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n-Heptylammonium dihydrogenarsenate, (C7H18N)[As(O)2(OH)2] (C7ADA), is ferroelastic at room temperature and isostructural with n-heptylammonium dihydrogenphosphate (C7ADP). In contrast to the other known n-alkylammonium dihydrogenphosphates (CnADP) and dihydrogenarsenates (CnADA), two independent anions in the present structure are substantially disordered (∼88 and ∼12%, respectively). There are strong hydrogen bonds between the dihydrogenarsenates themselves, and moderate hydrogen bonds between the dihydrogenarsenates and the n-alkylammonium groups. The hydrogen-bond distances correspond well to those observed in the dihydrogenphosphates. There are two H atoms in the structure which are involved in asymmetric hydrogen bonds between respective oxygen pairs. These H atoms jump from the donor to the acceptor O atoms during ferroelastic switching.
Supporting information
CCDC reference: 163903
Data collection: COLLECT (Nonius BV, 1997-2000); cell refinement: HKL SCALEPACK (Otwinowski & Minor, 1997); data reduction: HKL DENZO and SCALEPACK (Otwinowski & Minor, 1997); program(s) used to refine structure: JANA2000 (Petříček & Dušek, 2000); molecular graphics: ORTEPIII (Burnett & Johnson, 1996); software used to prepare material for publication: JANA2000.
n-heptylammonium dihydrogenarsenate
top
Crystal data top
C7H18N+·[As(O)2(OH)2]− | F(000) = 1072 |
Mr = 257.16 | Dx = 1.510 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
a = 9.3261 (3) Å | Cell parameters from 24037 reflections |
b = 32.34003 (14) Å | θ = 1.0–27.5° |
c = 7.5005 (3) Å | µ = 2.99 mm−1 |
β = 90.595 (2)° | T = 290 K |
V = 2262.1 (1) Å3 | Prism, colourless |
Z = 8 | 0.22 × 0.12 × 0.05 mm |
Data collection top
Nonius KappaCCD diffractometer | 4974 independent reflections |
Radiation source: fine-focus sealed X-ray tube | 2700 reflections with I > 3σ(I) |
Graphite monochromator | Rint = 0.052 |
CCD scans | θmax = 27.5°, θmin = 1.3° |
Absorption correction: integration Gaussian integration (Coppens et al., 1965) | h = −12→12 |
Tmin = 0.614, Tmax = 0.860 | k = −42→41 |
13013 measured reflections | l = 0→9 |
Refinement top
Refinement on F | 65 restraints |
Least-squares matrix: full with fixed elements per cycle | 27 constraints |
R[F > 3σ(F)] = 0.044 | H atoms treated by a mixture of independent and constrained refinement |
wR(F) = 0.053 | Weighting scheme based on measured s.u.'s w = [σ2(Fo) + 0.0001(Fo)2]-1 |
S = 1.46 | (Δ/σ)max = 0.001 |
4972 reflections | Δρmax = 1.22 e Å−3 |
369 parameters | Δρmin = −1.07 e Å−3 |
Special details top
Experimental. rotation scans: 10 images collected by ω scans, rotation per image 10°, 202 s
exposure, crystal to detector distance 35 mm. |
Refinement. Though the structure was intended to be refined as a twin the trial measurement
on a 4-dircle diffractometer with a point detector did not indicate existence
of a second domain. Nevertheless the twinning was evidenced on other sample. The twinning matrix is
given in _diffrn_reflns_transf_matrix_ items The H atoms except of those which are bonded to the O atoms were restrained by
the distfix and anglefix functions of JANA2000: The values for distfix were
0.85(0.021) Å for O—H distances. The values for distfix were 0.90(0.022) Å for N—H distances. The values for distfix were 0.9(0.022) Å for
methyl-H distances. The values for distfix were 0.95(0.013) Å for
methylene-H distances. The values for anglefix were 109.47(1.00) ° for all
H—N—H; H—C—H angles, and 170 (2) ° for O11—HO11···O32 {1_455}. The dihydrogenarsenates are disordered (there are two independent
dihydrogenarsenates in the structure). There were made two refinements which
described the disorder. One, whose results are listed in the tables below, is
based on the assumption of the stacking faults (1/2,0,0). The second one
expressed disorder of dihydrogenarsenates which were disordered in two sites.
