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The title salt, NH4+·C8H11O4-, contains tetrahedrally coordinated ammonium ions and monodeprotonated anions of rac-trans-1,2-cyclohexanedicarboxylic acid. In the anions, carboxylic acid and carboxylate fragments are identified by their clearly differentiated C-O bond distances. The cations and anions form columns along the b axis, which are arranged in the crystal structure to give tilted, alternating hydrophobic (back-to-back cyclohexyl) and hydrophilic (ammonium, carboxylate and carboxylic acid) layers stacked along the a direction. The ammonium ion utilizes each of its four H atoms to form five hydrogen bonds with the negatively charged carboxylate O atoms. A hydrogen bond between a carboxylate O atom and the hydroxyl group of the carboxylic acid fragment completes an extensive interionic hydrogen-bonding network.
Supporting information
CCDC reference: 242330
Key indicators
- Single-crystal X-ray study
- T = 297 K
- Mean (C-C) = 0.004 Å
- R factor = 0.054
- wR factor = 0.154
- Data-to-parameter ratio = 9.7
checkCIF/PLATON results
No syntax errors found
Alert level B
ABSTM02_ALERT_3_B The ratio of expected to reported Tmax/Tmin(RR') is < 0.75
Tmin and Tmax reported: 0.678 1.000
Tmin' and Tmax expected: 0.947 0.998
RR' = 0.714
Please check that your absorption correction is appropriate.
PLAT061_ALERT_3_B Tmax/Tmin Range Test RR' too Large ............. 0.71
Alert level C
PLAT088_ALERT_3_C Poor Data / Parameter Ratio .................... 9.72
PLAT242_ALERT_2_C Check Low U(eq) as Compared to Neighbors .... C7
0 ALERT level A = In general: serious problem
2 ALERT level B = Potentially serious problem
2 ALERT level C = Check and explain
0 ALERT level G = General alerts; check
0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
1 ALERT type 2 Indicator that the structure model may be wrong or deficient
3 ALERT type 3 Indicator that the structure quality may be low
0 ALERT type 4 Improvement, methodology, query or suggestion
Data collection: SMART (Bruker, 2000); cell refinement: SMART; data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPIII (Burnett & Johnson, 1996) and ORTEP-32 (Farrugia, 1997); software used to prepare material for publication: SHELXTL (Bruker, 2000).
rac-ammonium
trans-2-carboxycyclohexanecarboxylate
top
Crystal data top
NH4+·C8H11O4− | F(000) = 408 |
Mr = 189.21 | Dx = 1.295 Mg m−3 |
Monoclinic, P21/c | Melting point: 493 K K |
Hall symbol: -P 2ybc | Mo Kα radiation, λ = 0.71073 Å |
a = 15.712 (7) Å | Cell parameters from 710 reflections |
b = 6.141 (3) Å | θ = 2.7–21.4° |
c = 10.464 (5) Å | µ = 0.10 mm−1 |
β = 104.96 (4)° | T = 297 K |
V = 975.5 (8) Å3 | Plate, colorless |
Z = 4 | 0.52 × 0.28 × 0.02 mm |
Data collection top
Bruker SMART CCD area-detector diffractometer | 1731 independent reflections |
Radiation source: fine-focus sealed tube | 1155 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.058 |
φ and ω scans | θmax = 25.1°, θmin = 2.7° |
Absorption correction: multi-scan (SADABS, Blessing, 1995) | h = −18→18 |
Tmin = 0.678, Tmax = 1.00 | k = −7→7 |
