Crystal structures and hydrogen bonding in the isotypic series of hydrated alkali metal (K, Rb and Cs) complexes with 4-amino-phenyl-arsonic acid.

The structures of the alkali metal (K, Rb and Cs) complex salts with 4-amino-phenyl-arsonic acid (p-arsanilic acid) manifest an isotypic series with the general formula [M2(C6H7AsNO3)2(H2O)3], with M = K {poly[di-μ3-4-amino-phenyl-arsonato-tri-μ2-aqua-dipotassium], [K2(C6H7AsNO3)2(H2O)3], (I)}, Rb {poly[di-μ3-4-amino-phenyl-arsonato-tri-μ2-aqua-dirubidium], [Rb2(C6H7AsNO3)2(H2O)3], (II)}, and Cs {poly[di-μ3-4-amino-phenyl-arsonato-tri-μ2-aqua-dirubidium], [Cs2(C6H7AsNO3)2(H2O)3], (III)}, in which the repeating structural units lie across crystallographic mirror planes containing two independent and different metal cations and a bridging water mol-ecule, with the two hydrogen p-arsanilate ligands and the second water mol-ecule lying outside the mirror plane. The bonding about the two metal cations in all complexes is similar, one five-coordinate, the other progressing from five-coordinate in (I) to eight-coordinate in both (II) and (III), with overall M-O bond-length ranges of 2.694 (5)-3.009 (7) (K), 2.818 (4)-3.246 (4) (Rb) and 2.961 (9)-3.400 (10) Å (Cs). The additional three bonds in (II) and (III) are the result of inter-metal bridging through the water ligands. Two-dimensional coordination polymeric structures with the layers lying parallel to (100) are generated through a number of bridging bonds involving the water mol-ecules (including hydrogen-bonding inter-actions), as well as through the arsanilate O atoms. These layers are linked across [100] through amine N-H⋯O hydrogen bonds to arsonate and water O-atom acceptors, giving overall three-dimensional network structures.

Chemical context

Arsenical 4-amino­phenyl­arsonic acid (p-arsanilic acid) has biological significance as an anti-helminth in veterinary applications (Steverding, 2010 ▸; O’Neil, 2001 ▸) and as a hydrated sodium salt (atox­yl) that had early usage as an anti-syphilitic (Ehrlich & Bertheim, 1907 ▸; Bosch & Rosich, 2008 ▸). The crystal structure of this salt has been determined together with the NH4 + salt (Smith & Wermuth, 2014 ▸); the structure of the parent p-arsanilic acid, which exists as a zwitterion, is also known (Shimada, 1961 ▸; Nuttall & Hunter, 1996 ▸). We have also determined the structures of the alkaline earth metal (Mg, Ca, Sr, Ba) salts of the acid (Smith & Wermuth, 2017 ▸). However, simple p-arsanilate single-metal complex structures are not common in the Cambridge Structure Database (Groom et al., 2016 ▸), examples being with AgI (three forms), Zn, Pb and Cd (Lesikar-Parrish et al., 2013 ▸; Xiao et al., 2015 ▸); Zn (Lin et al., 2012 ▸); Cd (Liu et al., 2010 ▸); SnIV (Xie et al., 2008 ▸); VIV and VV (Breen et al., 2012 ▸; Chen et al., 2012 ▸; Khan et al., 1992 ▸); UO2 (Adelani et al., 2012 ▸). Mixed-metal and/or mixed-ligand complexes are common, e.g. CoII/Mo=O, NiII/Mo=O, CuII/Mo=O and Zn/Mo=O with p-arsanilate and ligands such as 2,2′-bi­pyridine, 4,4′-bi­pyridine and 1,10-phenanthroline (Smith et al., 2013 ▸).

In an attempt to complete the structures of the alkali metal series of p-arsanilate salts, our reaction of the acid with potassium carbonate, rubidium carbonate and caesium carbonate in ethanol/water resulted in the formation of the crystalline hydrated salts with general formula [M + 2(C6H7AsNO3)− 2·3H2O]. Compounds (I) (M = K), (II) (Rb) and (III) (Cs) and their crystal structures are reported herein. However, suitable crystals of the Li analogue were not obtained to allow its crystal structure determination.

Structural commentary

The structures of the three title compounds [(I), (II) and (III)] form an isotypic series, with the asymmetric units in each comprising two independent and different metal complex cations (M1 and M2), which lie on crystallographic mirror planes that also contain one of the coordinating water mol­ecules (O2W), with the hydrogen p-arsanilate ligands and the second water mol­ecules (OW1, O1W ii) [symmetry code: (ii) −x + 1, −y, z] lying across the mirror plane (Figs. 1 ▸, 2 ▸ and 3 ▸, respectively). In all three examples, the M2 cation is five-coordinate, while with M1, the coordination spheres progress from five-coordinate in (I) to eight-coordinate in (II) and (III). The overall M—O bond length ranges are 2.694 (5)–3.009 (7) Å (K) (Table 1 ▸), 2.818 (4)–3.246 (4) Å (Rb) (Table 2 ▸) and 2.961 (9)–3.400 (10) Å (Cs) (Table 2 ▸). The amine N atom is not involved in bonding to the metal, as is the case in a number of other p-arsanilate complexes, e.g. with Zn (Lin et al., 2012 ▸). The M1O5 polyhedra in all three structures comprise four bridging arsonate O atoms and the μ 2 bridging water mol­ecule (O2W) (Tables 1 ▸, 2 ▸ and 3 ▸). The second M2O5 polyhedron in (I) comprises the bridging O11 and O11ii donors, the μ 2-O2W i [symmetry code: (i) −x + 1, −y + 2, z + ] donor and two monodentate water mol­ecules (O1W and O1W i) (Table 1 ▸).

Figure 1

The mol­ecular configuration and atom numbering scheme for the complex unit in (I). The metal cations (K1 and K2) and the water mol­ecule (O2W) lie on a mirror plane with mirror-related atoms indicated by symmetry code (ii) −x + 1, −y, z + . For other codes, see Table 1 ▸. Non-H atoms are shown as displacement ellipsoids at the 40% probability level.

Figure 2

The mol­ecular configuration and atom numbering scheme for the complex unit in the isotypic structure (II). The metal cations (Rb1 and Rb2) and the water mol­ecule (O2W) also lie on a mirror plane. For symmetry codes, see Table 2 ▸. Non-H atoms are shown as displacement ellipsoids at the 40% probability level.

Figure 3

The mol­ecular configuration and atom numbering scheme for the complex unit in the isotypic structure (III). The metal cations (Cs1 and Cs2) and the water mol­ecule (O2W) also lie on a mirror plane. For symmetry codes, see Table 3 ▸. Non-H atoms are shown as displacement ellipsoids at the 40% probability level.

Table 1

Selected bond lengths (Å) for (I)

K1—O1W	2.766 (5)	K2—O2W	3.009 (7)
K1—O11	2.824 (4)	K2—O11	2.713 (5)
K1—O2W i	2.959 (7)	K2—O12iii	2.694 (5)
K1—O1W ii	2.766 (5)	K2—O11ii	2.713 (5)
K1—O11ii	2.824 (4)	K2—O12iv	2.694 (5)

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) .

Table 2

Selected bond lengths (Å) for (II)

Rb1—O1W	2.917 (4)	Rb1—O1W v	3.246 (4)
Rb1—O11	2.925 (3)	Rb2—O2W	3.193 (6)
Rb1—O2W i	3.151 (6)	Rb2—O11	2.863 (3)
Rb1—O1W ii	3.246 (4)	Rb2—O12vi	2.818 (4)
Rb1—O2W iii	3.109 (5)	Rb2—O11iv	2.863 (3)
Rb1—O1W iv	2.917 (4)	Rb2—O12vii	2.818 (4)
Rb1—O11iv	2.925 (3)

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) ; (v) ; (vi) ; (vii) .

