Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807023719/lh2394sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807023719/lh2394Isup2.hkl |
CCDC reference: 654756
0.5 M Aqueous solutions of 1,6-diaminohexane (10 ml) and arsenic acid (10 ml) were mixed, resulting in a colourless liquid. Aqueous ammonia was then added to the mixture to raise the pH to 11. Colourless slabs of (I) grew as the water slowly evaporated at 298 K.
The highest difference peak is 0.82 Å from As2, and the deepest difference hole is 0.62 Å from As2 perhaps indicating disorder of the (HAs2O4)2- group, but refinements attempting to model this were unstable. The next-highest feature in the final difference map (0.76 e Å3) is at the noise level.
H1 was located in a difference map and refined as riding. H2, H3 and the C– and N-bonded hydrogen atoms were placed in idealized positions (O—H = 0.90 Å, C—H = 0.99 Å, N—H = 0.91 Å) and refined as riding with Uiso(H) = 1.2Ueq(carrier).
The H atoms of the water molecules could not be located.
The title compound, (I), was prepared as part of our ongoing studies of hydrogen bonding interactions in the molecular salts of arsenic oxo-anions (Wilkinson & Harrison, 2007a,b). Its asymmetric unit contains two organic cations, two anions and three-and-a-half water molecules (Fig. 1).
The tetrahedral (HAs1O4)2- anion in (I) shows the expected distinction (Table 1) between its protonated and unprotonated As—O bond lengths. The situation for the (HAs2O4)2- group is less clear cut, and seems to be correlated with disorder of its H atoms (see below). Both C2H10N22+ dications are in their extended conformations with all their backbone torsion angles close to 180°. Three fully occupied (O9, O10, O11) water molecules and one half occupied (O12) water molecule complete the structure. O12 cannot be more than half occupied due to a close O12···O12xx (xx = -x, 1 - y, -z) contact of 2.21 (1) Å.
As well as Coulombic forces, the component species in (I) interact by way of a network of N—H···O and O—H···O hydrogen bonds (Table 2). The (HAsO4)2- units are linked by way of O—H···O bonds into distinctive, isolated, tetramers (Fig. 2). The complete assembly is generated by inversion, thus the central O5—H2···O5i (see Table 2 for symmetry code) link must be disordered (i.e. O5—H2···O5i + O5i—H2i···O5 bonds) or possibly a symmetric O5···H2···O5i bond (i.e. the H atom occupies the inversion centre (Wilson, 2001). These possibilities could not be distinguished in the present experiment and a disordered model was assumed. Either of these possibilities necessitates disorder of the H atoms of the As2-hydrogenarsenate group, with one of the (HAsO4)2- moieties directing its H atom elsewhere. The extended As2—O6 bond length suggests that O6 bears the H atom and if so, it makes an O—H···O link to the disordered O12 water molecule O atom (Fig. 2).
The cations interact with the anion tetramers by way of a large number of N—H···O bonds (Table 2), with each NH3+ group making three such links, as is typically seen in these systems (Wilkinson & Harrison, 2007a). Unfortunately the H atoms of the water molecules in (I) could not be located in the present study. The disorder of the As2 H atoms and O12 seems to require that at least some of the water H atoms are also disordered, and the situation is too uncertain to allow their geometrical placement with any confidence.
The packing for (I) results in a distinctive structure (Fig. 3) in which hydrogen-bonded (001) sheets of tetrahedral tetramers are bridged by the organic molecules to result in a framework encapsulating [100] channels, which are occupied by the water molecules.
The structure of 1,6-diamminiumhexane bis(dihydrogenarsenate), C6H18N2·(H2AsO4)2, (II), (Wilkinson & Harrison, 2007a), in which the arsenic-containing anion bears two protons, is entirely different to that of (I). In (II), infinite sheets of H-bonded tetrahedra arise and the centrosymmetric cation adopts a gauche conformation. Other types of supramolecular networks based on hydrogen bonded organic cations and arsenate tetrahedra are descibed by Wilkinson & Harrison (2007b).
For related structures and background literature, see: Wilkinson & Harrison (2007a,b); Wilson (2001).
Data collection: COLLECT (Nonius, 1998); cell refinement: HKL SCALEPACK (Otwinowski & Minor, 1997); data reduction: HKL DENZO and SCALEPACK (Otwinowski & Minor, 1997) and SORTAV (Blessing, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97.
