The title compounds, (C
8H
20N)[H
2AsO
4][H
3AsO
4]
2, (I), and (C
6H
14N
2)[H
2AsO
4]
2[H
3AsO
4], (II), are unusual salts containing organic cations, dihydrogenarsenate anions and neutral arsenic acid molecules. In (I), the dihydrogenarsenate anion lies across a twofold rotation axis in the space group
C2/
c, while the cation is disordered across a centre of inversion. The [H
2AsO
4]
− and H
3AsO
4 species interact by way of O—H
O hydrogen bonds, leading to sheets and a three-dimensional network for (I) and (II), respectively.
Supporting information
CCDC references: 655489; 655490
For (I), 10 ml each of 0.5 mol dm-3 aqueous solutions of tetraethylammonium
hydroxide (TEAOH) and arsenic acid were mixed in a Petri dish, resulting in a
clear solution. Colourless rods and bars of (I) grew over a few days, as the
water evaporated. For (II), a 0.5 mol dm-3 aqueous
1,4-diazabicyclo[2.2.2]octane solution (10 ml) replaced the TEAOH solution,
and colourless blocks of (II) were formed using the same experimental
procedure as for (I).
The methylene groups of the organic molecule in (I) are disordered over two
conformations, required to have equal occupancies by symmetry. Their H atoms
were geometrically placed (C—H = 0.97 Å) and refined as riding. The H
atoms of the terminal methyl groups were placed in two orientations (C—H =
0.92–0.98 Å), to achieve reasonable C—C—H angles for both disorder
components of the bridging methylene groups, and refined as riding. For (II),
the C– and N-bound H atoms were geometrically placed (C—H = 0.97 Å, N—H
= 0.91 Å) and refined as riding atoms. For both (I) and (II), the O-bound H
atoms were located in difference maps and refined as riding atoms in the
positions found from the difference maps, giving a range of O—H distances of
0.83–0.96 Å. For both (I) and (II), Uiso(H) values were set at
1.2Ueq(carrier) or 1.5Ueq(methyl C).
For both compounds, data collection: SMART (Bruker, 1999); cell refinement: SAINT (Bruker, 1999); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997) and ATOMS (Shape Software, 2000); software used to prepare material for publication: SHELXL97.
(I) Tetraethylammonium dihydrogenarsenate bis(arsenic acid) and
1,4-diazoniabicyclo[2.2.2]octane bis(dihydrogenarsenate) arsenic acid. ?
top
Crystal data top
(C8H20N)[H2AsO4][H3AsO4]2 | F(000) = 1112 |
Mr = 555.08 | Dx = 1.834 Mg m−3 |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -C 2yc | Cell parameters from 2724 reflections |
a = 20.0518 (13) Å | θ = 2.3–29.6° |
b = 7.3138 (4) Å | µ = 5.01 mm−1 |
c = 15.251 (1) Å | T = 293 K |
β = 115.969 (1)° | Rod, colourless |
V = 2010.7 (2) Å3 | 0.25 × 0.08 × 0.06 mm |
Z = 4 | |
Data collection top
Bruker SMART 1000 CCD diffractometer | 3610 independent reflections |
Radiation source: fine-focus sealed tube | 2301 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.032 |
ω scans | θmax = 32.5°, θmin = 2.3° |
Absorption correction: multi-scan (SADABS; Bruker, 1999) | h = −30→30 |
Tmin = 0.360, Tmax = 0.739 | k = −11→8 |
9940 measured reflections | l = −18→23 |
Refinement top
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)] = 0.031 | H-atom parameters constrained |
wR(F2) = 0.066 | w = 1/[σ2(Fo2) + (0.0287P)2] where P = (Fo2 + 2Fc2)/3 |
S = 0.86 | (Δ/σ)max = 0.001 |
3610 reflections | Δρmax = 0.65 e Å−3 |
130 parameters | Δρmin = −0.43 e Å−3 |
0 restraints | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.00088 (8) |
Crystal data top
(C8H20N)[H2AsO4][H3AsO4]2 | V = 2010.7 (2) Å3 |
Mr = 555.08 | Z = 4 |
Monoclinic, C2/c | Mo Kα radiation |