Table 3

Selected bond lengths (Å) for (III)

Cs1—O1W	3.087 (9)	Cs1—O1W iii	3.400 (10)
Cs1—O2W	3.286 (13)	Cs2—O11	3.024 (8)
Cs1—O11	3.040 (8)	Cs2—O2W iv	3.324 (13)
Cs1—O1W i	3.400 (10)	Cs2—O12v	2.961 (9)
Cs1—O2W i	3.295 (12)	Cs2—O11ii	3.024 (8)
Cs1—O1W ii	3.087 (9)	Cs2—O12vi	2.961 (9)
Cs1—O11ii	3.040 (8)

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) ; (v) ; (vi) .

With (II) and (III), the irregular M2O8 coordination sphere comprises all bonds mentioned in the description of the K complex (I), and in addition, the Rb and Cs bond length expansion allows further coordination sites through additional bridging bonds to both of the water mol­ecules (two through O1W and one through O2W), (Tables 2 ▸ and 3 ▸). The M1⋯M2 separations are 4.139 (3) Å [for (I)], 4.2500 (11) Å [for (II)] and 4.3498 (15) Å [for (III)]. There are also slightly shorter M1⋯M1i separations in all structures: 4.079 (3) Å (I), 4.1953 (13) Å (II) and 4.3127 (16) Å (III). Relatively short M2⋯As1 separations are present within the repeat unit in all three structures: 3.6369 (19) Å (I), 3.7796 (8) Å (II) and 3.9488 (14) Å (III).

In all structures, two-dimensional coordination polymeric complex structures are generated, with the layers lying in the mirror planes parallel to (100). Fig. 4 ▸ shows the basic makeup of the layer in (I) while those for (II) or (III) are shown in Fig. 5 ▸. The water mol­ecule O2W provides hydrogen-bonding links across the mirror plane to arsonate O13 acceptors (Tables 4 ▸, 5 ▸ and 6 ▸).

Figure 4

A partial expansion of the two-dimensional coordination polymeric sheet structure of (I), which extends across the mirror plane parallel to (100). Aromatic H atoms are omitted. For symmetry codes, see Table 1 ▸.

Figure 5

A partial expansion of the two-dimensional coordination polymeric sheet structure of (II) [or (III)], which extends across the mirror plane parallel to (100). Aromatic H atoms have been omitted.

Table 4

Hydrogen-bond geometry (Å, °) for (I)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1W—H11W⋯N4v	0.88 (6)	2.05 (6)	2.915 (7)	171 (5)
O1W—H12W⋯O11vi	0.89 (5)	1.77 (5)	2.660 (6)	175 (7)
O2W—H21W⋯O13vii	0.86 (5)	2.09 (6)	2.819 (6)	142 (6)
O12—H12⋯O13iv	0.87 (6)	1.70 (6)	2.538 (7)	160 (7)
N4—H41⋯O1W viii	0.86 (5)	2.17 (5)	3.010 (7)	164 (5)
N4—H42⋯O13ix	0.87 (6)	2.15 (6)	2.984 (7)	160 (5)

Symmetry codes: (iv) ; (v) ; (vi) ; (vii) ; (viii) ; (ix) .

Table 5

Hydrogen-bond geometry (Å, °) for (II)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1W—H11W⋯N4viii	0.89 (5)	2.04 (4)	2.923 (6)	176 (5)
O2W—H21W⋯O13ix	0.88 (4)	1.97 (4)	2.852 (5)	173 (5)
O12—H12⋯O13vii	0.86 (3)	1.73 (4)	2.552 (5)	158 (5)
N4—H41⋯O13x	0.86 (5)	2.18 (4)	3.022 (5)	167 (4)
N4—H42⋯O1W xi	0.88 (4)	2.13 (4)	3.005 (6)	176 (4)

Symmetry codes: (vii) ; (viii) ; (ix) ; (x) ; (xi) .

Table 6

Hydrogen-bond geometry (Å, °) for (III)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1W—H11W⋯N4vii	0.89 (9)	2.28 (13)	2.952 (13)	132 (10)
O2W—H21W⋯O13	0.89 (12)	2.16 (12)	2.850 (10)	134 (12)
O12—H12⋯O13vi	0.88 (5)	2.00 (12)	2.567 (13)	121 (12)
N4—H41⋯O1W viii	0.83 (14)	2.12 (15)	2.928 (15)	164 (9)
N4—H42⋯O13ix	0.91 (14)	2.20 (14)	3.082 (13)	166 (15)

Symmetry codes: (vi) ; (vii) ; (viii) ; (ix) .

Supra­molecular features

In the crystals of all three compounds, similar overall packing modes are observed, with the coordination polymeric layers lying along the mirror planes inter-linked across [100] through amine N4—H⋯O hydrogen bonds to arsonate O13 and water O1W acceptors (Tables 4 ▸, 5 ▸ and 6 ▸). In this respect, they resemble the crystal packing of the Na p-arsanilate analogue (Smith & Wermuth, 2014 ▸) but the structure of that compound (a trihydrate) differs from the current isotypic set in having significantly different coordination spheres, also lacking the mirror symmetry of the primary polymeric layers in (I)–(III). With these, the N4 amino group acts as an acceptor to an O1W hydrogen bond. The water mol­ecule O1W also forms a hydrogen bond with O11vi [symmetry code: (vi) x, −y + 2, z + ] in (I), but not in (II) or (III). The protonated p-arsanilate O atom (O12) forms an intra-layer hydrogen bond with an O11 acceptor, giving overall three-dimensional network structures in all cases (Figs. 6 ▸ and 7 ▸). No π–π associations are present in the structures.

Figure 6

A view of the packing in the unit cell of (I) along [010], showing the associated cation/anion sheets linked peripherally across [100] by hydrogen bonds involving the anilinium amine groups. Hydrogen-bonding inter­actions are shown as dashed lines and aromatic H atoms have been omitted.

Figure 7

A view of the packing in the unit cell of (II) [or (III)] along [010], showing the associated cation/anion sheets linked peripherally across [100] by hydrogen bonds involving the amine groups.

Database survey

Three-dimensional supra­molecular structures involving complexes of hydrogen p-arsanilate and mixed metal types, as distinct from those involving uni-metal types, such as in (I)–(III) and in those examples which have been previously mentioned in the Chemical context section of this article, are worthy of noting here. Mixed-metal-ligand examples (Smith et al., 2013 ▸) as well as mixed–metal structures add to the complexity of the coordination polymeric structures commonly generated, e.g. in the Mo/Ag, Mo/Cu and W/Na polyoxidometallate compounds (Johnson et al., 2002 ▸), the Mo/V cage structure (Onet et al., 2011 ▸) or the V/Na structure (Breen & Schmitt, 2008 ▸).

Synthesis and crystallization

Compounds (I)–(III) were synthesized by heating together for 5 min, 1 mmol qu­anti­ties of 4-amino­phenyl­arsonic acid and 0.5 mmol of either K2CO3 [for (I)], Rb2CO3 [for (II)] or Cs2CO3 [for (III)], in 20 ml of 50% ethanol/water (v/v). Room temperature evaporation of the solutions gave colourless crystal plates of the title compounds from which specimens were cleaved for the X-ray analyses.