4C6H18N22+·4HAsO42−·7H2O | Z = 1 |
Mr = 1158.72 | F(000) = 606 |
Triclinic, P1 | Dx = 1.521 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 10.2206 (2) Å | Cell parameters from 5718 reflections |
b = 11.2773 (4) Å | θ = 2.9–27.5° |
c = 12.7211 (4) Å | µ = 2.70 mm−1 |
α = 109.6648 (12)° | T = 120 K |
β = 108.0176 (18)° | Slab, colourless |
γ = 97.7941 (18)° | 0.42 × 0.22 × 0.06 mm |
V = 1265.11 (6) Å3 |
Bruker-Nonius KappaCCD diffractometer | 5804 independent reflections |
Radiation source: fine-focus sealed tube | 4788 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.053 |
ω and φ scans | θmax = 27.6°, θmin = 3.3° |
Absorption correction: multi-scan (SADABS; Bruker, 2003) | h = −13→13 |
Tmin = 0.397, Tmax = 0.855 | k = −14→14 |
25594 measured reflections | l = −16→16 |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.047 | Hydrogen site location: difmap and geom |
wR(F2) = 0.126 | H-atom parameters constrained |
S = 1.07 | w = 1/[σ2(Fo2) + (0.0593P)2 + 3.4341P] where P = (Fo2 + 2Fc2)/3 |
5804 reflections | (Δ/σ)max < 0.001 |
275 parameters | Δρmax = 3.79 e Å−3 |
0 restraints | Δρmin = −1.87 e Å−3 |
4C6H18N22+·4HAsO42−·7H2O | γ = 97.7941 (18)° |
Mr = 1158.72 | V = 1265.11 (6) Å3 |
Triclinic, P1 | Z = 1 |
a = 10.2206 (2) Å | Mo Kα radiation |
b = 11.2773 (4) Å | µ = 2.70 mm−1 |
c = 12.7211 (4) Å | T = 120 K |
α = 109.6648 (12)° | 0.42 × 0.22 × 0.06 mm |
β = 108.0176 (18)° |
Bruker-Nonius KappaCCD diffractometer | 5804 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2003) | 4788 reflections with I > 2σ(I) |
Tmin = 0.397, Tmax = 0.855 | Rint = 0.053 |
25594 measured reflections |
R[F2 > 2σ(F2)] = 0.047 | 0 restraints |
wR(F2) = 0.126 | H-atom parameters constrained |
S = 1.07 | Δρmax = 3.79 e Å−3 |
5804 reflections | Δρmin = −1.87 e Å−3 |
275 parameters |
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s 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 > σ(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 | Occ. (<1) | |
As1 | 0.26080 (3) | 0.19642 (3) | 0.50711 (3) | 0.01311 (11) | |
O1 | 0.3494 (3) | 0.3195 (3) | 0.6417 (2) | 0.0214 (6) | |
O2 | 0.3187 (3) | 0.0621 (2) | 0.4901 (2) | 0.0183 (5) | |
O3 | 0.0842 (3) | 0.1579 (3) | 0.4714 (2) | 0.0204 (5) | |
O4 | 0.2927 (3) | 0.2388 (3) | 0.3965 (2) | 0.0208 (6) | |
H1 | 0.2858 | 0.3203 | 0.4126 | 0.025* | |