a = 20.0518 (13) Å | µ = 5.01 mm−1 |
b = 7.3138 (4) Å | T = 293 K |
c = 15.251 (1) Å | 0.25 × 0.08 × 0.06 mm |
β = 115.969 (1)° | |
Data collection top
Bruker SMART 1000 CCD diffractometer | 3610 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 1999) | 2301 reflections with I > 2σ(I) |
Tmin = 0.360, Tmax = 0.739 | Rint = 0.032 |
9940 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.031 | 0 restraints |
wR(F2) = 0.066 | H-atom parameters constrained |
S = 0.86 | Δρmax = 0.65 e Å−3 |
3610 reflections | Δρmin = −0.43 e Å−3 |
130 parameters | |
Special details top
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. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | Occ. (<1) |
As1 | 0.0000 | 0.24048 (4) | 0.2500 | 0.03836 (10) | |
O1 | 0.01538 (10) | 0.1174 (2) | 0.34778 (11) | 0.0469 (4) | |
O2 | 0.07580 (11) | 0.3764 (2) | 0.28257 (12) | 0.0637 (6) | |
H1 | 0.0750 | 0.4231 | 0.2308 | 0.076* | |
As2 | 0.055937 (13) | 0.28268 (3) | 0.583774 (16) | 0.03564 (8) | |
O3 | 0.10288 (9) | 0.2190 (2) | 0.51990 (13) | 0.0530 (5) | |
H2 | 0.0738 | 0.1825 | 0.4586 | 0.064* | |
O4 | 0.07940 (10) | 0.4933 (2) | 0.62311 (12) | 0.0470 (4) | |
O5 | 0.07817 (10) | 0.1406 (2) | 0.67900 (12) | 0.0625 (5) | |
H3 | 0.0422 | 0.0600 | 0.6622 | 0.075* | |
O6 | −0.03622 (9) | 0.2541 (2) | 0.51201 (12) | 0.0491 (4) | |
H4 | −0.0491 | 0.3282 | 0.4577 | 0.059* | |
N1 | 0.2500 | 0.2500 | 0.0000 | 0.0402 (6) | |
C4 | 0.3162 (3) | 0.3614 (7) | 0.0706 (4) | 0.0499 (13) | 0.50 |
H4A | 0.3484 | 0.3934 | 0.0406 | 0.060* | 0.50 |
H4B | 0.3446 | 0.2920 | 0.1295 | 0.060* | 0.50 |
C5 | 0.2144 (3) | 0.4283 (6) | 0.0171 (4) | 0.0497 (13) | 0.50 |
H5A | 0.1784 | 0.3985 | 0.0414 | 0.060* | 0.50 |
H5B | 0.1894 | 0.4956 | −0.0435 | 0.060* | 0.50 |
C6 | 0.2811 (2) | 0.5485 (4) | 0.0962 (3) | 0.0843 (11) | |
H6A | 0.3212 | 0.6229 | 0.1405 | 0.126* | 0.50 |
H6B | 0.2494 | 0.5156 | 0.1260 | 0.126* | 0.50 |
H6C | 0.2532 | 0.6158 | 0.0374 | 0.126* | 0.50 |
H6D | 0.2593 | 0.6540 | 0.1080 | 0.126* | 0.50 |
H6E | 0.3148 | 0.5706 | 0.0716 | 0.126* | 0.50 |
H6F | 0.3025 | 0.4737 | 0.1550 | 0.126* | 0.50 |
C1 | 0.2001 (3) | 0.1994 (7) | 0.0470 (4) | 0.0550 (14) | 0.50 |
H1A | 0.1621 | 0.1161 | 0.0045 | 0.066* | 0.50 |
H1B | 0.1757 | 0.3087 | 0.0545 | 0.066* | 0.50 |
C2 | 0.2936 (3) | 0.1534 (7) | 0.0926 (4) | 0.0576 (14) | 0.50 |
H2A | 0.3353 | 0.2288 | 0.1340 | 0.069* | 0.50 |
H2B | 0.3129 | 0.0406 | 0.0794 | 0.069* | 0.50 |
C3 | 0.2437 (2) | 0.1074 (5) | 0.1491 (2) | 0.0892 (11) | |
H3A | 0.2100 | 0.0784 | 0.1764 | 0.134* | 0.50 |
H3B | 0.2810 | 0.1901 | 0.1918 | 0.134* | 0.50 |
H3C | 0.2669 | −0.0026 | 0.1419 | 0.134* | 0.50 |
H3D | 0.2761 | 0.0438 | 0.2084 | 0.134* | 0.50 |
H3E | 0.2059 | 0.0279 | 0.1078 | 0.134* | 0.50 |
H3F | 0.2262 | 0.2157 | 0.1628 | 0.134* | 0.50 |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
As1 | 0.0547 (2) | 0.03502 (18) | 0.02475 (16) | 0.000 | 0.01683 (15) | 0.000 |
O1 | 0.0669 (12) | 0.0438 (9) | 0.0266 (8) | −0.0077 (8) | 0.0173 (8) | 0.0030 (7) |
O2 | 0.0782 (15) | 0.0663 (12) | 0.0393 (10) | −0.0273 (10) | 0.0190 (10) | 0.0010 (8) |
As2 | 0.03761 (13) | 0.03770 (13) | 0.02809 (12) | −0.00035 (10) | 0.01113 (10) | 0.00172 (9) |
O3 | 0.0407 (10) | 0.0749 (12) | 0.0401 (10) | 0.0053 (8) | 0.0147 (8) | −0.0164 (8) |
O4 | 0.0588 (12) | 0.0369 (9) | 0.0394 (9) | 0.0004 (8) | 0.0162 (8) | −0.0043 (7) |
O5 | 0.0643 (13) | 0.0636 (12) | 0.0387 (10) | −0.0163 (10) | 0.0031 (9) | 0.0174 (8) |
O6 | 0.0372 (10) | 0.0630 (11) | 0.0423 (10) | −0.0071 (8) | 0.0131 (8) | 0.0104 (7) |