Refinement details

Crystal data, data collection and structure refinement details are summarized in Table 7 ▸. Hydrogen atoms potentially involved in hydrogen-bonding inter­actions were located by difference methods but their positional parameters were restrained in the refinement with N—H = 0.88 Å and O—H = 0.86 Å, and with U iso(H) = 1.2U eq(N) or 1.5U eq(O). Other H atoms were included in the refinement at calculated positions, C—H = 0.95 Å, and treated as riding with U iso(H) = 1.2U eq(C).

Table 7

Experimental details

	(I)	(II)	(III)
Crystal data
Chemical formula	[K2(C6H7AsNO3)2(H2O)3]	[Rb2(C6H7AsNO3)2(H2O)3]	[Cs2(C6H7AsNO3)2(H2O)3]
M r	564.34	657.08	751.96
Crystal system, space group	Orthorhombic, C m c21	Orthorhombic, C m c21	Orthorhombic, C m c21
Temperature (K)	200	200	200
a, b, c (Å)	24.3426 (18), 10.4266 (7), 7.8315 (6)	24.4783 (19), 10.4577 (9), 8.0978 (7)	24.650 (3), 10.4373 (9), 8.3992 (7)
V (Å3)	1987.7 (3)	2072.9 (3)	2160.9 (4)
Z	4	4	4
Radiation type	Mo Kα	Mo Kα	Mo Kα
μ (mm−1)	3.83	7.94	6.46
Crystal size (mm)	0.35 × 0.22 × 0.11	0.35 × 0.20 × 0.12	0.40 × 0.22 × 0.10
Data collection
Diffractometer	Oxford Diffraction Gemini-S CCD-detector	Oxford Diffraction Gemini-S CCD-detector	Oxford Diffraction Gemini-S CCD-detector
Absorption correction	Multi-scan (CrysAlis PRO; Rigaku OD, 2015 ▸)	Multi-scan (CrysAlis PRO; Rigaku OD, 2015 ▸)	Multi-scan (CrysAlis PRO; Rigaku OD, 2015 ▸)
T min, T max	0.650, 0.980	0.375, 0.980	0.217, 0.980
No. of measured, independent and observed [I > 2σ(I)] reflections	2874, 1834, 1710	3623, 2093, 1899	4941, 1883, 1787
R int	0.020	0.026	0.030
(sin θ/λ)max (Å−1)	0.688	0.683	0.687
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S	0.030, 0.125, 1.23	0.032, 0.072, 1.03	0.041, 0.160, 1.18
No. of reflections	1834	2093	1883
No. of parameters	145	146	145
No. of restraints	8	8	8
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)	0.50, −0.84	0.70, −0.46	1.69, −1.00
Absolute structure	Flack (1983 ▸), 1281 Friedel pairs	Flack (1983 ▸), 1309 Friedel pairs	Flack (1983 ▸), 1405 Friedel pairs
Absolute structure parameter	0.03 (2)	−0.008 (12)	0.10 (4)

Computer programs: CrysAlis PRO (Rigaku OD, 2015 ▸), SIR92 (Altomare et al., 1993 ▸), SHELXL97 (Sheldrick, 2008 ▸) within WinGX (Farrugia, 2012 ▸) and PLATON (Spek, 2009 ▸).

Crystal structure: contains datablock(s) global, I, II, III. DOI: 10.1107/S2056989017000445/wm5350sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989017000445/wm5350Isup2.hkl

Structure factors: contains datablock(s) II. DOI: 10.1107/S2056989017000445/wm5350IIsup3.hkl

Structure factors: contains datablock(s) III. DOI: 10.1107/S2056989017000445/wm5350IIIsup4.hkl

CCDC references: 1526425, 1526424, 1526423

Additional supporting information: crystallographic information; 3D view; checkCIF report

[K2(C6H7AsNO3)2(H2O)3]	F(000) = 1128
Mr = 564.34	Dx = 1.886 Mg m−3
Orthorhombic, Cmc21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: C 2c -2	Cell parameters from 1421 reflections
a = 24.3426 (18) Å	θ = 4.1–28.7°
b = 10.4266 (7) Å	µ = 3.83 mm−1
c = 7.8315 (6) Å	T = 200 K
V = 1987.7 (3) Å3	Prism, colourless
Z = 4	0.35 × 0.22 × 0.11 mm

Oxford Diffraction Gemini-S CCD-detector diffractometer	1834 independent reflections
Radiation source: Enhance (Mo) X-ray source	1710 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.020
Detector resolution: 16.077 pixels mm-1	θmax = 29.3°, θmin = 3.2°
ω scans	h = −32→17
Absorption correction: multi-scan (CrysAlis PRO; Rigaku OD, 2015)	k = −13→13
Tmin = 0.650, Tmax = 0.980	l = −9→10
2874 measured reflections

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.030	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.125	w = 1/[σ2(Fo2) + (0.0744P)2] where P = (Fo2 + 2Fc2)/3
S = 1.23	(Δ/σ)max = 0.001
1834 reflections	Δρmax = 0.50 e Å−3
145 parameters	Δρmin = −0.84 e Å−3
8 restraints	Absolute structure: Flack (1983), 1281 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.03 (2)

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell esds are taken into account in the estimation of distances, angles and torsion angles

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.

	x	y	z	Uiso*/Ueq
As1	0.60155 (2)	0.63813 (4)	0.55509 (10)	0.0164 (2)
K1	0.50000	0.94523 (15)	0.5457 (3)	0.0224 (4)
K2	0.50000	0.63621 (19)	0.2140 (3)	0.0279 (6)
O1W	0.5845 (2)	1.0465 (4)	0.7396 (6)	0.0260 (12)
O2W	0.50000	0.7951 (6)	−0.1067 (9)	0.0263 (19)
O11	0.57103 (16)	0.7477 (4)	0.4358 (6)	0.0227 (12)
O12	0.5720 (2)	0.4898 (4)	0.5138 (6)	0.0333 (16)
O13	0.59063 (19)	0.6581 (4)	0.7630 (7)	0.0247 (14)
N4	0.8483 (2)	0.6311 (5)	0.4372 (8)	0.0243 (17)
C1	0.6778 (3)	0.6280 (5)	0.5052 (8)	0.0197 (16)
C2	0.7027 (3)	0.7225 (5)	0.4072 (8)	0.0203 (16)
C3	0.7583 (3)	0.7230 (5)	0.3828 (8)	0.0230 (17)
C4	0.7918 (3)	0.6313 (5)	0.4615 (7)	0.0170 (17)
C5	0.7669 (2)	0.5344 (4)	0.5574 (10)	0.0203 (14)
C6	0.7104 (2)	0.5332 (5)	0.5803 (8)	0.0197 (16)
H2	0.68080	0.78760	0.35650	0.0240*
H3	0.77440	0.78640	0.31150	0.0270*
H5	0.78880	0.46900	0.60720	0.0240*
H6	0.69380	0.46780	0.64730	0.0240*
H11W	0.608 (2)	0.998 (6)	0.795 (9)	0.0300*
H12	0.585 (3)	0.450 (6)	0.425 (6)	0.0300*
H12W	0.582 (3)	1.116 (4)	0.806 (8)	0.0300*
H21W	0.525 (2)	0.781 (7)	−0.181 (7)	0.0300*
H41	0.866 (3)	0.622 (5)	0.532 (5)	0.0240*
H42	0.863 (3)	0.683 (6)	0.363 (7)	0.0240*