As2 | 0.21274 (4) | 0.58973 (4) | 0.44105 (4) | 0.02178 (12) | |
O5 | 0.0387 (3) | 0.5234 (3) | 0.4168 (3) | 0.0289 (6) | |
H2 | 0.0125 | 0.5075 | 0.4732 | 0.035* | 0.50 |
O6 | 0.1964 (3) | 0.6605 (3) | 0.3415 (3) | 0.0309 (7) | |
H3 | 0.1460 | 0.6094 | 0.2632 | 0.037* | 0.50 |
O7 | 0.2942 (3) | 0.7031 (2) | 0.5818 (2) | 0.0206 (5) | |
O8 | 0.2976 (3) | 0.4749 (2) | 0.4154 (2) | 0.0219 (6) | |
N1 | 0.4702 (3) | −0.0659 (3) | 0.6085 (3) | 0.0160 (6) | |
H1A | 0.5363 | −0.0810 | 0.5750 | 0.019* | |
H1B | 0.4155 | −0.0210 | 0.5747 | 0.019* | |
H1C | 0.4137 | −0.1434 | 0.5949 | 0.019* | |
C1 | 0.5434 (4) | 0.0118 (4) | 0.7400 (3) | 0.0170 (7) | |
H1D | 0.6166 | 0.0891 | 0.7549 | 0.020* | |
H1E | 0.5925 | −0.0417 | 0.7782 | 0.020* | |
C2 | 0.4383 (4) | 0.0566 (4) | 0.7969 (3) | 0.0185 (7) | |
H2A | 0.3662 | −0.0206 | 0.7836 | 0.022* | |
H2B | 0.3879 | 0.1088 | 0.7577 | 0.022* | |
C3 | 0.5151 (4) | 0.1388 (4) | 0.9319 (3) | 0.0194 (7) | |
H3A | 0.5918 | 0.2120 | 0.9444 | 0.023* | |
H3B | 0.5608 | 0.0843 | 0.9707 | 0.023* | |
C4 | 0.4182 (4) | 0.1948 (4) | 0.9946 (3) | 0.0203 (8) | |
H4A | 0.3691 | 0.2469 | 0.9545 | 0.024* | |
H4B | 0.3443 | 0.1222 | 0.9867 | 0.024* | |
C5 | 0.5023 (4) | 0.2805 (4) | 1.1273 (3) | 0.0186 (7) | |
H5A | 0.5784 | 0.3509 | 1.1348 | 0.022* | |
H5B | 0.5488 | 0.2273 | 1.1674 | 0.022* | |
C6 | 0.4099 (4) | 0.3416 (4) | 1.1915 (3) | 0.0174 (7) | |
H6A | 0.3597 | 0.3918 | 1.1497 | 0.021* | |
H6B | 0.3371 | 0.2717 | 1.1886 | 0.021* | |
N2 | 0.4985 (3) | 0.4299 (3) | 1.3197 (3) | 0.0164 (6) | |
H2C | 0.4405 | 0.4539 | 1.3601 | 0.020* | |
H2D | 0.5534 | 0.5024 | 1.3225 | 0.020* | |
H2E | 0.5558 | 0.3875 | 1.3546 | 0.020* | |
N3 | 0.0774 (3) | −0.2552 (3) | 0.6731 (3) | 0.0237 (7) | |
H3C | 0.1528 | −0.2535 | 0.6494 | 0.028* | |
H3D | 0.0206 | −0.2099 | 0.6421 | 0.028* | |
H3E | 0.0262 | −0.3395 | 0.6458 | 0.028* | |
C7 | 0.1305 (4) | −0.1947 (5) | 0.8063 (4) | 0.0283 (9) | |
H7A | 0.1786 | −0.1011 | 0.8348 | 0.034* | |
H7B | 0.2024 | −0.2368 | 0.8395 | 0.034* | |
C8 | 0.0135 (4) | −0.2063 (4) | 0.8551 (4) | 0.0236 (8) | |
H8A | −0.0452 | −0.2980 | 0.8176 | 0.028* | |
H8B | −0.0495 | −0.1511 | 0.8353 | 0.028* | |
C9 | 0.0814 (4) | −0.1622 (4) | 0.9913 (3) | 0.0239 (8) | |
H9A | 0.1458 | −0.2171 | 1.0090 | 0.029* | |
H9B | 0.1409 | −0.0710 | 1.0266 | 0.029* | |
C10 | −0.0225 (4) | −0.1685 (4) | 1.0540 (3) | 0.0225 (8) | |
