2	144.3 (3)
N2^iv—Rb1—N2^vi	79.1 (2)	Rb1^viii—O2—Rb2^xiv	134.1 (3)
N1^vii—Rb1—Rb2ⁱ	100.3 (2)	Rb1—O2—Rb2^xiv	78.75 (10)
N1—Rb1—Rb2ⁱ	100.3 (2)	Rb1—O2—Rb2ⁱ	78.45 (8)
N1—Rb1—O1ⁱⁱ	119.1 (3)	Rb1—O2—Rb2^xv	134.1 (3)
N1^vii—Rb1—O1ⁱⁱ	119.1 (3)	Rb1^viii—O2—Rb2ⁱ	144.3 (3)
N1—Rb1—N2^v	70.0 (3)	Rb1^viii—O2—Rb2^xv	78.75 (10)
N1^vii—Rb1—N2^vi	70.0 (3)	Rb2ⁱ—O2—Rb2	89.1 (2)
N1—Rb1—N2^iv	70.0 (3)	Rb2^xiv—O2—Rb2^xv	76.22 (17)
N1^vii—Rb1—N2^iv	108.5 (3)	Rb2—O2—Rb2^xv	78.31 (10)
N1—Rb1—N2^vi	108.5 (3)	Rb2ⁱ—O2—Rb2^xiv	78.32 (10)
N1—Rb1—N2ⁱⁱⁱ	143.4 (3)	Rb2—O2—Rb2^xiv	131.6 (3)
N1^vii—Rb1—N2ⁱⁱⁱ	143.4 (3)	Rb2ⁱ—O2—Rb2^xv	131.6 (3)
N1^vii—Rb1—N2^v	108.5 (3)	O1—O2—Rb1	72.6 (3)
N1—Rb1—N1^vii	62.4 (6)	O1—O2—Rb1^viii	72.6 (3)
O1—Rb2—O1^viii	92.3 (2)	O1—O2—Rb2	71.8 (3)
O1^viii—Rb2—O2^ix	95.11 (15)	O1—O2—Rb2^xv	141.86 (9)
O1—Rb2—O2^viii	98.78 (18)	O1—O2—Rb2^xiv	141.86 (9)
O1—Rb2—O2^x	95.11 (15)	O1—O2—Rb2ⁱ	71.8 (3)
O1^viii—Rb2—O2^x	168.22 (18)	Rb1^iv—N2—Rb1^xvi	73.7 (2)
O1—Rb2—O2^ix	168.22 (18)	Rb1^iv—N2—Rb1^xvii	79.1 (2)
O1^viii—Rb2—O2^viii	30.8 (2)	Rb1^xvii—N2—Rb1^xvi	73.7 (2)
O1^viii—Rb2—O2	98.77 (18)	Rb1^xvi—N2—Rb2^xviii	66.4 (2)
O1—Rb2—O2	30.8 (2)	Rb1^xvii—N2—Rb2^xviii	123.1 (3)
O1—Rb2—N2^xi	56.23 (17)	Rb1^iv—N2—Rb2^xviii	123.1 (3)
O1^viii—Rb2—N2^xi	56.23 (17)	Rb1—N1—Rb1^viii	73.5 (3)
O1^viii—Rb2—N1^ix	85.1 (3)	Rb1—N1—Rb2^xvi	161.2 (5)
O1—Rb2—N1^ix	134.7 (3)	Rb1—N1—Rb2^xv	116.4 (4)
O1—Rb2—N1^x	76.0 (3)	Rb2^xiv—N1—Rb1	79.2 (4)
O1—Rb2—N1^xi	119.6 (3)	Rb2^xvi—N1—Rb1^viii	93.0 (4)
O1—Rb2—N1^xii	74.5 (3)	Rb2^xv—N1—Rb1^viii	66.4 (3)
O1^viii—Rb2—N1^xiii	134.7 (3)	Rb2^xviii—N1—Rb1	114.5 (5)
O1^viii—Rb2—N1^xii	119.6 (3)	Rb2^xiv—N1—Rb1^viii	116.9 (4)
O1^viii—Rb2—N1^xi	74.5 (3)	Rb2^xviii—N1—Rb1^viii	162.1 (5)
O1^viii—Rb2—N1^x	140.3 (3)	Rb2^xviii—N1—Rb2^xvi	75.0 (3)
O1—Rb2—N1^xiii	85.1 (3)	Rb2^xviii—N1—Rb2^xv	118.8 (4)
O2^x—Rb2—O2^ix	76.22 (17)	Rb2^xv—N1—Rb2^xvi	67.5 (3)
O2—Rb2—O2^ix	154.83 (12)	Rb2^xiv—N1—Rb2^xv	77.7 (3)
O2^viii—Rb2—O2^ix	92.24 (11)	Rb2^xiv—N1—Rb2^xvi	119.1 (4)
O2^viii—Rb2—O2	89.1 (2)	Rb2^xiv—N1—Rb2^xviii	80.9 (4)
O2^viii—Rb2—O2^x	154.83 (12)	N1^xix—N1—Rb1^viii	47.7 (2)
O2—Rb2—O2^x	92.24 (11)	N1^xix—N1—Rb1	121.2 (3)
O2^viii—Rb2—N2^xi	83.6 (2)	N1^xix—N1—Rb2^xv	45.5 (2)
O2^ix—Rb2—N2^xi	121.53 (19)	N1^xix—N1—Rb2^xvi	46.9 (3)
O2^x—Rb2—N2^xi	121.53 (19)	N1^xix—N1—Rb2^xiv	123.2 (3)
O2—Rb2—N2^xi	83.6 (2)	N1^xix—N1—Rb2^xviii	121.9 (3)
O2^viii—Rb2—N1^xii	150.4 (3)

Symmetry codes: (i) x, y−1, z; (ii) −x, −y+1, −z+1; (iii) x−1, y, z; (iv) −x+1, −y+1, −z+1; (v) −x+1, y+1/2, −z+1; (vi) −x+1, y−1/2, −z+1; (vii) x, −y+1/2, z; (viii) x, y+1, z; (ix) x−1/2, y+1, −z+1/2; (x) x−1/2, y, −z+1/2; (xi) x−1, y+1, z; (xii) x−1, −y+3/2, z; (xiii) x−1/2, −y+3/2, −z+1/2; (xiv) x+1/2, y−1, −z+1/2; (xv) x+1/2, y, −z+1/2; (xvi) x+1, y, z; (xvii) −x+1, −y, −z+1; (xviii) x+1, y−1, z; (xix) x, −y+3/2, z.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O2	1.05 (14)	1.98 (15)	2.941 (16)	151 (8)
N1—H1B···O2^xx	0.97 (13)	2.04 (15)	2.926 (15)	151 (8)
N1—H1C···O1^xvi	0.82 (14)	3.07 (16)	3.597 (16)	125 (11)
N2—H2A···N2^iv	0.74 (16)	3.03 (12)	3.57 (2)	131 (6)
N2—H2A···N2^vi	0.74 (16)	3.03 (12)	3.57 (2)	131 (6)
N2—H2A···N2^v	0.74 (16)	3.03 (12)	3.57 (2)	131 (6)
N2—H2B···O1^xvi	1.01 (11)	1.95 (11)	2.955 (10)	173 (8)

Symmetry codes: (iv) −x+1, −y+1, −z+1; (v) −x+1, y+1/2, −z+1; (vi) −x+1, y−1/2, −z+1; (xvi) x+1, y, z; (xx) x+1/2, −y+3/2, −z+1/2.

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