6692 measured reflections | l = −11→12 |
Refinement top
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)] = 0.054 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.154 | All H-atom parameters refined |
S = 1.00 | w = 1/[σ2(Fo2) + (0.0903P)2] where P = (Fo2 + 2Fc2)/3 |
1731 reflections | (Δ/σ)max < 0.001 |
178 parameters | Δρmax = 0.23 e Å−3 |
0 restraints | Δρmin = −0.18 e Å−3 |
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 | |
O1 | 0.36646 (13) | 0.4072 (4) | 0.8366 (2) | 0.0871 (8) | |
O2 | 0.26140 (12) | 0.1685 (3) | 0.76074 (18) | 0.0679 (6) | |
O3 | 0.40577 (11) | 0.8115 (3) | 1.04577 (18) | 0.0668 (6) | |
O4 | 0.36775 (10) | 0.5274 (3) | 1.14467 (15) | 0.0560 (5) | |
N | 0.50664 (17) | 0.8000 (5) | 0.8588 (2) | 0.0496 (6) | |
C1 | 0.23173 (14) | 0.4412 (4) | 0.9014 (2) | 0.0456 (6) | |
C2 | 0.26233 (14) | 0.6663 (4) | 0.9544 (2) | 0.0450 (6) | |
C3 | 0.19661 (17) | 0.7735 (5) | 1.0198 (3) | 0.0576 (7) | |
C4 | 0.1036 (2) | 0.7731 (7) | 0.9319 (4) | 0.0818 (10) | |
C5 | 0.0747 (2) | 0.5473 (7) | 0.8875 (4) | 0.0818 (11) | |
C6 | 0.13675 (17) | 0.4425 (7) | 0.8155 (3) | 0.0651 (8) | |
C7 | 0.29450 (15) | 0.3406 (4) | 0.8308 (2) | 0.0476 (6) | |
C8 | 0.35197 (15) | 0.6669 (4) | 1.0533 (2) | 0.0445 (6) | |
H1 | 0.2367 (14) | 0.350 (4) | 0.978 (2) | 0.045 (6)* | |
H2 | 0.2666 (16) | 0.757 (4) | 0.878 (3) | 0.061 (7)* | |
H31 | 0.2022 (14) | 0.694 (4) | 1.105 (3) | 0.053 (7)* | |
H32 | 0.2191 (18) | 0.919 (5) | 1.043 (3) | 0.072 (9)* | |
H41 | 0.063 (3) | 0.830 (6) | 0.980 (4) | 0.110 (12)* | |
H42 | 0.100 (2) | 0.862 (5) | 0.855 (3) | 0.083 (10)* | |
H51 | 0.077 (2) | 0.455 (5) | 0.970 (3) | 0.082 (9)* | |
H52 | 0.017 (3) | 0.546 (5) | 0.833 (3) | 0.095 (10)* | |
H61 | 0.1205 (19) | 0.294 (5) | 0.794 (3) | 0.075 (9)* | |
H62 | 0.1334 (19) | 0.514 (5) | 0.733 (3) | 0.079 (9)* | |
H2O | 0.306 (2) | 0.108 (5) | 0.725 (3) | 0.096 (11)* | |
H51N | 0.471 (2) | 0.822 (4) | 0.785 (3) | 0.069 (9)* | |
H52N | 0.550 (2) | 0.690 (6) | 0.862 (3) | 0.093 (11)* | |
H53N | 0.473 (2) | 0.783 (5) | 0.914 (3) | 0.073 (9)* | |
H54N | 0.539 (2) | 0.913 (5) | 0.883 (3) | 0.072 (10)* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
O1 | 0.0594 (13) | 0.0984 (16) | 0.1176 (17) | −0.0311 (11) | 0.0484 (11) | −0.0500 (13) |
O2 | 0.0594 (12) | 0.0698 (14) | 0.0782 (12) | −0.0123 (10) | 0.0247 (10) | −0.0291 (10) |
O3 | 0.0613 (12) | 0.0705 (13) | 0.0734 (12) | −0.0289 (10) | 0.0263 (9) | −0.0155 (9) |
O4 | 0.0444 (10) | 0.0695 (12) | 0.0516 (9) | 0.0018 (8) | 0.0080 (7) | 0.0121 (9) |
N | 0.0458 (14) | 0.0544 (15) | 0.0472 (13) | −0.0041 (13) | 0.0094 (12) | −0.0001 (11) |
C1 | 0.0430 (13) | 0.0538 (15) | 0.0406 (12) | −0.0078 (11) | 0.0119 (10) | −0.0013 (12) |
C2 | 0.0458 (14) | 0.0457 (14) | 0.0427 (12) | −0.0006 (11) | 0.0101 (10) | 0.0020 (11) |
C3 | 0.0527 (16) | 0.0572 (18) | 0.0609 (16) | 0.0093 (13) | 0.0111 (12) | −0.0043 (15) |
C4 | 0.060 (2) | 0.101 (3) | 0.082 (2) | 0.0281 (19) | 0.0125 (16) | −0.002 (2) |
C5 | 0.0366 (16) | 0.123 (3) | 0.084 (2) | −0.0010 (17) | 0.0118 (15) | −0.022 (2) |
C6 | 0.0411 (15) | 0.092 (3) | 0.0604 (17) | −0.0104 (15) | 0.0107 (12) | −0.0174 (17) |