H10A | −0.0775 | −0.1036 | 1.0483 | 0.027* | |
H10B | −0.0907 | −0.2564 | 1.0133 | 0.027* | |
C11 | 0.0575 (4) | −0.1407 (4) | 1.1859 (3) | 0.0204 (8) | |
H11A | 0.1177 | −0.2020 | 1.1902 | 0.025* | |
H11B | 0.1220 | −0.0511 | 1.2262 | 0.025* | |
C12 | −0.0375 (4) | −0.1525 (4) | 1.2549 (3) | 0.0200 (7) | |
H12A | −0.0848 | −0.0808 | 1.2648 | 0.024* | |
H12B | −0.1125 | −0.2366 | 1.2091 | 0.024* | |
N4 | 0.0499 (3) | −0.1459 (3) | 1.3753 (3) | 0.0177 (6) | |
H4C | −0.0065 | −0.1489 | 1.4180 | 0.021* | |
H4D | 0.1209 | −0.0700 | 1.4159 | 0.021* | |
H4E | 0.0888 | −0.2149 | 1.3658 | 0.021* | |
O9 | 0.8047 (3) | 0.5471 (3) | 1.2428 (3) | 0.0365 (7) | |
O10 | 0.6206 (4) | 0.3245 (3) | 0.7704 (4) | 0.0487 (10) | |
O11 | 0.7583 (5) | 0.5024 (5) | 1.0047 (4) | 0.0727 (14) | |
O12 | 0.0334 (8) | 0.4948 (8) | 0.0893 (7) | 0.0505 (19) | 0.50 |
U11 | U22 | U33 | U12 | U13 | U23 | |
As1 | 0.01328 (18) | 0.01261 (18) | 0.01532 (19) | 0.00403 (13) | 0.00671 (14) | 0.00644 (14) |
O1 | 0.0217 (13) | 0.0167 (13) | 0.0159 (13) | 0.0013 (10) | 0.0032 (10) | 0.0001 (10) |
O2 | 0.0250 (13) | 0.0156 (12) | 0.0212 (13) | 0.0100 (10) | 0.0114 (11) | 0.0112 (11) |
O3 | 0.0103 (11) | 0.0293 (14) | 0.0210 (14) | 0.0025 (10) | 0.0065 (10) | 0.0099 (12) |
O4 | 0.0324 (15) | 0.0173 (13) | 0.0246 (14) | 0.0104 (11) | 0.0193 (12) | 0.0134 (11) |
As2 | 0.0211 (2) | 0.0165 (2) | 0.0222 (2) | 0.00862 (15) | 0.00423 (16) | 0.00361 (16) |
O5 | 0.0213 (14) | 0.0269 (15) | 0.0310 (16) | 0.0043 (12) | 0.0083 (12) | 0.0051 (13) |
O6 | 0.0370 (17) | 0.0348 (17) | 0.0321 (17) | 0.0191 (13) | 0.0139 (13) | 0.0221 (14) |
O7 | 0.0204 (13) | 0.0176 (13) | 0.0183 (13) | 0.0024 (10) | 0.0059 (11) | 0.0031 (11) |
O8 | 0.0278 (14) | 0.0156 (12) | 0.0282 (15) | 0.0102 (11) | 0.0147 (12) | 0.0103 (11) |
N1 | 0.0163 (14) | 0.0159 (14) | 0.0191 (16) | 0.0055 (11) | 0.0085 (12) | 0.0087 (12) |
C1 | 0.0150 (16) | 0.0198 (17) | 0.0175 (18) | 0.0056 (14) | 0.0073 (14) | 0.0076 (15) |
C2 | 0.0154 (16) | 0.0204 (18) | 0.0162 (18) | 0.0033 (14) | 0.0065 (14) | 0.0031 (15) |
C3 | 0.0173 (17) | 0.0229 (18) | 0.0160 (18) | 0.0061 (14) | 0.0068 (14) | 0.0050 (15) |
C4 | 0.0144 (17) | 0.0219 (18) | 0.0178 (18) | 0.0029 (14) | 0.0042 (14) | 0.0022 (15) |
C5 | 0.0154 (17) | 0.0233 (18) | 0.0154 (18) | 0.0042 (14) | 0.0066 (14) | 0.0054 (15) |