The geometry of the disordered molecules which were displaced by [1/2, 0, 0]
was considered to be the same, the sum in each site was supposed to equal to
1. The occupancy of the disordered molecules in each site equalled to 0.883 (1)
and its complement to 1. |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
As1 | 0.06360 (3) | 0.298272 (15) | 0.25206 (5) | 0.02414 (17) | |
O11 | −0.0637 (2) | 0.33579 (11) | 0.2237 (4) | 0.0426 (13) | |
O21 | 0.0972 (2) | 0.28957 (9) | 0.4659 (3) | 0.0367 (11) | |
O31 | 0.2013 (2) | 0.31177 (9) | 0.1279 (3) | 0.0343 (10) | |
O41 | −0.0084 (3) | 0.25314 (9) | 0.1745 (4) | 0.0355 (11) | |
As2 | 0.55964 (4) | 0.295829 (15) | 0.26254 (5) | 0.02436 (17) | |
O12 | 0.4441 (2) | 0.33554 (10) | 0.2642 (4) | 0.0412 (13) | |
O22 | 0.5958 (3) | 0.28693 (11) | 0.0428 (3) | 0.0411 (12) | |
O32 | 0.7032 (2) | 0.31035 (9) | 0.3735 (3) | 0.0349 (11) | |
O42 | 0.4876 (2) | 0.25269 (9) | 0.3404 (3) | 0.0308 (10) | |
N1 | 0.2172 (3) | 0.69637 (11) | 0.2682 (4) | 0.0300 (14) | |
C11 | 0.1382 (4) | 0.65713 (16) | 0.2479 (6) | 0.0336 (18) | |
C21 | 0.2357 (4) | 0.61974 (17) | 0.2575 (6) | 0.0380 (19) | |
C31 | 0.1529 (4) | 0.57983 (16) | 0.2468 (6) | 0.038 (2) | |
C41 | 0.2446 (4) | 0.54138 (16) | 0.2510 (6) | 0.0378 (19) | |
C51 | 0.1619 (4) | 0.50152 (17) | 0.2502 (6) | 0.039 (2) | |
C61 | 0.2510 (5) | 0.46284 (18) | 0.2553 (6) | 0.047 (2) | |
C71 | 0.1678 (5) | 0.42272 (18) | 0.2568 (7) | 0.061 (2) | |
N2 | 0.7241 (3) | 0.69623 (11) | 0.2298 (4) | 0.0310 (14) | |
C12 | 0.6425 (4) | 0.65681 (16) | 0.2504 (6) | 0.0327 (18) | |
C22 | 0.7371 (4) | 0.62007 (15) | 0.2438 (6) | 0.0332 (17) | |
C32 | 0.6541 (4) | 0.57942 (17) | 0.2508 (7) | 0.041 (2) | |
C42 | 0.7455 (5) | 0.54140 (16) | 0.2482 (6) | 0.0362 (18) | |
C52 | 0.6610 (4) | 0.50092 (17) | 0.2473 (7) | 0.042 (2) | |
C62 | 0.7525 (5) | 0.46253 (17) | 0.2457 (7) | 0.042 (2) | |
C72 | 0.6649 (5) | 0.42279 (17) | 0.2445 (7) | 0.058 (2) | |
H1n1 | 0.245 (3) | 0.6968 (11) | 0.384 (2) | 0.044 (8)* | |
H2n1 | 0.170 (3) | 0.7180 (8) | 0.245 (3) | 0.044 (8)* | |
H3n1 | 0.293 (2) | 0.6959 (10) | 0.199 (3) | 0.044 (8)* | |
H1c11 | 0.084 (2) | 0.6558 (13) | 0.352 (2) | 0.047 (6)* | |
H2c11 | 0.079 (2) | 0.6512 (13) | 0.148 (2) | 0.047 (6)* | |
H1c21 | 0.294 (3) | 0.6238 (14) | 0.156 (2) | 0.058 (7)* | |
H2c21 | 0.295 (3) | 0.6198 (14) | 0.359 (2) | 0.058 (7)* | |