	U11	U22	U33	U12	U13	U23
As1	0.0178 (3)	0.0148 (3)	0.0167 (3)	−0.0020 (2)	0.0030 (3)	−0.0007 (3)
K1	0.0198 (7)	0.0217 (7)	0.0256 (8)	0.0000	0.0000	−0.0055 (9)
K2	0.0186 (9)	0.0387 (11)	0.0264 (10)	0.0000	0.0000	−0.0114 (8)
O1W	0.028 (2)	0.023 (2)	0.027 (2)	0.0021 (19)	−0.006 (2)	−0.001 (2)
O2W	0.018 (3)	0.027 (3)	0.034 (4)	0.0000	0.0000	−0.003 (3)
O11	0.019 (2)	0.026 (2)	0.023 (2)	−0.0026 (17)	0.0023 (18)	0.0053 (18)
O12	0.037 (3)	0.022 (2)	0.041 (3)	−0.0120 (19)	0.022 (2)	−0.014 (2)
O13	0.023 (2)	0.024 (2)	0.027 (3)	0.0033 (19)	0.008 (2)	0.004 (2)
N4	0.019 (3)	0.024 (3)	0.030 (3)	0.002 (2)	−0.001 (2)	0.002 (2)
C1	0.022 (3)	0.015 (2)	0.022 (3)	−0.001 (2)	0.001 (2)	−0.002 (2)
C2	0.022 (3)	0.017 (2)	0.022 (3)	0.007 (2)	−0.001 (2)	0.000 (2)
C3	0.026 (3)	0.018 (3)	0.025 (3)	−0.003 (2)	0.006 (2)	0.011 (3)
C4	0.025 (3)	0.021 (3)	0.005 (3)	0.005 (2)	0.005 (2)	−0.0027 (19)
C5	0.025 (2)	0.013 (2)	0.023 (3)	0.0061 (18)	−0.002 (3)	0.003 (3)
C6	0.024 (3)	0.016 (2)	0.019 (3)	0.0002 (19)	0.007 (2)	0.001 (2)

K1—O1W	2.766 (5)	O2W—H21W	0.86 (5)
K1—O11	2.824 (4)	O2W—H21Wii	0.86 (5)
K1—O2Wi	2.959 (7)	O12—H12	0.87 (6)
K1—O1Wii	2.766 (5)	N4—C4	1.389 (9)
K1—O11ii	2.824 (4)	N4—H41	0.86 (5)
K2—O2W	3.009 (7)	N4—H42	0.87 (6)
K2—O11	2.713 (5)	C1—C2	1.388 (8)
K2—O12iii	2.694 (5)	C1—C6	1.397 (8)
K2—O11ii	2.713 (5)	C2—C3	1.367 (10)
K2—O12iv	2.694 (5)	C3—C4	1.400 (9)
As1—O11	1.652 (4)	C4—C5	1.397 (8)
As1—O12	1.736 (4)	C5—C6	1.387 (7)
As1—O13	1.663 (5)	C2—H2	0.9500
As1—C1	1.900 (7)	C3—H3	0.9500
O1W—H11W	0.88 (6)	C5—H5	0.9500
O1W—H12W	0.89 (5)	C6—H6	0.9500
O11—As1—O12	108.9 (2)	K1—O1W—H12W	125 (5)
O11—As1—O13	113.3 (2)	H11W—O1W—H12W	103 (6)
O11—As1—C1	111.2 (2)	K1v—O2W—H21W	116 (5)
O12—As1—O13	103.2 (2)	H21W—O2W—H21Wii	91 (5)
O12—As1—C1	108.5 (2)	K1v—O2W—H21Wii	116 (5)
O13—As1—C1	111.4 (3)	K2—O2W—H21W	118 (4)
O1W—K1—O11	89.45 (13)	K2—O2W—H21Wii	118 (4)
O1W—K1—O2Wi	82.66 (13)	K2vi—O12—H12	118 (4)
O1W—K1—O1Wii	96.08 (15)	As1—O12—H12	115 (4)
O1W—K1—O11ii	154.31 (14)	C4—N4—H41	112 (4)
O2Wi—K1—O11	122.99 (14)	H41—N4—H42	116 (6)
O1Wii—K1—O11	154.31 (14)	C4—N4—H42	120 (5)
O11—K1—O11ii	75.52 (12)	As1—C1—C6	120.5 (4)
O1Wii—K1—O2Wi	82.66 (13)	As1—C1—C2	120.1 (5)
O2Wi—K1—O11ii	122.99 (14)	C2—C1—C6	119.1 (6)
O1Wii—K1—O11ii	89.45 (13)	C1—C2—C3	120.8 (6)
O2W—K2—O11	107.37 (14)	C2—C3—C4	120.9 (6)
O2W—K2—O12iii	77.45 (14)	C3—C4—C5	118.6 (6)
O2W—K2—O11ii	107.37 (14)	N4—C4—C3	121.2 (5)
O2W—K2—O12iv	77.45 (14)	N4—C4—C5	120.2 (5)
O11—K2—O12iii	175.18 (16)	C4—C5—C6	120.4 (5)
O11—K2—O11ii	79.20 (14)	C1—C6—C5	120.2 (5)
O11—K2—O12iv	99.61 (13)	C1—C2—H2	120.00
O11ii—K2—O12iii	99.61 (13)	C3—C2—H2	120.00
O12iii—K2—O12iv	81.18 (15)	C2—C3—H3	120.00
O11ii—K2—O12iv	175.18 (16)	C4—C3—H3	120.00
K1v—O2W—K2	99.6 (2)	C4—C5—H5	120.00
K1—O11—K2	96.75 (13)	C6—C5—H5	120.00
As1—O12—K2vi	126.6 (2)	C1—C6—H6	120.00
K1—O1W—H11W	122 (4)	C5—C6—H6	120.00
O12—As1—O11—K1	109.9 (3)	O11ii—K1—O11—K2	25.38 (14)
O12—As1—O11—K2	−6.6 (3)	O1W—K1—O11ii—K2	−81.4 (4)
O13—As1—O11—K1	−4.3 (3)	O11—K1—O11ii—K2	−25.38 (14)
O13—As1—O11—K2	−120.8 (2)	O2W—K2—O11—As1	−146.8 (2)
C1—As1—O11—K1	−130.6 (3)	O2W—K2—O11—K1	78.91 (15)
C1—As1—O11—K2	112.9 (2)	O11ii—K2—O11—As1	108.2 (2)
O11—As1—O12—K2vi	−103.8 (3)	O11ii—K2—O11—K1	−26.09 (14)
O13—As1—O12—K2vi	16.9 (3)	O12iv—K2—O11—As1	−67.1 (2)
C1—As1—O12—K2vi	135.1 (3)	O12iv—K2—O11—K1	158.66 (14)
O11—As1—C1—C2	12.4 (6)	O11—K2—O11ii—K1	26.09 (14)
O11—As1—C1—C6	−174.0 (5)	As1—C1—C2—C3	174.1 (5)
O12—As1—C1—C2	132.2 (5)	C6—C1—C2—C3	0.5 (9)
O12—As1—C1—C6	−54.3 (5)	As1—C1—C6—C5	−173.3 (5)
O13—As1—C1—C2	−114.9 (5)	C2—C1—C6—C5	0.3 (9)
O13—As1—C1—C6	58.6 (5)	C1—C2—C3—C4	−2.6 (9)
O1W—K1—O11—As1	61.8 (3)	C2—C3—C4—N4	179.9 (6)
O1W—K1—O11—K2	−175.68 (15)	C2—C3—C4—C5	3.8 (9)
O2Wi—K1—O11—As1	142.7 (2)	N4—C4—C5—C6	−179.2 (6)
O1Wii—K1—O11—As1	−41.1 (5)	C3—C4—C5—C6	−3.0 (9)
O1Wii—K1—O11—K2	81.4 (4)	C4—C5—C6—C1	1.0 (9)
O11ii—K1—O11—As1	−97.1 (3)