C6 | 0.0135 (16) | 0.0193 (17) | 0.0154 (17) | 0.0019 (13) | 0.0041 (13) | 0.0044 (14) |
N2 | 0.0174 (14) | 0.0169 (14) | 0.0149 (15) | 0.0053 (12) | 0.0061 (12) | 0.0061 (12) |
N3 | 0.0174 (15) | 0.0352 (19) | 0.0227 (17) | 0.0067 (14) | 0.0088 (13) | 0.0155 (15) |
C7 | 0.0175 (18) | 0.048 (3) | 0.022 (2) | 0.0078 (17) | 0.0079 (16) | 0.0177 (19) |
C8 | 0.0168 (18) | 0.036 (2) | 0.022 (2) | 0.0053 (16) | 0.0078 (15) | 0.0164 (18) |
C9 | 0.0164 (18) | 0.036 (2) | 0.021 (2) | 0.0052 (16) | 0.0066 (15) | 0.0158 (18) |
C10 | 0.0153 (17) | 0.031 (2) | 0.0212 (19) | 0.0030 (15) | 0.0062 (15) | 0.0127 (17) |
C11 | 0.0160 (17) | 0.028 (2) | 0.0203 (19) | 0.0048 (15) | 0.0079 (14) | 0.0127 (16) |
C12 | 0.0170 (17) | 0.0246 (19) | 0.0168 (18) | 0.0036 (14) | 0.0045 (14) | 0.0088 (15) |
N4 | 0.0191 (15) | 0.0153 (14) | 0.0185 (16) | 0.0018 (12) | 0.0076 (12) | 0.0072 (12) |
O9 | 0.0394 (18) | 0.0360 (18) | 0.0305 (17) | 0.0069 (14) | 0.0184 (14) | 0.0056 (14) |
O10 | 0.0305 (18) | 0.0350 (19) | 0.064 (3) | 0.0062 (14) | −0.0029 (16) | 0.0200 (18) |
O11 | 0.062 (3) | 0.105 (4) | 0.048 (3) | 0.011 (3) | 0.015 (2) | 0.036 (3) |
O12 | 0.040 (4) | 0.054 (5) | 0.040 (4) | 0.002 (3) | 0.006 (3) | 0.010 (4) |
As1—O1 | 1.667 (3) | C6—H6A | 0.9900 |
As1—O2 | 1.671 (2) | C6—H6B | 0.9900 |
As1—O3 | 1.674 (2) | N2—H2C | 0.9100 |
As1—O4 | 1.734 (2) | N2—H2D | 0.9100 |
O4—H1 | 0.8895 | N2—H2E | 0.9100 |
As2—O8 | 1.652 (3) | N3—C7 | 1.478 (5) |
As2—O7 | 1.668 (3) | N3—H3C | 0.9100 |
As2—O6 | 1.689 (3) | N3—H3D | 0.9100 |
As2—O5 | 1.721 (3) | N3—H3E | 0.9100 |
O5—H2 | 0.8999 | C7—C8 | 1.518 (5) |
O6—H3 | 0.8975 | C7—H7A | 0.9900 |
N1—C1 | 1.479 (5) | C7—H7B | 0.9900 |
N1—H1A | 0.9100 | C8—C9 | 1.521 (5) |
N1—H1B | 0.9100 | C8—H8A | 0.9900 |
N1—H1C | 0.9100 | C8—H8B | 0.9900 |
C1—C2 | 1.522 (5) | C9—C10 | 1.519 (5) |
C1—H1D | 0.9900 | C9—H9A | 0.9900 |
C1—H1E | 0.9900 | C9—H9B | 0.9900 |
C2—C3 | 1.524 (5) | C10—C11 | 1.519 (5) |
C2—H2A | 0.9900 | C10—H10A | 0.9900 |
C2—H2B | 0.9900 | C10—H10B | 0.9900 |
C3—C4 | 1.528 (5) | C11—C12 | 1.517 (5) |
C3—H3A | 0.9900 | C11—H11A | 0.9900 |
C3—H3B | 0.9900 | C11—H11B | 0.9900 |
C4—C5 | 1.517 (5) | C12—N4 | 1.486 (5) |
C4—H4A | 0.9900 | C12—H12A | 0.9900 |
C4—H4B | 0.9900 | C12—H12B | 0.9900 |
C5—C6 | 1.519 (5) | N4—H4C | 0.9100 |
C5—H5A | 0.9900 | N4—H4D | 0.9100 |
C5—H5B | 0.9900 | N4—H4E | 0.9100 |
C6—N2 | 1.489 (4) | ||