C7 | 0.0434 (14) | 0.0558 (16) | 0.0433 (12) | −0.0097 (12) | 0.0105 (10) | −0.0071 (11) |
C8 | 0.0452 (13) | 0.0487 (14) | 0.0434 (12) | −0.0059 (12) | 0.0180 (10) | −0.0092 (11) |
Geometric parameters (Å, º) top
O1—C7 | 1.189 (3) | C2—C3 | 1.528 (4) |
O2—C7 | 1.315 (3) | C2—H2 | 0.99 (3) |
O2—H2O | 0.95 (4) | C3—C4 | 1.512 (4) |
O3—C8 | 1.243 (3) | C3—H31 | 1.01 (3) |
O4—C8 | 1.260 (3) | C3—H32 | 0.97 (3) |
N—H51N | 0.84 (3) | C4—C5 | 1.496 (5) |
N—H52N | 0.95 (4) | C4—H41 | 0.97 (4) |
N—H53N | 0.88 (3) | C4—H42 | 0.96 (3) |
N—H54N | 0.85 (4) | C5—C6 | 1.521 (4) |
C1—C7 | 1.509 (3) | C5—H51 | 1.02 (3) |
C1—C2 | 1.521 (3) | C5—H52 | 0.93 (4) |
C1—C6 | 1.531 (4) | C6—H61 | 0.96 (3) |
C1—H1 | 0.96 (2) | C6—H62 | 0.96 (3) |
C2—C8 | 1.517 (3) | | |
| | | |
C7—O2—H2O | 108 (2) | C5—C4—C3 | 111.0 (3) |
H51N—N—H52N | 117 (3) | C5—C4—H41 | 108 (2) |
H51N—N—H53N | 104 (3) | C3—C4—H41 | 110 (2) |
H52N—N—H53N | 116 (3) | C5—C4—H42 | 108.3 (18) |
H51N—N—H54N | 110 (3) | C3—C4—H42 | 110.5 (19) |
H52N—N—H54N | 102 (3) | H41—C4—H42 | 109 (3) |
H53N—N—H54N | 108 (3) | C4—C5—C6 | 111.3 (3) |
C7—C1—C2 | 111.45 (19) | C4—C5—H51 | 108.0 (17) |
C7—C1—C6 | 112.06 (19) | C6—C5—H51 | 106.9 (17) |
C2—C1—C6 | 112.2 (2) | C4—C5—H52 | 112 (2) |
C7—C1—H1 | 104.1 (13) | C6—C5—H52 | 110 (2) |
C2—C1—H1 | 106.1 (12) | H51—C5—H52 | 109 (3) |
C6—C1—H1 | 110.4 (13) | C5—C6—C1 | 111.3 (2) |
C8—C2—C1 | 113.65 (19) | C5—C6—H61 | 110.5 (17) |
C8—C2—C3 | 108.03 (19) | C1—C6—H61 | 107.0 (17) |
C1—C2—C3 | 111.6 (2) | C5—C6—H62 | 111.1 (17) |
C8—C2—H2 | 107.8 (15) | C1—C6—H62 | 110.5 (18) |
C1—C2—H2 | 107.2 (14) | H61—C6—H62 | 106 (3) |
C3—C2—H2 | 108.4 (15) | O1—C7—O2 | 122.6 (2) |
C4—C3—C2 | 112.7 (3) | O1—C7—C1 | 124.6 (2) |
C4—C3—H31 | 113.0 (13) | O2—C7—C1 | 112.8 (2) |
C2—C3—H31 | 106.0 (13) | O3—C8—O4 | 122.0 (2) |
C4—C3—H32 | 112.8 (16) | O3—C8—C2 | 119.1 (2) |
C2—C3—H32 | 105.5 (16) | O4—C8—C2 | 118.8 (2) |
H31—C3—H32 | 106 (2) | | |
| | | |
C7—C1—C2—C8 | −60.4 (3) | C2—C1—C6—C5 | −52.9 (4) |
C6—C1—C2—C8 | 173.0 (2) | C2—C1—C7—O1 | 13.3 (3) |
C7—C1—C2—C3 | 177.10 (19) | C6—C1—C7—O1 | 140.0 (3) |
C6—C1—C2—C3 | 50.5 (3) | C2—C1—C7—O2 | −166.66 (19) |
C8—C2—C3—C4 | −177.5 (3) | C6—C1—C7—O2 | −40.0 (3) |
C1—C2—C3—C4 | −51.8 (3) | C1—C2—C8—O3 | 137.3 (2) |
C2—C3—C4—C5 | 55.3 (4) | C3—C2—C8—O3 | −98.3 (3) |
C3—C4—C5—C6 | −57.3 (5) | C1—C2—C8—O4 | −46.4 (3) |
C4—C5—C6—C1 | 56.3 (4) | C3—C2—C8—O4 | 78.0 (3) |
C7—C1—C6—C5 | −179.2 (3) | | |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2O···O4i | 0.95 (3) | 1.66 (3) | 2.601 (3) | 169 (3) |
N—H51N···O3ii | 0.84 (3) | 2.58 (3) | 3.321 (3) | 148 (2) |
N—H51N···O4ii | 0.84 (3) | 2.10 (3) | 2.895 (3) | 158 (3) |
N—H52N···O4iii | 0.95 (3) | 1.87 (3) | 2.824 (4) | 176 (3) |
N—H53N···O3 | 0.88 (3) | 1.95 (3) | 2.819 (3) | 168 (3) |
N—H54N···O3iv | 0.86 (3) | 1.96 (4) | 2.806 (3) | 169 (3) |
C1—H1···O4 | 0.96 (2) | 2.57 (2) | 2.919 (3) | 101.3 (16) |
Symmetry codes: (i) x, −y+1/2, z−1/2; (ii) x, −y+3/2, z−1/2; (iii) −x+1, −y+1, −z+2; (iv) −x+1, −y+2, −z+2. |
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