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H11W···N4vii	0.88 (6)	2.05 (6)	2.915 (7)	171 (5)
O1W—H12W···O11viii	0.89 (5)	1.77 (5)	2.660 (6)	175 (7)
O2W—H21W···O13ix	0.86 (5)	2.09 (6)	2.819 (6)	142 (6)
O12—H12···O13iv	0.87 (6)	1.70 (6)	2.538 (7)	160 (7)
N4—H41···O1Wx	0.86 (5)	2.17 (5)	3.010 (7)	164 (5)
N4—H42···O13xi	0.87 (6)	2.15 (6)	2.984 (7)	160 (5)

[Rb2(C6H7AsNO3)2(H2O)3]	F(000) = 1272
Mr = 657.08	Dx = 2.105 Mg m−3
Orthorhombic, Cmc21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: C 2c -2	Cell parameters from 1374 reflections
a = 24.4783 (19) Å	θ = 4.0–28.7°
b = 10.4577 (9) Å	µ = 7.94 mm−1
c = 8.0978 (7) Å	T = 200 K
V = 2072.9 (3) Å3	Prism, colourless
Z = 4	0.35 × 0.20 × 0.12 mm

Oxford Diffraction Gemini-S CCD-detector diffractometer	2093 independent reflections
Radiation source: Enhance (Mo) X-ray source	1899 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.026
Detector resolution: 16.077 pixels mm-1	θmax = 29.0°, θmin = 3.9°
ω scans	h = −33→15
Absorption correction: multi-scan (CrysAlis PRO; Rigaku OD, 2015)	k = −14→13
Tmin = 0.375, Tmax = 0.980	l = −10→10
3623 measured reflections

Refinement on F2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F2 > 2σ(F2)] = 0.032	w = 1/[σ2(Fo2) + (0.0392P)2] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.072	(Δ/σ)max = 0.003
S = 1.03	Δρmax = 0.70 e Å−3
2093 reflections	Δρmin = −0.46 e Å−3
146 parameters	Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
8 restraints	Extinction coefficient: 0.00306 (19)
Primary atom site location: structure-invariant direct methods	Absolute structure: Flack (1983), 1309 Friedel pairs
Secondary atom site location: difference Fourier map	Absolute structure parameter: −0.008 (12)

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell esds are taken into account in the estimation of distances, angles and torsion angles

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.

	x	y	z	Uiso*/Ueq
Rb1	0.50000	0.94747 (5)	0.57916 (11)	0.0264 (2)
Rb2	0.50000	0.63207 (8)	0.24818 (10)	0.0376 (3)
As1	0.60556 (2)	0.63552 (4)	0.58879 (6)	0.0200 (1)
O1W	0.58793 (16)	1.0545 (3)	0.7791 (5)	0.0333 (11)
O2W	0.50000	0.7864 (5)	−0.0920 (7)	0.0337 (17)
O11	0.57535 (14)	0.7458 (3)	0.4753 (4)	0.0302 (11)
O12	0.57765 (17)	0.4882 (3)	0.5436 (5)	0.0404 (13)
O13	0.59344 (15)	0.6516 (3)	0.7898 (4)	0.0275 (11)
N4	0.85111 (17)	0.6329 (4)	0.4734 (6)	0.0287 (16)
C1	0.68166 (19)	0.6279 (4)	0.5443 (6)	0.0200 (14)
C2	0.7060 (2)	0.7197 (5)	0.4430 (6)	0.0250 (16)
C3	0.7614 (2)	0.7222 (5)	0.4197 (7)	0.0270 (17)
C4	0.7946 (2)	0.6315 (4)	0.4982 (6)	0.0230 (16)
C5	0.77044 (19)	0.5380 (4)	0.5957 (8)	0.0270 (14)
C6	0.7146 (2)	0.5357 (4)	0.6178 (6)	0.0260 (16)
H2	0.68380	0.78150	0.38940	0.0300*
H3	0.77730	0.78530	0.35030	0.0320*
H5	0.79260	0.47510	0.64760	0.0320*
H6	0.69850	0.47060	0.68370	0.0310*
H11W	0.6067 (19)	1.001 (4)	0.842 (6)	0.0370*
H12	0.582 (2)	0.459 (5)	0.445 (3)	0.0370*
H12W	0.589 (3)	1.127 (3)	0.833 (6)	0.0370*
H21W	0.5290 (15)	0.741 (4)	−0.120 (7)	0.0370*
H41	0.864 (2)	0.689 (4)	0.407 (6)	0.0300*
H42	0.8680 (19)	0.613 (4)	0.566 (4)	0.0300*

	U11	U22	U33	U12	U13	U23
Rb1	0.0241 (3)	0.0282 (3)	0.0268 (3)	0.0000	0.0000	−0.0051 (4)
Rb2	0.0227 (4)	0.0597 (5)	0.0304 (4)	0.0000	0.0000	−0.0179 (4)
As1	0.0210 (2)	0.0183 (2)	0.0206 (2)	−0.0019 (2)	0.0036 (2)	−0.0007 (3)
O1W	0.032 (2)	0.0309 (19)	0.037 (2)	−0.0008 (16)	−0.0036 (19)	−0.0005 (18)
O2W	0.032 (3)	0.027 (3)	0.042 (3)	0.0000	0.0000	−0.006 (2)
O11	0.0206 (19)	0.037 (2)	0.033 (2)	−0.0005 (16)	−0.0041 (16)	0.0069 (16)
O12	0.046 (2)	0.0303 (18)	0.045 (3)	−0.0176 (17)	0.0261 (19)	−0.0182 (19)
O13	0.036 (2)	0.0257 (18)	0.0207 (18)	0.0053 (15)	0.0064 (16)	0.0031 (15)
N4	0.019 (2)	0.035 (3)	0.032 (3)	0.0024 (18)	0.0042 (19)	0.006 (2)
C1	0.019 (2)	0.021 (2)	0.020 (3)	0.0003 (17)	0.0009 (18)	−0.0017 (18)
C2	0.025 (3)	0.021 (2)	0.029 (3)	0.001 (2)	0.002 (2)	0.005 (2)
C3	0.023 (3)	0.025 (3)	0.033 (3)	0.001 (2)	0.006 (2)	0.009 (2)
C4	0.025 (3)	0.021 (2)	0.023 (3)	0.0018 (19)	0.004 (2)	−0.0043 (19)
C5	0.031 (2)	0.020 (2)	0.030 (3)	0.0078 (17)	0.003 (3)	0.003 (3)
C6	0.036 (3)	0.018 (2)	0.024 (3)	−0.0023 (19)	0.006 (2)	0.0040 (19)