O1—As1—O2 | 114.20 (13) | H6A—C6—H6B | 108.1 |
O1—As1—O3 | 112.72 (13) | C6—N2—H2C | 109.5 |
O2—As1—O3 | 109.82 (13) | C6—N2—H2D | 109.5 |
O1—As1—O4 | 109.54 (13) | H2C—N2—H2D | 109.5 |
O2—As1—O4 | 101.96 (12) | C6—N2—H2E | 109.5 |
O3—As1—O4 | 107.90 (13) | H2C—N2—H2E | 109.5 |
As1—O4—H1 | 106.7 | H2D—N2—H2E | 109.5 |
O8—As2—O7 | 111.21 (13) | C7—N3—H3C | 109.5 |
O8—As2—O6 | 111.64 (14) | C7—N3—H3D | 109.5 |
O7—As2—O6 | 110.05 (14) | H3C—N3—H3D | 109.5 |
O8—As2—O5 | 110.83 (14) | C7—N3—H3E | 109.5 |
O7—As2—O5 | 109.28 (13) | H3C—N3—H3E | 109.5 |
O6—As2—O5 | 103.56 (15) | H3D—N3—H3E | 109.5 |
As2—O5—H2 | 123.3 | N3—C7—C8 | 113.4 (3) |
As2—O6—H3 | 117.5 | N3—C7—H7A | 108.9 |
C1—N1—H1A | 109.5 | C8—C7—H7A | 108.9 |
C1—N1—H1B | 109.5 | N3—C7—H7B | 108.9 |
H1A—N1—H1B | 109.5 | C8—C7—H7B | 108.9 |
C1—N1—H1C | 109.5 | H7A—C7—H7B | 107.7 |
H1A—N1—H1C | 109.5 | C7—C8—C9 | 109.0 (3) |
H1B—N1—H1C | 109.5 | C7—C8—H8A | 109.9 |
N1—C1—C2 | 111.2 (3) | C9—C8—H8A | 109.9 |
N1—C1—H1D | 109.4 | C7—C8—H8B | 109.9 |
C2—C1—H1D | 109.4 | C9—C8—H8B | 109.9 |
N1—C1—H1E | 109.4 | H8A—C8—H8B | 108.3 |
C2—C1—H1E | 109.4 | C10—C9—C8 | 115.5 (3) |
H1D—C1—H1E | 108.0 | C10—C9—H9A | 108.4 |
C1—C2—C3 | 110.9 (3) | C8—C9—H9A | 108.4 |
C1—C2—H2A | 109.5 | C10—C9—H9B | 108.4 |
C3—C2—H2A | 109.5 | C8—C9—H9B | 108.4 |
C1—C2—H2B | 109.5 | H9A—C9—H9B | 107.5 |
C3—C2—H2B | 109.5 | C11—C10—C9 | 110.4 (3) |
H2A—C2—H2B | 108.0 | C11—C10—H10A | 109.6 |
C2—C3—C4 | 114.2 (3) | C9—C10—H10A | 109.6 |
C2—C3—H3A | 108.7 | C11—C10—H10B | 109.6 |
C4—C3—H3A | 108.7 | C9—C10—H10B | 109.6 |
C2—C3—H3B | 108.7 | H10A—C10—H10B | 108.1 |
C4—C3—H3B | 108.7 | C12—C11—C10 | 114.5 (3) |
H3A—C3—H3B | 107.6 | C12—C11—H11A | 108.6 |
C5—C4—C3 | 111.5 (3) | C10—C11—H11A | 108.6 |
C5—C4—H4A | 109.3 | C12—C11—H11B | 108.6 |
C3—C4—H4A | 109.3 | C10—C11—H11B | 108.6 |
C5—C4—H4B | 109.3 | H11A—C11—H11B | 107.6 |
C3—C4—H4B | 109.3 | N4—C12—C11 | 109.6 (3) |
H4A—C4—H4B | 108.0 | N4—C12—H12A | 109.7 |
C4—C5—C6 | 112.9 (3) | C11—C12—H12A | 109.7 |
C4—C5—H5A | 109.0 | N4—C12—H12B | 109.7 |
C6—C5—H5A | 109.0 | C11—C12—H12B | 109.7 |
C4—C5—H5B | 109.0 | H12A—C12—H12B | 108.2 |
C6—C5—H5B | 109.0 | C12—N4—H4C | 109.5 |
H5A—C5—H5B | 107.8 | C12—N4—H4D | 109.5 |
N2—C6—C5 | 110.7 (3) | H4C—N4—H4D | 109.5 |
N2—C6—H6A | 109.5 | C12—N4—H4E | 109.5 |
C5—C6—H6A | 109.5 | H4C—N4—H4E | 109.5 |