H1c31 | 0.092 (2) | 0.5789 (14) | 0.348 (2) | 0.048 (6)* | |
H2c31 | 0.097 (2) | 0.5760 (13) | 0.141 (2) | 0.048 (6)* | |
H1c41 | 0.308 (2) | 0.5418 (13) | 0.152 (2) | 0.048 (6)* | |
H2c41 | 0.301 (2) | 0.5402 (13) | 0.359 (2) | 0.048 (6)* | |
H1c51 | 0.105 (2) | 0.5037 (12) | 0.145 (2) | 0.038 (5)* | |
H2c51 | 0.101 (2) | 0.5025 (13) | 0.350 (2) | 0.038 (5)* | |
H1c61 | 0.300 (3) | 0.4616 (13) | 0.145 (2) | 0.049 (7)* | |
H2c61 | 0.319 (2) | 0.4656 (14) | 0.349 (2) | 0.049 (7)* | |
H1c71 | 0.097 (3) | 0.4245 (13) | 0.353 (3) | 0.079 (6)* | |
H2c71 | 0.219 (4) | 0.3977 (10) | 0.267 (4) | 0.079 (6)* | |
H3c71 | 0.119 (3) | 0.4232 (13) | 0.144 (3) | 0.079 (6)* | |
H1n2 | 0.782 (2) | 0.6946 (9) | 0.319 (3) | 0.034 (7)* | |
H2n2 | 0.664 (3) | 0.7180 (8) | 0.246 (3) | 0.034 (7)* | |
H3n2 | 0.775 (2) | 0.7002 (9) | 0.130 (2) | 0.034 (7)* | |
H1c12 | 0.588 (2) | 0.6588 (13) | 0.355 (2) | 0.047 (6)* | |
H2c12 | 0.581 (2) | 0.6578 (13) | 0.151 (2) | 0.047 (6)* | |
H1c22 | 0.787 (3) | 0.6211 (14) | 0.136 (2) | 0.058 (7)* | |
H2c22 | 0.804 (2) | 0.6199 (14) | 0.341 (3) | 0.058 (7)* | |
H1c32 | 0.591 (2) | 0.5774 (14) | 0.349 (2) | 0.048 (6)* | |
H2c32 | 0.602 (2) | 0.5769 (14) | 0.144 (2) | 0.048 (6)* | |
H1c42 | 0.792 (2) | 0.5416 (13) | 0.136 (2) | 0.048 (6)* | |
H2c42 | 0.817 (2) | 0.5417 (13) | 0.340 (2) | 0.048 (6)* | |
H1c52 | 0.600 (2) | 0.5016 (12) | 0.143 (2) | 0.038 (5)* | |
H2c52 | 0.604 (2) | 0.5005 (13) | 0.350 (2) | 0.038 (5)* | |
H1c62 | 0.820 (2) | 0.4658 (14) | 0.153 (2) | 0.049 (7)* | |
H2c62 | 0.802 (3) | 0.4617 (13) | 0.358 (2) | 0.049 (7)* | |
H1c72 | 0.597 (3) | 0.4203 (13) | 0.346 (3) | 0.079 (6)* | |
H2c72 | 0.731 (4) | 0.4004 (11) | 0.248 (4) | 0.079 (6)* | |
H3c72 | 0.612 (3) | 0.4222 (13) | 0.136 (3) | 0.079 (6)* | |
Ho12 | 0.360 (2) | 0.3273 (11) | 0.240 (4) | 0.018 (11)* | |
Ho22 | 0.611 (6) | 0.2631 (10) | −0.009 (6) | 0.13 (2)* | |
Ho41 | −0.002 (4) | 0.2451 (14) | 0.063 (3) | 0.065 (16)* | |
Ho11 | −0.131 (2) | 0.3247 (11) | 0.282 (5) | 0.064 (17)* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
As1 | 0.0220 (2) | 0.0281 (3) | 0.0226 (2) | −0.0013 (2) | 0.00170 (18) | 0.0029 (2) |
O11 | 0.0260 (16) | 0.041 (2) | 0.061 (2) | 0.0058 (16) | 0.0077 (15) | 0.0180 (17) |
O21 | 0.0491 (17) | 0.041 (2) | 0.0203 (16) | −0.0029 (14) | −0.0037 (13) | 0.0063 (13) |
O31 | 0.0236 (14) | 0.048 (2) | 0.0314 (17) | −0.0088 (14) | 0.0065 (12) | 0.0016 (14) |