N1 | 0.0263 (13) | 0.0474 (16) | 0.0410 (16) | −0.0019 (11) | 0.0094 (12) | 0.0008 (11) |
C4 | 0.038 (3) | 0.060 (3) | 0.043 (3) | −0.016 (2) | 0.010 (2) | −0.002 (2) |
C5 | 0.042 (3) | 0.048 (3) | 0.058 (3) | 0.009 (2) | 0.021 (3) | 0.004 (2) |
C6 | 0.111 (3) | 0.0551 (19) | 0.092 (3) | −0.0263 (19) | 0.048 (2) | −0.0258 (17) |
C1 | 0.034 (3) | 0.062 (3) | 0.074 (4) | −0.013 (2) | 0.029 (3) | −0.008 (3) |
C2 | 0.044 (3) | 0.056 (3) | 0.050 (3) | 0.002 (2) | −0.001 (2) | 0.008 (3) |
C3 | 0.112 (3) | 0.099 (3) | 0.060 (2) | −0.020 (2) | 0.040 (2) | 0.0173 (18) |
Geometric parameters (Å, º) top
As1—O1i | 1.6510 (15) | C4—H4B | 0.9700 |
As1—O1 | 1.6510 (15) | C5—C6 | 1.615 (6) |
As1—O2 | 1.6982 (17) | C5—H5A | 0.9700 |
As1—O2i | 1.6982 (17) | C5—H5B | 0.9700 |
O2—H1 | 0.8534 | C6—H6A | 0.9600 |
As2—O4 | 1.6454 (15) | C6—H6B | 0.9600 |
As2—O5 | 1.6797 (16) | C6—H6C | 0.9600 |
As2—O3 | 1.6895 (17) | C6—H6D | 0.9418 |
As2—O6 | 1.6985 (16) | C6—H6E | 0.9195 |
O3—H2 | 0.8987 | C6—H6F | 0.9748 |
O5—H3 | 0.8780 | C1—C3 | 1.565 (6) |
O6—H4 | 0.9266 | C1—H1A | 0.9700 |
N1—C2ii | 1.475 (5) | C1—H1B | 0.9700 |
N1—C2 | 1.475 (5) | C2—C3 | 1.615 (7) |
N1—C1ii | 1.510 (5) | C2—H2A | 0.9700 |
N1—C1 | 1.510 (5) | C2—H2B | 0.9700 |
N1—C4 | 1.527 (4) | C3—H3A | 0.9600 |
N1—C4ii | 1.527 (4) | C3—H3B | 0.9600 |
N1—C5ii | 1.562 (5) | C3—H3C | 0.9600 |
N1—C5 | 1.562 (5) | C3—H3D | 0.9700 |
C4—C6 | 1.662 (6) | C3—H3E | 0.9446 |
C4—H4A | 0.9700 | C3—H3F | 0.9267 |
| | | |
O1i—As1—O1 | 113.94 (11) | H4B—C4—H6E | 121.3 |
O1i—As1—O2 | 111.87 (9) | N1—C5—C6 | 106.8 (3) |
O1—As1—O2 | 105.40 (8) | N1—C5—H5A | 110.4 |
O1i—As1—O2i | 105.40 (8) | C6—C5—H5A | 110.4 |
O1—As1—O2i | 111.87 (9) | N1—C5—H5B | 110.4 |
O2—As1—O2i | 108.34 (14) | C6—C5—H5B | 110.4 |
As1—O2—H1 | 108.2 | H5A—C5—H5B | 108.6 |
O4—As2—O5 | 109.81 (8) | N1—C5—H6C | 123.3 |
O4—As2—O3 | 109.00 (9) | H5A—C5—H6C | 121.2 |
O5—As2—O3 | 108.91 (10) | C5—C6—C4 | 70.9 (3) |
O4—As2—O6 | 114.01 (8) | C5—C6—H6A | 177.0 |
O5—As2—O6 | 106.43 (8) | C4—C6—H6A | 108.8 |
O3—As2—O6 | 108.55 (8) | C4—C6—H6B | 110.0 |
As2—O3—H2 | 114.2 | H6A—C6—H6B | 109.5 |
As2—O5—H3 | 106.9 | C4—C6—H6C | 109.6 |
As2—O6—H4 | 107.6 | H6A—C6—H6C | 109.5 |
C2ii—N1—C2 | 180.0 (7) | H6B—C6—H6C | 109.5 |
C2ii—N1—C1ii | 70.5 (3) | C5—C6—H6D | 106.7 |
C2—N1—C1ii | 109.5 (3) | C5—C6—H6E | 107.9 |
C2ii—N1—C1 | 109.5 (3) | H6D—C6—H6E | 114.8 |
C2—N1—C1 | 70.5 (3) | C5—C6—H6F | 105.6 |
C1ii—N1—C1 | 180.0 (5) | H6D—C6—H6F | 109.7 |
C2ii—N1—C4 | 112.7 (3) | H6E—C6—H6F | 111.7 |
C2—N1—C4 | 67.3 (3) | N1—C1—C3 | 112.4 (3) |
C1ii—N1—C4 | 69.6 (3) | N1—C1—H1A | 109.1 |
C1—N1—C4 | 110.4 (3) | C3—C1—H1A | 109.1 |
C2ii—N1—C4ii | 67.3 (3) | N1—C1—H1B | 109.1 |
C2—N1—C4ii | 112.7 (3) | C3—C1—H1B | 109.1 |
C1ii—N1—C4ii | 110.4 (3) | H1A—C1—H1B | 107.9 |
C1—N1—C4ii | 69.6 (3) | N1—C1—H3E | 126.7 |
C4—N1—C4ii | 180.0 (6) | H1B—C1—H3E | 120.7 |
C2ii—N1—C5ii | 111.2 (3) | N1—C2—C3 | 111.4 (4) |
C2—N1—C5ii | 68.8 (3) | N1—C2—H2A | 109.3 |
C1ii—N1—C5ii | 71.3 (3) | C3—C2—H2A | 109.3 |
C1—N1—C5ii | 108.7 (3) | N1—C2—H2B | 109.3 |
C4—N1—C5ii | 104.1 (3) | C3—C2—H2B | 109.3 |
C4ii—N1—C5ii | 75.9 (3) | H2A—C2—H2B | 108.0 |
C2ii—N1—C5 | 68.8 (3) | N1—C2—H3C | 128.2 |
C2—N1—C5 | 111.2 (3) | H2A—C2—H3C | 118.4 |
C1ii—N1—C5 | 108.7 (3) | C1—C3—H3A | 109.5 |
C1—N1—C5 | 71.3 (3) | C1—C3—H3B | 109.5 |
C4—N1—C5 | 75.9 (3) | H3A—C3—H3B | 109.5 |
C4ii—N1—C5 | 104.1 (3) | C1—C3—H3C | 109.5 |
C5ii—N1—C5 | 180.0 (5) | H3A—C3—H3C | 109.5 |
N1—C4—C6 | 106.2 (3) | H3B—C3—H3C | 109.5 |
N1—C4—H4A | 110.5 | C2—C3—H3D | 106.2 |