N2—C6—H6B | 109.5 | H4D—N4—H4E | 109.5 |
C5—C6—H6B | 109.5 | ||
N1—C1—C2—C3 | −178.9 (3) | N3—C7—C8—C9 | 170.5 (4) |
C1—C2—C3—C4 | 176.4 (3) | C7—C8—C9—C10 | −179.8 (4) |
C2—C3—C4—C5 | −177.4 (3) | C8—C9—C10—C11 | 172.1 (3) |
C3—C4—C5—C6 | 178.1 (3) | C9—C10—C11—C12 | −176.6 (3) |
C4—C5—C6—N2 | −177.1 (3) | C10—C11—C12—N4 | 170.3 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
O4—H1···O8 | 0.89 | 1.72 | 2.584 (4) | 163 |
O5—H2···O5i | 0.90 | 1.76 | 2.657 (6) | 180 |
O6—H3···O12 | 0.90 | 2.00 | 2.894 (8) | 180 |
N1—H1A···O2ii | 0.91 | 1.93 | 2.814 (4) | 164 |
N1—H1B···O2 | 0.91 | 1.81 | 2.717 (4) | 171 |
N1—H1C···O7iii | 0.91 | 1.90 | 2.810 (4) | 174 |
N2—H2C···O8iv | 0.91 | 1.82 | 2.716 (4) | 169 |
N2—H2D···O1v | 0.91 | 1.95 | 2.836 (4) | 165 |
N2—H2E···O7v | 0.91 | 2.06 | 2.965 (4) | 171 |
N3—H3C···O7iii | 0.91 | 1.94 | 2.826 (4) | 166 |
N3—H3D···O3vi | 0.91 | 1.83 | 2.699 (4) | 158 |
N3—H3E···O5vi | 0.91 | 1.89 | 2.779 (5) | 166 |
N4—H4C···O3vii | 0.91 | 1.84 | 2.735 (4) | 167 |
N4—H4D···O2iv | 0.91 | 2.06 | 2.941 (4) | 162 |
N4—H4E···O6viii | 0.91 | 1.90 | 2.801 (4) | 169 |
Symmetry codes: (i) −x, −y+1, −z+1; (ii) −x+1, −y, −z+1; (iii) x, y−1, z; (iv) x, y, z+1; (v) −x+1, −y+1, −z+2; (vi) −x, −y, −z+1; (vii) −x, −y, −z+2; (viii) x, y−1, z+1. |
Experimental details
Crystal data | |
Chemical formula | 4C6H18N22+·4HAsO42−·7H2O |
Mr | 1158.72 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 120 |
a, b, c (Å) | 10.2206 (2), 11.2773 (4), 12.7211 (4) |
α, β, γ (°) | 109.6648 (12), 108.0176 (18), 97.7941 (18) |
V (Å3) | 1265.11 (6) |
Z | 1 |
Radiation type | Mo Kα |
µ (mm−1) | 2.70 |
Crystal size (mm) | 0.42 × 0.22 × 0.06 |
Data collection | |
Diffractometer | Bruker-Nonius KappaCCD |
Absorption correction | Multi-scan (SADABS; Bruker, 2003) |
Tmin, Tmax | 0.397, 0.855 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 25594, 5804, 4788 |
Rint | 0.053 |
(sin θ/λ)max (Å−1) | 0.651 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.047, 0.126, 1.07 |
No. of reflections | 5804 |
No. of parameters | 275 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 3.79, −1.87 |
Computer programs: COLLECT (Nonius, 1998), HKL SCALEPACK (Otwinowski & Minor, 1997), HKL DENZO and SCALEPACK (Otwinowski & Minor, 1997) and SORTAV (Blessing, 1995), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEP-3 (Farrugia, 1997), SHELXL97.