O41 | 0.0472 (16) | 0.030 (2) | 0.0292 (19) | −0.0120 (15) | 0.0065 (14) | −0.0019 (14) |
As2 | 0.0227 (2) | 0.0284 (3) | 0.0222 (2) | −0.0014 (2) | −0.00044 (18) | −0.0013 (2) |
O12 | 0.0298 (18) | 0.027 (2) | 0.067 (2) | −0.0009 (16) | −0.0076 (15) | −0.0059 (16) |
O22 | 0.063 (2) | 0.039 (2) | 0.0217 (17) | −0.0042 (17) | 0.0081 (14) | 0.0011 (15) |
O32 | 0.0227 (14) | 0.049 (2) | 0.0330 (18) | −0.0075 (14) | −0.0055 (12) | 0.0010 (14) |
O42 | 0.0375 (15) | 0.029 (2) | 0.0256 (17) | −0.0084 (14) | −0.0006 (12) | 0.0023 (13) |
N1 | 0.0227 (18) | 0.032 (3) | 0.035 (2) | 0.0039 (18) | −0.0040 (15) | 0.0010 (17) |
C11 | 0.030 (2) | 0.033 (3) | 0.038 (3) | −0.006 (2) | −0.004 (2) | 0.002 (2) |
C21 | 0.030 (2) | 0.034 (3) | 0.050 (3) | −0.002 (2) | 0.001 (2) | 0.004 (2) |
C31 | 0.036 (2) | 0.026 (3) | 0.051 (3) | 0.003 (2) | −0.002 (2) | 0.000 (2) |
C41 | 0.038 (2) | 0.030 (3) | 0.045 (3) | −0.010 (2) | −0.001 (2) | −0.001 (2) |
C51 | 0.043 (2) | 0.032 (3) | 0.043 (3) | −0.003 (2) | 0.004 (2) | 0.004 (2) |
C61 | 0.057 (3) | 0.041 (4) | 0.042 (3) | 0.006 (3) | 0.003 (2) | −0.002 (2) |
C71 | 0.081 (4) | 0.029 (4) | 0.072 (4) | 0.003 (3) | −0.006 (3) | −0.003 (2) |
N2 | 0.035 (2) | 0.028 (2) | 0.030 (2) | 0.006 (2) | 0.0004 (16) | 0.0025 (17) |
C12 | 0.027 (2) | 0.030 (3) | 0.042 (3) | 0.003 (2) | 0.006 (2) | 0.000 (2) |
C22 | 0.033 (2) | 0.027 (3) | 0.040 (3) | 0.002 (2) | 0.001 (2) | 0.000 (2) |
C32 | 0.037 (2) | 0.033 (4) | 0.054 (3) | −0.006 (2) | 0.000 (2) | 0.002 (2) |
C42 | 0.041 (2) | 0.031 (3) | 0.036 (3) | 0.003 (2) | 0.003 (2) | 0.002 (2) |
C52 | 0.040 (2) | 0.031 (4) | 0.056 (3) | −0.002 (2) | −0.006 (2) | −0.001 (2) |
C62 | 0.049 (2) | 0.033 (3) | 0.045 (3) | 0.000 (3) | 0.002 (2) | 0.004 (2) |
C72 | 0.080 (4) | 0.031 (4) | 0.065 (4) | −0.007 (3) | −0.007 (3) | 0.008 (2) |
Geometric parameters (Å, º) top
As1—O11 | 1.709 (3) | C61—H2c61 | 0.95 (2) |
As1—O21 | 1.655 (2) | C71—H1c71 | 0.98 (3) |
As1—O31 | 1.653 (2) | C71—H2c71 | 0.94 (3) |
As1—O41 | 1.707 (3) | C71—H3c71 | 0.96 (2) |
As2—O12 | 1.677 (3) | O11—Ho11 | 0.84 (3) |
As2—O22 | 1.710 (3) | O41—Ho41 | 0.88 (2) |
As2—O32 | 1.638 (2) | O12—Ho12 | 0.84 (2) |
As2—O42 | 1.657 (2) | O22—Ho22 | 0.88 (4) |
N1—C11 | 1.475 (6) | N2—H1n2 | 0.86 (2) |
C11—C21 | 1.514 (7) | N2—H2n2 | 0.91 (2) |
C21—C31 | 1.506 (7) | N2—H3n2 | 0.90 (2) |
C31—C41 | 1.509 (7) | C12—H1c12 | 0.95 (2) |