C6—C4—H4A | 110.5 | C2—C3—H3E | 106.0 |
N1—C4—H4B | 110.5 | H3D—C3—H3E | 109.9 |
C6—C4—H4B | 110.5 | C2—C3—H3F | 109.0 |
H4A—C4—H4B | 108.7 | H3D—C3—H3F | 111.5 |
N1—C4—H6E | 121.8 | H3E—C3—H3F | 113.8 |
| | | |
C2ii—N1—C4—C6 | 62.4 (4) | C2ii—N1—C1—C3 | −176.3 (4) |
C2—N1—C4—C6 | −117.6 (4) | C2—N1—C1—C3 | 3.7 (4) |
C1ii—N1—C4—C6 | 119.5 (4) | C4—N1—C1—C3 | −51.6 (4) |
C1—N1—C4—C6 | −60.5 (4) | C4ii—N1—C1—C3 | 128.4 (4) |
C5ii—N1—C4—C6 | −177.0 (3) | C5ii—N1—C1—C3 | 61.9 (4) |
C5—N1—C4—C6 | 3.0 (3) | C5—N1—C1—C3 | −118.1 (4) |
C2ii—N1—C5—C6 | −124.8 (4) | C1ii—N1—C2—C3 | 176.4 (3) |
C2—N1—C5—C6 | 55.2 (4) | C1—N1—C2—C3 | −3.6 (3) |
C1ii—N1—C5—C6 | −65.5 (4) | C4—N1—C2—C3 | 119.7 (5) |
C1—N1—C5—C6 | 114.5 (4) | C4ii—N1—C2—C3 | −60.3 (5) |
C4—N1—C5—C6 | −3.1 (3) | C5ii—N1—C2—C3 | −123.8 (4) |
C4ii—N1—C5—C6 | 176.9 (3) | C5—N1—C2—C3 | 56.2 (4) |
N1—C5—C6—C4 | 3.0 (3) | N1—C1—C3—C2 | −3.5 (3) |
N1—C4—C6—C5 | −3.0 (3) | N1—C2—C3—C1 | 3.6 (3) |
Symmetry codes: (i) −x, y, −z+1/2; (ii) −x+1/2, −y+1/2, −z. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H1···O4iii | 0.85 | 1.79 | 2.642 (2) | 175 |
O3—H2···O1 | 0.90 | 1.65 | 2.547 (2) | 176 |
O5—H3···O1iv | 0.88 | 1.70 | 2.564 (2) | 168 |
O6—H4···O4v | 0.93 | 1.71 | 2.617 (2) | 164 |
Symmetry codes: (iii) x, −y+1, z−1/2; (iv) −x, −y, −z+1; (v) −x, −y+1, −z+1. |
(II) 1,4-diazoniabicyclo[2.2.2]octane bis(dihydrogenarsenate) arsenic acid
top
Crystal data top
(C6H14N2)[H2AsO4]2[H3AsO4] | F(000) = 1064 |
Mr = 538.01 | Dx = 2.076 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yn | Cell parameters from 5683 reflections |
a = 8.1285 (3) Å | θ = 2.8–32.1° |
b = 22.2104 (9) Å | µ = 5.85 mm−1 |
c = 10.0056 (4) Å | T = 293 K |
β = 107.637 (1)° | Block, colourless |
V = 1721.47 (12) Å3 | 0.24 × 0.20 × 0.14 mm |
Z = 4 | |
Data collection top
Bruker SMART 1000 CCD diffractometer | 6212 independent reflections |
Radiation source: fine-focus sealed tube | 4321 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.032 |
ω scans | θmax = 32.6°, θmin = 1.8° |
Absorption correction: multi-scan (SADABS; Bruker, 1999) | h = −12→11 |
Tmin = 0.297, Tmax = 0.441 | k = −33→30 |
17889 measured reflections | l = −8→15 |
Refinement top
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)] = 0.028 | H-atom parameters constrained |
wR(F2) = 0.056 | w = 1/[σ2(Fo2) + (0.0233P)2] where P = (Fo2 + 2Fc2)/3 |
S = 0.89 | (Δ/σ)max = 0.002 |
6212 reflections | Δρmax = 0.64 e Å−3 |
209 parameters | Δρmin = −0.45 e Å−3 |
0 restraints | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.00252 (11) |
Crystal data top
(C6H14N2)[H2AsO4]2[H3AsO4] | V = 1721.47 (12) Å3 |
Mr = 538.01 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 8.1285 (3) Å | µ = 5.85 mm−1 |
b = 22.2104 (9) Å | T = 293 K |
c = 10.0056 (4) Å | 0.24 × 0.20 × 0.14 mm |
β = 107.637 (1)° | |
Data collection top
Bruker SMART 1000 CCD diffractometer | 6212 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 1999) | 4321 reflections with I > 2σ(I) |
Tmin = 0.297, Tmax = 0.441 | Rint = 0.032 |
17889 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.028 | 0 restraints |
wR(F2) = 0.056 | H-atom parameters constrained |
S = 0.89 | Δρmax = 0.64 e Å−3 |
6212 reflections | Δρmin = −0.45 e Å−3 |
209 parameters | |
Special details top
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. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
As1 | −0.20979 (3) | 0.134143 (10) | 0.23649 (3) | 0.02638 (6) | |
O1 | −0.4053 (2) | 0.11193 (7) | 0.12768 (18) | 0.0397 (4) | |
H1 | −0.4289 | 0.0815 | 0.1760 | 0.048* | |