As1—O1 | 1.667 (3) | As2—O8 | 1.652 (3) |
As1—O2 | 1.671 (2) | As2—O7 | 1.668 (3) |
As1—O3 | 1.674 (2) | As2—O6 | 1.689 (3) |
As1—O4 | 1.734 (2) | As2—O5 | 1.721 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
O4—H1···O8 | 0.89 | 1.72 | 2.584 (4) | 163 |
O5—H2···O5i | 0.90 | 1.76 | 2.657 (6) | 180 |
O6—H3···O12 | 0.90 | 2.00 | 2.894 (8) | 180 |
N1—H1A···O2ii | 0.91 | 1.93 | 2.814 (4) | 164 |
N1—H1B···O2 | 0.91 | 1.81 | 2.717 (4) | 171 |
N1—H1C···O7iii | 0.91 | 1.90 | 2.810 (4) | 174 |
N2—H2C···O8iv | 0.91 | 1.82 | 2.716 (4) | 169 |
N2—H2D···O1v | 0.91 | 1.95 | 2.836 (4) | 165 |
N2—H2E···O7v | 0.91 | 2.06 | 2.965 (4) | 171 |
N3—H3C···O7iii | 0.91 | 1.94 | 2.826 (4) | 166 |
N3—H3D···O3vi | 0.91 | 1.83 | 2.699 (4) | 158 |
N3—H3E···O5vi | 0.91 | 1.89 | 2.779 (5) | 166 |
N4—H4C···O3vii | 0.91 | 1.84 | 2.735 (4) | 167 |
N4—H4D···O2iv | 0.91 | 2.06 | 2.941 (4) | 162 |
N4—H4E···O6viii | 0.91 | 1.90 | 2.801 (4) | 169 |
Symmetry codes: (i) −x, −y+1, −z+1; (ii) −x+1, −y, −z+1; (iii) x, y−1, z; (iv) x, y, z+1; (v) −x+1, −y+1, −z+2; (vi) −x, −y, −z+1; (vii) −x, −y, −z+2; (viii) x, y−1, z+1. |
The title compound, (I), was prepared as part of our ongoing studies of hydrogen bonding interactions in the molecular salts of arsenic oxo-anions (Wilkinson & Harrison, 2007a,b). Its asymmetric unit contains two organic cations, two anions and three-and-a-half water molecules (Fig. 1).
The tetrahedral (HAs1O4)2- anion in (I) shows the expected distinction (Table 1) between its protonated and unprotonated As—O bond lengths. The situation for the (HAs2O4)2- group is less clear cut, and seems to be correlated with disorder of its H atoms (see below). Both C2H10N22+ dications are in their extended conformations with all their backbone torsion angles close to 180°. Three fully occupied (O9, O10, O11) water molecules and one half occupied (O12) water molecule complete the structure. O12 cannot be more than half occupied due to a close O12···O12xx (xx = -x, 1 - y, -z) contact of 2.21 (1) Å.
As well as Coulombic forces, the component species in (I) interact by way of a network of N—H···O and O—H···O hydrogen bonds (Table 2). The (HAsO4)2- units are linked by way of O—H···O bonds into distinctive, isolated, tetramers (Fig. 2). The complete assembly is generated by inversion, thus the central O5—H2···O5i (see Table 2 for symmetry code) link must be disordered (i.e. O5—H2···O5i + O5i—H2i···O5 bonds) or possibly a symmetric O5···H2···O5i bond (i.e. the H atom occupies the inversion centre (Wilson, 2001). These possibilities could not be distinguished in the present experiment and a disordered model was assumed. Either of these possibilities necessitates disorder of the H atoms of the As2-hydrogenarsenate group, with one of the (HAsO4)2- moieties directing its H atom elsewhere. The extended As2—O6 bond length suggests that O6 bears the H atom and if so, it makes an O—H···O link to the disordered O12 water molecule O atom (Fig. 2).
The cations interact with the anion tetramers by way of a large number of N—H···O bonds (Table 2), with each NH3+ group making three such links, as is typically seen in these systems (Wilkinson & Harrison, 2007a). Unfortunately the H atoms of the water molecules in (I) could not be located in the present study. The disorder of the As2 H atoms and O12 seems to require that at least some of the water H atoms are also disordered, and the situation is too uncertain to allow their geometrical placement with any confidence.
The packing for (I) results in a distinctive structure (Fig. 3) in which hydrogen-bonded (001) sheets of tetrahedral tetramers are bridged by the organic molecules to result in a framework encapsulating [100] channels, which are occupied by the water molecules.
The structure of 1,6-diamminiumhexane bis(dihydrogenarsenate), C6H18N2·(H2AsO4)2, (II), (Wilkinson & Harrison, 2007a), in which the arsenic-containing anion bears two protons, is entirely different to that of (I). In (II), infinite sheets of H-bonded tetrahedra arise and the centrosymmetric cation adopts a gauche conformation. Other types of supramolecular networks based on hydrogen bonded organic cations and arsenate tetrahedra are descibed by Wilkinson & Harrison (2007b).