Rb1—O1W	2.917 (4)	O1W—H12W	0.88 (4)
Rb1—O11	2.925 (3)	O2W—H21W	0.88 (4)
Rb1—O2Wi	3.151 (6)	O2W—H21Wiv	0.88 (4)
Rb1—O1Wii	3.246 (4)	O12—H12	0.86 (3)
Rb1—O2Wiii	3.109 (5)	N4—C4	1.398 (6)
Rb1—O1Wiv	2.917 (4)	N4—H41	0.86 (5)
Rb1—O11iv	2.925 (3)	N4—H42	0.88 (4)
Rb1—O1Wv	3.246 (4)	C1—C2	1.396 (7)
Rb2—O2W	3.193 (6)	C1—C6	1.391 (6)
Rb2—O11	2.863 (3)	C2—C3	1.369 (7)
Rb2—O12vi	2.818 (4)	C3—C4	1.402 (7)
Rb2—O11iv	2.863 (3)	C4—C5	1.389 (7)
Rb2—O12vii	2.818 (4)	C5—C6	1.379 (7)
As1—O11	1.650 (3)	C2—H2	0.9500
As1—O12	1.725 (3)	C3—H3	0.9500
As1—O13	1.663 (3)	C5—H5	0.9500
As1—C1	1.899 (5)	C6—H6	0.9500
O1W—H11W	0.89 (5)
O1W—Rb1—O11	88.34 (10)	Rb1—O1W—Rb1iii	85.63 (10)
O1W—Rb1—O2Wi	74.69 (10)	Rb1viii—O2W—Rb2	178.05 (19)
O1W—Rb1—O1Wii	155.13 (9)	Rb1ii—O2W—Rb2	93.89 (15)
O1W—Rb1—O2Wiii	84.49 (10)	Rb1viii—O2W—Rb1ii	84.16 (13)
O1W—Rb1—O1Wiv	95.12 (11)	Rb1—O11—Rb2	94.47 (10)
O1W—Rb1—O11iv	154.37 (10)	Rb1—O11—As1	128.79 (16)
O1W—Rb1—O1Wv	85.91 (10)	Rb2—O11—As1	110.86 (15)
O2Wi—Rb1—O11	81.81 (10)	Rb2ix—O12—As1	122.77 (19)
O1Wii—Rb1—O11	101.44 (9)	Rb1iii—O1W—H12W	70 (4)
O2Wiii—Rb1—O11	121.14 (10)	Rb1—O1W—H12W	129 (5)
O1Wiv—Rb1—O11	154.37 (10)	H11W—O1W—H12W	104 (5)
O11—Rb1—O11iv	78.18 (9)	Rb1—O1W—H11W	117 (3)
O1Wv—Rb1—O11	50.37 (9)	Rb1iii—O1W—H11W	85 (3)
O1Wii—Rb1—O2Wi	128.99 (8)	Rb2—O2W—H21Wiv	87 (4)
O2Wi—Rb1—O2Wiii	148.79 (14)	Rb1viii—O2W—H21W	94 (4)
O1Wiv—Rb1—O2Wi	74.69 (10)	Rb2—O2W—H21W	87 (4)
O2Wi—Rb1—O11iv	81.81 (10)	H21W—O2W—H21Wiv	107 (4)
O1Wv—Rb1—O2Wi	128.99 (8)	Rb1viii—O2W—H21Wiv	94 (4)
O1Wii—Rb1—O2Wiii	70.85 (9)	Rb1ii—O2W—H21W	127 (3)
O1Wii—Rb1—O1Wiv	85.91 (10)	Rb1ii—O2W—H21Wiv	127 (3)
O1Wii—Rb1—O11iv	50.37 (9)	Rb2ix—O12—H12	118 (3)
O1Wii—Rb1—O1Wv	83.07 (10)	As1—O12—H12	118 (3)
O1Wiv—Rb1—O2Wiii	84.49 (10)	C4—N4—H41	118 (3)
O2Wiii—Rb1—O11iv	121.14 (10)	C4—N4—H42	110 (3)
O1Wv—Rb1—O2Wiii	70.85 (9)	H41—N4—H42	122 (4)
O1Wiv—Rb1—O11iv	88.34 (10)	C2—C1—C6	118.7 (4)
O1Wiv—Rb1—O1Wv	155.13 (9)	As1—C1—C2	120.1 (3)
O1Wv—Rb1—O11iv	101.44 (9)	As1—C1—C6	121.1 (3)
O2W—Rb2—O11	110.13 (10)	C1—C2—C3	121.1 (5)
O2W—Rb2—O12vi	73.64 (10)	C2—C3—C4	119.9 (5)
O2W—Rb2—O11iv	110.13 (10)	N4—C4—C5	120.7 (4)
O2W—Rb2—O12vii	73.64 (10)	N4—C4—C3	120.1 (4)
O11—Rb2—O12vi	176.01 (11)	C3—C4—C5	119.2 (4)
O11—Rb2—O11iv	80.20 (10)	C4—C5—C6	120.5 (4)
O11—Rb2—O12vii	97.38 (11)	C1—C6—C5	120.5 (4)
O11iv—Rb2—O12vi	97.38 (11)	C1—C2—H2	119.00
O12vi—Rb2—O12vii	84.84 (12)	C3—C2—H2	119.00
O11iv—Rb2—O12vii	176.01 (11)	C2—C3—H3	120.00
O11—As1—O12	109.20 (17)	C4—C3—H3	120.00
O11—As1—O13	113.24 (16)	C4—C5—H5	120.00
O11—As1—C1	111.30 (18)	C6—C5—H5	120.00
O12—As1—O13	103.14 (18)	C1—C6—H6	120.00
O12—As1—C1	108.11 (19)	C5—C6—H6	120.00
O13—As1—C1	111.40 (19)
O11—Rb1—O1W—Rb1iii	−128.95 (9)	O13—As1—O11—Rb1	−4.5 (3)
O1W—Rb1—O11—Rb2	−175.57 (10)	O13—As1—O11—Rb2	−118.92 (17)
O1W—Rb1—O11—As1	63.0 (2)	C1—As1—O11—Rb1	−130.9 (2)
O2Wi—Rb1—O11—As1	−11.8 (2)	C1—As1—O11—Rb2	114.66 (18)
O1Wii—Rb1—O11—Rb2	−18.62 (11)	O11—As1—O12—Rb2ix	−101.6 (2)
O1Wii—Rb1—O11—As1	−140.0 (2)	O13—As1—O12—Rb2ix	19.1 (2)
O2Wiii—Rb1—O11—As1	145.56 (19)	C1—As1—O12—Rb2ix	137.2 (2)
O1Wiv—Rb1—O11—Rb2	86.1 (2)	O11—As1—C1—C2	7.8 (4)
O1Wiv—Rb1—O11—As1	−35.4 (4)	O11—As1—C1—C6	−175.6 (4)
O11iv—Rb1—O11—Rb2	26.37 (9)	O12—As1—C1—C2	127.7 (4)
O11iv—Rb1—O11—As1	−95.1 (2)	O12—As1—C1—C6	−55.6 (4)
O1Wv—Rb1—O11—Rb2	−89.51 (13)	O13—As1—C1—C2	−119.7 (4)
O1Wv—Rb1—O11—As1	149.1 (3)	O13—As1—C1—C6	57.0 (4)
O1W—Rb1—O11iv—Rb2	−86.1 (2)	As1—C1—C2—C3	174.8 (4)
O11—Rb1—O11iv—Rb2	−26.37 (9)	C6—C1—C2—C3	−2.0 (7)
O2W—Rb2—O11—Rb1	81.20 (11)	As1—C1—C6—C5	−174.4 (4)
O2W—Rb2—O11—As1	−144.19 (15)	C2—C1—C6—C5	2.4 (7)
O11iv—Rb2—O11—Rb1	−26.79 (9)	C1—C2—C3—C4	0.0 (8)
O11iv—Rb2—O11—As1	107.83 (17)	C2—C3—C4—N4	179.3 (5)
O12vii—Rb2—O11—Rb1	156.43 (10)	C2—C3—C4—C5	1.6 (8)
O12vii—Rb2—O11—As1	−68.96 (17)	N4—C4—C5—C6	−179.0 (5)
O11—Rb2—O11iv—Rb1	26.79 (9)	C3—C4—C5—C6	−1.3 (8)
O12—As1—O11—Rb1	109.8 (2)	C4—C5—C6—C1	−0.8 (8)
O12—As1—O11—Rb2	−4.6 (2)