O2 | −0.0777 (2) | 0.07695 (7) | 0.29270 (19) | 0.0400 (4) | |
O3 | −0.2434 (2) | 0.16451 (8) | 0.38238 (18) | 0.0507 (5) | |
H3 | −0.3371 | 0.1821 | 0.3723 | 0.061* | |
O4 | −0.1462 (2) | 0.18726 (8) | 0.1465 (2) | 0.0467 (5) | |
As2 | 0.34076 (3) | 0.024094 (10) | 0.30675 (3) | 0.02488 (6) | |
O5 | 0.1507 (2) | 0.04422 (8) | 0.19015 (18) | 0.0395 (4) | |
H5 | 0.0865 | 0.0660 | 0.2326 | 0.047* | |
O6 | 0.48508 (19) | 0.01777 (7) | 0.22083 (18) | 0.0316 (4) | |
O7 | 0.4021 (2) | 0.07085 (7) | 0.44236 (17) | 0.0342 (4) | |
O8 | 0.2994 (2) | −0.04542 (7) | 0.36429 (18) | 0.0388 (4) | |
H8 | 0.3932 | −0.0570 | 0.4345 | 0.047* | |
As3 | 0.29256 (3) | 0.228100 (10) | 0.33337 (3) | 0.02591 (6) | |
O9 | 0.2756 (2) | 0.17439 (7) | 0.44770 (19) | 0.0430 (4) | |
H9 | 0.3353 | 0.1396 | 0.4435 | 0.052* | |
O10 | 0.2095 (2) | 0.29091 (7) | 0.38400 (19) | 0.0413 (4) | |
H10 | 0.2532 | 0.3018 | 0.4810 | 0.050* | |
O11 | 0.48942 (19) | 0.23803 (7) | 0.3267 (2) | 0.0380 (4) | |
O12 | 0.1643 (2) | 0.21237 (9) | 0.17108 (18) | 0.0463 (5) | |
H12 | 0.0587 | 0.2004 | 0.1686 | 0.056* | |
N1 | 0.6253 (2) | 0.34281 (8) | 0.3066 (2) | 0.0303 (4) | |
H13 | 0.5696 | 0.3092 | 0.3221 | 0.036* | |
N2 | 0.7753 (2) | 0.43453 (8) | 0.2628 (2) | 0.0267 (4) | |
H14 | 0.8311 | 0.4680 | 0.2471 | 0.032* | |
C1 | 0.8104 (3) | 0.32797 (10) | 0.3286 (3) | 0.0403 (6) | |
H1A | 0.8196 | 0.2933 | 0.2724 | 0.048* | |
H1B | 0.8664 | 0.3184 | 0.4265 | 0.048* | |
C2 | 0.5431 (3) | 0.36381 (12) | 0.1600 (3) | 0.0409 (6) | |
H2A | 0.4197 | 0.3682 | 0.1425 | 0.049* | |
H2B | 0.5622 | 0.3345 | 0.0944 | 0.049* | |
C3 | 0.6106 (4) | 0.39077 (11) | 0.4064 (3) | 0.0437 (6) | |
H3A | 0.6508 | 0.3757 | 0.5018 | 0.052* | |
H3B | 0.4909 | 0.4028 | 0.3867 | 0.052* | |
C4 | 0.8970 (3) | 0.38193 (9) | 0.2861 (3) | 0.0310 (5) | |
H4A | 1.0030 | 0.3914 | 0.3592 | 0.037* | |
H4B | 0.9253 | 0.3731 | 0.2007 | 0.037* | |
C5 | 0.6213 (3) | 0.42404 (10) | 0.1393 (2) | 0.0333 (5) | |
H5A | 0.6547 | 0.4233 | 0.0540 | 0.040* | |
H5B | 0.5378 | 0.4561 | 0.1314 | 0.040* | |
C6 | 0.7194 (3) | 0.44446 (9) | 0.3905 (2) | 0.0303 (5) | |
H6A | 0.6522 | 0.4812 | 0.3805 | 0.036* | |
H6B | 0.8195 | 0.4482 | 0.4727 | 0.036* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
As1 | 0.02053 (10) | 0.02777 (11) | 0.02869 (13) | 0.00083 (8) | 0.00423 (9) | 0.00449 (10) |
O1 | 0.0317 (9) | 0.0438 (10) | 0.0340 (10) | −0.0131 (7) | −0.0043 (8) | 0.0091 (8) |
O2 | 0.0351 (9) | 0.0374 (9) | 0.0506 (11) | 0.0144 (7) | 0.0178 (9) | 0.0128 (8) |
O3 | 0.0464 (11) | 0.0636 (12) | 0.0360 (11) | 0.0239 (9) | 0.0035 (9) | −0.0082 (9) |
O4 | 0.0326 (9) | 0.0498 (11) | 0.0501 (11) | −0.0135 (8) | 0.0012 (9) | 0.0216 (9) |
As2 | 0.02144 (10) | 0.02655 (11) | 0.02791 (13) | 0.00271 (8) | 0.00935 (9) | 0.00314 (9) |
O5 | 0.0296 (8) | 0.0548 (11) | 0.0324 (9) | 0.0157 (8) | 0.0068 (8) | 0.0059 (8) |
O6 | 0.0293 (8) | 0.0318 (8) | 0.0406 (10) | 0.0035 (6) | 0.0209 (8) | 0.0024 (7) |
O7 | 0.0367 (9) | 0.0318 (8) | 0.0316 (9) | 0.0071 (7) | 0.0066 (8) | −0.0032 (7) |
O8 | 0.0325 (9) | 0.0366 (9) | 0.0437 (11) | −0.0069 (7) | 0.0063 (8) | 0.0102 (8) |
As3 | 0.02443 (11) | 0.02288 (10) | 0.03107 (13) | −0.00267 (8) | 0.00938 (10) | −0.00219 (9) |
O9 | 0.0618 (12) | 0.0296 (9) | 0.0486 (11) | 0.0054 (8) | 0.0335 (10) | 0.0056 (8) |
O10 | 0.0443 (10) | 0.0323 (9) | 0.0428 (11) | 0.0145 (7) | 0.0062 (9) | −0.0052 (8) |
O11 | 0.0243 (8) | 0.0277 (8) | 0.0639 (12) | −0.0024 (6) | 0.0162 (8) | 0.0016 (8) |
O12 | 0.0356 (9) | 0.0699 (13) | 0.0317 (10) | −0.0152 (9) | 0.0075 (8) | −0.0126 (9) |