C41—C51 | 1.502 (7) | C12—H2c12 | 0.94 (2) |
C51—C61 | 1.502 (7) | C22—H1c22 | 0.94 (2) |
C61—C71 | 1.512 (8) | C22—H2c22 | 0.95 (2) |
N2—C12 | 1.493 (6) | C32—H1c32 | 0.95 (2) |
C12—C22 | 1.481 (6) | C32—H2c32 | 0.94 (2) |
C22—C32 | 1.527 (7) | C42—H1c42 | 0.95 (2) |
C32—C42 | 1.496 (7) | C42—H2c42 | 0.95 (2) |
C42—C52 | 1.528 (7) | C52—H1c52 | 0.96 (2) |
C52—C62 | 1.506 (7) | C52—H2c52 | 0.94 (2) |
C62—C72 | 1.523 (7) | C62—H1c62 | 0.95 (2) |
N1—H1n1 | 0.90 (2) | C62—H2c62 | 0.96 (2) |
N1—H2n1 | 0.84 (2) | C72—H1c72 | 1.00 (3) |
N1—H3n1 | 0.88 (2) | C72—H2c72 | 0.95 (3) |
C11—H1c11 | 0.94 (2) | C72—H3c72 | 0.95 (2) |
C11—H2c11 | 0.95 (2) | O11—O32i | 2.592 (4) |
C21—H1c21 | 0.95 (2) | O21—O22ii | 2.541 (5) |
C21—H2c21 | 0.94 (2) | O31—O12 | 2.591 (4) |
C31—H1c31 | 0.95 (2) | O41—O42iii | 2.513 (4) |
C31—H2c31 | 0.95 (2) | N1—O22iv | 2.976 (5) |
C41—H1c41 | 0.95 (2) | N1—O32v | 2.789 (4) |
C41—H2c41 | 0.96 (2) | N1—O42vi | 2.756 (4) |
C51—H1c51 | 0.95 (2) | N2—O21v | 2.850 (4) |
C51—H2c51 | 0.94 (2) | N2—O31iv | 2.791 (4) |
C61—H1c61 | 0.95 (2) | N2—O41vi | 2.824 (5) |
| | | |
O11—As1—O21 | 111.45 (15) | O12—As2—O22 | 105.62 (16) |
O11—As1—O31 | 106.57 (15) | O12—As2—O32 | 107.37 (15) |
O11—As1—O41 | 107.11 (14) | O12—As2—O42 | 112.28 (14) |
O21—As1—O31 | 116.75 (13) | O22—As2—O32 | 111.70 (14) |
O21—As1—O41 | 104.77 (15) | O22—As2—O42 | 106.42 (15) |
O31—As1—O41 | 109.84 (15) | O32—As2—O42 | 113.24 (14) |
Symmetry codes: (i) x−1, y, z; (ii) x−1/2, −y+1/2, z+1/2; (iii) x−1/2, −y+1/2, z−1/2; (iv) −x+1, −y+1, −z; (v) −x+1, −y+1, −z+1; (vi) −x+1/2, y+1/2, −z+1/2. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | D···A | D—H···A |
O11—HO11···O32i | 0.84 (3) | 2.592 (4) | 166 (3) |
O41—HO41···O42iii | 0.88 (3) | 2.513 (4) | 159 (4) |
O12—HO12···O31 | 0.84 (2) | 2.591 (4) | 164 (3) |
O22—HO22···O21vii | 0.88 (4) | 2.541 (5) | 155 (5) |
N1—H3n1···O22iv | 0.88 (3) | 2.976 (5) | 152 (3) |
N1—H1n1···O32v | 0.90 (2) | 2.789 (4) | 172 (3) |
N1—H2n1···O42vi | 0.84 (3) | 2.756 (4) | 159 (3) |
N2—H1n2···O21v | 0.86 (2) | 2.850 (4) | 161 (3) |
N2—H3n2···O31iv | 0.90 (2) | 2.791 (4) | 148 (2) |
N2—H2n2···O41vi | 0.91 (3) | 2.824 (5) | 164 (3) |
Symmetry codes: (i) x−1, y, z; (iii) x−1/2, −y+1/2, z−1/2; (iv) −x+1, −y+1, −z; (v) −x+1, −y+1, −z+1; (vi) −x+1/2, y+1/2, −z+1/2; (vii) x+1/2, −y+1/2, z−1/2. |
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