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H11W···N4x	0.89 (5)	2.04 (4)	2.923 (6)	176 (5)
O2W—H21W···O13viii	0.88 (4)	1.97 (4)	2.852 (5)	173 (5)
O12—H12···O13vii	0.86 (3)	1.73 (4)	2.552 (5)	158 (5)
N4—H41···O13xi	0.86 (5)	2.18 (4)	3.022 (5)	167 (4)
N4—H42···O1Wxii	0.88 (4)	2.13 (4)	3.005 (6)	176 (4)

[Cs2(C6H7AsNO3)2(H2O)3]	F(000) = 1416
Mr = 751.96	Dx = 2.311 Mg m−3
Orthorhombic, Cmc21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: C 2c -2	Cell parameters from 1999 reflections
a = 24.650 (3) Å	θ = 4.0–28.9°
b = 10.4373 (9) Å	µ = 6.46 mm−1
c = 8.3992 (7) Å	T = 200 K
V = 2160.9 (4) Å3	Prism, colourless
Z = 4	0.40 × 0.22 × 0.10 mm

Oxford Diffraction Gemini-S CCD-detector diffractometer	1883 independent reflections
Radiation source: Enhance Mo X-ray source	1787 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.030
Detector resolution: 16.077 pixels mm-1	θmax = 29.3°, θmin = 3.2°
ω scans	h = −33→29
Absorption correction: multi-scan (CrysAlis PRO; Rigaku OD, 2015)	k = −14→13
Tmin = 0.217, Tmax = 0.980	l = −11→6
4941 measured reflections

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.041	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.160	w = 1/[σ2(Fo2) + (0.1178P)2] where P = (Fo2 + 2Fc2)/3
S = 1.18	(Δ/σ)max = 0.001
1883 reflections	Δρmax = 1.69 e Å−3
145 parameters	Δρmin = −1.00 e Å−3
8 restraints	Absolute structure: Flack (1983), 1405 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.10 (4)

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell esds are taken into account in the estimation of distances, angles and torsion angles

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.

	x	y	z	Uiso*/Ueq
Cs1	0.50000	0.95299 (7)	0.67229 (13)	0.0217 (2)
Cs2	0.50000	0.62982 (10)	0.99928 (13)	0.0311 (3)
As1	0.61041 (4)	0.63299 (7)	0.65867 (12)	0.0166 (3)
O1W	0.5936 (4)	1.0619 (7)	0.4690 (11)	0.026 (3)
O2W	0.50000	0.7680 (11)	0.3558 (16)	0.027 (3)
O11	0.5799 (3)	0.7443 (8)	0.7661 (11)	0.028 (3)
O12	0.5841 (4)	0.4827 (8)	0.7086 (11)	0.036 (3)
O13	0.5962 (3)	0.6457 (7)	0.4668 (11)	0.024 (2)
N4	0.8542 (4)	0.6351 (9)	0.7686 (14)	0.025 (3)
C1	0.6861 (5)	0.6283 (7)	0.6996 (13)	0.016 (3)
C2	0.7088 (5)	0.7189 (9)	0.7999 (14)	0.022 (3)
C3	0.7634 (5)	0.7201 (9)	0.8256 (18)	0.025 (3)
C4	0.7983 (5)	0.6344 (9)	0.7490 (14)	0.022 (3)
C5	0.7752 (5)	0.5399 (9)	0.6487 (19)	0.031 (4)
C6	0.7202 (5)	0.5380 (8)	0.6236 (15)	0.023 (3)
H2	0.68620	0.78020	0.85100	0.0260*
H3	0.77820	0.78100	0.89760	0.0300*
H5	0.79770	0.47800	0.59880	0.0370*
H6	0.70480	0.47550	0.55480	0.0270*
H11W	0.624 (3)	1.039 (12)	0.420 (15)	0.0340*
H12	0.578 (7)	0.493 (15)	0.811 (5)	0.0340*
H12W	0.589 (4)	1.126 (12)	0.400 (12)	0.0340*
H21W	0.529 (4)	0.773 (13)	0.418 (16)	0.0340*
H41	0.865 (6)	0.602 (12)	0.685 (18)	0.0270*
H42	0.870 (6)	0.706 (11)	0.81 (2)	0.0270*

	U11	U22	U33	U12	U13	U23
Cs1	0.0185 (4)	0.0261 (4)	0.0204 (4)	0.0000	0.0000	0.0024 (4)
Cs2	0.0174 (5)	0.0525 (6)	0.0233 (5)	0.0000	0.0000	0.0136 (5)
As1	0.0146 (5)	0.0182 (4)	0.0169 (5)	−0.0016 (3)	−0.0029 (5)	0.0004 (4)
O1W	0.017 (4)	0.035 (4)	0.026 (5)	0.000 (3)	0.009 (4)	0.002 (4)
O2W	0.020 (6)	0.031 (5)	0.030 (7)	0.0000	0.0000	0.002 (5)
O11	0.020 (4)	0.032 (4)	0.031 (5)	−0.002 (3)	0.007 (4)	−0.005 (3)
O12	0.042 (5)	0.033 (4)	0.032 (5)	−0.021 (4)	−0.024 (4)	0.007 (4)
O13	0.019 (4)	0.029 (4)	0.025 (4)	0.005 (3)	0.000 (4)	0.001 (3)
N4	0.020 (5)	0.026 (4)	0.030 (5)	0.003 (3)	−0.015 (5)	−0.004 (4)
C1	0.019 (5)	0.015 (4)	0.014 (4)	0.000 (3)	−0.004 (4)	0.001 (3)
C2	0.027 (6)	0.020 (4)	0.019 (5)	0.006 (4)	−0.009 (4)	−0.011 (4)
C3	0.022 (5)	0.024 (4)	0.030 (6)	0.003 (4)	0.006 (6)	−0.002 (5)
C4	0.021 (6)	0.021 (4)	0.023 (6)	0.004 (4)	0.002 (5)	0.006 (4)
C5	0.028 (6)	0.024 (4)	0.041 (8)	0.006 (4)	−0.005 (6)	−0.013 (5)
C6	0.020 (5)	0.020 (4)	0.029 (6)	−0.003 (3)	−0.005 (5)	−0.002 (4)