N1 | 0.0265 (9) | 0.0253 (9) | 0.0400 (12) | −0.0061 (7) | 0.0113 (9) | 0.0006 (9) |
N2 | 0.0282 (9) | 0.0260 (9) | 0.0279 (10) | −0.0034 (7) | 0.0116 (8) | 0.0037 (8) |
C1 | 0.0253 (11) | 0.0292 (12) | 0.0638 (19) | 0.0033 (9) | 0.0093 (12) | 0.0074 (12) |
C2 | 0.0294 (12) | 0.0481 (15) | 0.0370 (15) | −0.0045 (11) | −0.0024 (11) | −0.0062 (12) |
C3 | 0.0641 (17) | 0.0386 (13) | 0.0392 (16) | −0.0110 (13) | 0.0319 (14) | −0.0090 (12) |
C4 | 0.0212 (10) | 0.0326 (12) | 0.0386 (14) | 0.0020 (9) | 0.0083 (10) | 0.0024 (10) |
C5 | 0.0320 (12) | 0.0419 (13) | 0.0237 (12) | 0.0076 (10) | 0.0053 (10) | 0.0035 (10) |
C6 | 0.0357 (12) | 0.0279 (11) | 0.0276 (12) | −0.0005 (9) | 0.0100 (10) | −0.0050 (9) |
Geometric parameters (Å, º) top
As1—O2 | 1.6483 (15) | N1—C2 | 1.491 (3) |
As1—O4 | 1.6585 (16) | N1—H13 | 0.9100 |
As1—O3 | 1.7037 (17) | N2—C5 | 1.486 (3) |
As1—O1 | 1.7045 (15) | N2—C6 | 1.497 (3) |
O1—H1 | 0.8857 | N2—C4 | 1.502 (3) |
O3—H3 | 0.8348 | N2—H14 | 0.9100 |
As2—O6 | 1.6571 (14) | C1—C4 | 1.515 (3) |
As2—O7 | 1.6608 (16) | C1—H1A | 0.9700 |
As2—O5 | 1.6896 (16) | C1—H1B | 0.9700 |
As2—O8 | 1.7163 (15) | C2—C5 | 1.522 (3) |
O5—H5 | 0.9060 | C2—H2A | 0.9700 |
O8—H8 | 0.9032 | C2—H2B | 0.9700 |
As3—O11 | 1.6365 (14) | C3—C6 | 1.522 (3) |
As3—O12 | 1.6793 (17) | C3—H3A | 0.9700 |
As3—O9 | 1.6871 (16) | C3—H3B | 0.9700 |
As3—O10 | 1.6928 (15) | C4—H4A | 0.9700 |
O9—H9 | 0.9205 | C4—H4B | 0.9700 |
O10—H10 | 0.9578 | C5—H5A | 0.9700 |
O12—H12 | 0.8918 | C5—H5B | 0.9700 |
N1—C3 | 1.490 (3) | C6—H6A | 0.9700 |
N1—C1 | 1.490 (3) | C6—H6B | 0.9700 |
| | | |
O2—As1—O4 | 117.10 (8) | N1—C1—C4 | 108.53 (17) |
O2—As1—O3 | 105.65 (9) | N1—C1—H1A | 110.0 |
O4—As1—O3 | 109.92 (10) | C4—C1—H1A | 110.0 |
O2—As1—O1 | 112.31 (9) | N1—C1—H1B | 110.0 |
O4—As1—O1 | 104.05 (8) | C4—C1—H1B | 110.0 |
O3—As1—O1 | 107.54 (9) | H1A—C1—H1B | 108.4 |
As1—O1—H1 | 100.8 | N1—C2—C5 | 109.15 (19) |
As1—O3—H3 | 117.4 | N1—C2—H2A | 109.9 |
O6—As2—O7 | 113.11 (8) | C5—C2—H2A | 109.9 |
O6—As2—O5 | 107.88 (8) | N1—C2—H2B | 109.9 |
O7—As2—O5 | 112.58 (8) | C5—C2—H2B | 109.9 |
O6—As2—O8 | 109.83 (8) | H2A—C2—H2B | 108.3 |
O7—As2—O8 | 109.22 (8) | N1—C3—C6 | 108.83 (18) |
O5—As2—O8 | 103.80 (8) | N1—C3—H3A | 109.9 |
As2—O5—H5 | 110.7 | C6—C3—H3A | 109.9 |
As2—O8—H8 | 108.1 | N1—C3—H3B | 109.9 |
O11—As3—O12 | 108.48 (9) | C6—C3—H3B | 109.9 |
O11—As3—O9 | 113.86 (9) | H3A—C3—H3B | 108.3 |
O12—As3—O9 | 110.75 (9) | N2—C4—C1 | 108.58 (16) |
O11—As3—O10 | 112.62 (8) | N2—C4—H4A | 110.0 |
O12—As3—O10 | 105.89 (9) | C1—C4—H4A | 110.0 |
O9—As3—O10 | 104.95 (8) | N2—C4—H4B | 110.0 |
As3—O9—H9 | 114.2 | C1—C4—H4B | 110.0 |
As3—O10—H10 | 116.8 | H4A—C4—H4B | 108.4 |
As3—O12—H12 | 113.5 | N2—C5—C2 | 107.78 (18) |
C3—N1—C1 | 110.0 (2) | N2—C5—H5A | 110.1 |
C3—N1—C2 | 109.45 (19) | C2—C5—H5A | 110.1 |
C1—N1—C2 | 110.3 (2) | N2—C5—H5B | 110.1 |
C3—N1—H13 | 109.0 | C2—C5—H5B | 110.1 |
C1—N1—H13 | 109.0 | H5A—C5—H5B | 108.5 |
C2—N1—H13 | 109.0 | N2—C6—C3 | 108.09 (18) |
C5—N2—C6 | 109.63 (17) | N2—C6—H6A | 110.1 |
C5—N2—C4 | 110.86 (17) | C3—C6—H6A | 110.1 |
C6—N2—C4 | 109.76 (18) | N2—C6—H6B | 110.1 |
C5—N2—H14 | 108.9 | C3—C6—H6B | 110.1 |
C6—N2—H14 | 108.9 | H6A—C6—H6B | 108.4 |
C4—N2—H14 | 108.9 | | |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1···O6i | 0.89 | 1.70 | 2.557 (2) | 163 |
O3—H3···O11i | 0.83 | 1.83 | 2.638 (2) | 163 |
O5—H5···O2 | 0.91 | 1.64 | 2.487 (2) | 154 |
O8—H8···O7ii | 0.90 | 1.77 | 2.666 (2) | 170 |
O9—H9···O7 | 0.92 | 1.62 | 2.526 (2) | 167 |
O10—H10···O4iii | 0.96 | 1.63 | 2.578 (3) | 171 |
O12—H12···O4 | 0.89 | 1.64 | 2.523 (2) | 171 |
N1—H13···O11 | 0.91 | 1.72 | 2.610 (2) | 167 |
N2—H14···O6iv | 0.91 | 1.81 | 2.655 (2) | 154 |
Symmetry codes: (i) x−1, y, z; (ii) −x+1, −y, −z+1; (iii) x+1/2, −y+1/2, z+1/2; (iv) −x+3/2, y+1/2, −z+1/2. |
Experimental details
| (I) | (II) |
Crystal data |
Chemical formula | (C8H20N)[H2AsO4][H3AsO4]2 | (C6H14N2)[H2AsO4]2[H3AsO4] |
Mr | 555.08 | 538.01 |
Crystal system, space group | Monoclinic, C2/c | Monoclinic, P21/n |
Temperature (K) | 293 | 293 |
a, b, c (Å) | 20.0518 (13), 7.3138 (4), 15.251 (1) | 8.1285 (3), 22.2104 (9), 10.0056 (4) |
β (°) | 115.969 (1) | 107.637 (1) |
V (Å3) | 2010.7 (2) | 1721.47 (12) |
Z | 4 | 4 |
Radiation type | Mo Kα | Mo Kα |
µ (mm−1) | 5.01 | 5.85 |
Crystal size (mm) | 0.25 × 0.08 × 0.06 | 0.24 × 0.20 × 0.14 |
|
Data collection |
Diffractometer | Bruker SMART 1000 CCD diffractometer | Bruker SMART 1000 CCD diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 1999) | Multi-scan (SADABS; Bruker, 1999) |
Tmin, Tmax | 0.360, 0.739 | 0.297, 0.441 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 9940, 3610, 2301 | 17889, 6212, 4321 |
Rint | 0.032 | 0.032 |
(sin θ/λ)max (Å−1) | 0.755 | 0.759 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.031, 0.066, 0.86 | 0.028, 0.056, 0.89 |
No. of reflections | 3610 | 6212 |
No. of parameters | 130 | 209 |
H-atom treatment | H-atom parameters constrained | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.65, −0.43 | 0.64, −0.45 |
Selected bond lengths (Å) for (I) topAs1—O1 | 1.6510 (15) | As2—O5 | 1.6797 (16) |
As1—O2 | 1.6982 (17) | As2—O3 | 1.6895 (17) |
As2—O4 | 1.6454 (15) | As2—O6 | 1.6985 (16) |
Hydrogen-bond geometry (Å, º) for (I) top
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H1···O4i | 0.85 | 1.79 | 2.642 (2) | 175 |
O3—H2···O1 | 0.90 | 1.65 | 2.547 (2) | 176 |
O5—H3···O1ii | 0.88 | 1.70 | 2.564 (2) | 168 |
O6—H4···O4iii | 0.93 | 1.71 | 2.617 (2) | 164 |
Symmetry codes: (i) x, −y+1, z−1/2; (ii) −x, −y, −z+1; (iii) −x, −y+1, −z+1. |
Selected bond lengths (Å) for (II) topAs1—O2 | 1.6483 (15) | As2—O5 | 1.6896 (16) |
As1—O4 | 1.6585 (16) | As2—O8 | 1.7163 (15) |
As1—O3 | 1.7037 (17) | As3—O11 | 1.6365 (14) |
As1—O1 | 1.7045 (15) | As3—O12 | 1.6793 (17) |
As2—O6 | 1.6571 (14) | As3—O9 | 1.6871 (16) |
As2—O7 | 1.6608 (16) | As3—O10 | 1.6928 (15) |
Hydrogen-bond geometry (Å, º) for (II) top
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1···O6i | 0.89 | 1.70 | 2.557 (2) | 163 |
O3—H3···O11i | 0.83 | 1.83 | 2.638 (2) | 163 |
O5—H5···O2 | 0.91 | 1.64 | 2.487 (2) | 154 |
O8—H8···O7ii | 0.90 | 1.77 | 2.666 (2) | 170 |
O9—H9···O7 | 0.92 | 1.62 | 2.526 (2) | 167 |
O10—H10···O4iii | 0.96 | 1.63 | 2.578 (3) | 171 |
O12—H12···O4 | 0.89 | 1.64 | 2.523 (2) | 171 |
N1—H13···O11 | 0.91 | 1.72 | 2.610 (2) | 167 |
N2—H14···O6iv | 0.91 | 1.81 | 2.655 (2) | 154 |
Symmetry codes: (i) x−1, y, z; (ii) −x+1, −y, −z+1; (iii) x+1/2, −y+1/2, z+1/2; (iv) −x+3/2, y+1/2, −z+1/2. |
Only a handful of crystal structures containing the neutral arsenic acid (H3AsO4) molecule have been determined, including N,N,N-trimetlylglycine (beatine) arsenic acid (Schildkamp et al., 1984), tetraphenylphosphonium chloride arsenic acid (Ruhlandt-Senge et al., 1992), L-histininium dihydrogen arsenate arsenic acid (Ratajczak et al., 2000) and DL-threonine arsenic acid 1:1 (Wilkinson & Harrison, 2005). We present here the syntheses and structures of the title compounds, (C8H20N)[H2AsO4][H3AsO4]2, (I), and (C6H14N2)[H2AsO4]2[H3AsO4], (II), which both contain organic cations, dihydrogenarsenate anions and neutral arsenic acid molecules.