Cs1—O1W	3.087 (9)	O1W—H12W	0.89 (12)
Cs1—O2W	3.286 (13)	O2W—H21W	0.89 (12)
Cs1—O11	3.040 (8)	O2W—H21Wii	0.89 (12)
Cs1—O1Wi	3.400 (10)	O12—H12	0.88 (5)
Cs1—O2Wi	3.295 (12)	N4—C4	1.388 (16)
Cs1—O1Wii	3.087 (9)	N4—H41	0.83 (14)
Cs1—O11ii	3.040 (8)	N4—H42	0.91 (14)
Cs1—O1Wiii	3.400 (10)	C1—C2	1.385 (15)
Cs2—O11	3.024 (8)	C1—C6	1.415 (15)
Cs2—O2Wiv	3.324 (13)	C2—C3	1.363 (17)
Cs2—O12v	2.961 (9)	C3—C4	1.398 (16)
Cs2—O11ii	3.024 (8)	C4—C5	1.417 (17)
Cs2—O12vi	2.961 (9)	C5—C6	1.372 (18)
As1—O11	1.652 (9)	C2—H2	0.9500
As1—O12	1.748 (9)	C3—H3	0.9500
As1—O13	1.655 (9)	C5—H5	0.9500
As1—C1	1.898 (12)	C6—H6	0.9500
O1W—H11W	0.89 (9)
O1W—Cs1—O2W	76.6 (2)	Cs1—O1W—Cs1vii	83.2 (2)
O1W—Cs1—O11	85.6 (2)	Cs1—O2W—Cs2viii	169.7 (4)
O1W—Cs1—O1Wi	158.4 (2)	Cs1—O2W—Cs1vii	81.9 (3)
O1W—Cs1—O2Wi	86.2 (2)	Cs1vii—O2W—Cs2viii	87.8 (3)
O1W—Cs1—O1Wii	96.7 (2)	Cs1—O11—Cs2	91.7 (2)
O1W—Cs1—O11ii	153.0 (2)	Cs1—O11—As1	131.1 (4)
O1W—Cs1—O1Wiii	85.1 (2)	Cs2—O11—As1	111.9 (4)
O2W—Cs1—O11	77.8 (2)	Cs2ix—O12—As1	118.2 (4)
O1Wi—Cs1—O2W	124.49 (19)	Cs1vii—O1W—H12W	58 (7)
O2W—Cs1—O2Wi	153.9 (3)	Cs1—O1W—H12W	123 (7)
O1Wii—Cs1—O2W	76.6 (2)	H11W—O1W—H12W	91 (11)
O2W—Cs1—O11ii	77.8 (2)	Cs1—O1W—H11W	142 (8)
O1Wiii—Cs1—O2W	124.49 (19)	Cs1vii—O1W—H11W	103 (8)
O1Wi—Cs1—O11	102.5 (2)	Cs1—O2W—H21Wii	59 (8)
O2Wi—Cs1—O11	120.8 (2)	Cs2viii—O2W—H21W	124 (7)
O1Wii—Cs1—O11	153.0 (2)	Cs1—O2W—H21W	59 (8)
O11—Cs1—O11ii	80.8 (2)	H21W—O2W—H21Wii	107 (11)
O1Wiii—Cs1—O11	48.5 (2)	Cs2viii—O2W—H21Wii	124 (8)
O1Wi—Cs1—O2Wi	72.4 (2)	Cs1vii—O2W—H21W	103 (8)
O1Wi—Cs1—O1Wii	85.1 (2)	Cs1vii—O2W—H21Wii	103 (9)
O1Wi—Cs1—O11ii	48.5 (2)	Cs2ix—O12—H12	121 (11)
O1Wi—Cs1—O1Wiii	85.5 (2)	As1—O12—H12	101 (10)
O1Wii—Cs1—O2Wi	86.2 (2)	C4—N4—H41	103 (10)
O2Wi—Cs1—O11ii	120.8 (2)	C4—N4—H42	119 (8)
O1Wiii—Cs1—O2Wi	72.4 (2)	H41—N4—H42	122 (13)
O1Wii—Cs1—O11ii	85.6 (2)	C2—C1—C6	119.3 (11)
O1Wii—Cs1—O1Wiii	158.4 (2)	As1—C1—C2	119.3 (8)
O1Wiii—Cs1—O11ii	102.5 (2)	As1—C1—C6	121.3 (8)
O2Wiv—Cs2—O11	114.3 (2)	C1—C2—C3	120.1 (11)
O11—Cs2—O12v	175.8 (2)	C2—C3—C4	121.9 (11)
O11—Cs2—O11ii	81.3 (2)	N4—C4—C5	118.3 (10)
O11—Cs2—O12vi	94.9 (2)	N4—C4—C3	123.6 (10)
O2Wiv—Cs2—O12v	68.7 (2)	C3—C4—C5	118.2 (11)
O2Wiv—Cs2—O11ii	114.3 (2)	C4—C5—C6	119.9 (11)
O2Wiv—Cs2—O12vi	68.7 (2)	C1—C6—C5	120.5 (10)
O11ii—Cs2—O12v	94.9 (2)	C1—C2—H2	120.00
O12v—Cs2—O12vi	88.9 (3)	C3—C2—H2	120.00
O11ii—Cs2—O12vi	175.8 (2)	C2—C3—H3	119.00
O11—As1—O12	109.3 (4)	C4—C3—H3	119.00
O11—As1—O13	112.3 (4)	C4—C5—H5	120.00
O11—As1—C1	111.5 (4)	C6—C5—H5	120.00
O12—As1—O13	103.1 (4)	C1—C6—H6	120.00
O12—As1—C1	107.3 (4)	C5—C6—H6	120.00
O13—As1—C1	112.8 (4)
O11—Cs1—O1W—Cs1vii	126.4 (2)	O13—As1—O11—Cs1	3.5 (6)
O1W—Cs1—O11—Cs2	175.0 (2)	O13—As1—O11—Cs2	116.5 (4)
O1W—Cs1—O11—As1	−63.7 (5)	C1—As1—O11—Cs1	131.1 (5)
O2W—Cs1—O11—Cs2	−107.8 (2)	C1—As1—O11—Cs2	−115.8 (4)
O2W—Cs1—O11—As1	13.5 (5)	O11—As1—O12—Cs2ix	98.9 (5)
O1Wi—Cs1—O11—Cs2	15.3 (3)	O13—As1—O12—Cs2ix	−20.8 (5)
O1Wi—Cs1—O11—As1	136.6 (5)	C1—As1—O12—Cs2ix	−140.0 (5)
O2Wi—Cs1—O11—As1	−146.6 (5)	O11—As1—C1—C2	−4.7 (10)
O1Wii—Cs1—O11—Cs2	−88.9 (5)	O11—As1—C1—C6	178.4 (8)
O1Wii—Cs1—O11—As1	32.4 (9)	O12—As1—C1—C2	−124.4 (8)
O11ii—Cs1—O11—Cs2	−28.4 (2)	O12—As1—C1—C6	58.7 (9)
O11ii—Cs1—O11—As1	93.0 (5)	O13—As1—C1—C2	122.7 (8)
O1Wiii—Cs1—O11—Cs2	87.6 (3)	O13—As1—C1—C6	−54.2 (9)
O1Wiii—Cs1—O11—As1	−151.1 (6)	As1—C1—C2—C3	−177.4 (9)
O1W—Cs1—O11ii—Cs2	88.9 (5)	C6—C1—C2—C3	−0.5 (16)
O11—Cs1—O11ii—Cs2	28.4 (2)	As1—C1—C6—C5	176.9 (9)
O2Wiv—Cs2—O11—As1	139.6 (4)	C2—C1—C6—C5	0.0 (16)
O11ii—Cs2—O11—Cs1	28.5 (2)	C1—C2—C3—C4	2.2 (18)
O11ii—Cs2—O11—As1	−107.6 (4)	C2—C3—C4—N4	178.1 (11)
O12vi—Cs2—O11—Cs1	−153.2 (2)	C2—C3—C4—C5	−3.4 (18)
O12vi—Cs2—O11—As1	70.7 (4)	N4—C4—C5—C6	−178.5 (11)
O11—Cs2—O11ii—Cs1	−28.5 (2)	C3—C4—C5—C6	2.9 (18)
O12—As1—O11—Cs1	−110.3 (5)	C4—C5—C6—C1	−1.2 (18)
O12—As1—O11—Cs2	2.7 (5)

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H11W···N4x	0.89 (9)	2.28 (13)	2.952 (13)	132 (10)
O2W—H21W···O13	0.89 (12)	2.16 (12)	2.850 (10)	134 (12)
O12—H12···O13vi	0.88 (5)	2.00 (12)	2.567 (13)	121 (12)
N4—H41···O1Wxi	0.83 (14)	2.12 (15)	2.928 (15)	164 (9)
N4—H42···O13xii	0.91 (14)	2.20 (14)	3.082 (13)	166 (15)