The structure of (I) (Fig. 1) is built up from C8H20N+ tetraethylammonium (TEA) cations, [H2AsO4]- dihydrogenarsenate anions and neutral H3AsO4 arsenic acid molecules in a 1:1:2 ratio. The N atom of the cation occupies a special position with site symmetry 1; thus the –CH2CH3 arms of the TEA species are disordered, as is often seen for this cation (Majumdar et al., 2006). The dihydrogenarsenate anion, containing As1, lies across a twofold rotation axis. The short and long As1—O bonds (Table 1) correspond to unprotonated As—O vertices with partial double bond character and to protonated AsOH groups, respectively. The neutral arsenic acid molecule in (I), containing As2, with a mean As—O distance of 1.678 (2) Å], contains one short, formal double bond (As2═O4) and three longer As—OH vertices, as seen in related structures (Wilkinson & Harrison, 2005).
As well as Coulombic and van der Waals forces, the component species in (I) interact by means of a network of O—H···O hydrogen bonds. All these bonds are short and near linear (Table 2). Pairs of arsenic acid molecules form inversion dimers via O6—H4···O4iii + O6iii—H4iii···O4 links (see Table 2 for symmetry codes. Similar dimers built up from [H2AsO4]- units have been seen in propane-1,2-diamminium hydrogenarsenate (Todd & Harrison, 2005). The As1-centred anion then serves to link the As2 dimers, by donating two O—H···O bonds and accepting two O—H···O bonds, into a sheet of tetrahedra propagating in (001) (Fig. 2). A number of unusual graph-set (Bernstein et al., 1995) loops occur within these arsenate sheets, including R23(10), R24(12) and R44(16) circuits, as well as the more familiar R22(8) inversion dimer arising from the As2 units.
The arsenate sheets sandwich the disordered organic cations in (I) (Fig. 3) to result in alternating inorganic and organic layers with respect to the c direction.
Compound (II) contains C2H14N22+ 1,4-diazoniabicyclo[2.2.2]octane dications accompanied by dihydrogenarsenate anions and arsenic acid molecules (Fig. 4), with all atoms occupying general crystallographic positions. Because the organic cation is divalent, a 1:2:1 ratio of C2H14N22+:H2AsO4-:H3AsO4 arises in (II). As in (I), the individual arsenate As—O bond lengths correlate with their protonation state (Table 3). The mean As—O distances for the As1, As2 and As3 (arsenic acid) tetrahedra are 1.679 (2), 1.681 (2) and 1.674 (2) Å, respectively
In (II), the As2-centred dihydrogenarsenate groups form inversion dimers via O—H···O bonds, which contrasts with (I), where the arsenic acid molecules formed similar dimers. The dimers are fused by further O—H···O hydrogen bonds (Table 4) to form chains of alternating As1- and As3-centred units, to result in slabs of tetrahedra propagating in [100] (Fig. 5). The graph-set loops found within the arsenate slabs in (II) include R22(8) inversion dimers, and R23(12), R33(12) and large R66(24) circuits.
The [100] slabs are crosslinked by the key O10—H10···O4iii bond (Table 4), to result in a three-dimensional hydorgen-bonded network encompassing [100] channels occupied by the organic cations. These very large channels can accommodate two organic cations side-by-side and are characterized by an R812(40) graph-set motif. In turn, the cations interact with the tetrahedral framework by way of N—H···O hydrogen bonds (Table 4). A related supramolecular hydrogen-bonded tetrahedral framework encapsulating organic cations was seen in 2-aminopyridinium dihydrogenphosphate (Czapla et al., 2003).