organic compounds
Ammonium hexafluoridophosphate–18-crown-6 (1/1)
aCollege of Chemistry and Chemical Engineering, Southeast University, Nanjing 210096, People's Republic of China
*Correspondence e-mail: wudh1971@sohu.com
In the 4+·PF6−·C12H24O6, the cation is situated in the 18-crown-6 ring, forming a supramolecular rotator-stator-like structure held by N—H⋯O hydrogen bonds. The six O atoms of the crown ether lie approximately in a plane [mean deviation 0.2129 (3) Å]; the N atom is displaced by 0.864 (3)Å from the centroid of the 18-crown-6 ring. The slightly distorted tetrahedral cations further interact with the slightly distorted octahedral anions via intermolecular N—H⋯F hydrogen bonds.
of the title compound, NHRelated literature
For background to 18-crown-6 compounds, see: Bajaj & Poonia (1988); Fender et al. (2002); Kryatova et al. (2004). For related structures. see: Dapporto et al. (1996); Pears et al. (1988).
Experimental
Crystal data
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Refinement
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Data collection: CrystalClear (Rigaku, 2005); cell CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL.
Supporting information
https://doi.org/10.1107/S160053681002920X/jh2185sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S160053681002920X/jh2185Isup2.hkl
In room temperature 18-crown-6 (4 mmol, 1.05 g) were dissolved in 50 ml me thanol, after addition of excess hexafluorophosphoric acid to afford a white microcrystallic precipitation for H3O+?PF6-(18-crown-6) (about 95% yield). Then dissolve the precipitation again in 50 ml water and addition of excess concentrated ammonia to afford the solution without any participation under stirring at the ambient temperature. Block colorless single crystals suitable for X-ray structure analysis were obtained by the slow evaporation of the above solution after a week in air.
The ε = C/(T–T0)), suggesting that this compound is not ferroelectric or there may be no distinct occurring within the measured temperature range between 93 K and433 K (below the compound melting point 463 K).
of the compound as a function of temperature indicates that the permittivity is basically temperature-independent (H atoms in the crown ring were placed in calculated positions with C—H = 0.97 Å for Csp3 atoms, assigned fixed Uiso values [Uiso(H) = 1.2Ueq(Csp3)] and allowed to ride. The four H atoms of NH4+ were found with N—H bond distances of between 0.7721 and 0.8282 Å in the difference electron density map.
Recently much attention has been devoted to
due to their ability to form non-covalent, H-bonding complexes with ammonium cations both in solid and in solution (Bajaj et al., 1988; Fender et al., 2002; Kryatova et al., 2004). Both the nature of the ammonium cation (NH4+,RNH3+, R2NH2+, etc.) and the size of the crown ether can work on the stability and stoichiometry of these host–guest complexes. The host molecules combine with the guest species by intermolecular interaction, 18-Crown-6 has a high affinity for RNH3+cations and most studies of 18-crown-6 and its derivatives invariably showed a 1:1 stoichiometry with RNH3+ cations. For similar structures, see: Dapporto et al., 1996; Pears et al., 1988. In our laboratory, the title compound has been synthesized and its is herein reported.The title compound crystallizes in the P21/n
with an consisting of a cationic [(NH4)(18-crown-6)]+ moiety and an isolated anionic PF6-(Fig 1). The NH4+ nests in the 18-crown-6 ring to form a superamolecular rotator-stator-like structure by intramolecular N—H···O hydrogen-bonded interactions between the NH4+ (H1C, H1D and H1F)and the six oxygen atoms of the crown ether (Fig 2). Intramolecular N—H···O hydrogen distances fall within the normal range: 2.871 (3) and 3.018 (3) Å (Table 1). The six oxygen atoms of the crown ether lie approximately in a plane with the mean deviation of 0.2129 Å, the N atom aparts from the center of the crown ring about 0.864 Å. The slightly distorted tetrahedralcations NH4+ further interact with F1i and F3i (symmetry code, i: 1 - x, 1 - y, -z) of the slightly distorted octahedral anions PF6- (The P—F bond lengths are within the range of 1.51 - 1.60 Å, the F—P—F bond angles are within the range of 87.78 - 92.48°) by intermolecular N—H···F hydrogen bonds (Table 1 and Fig 2).For background to 18-crown-6 compounds, see: Bajaj et al. (1988); Fender et al. (2002); Kryatova et al. (2004). For related structures. see: Dapporto et al. (1996); Pears et al. (1988).
Data collection: CrystalClear (Rigaku, 2005); cell
CrystalClear (Rigaku, 2005); data reduction: CrystalClear (Rigaku, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).Fig. 1. The molecular structure of the title compound, showing the atomic numbering scheme with 30% probability displacement ellipsoids. | |
Fig. 2. The packing of the title compound viewed along the b axis. The i suffix for atoms F1 and F3 denotes a transformation of (1 - x, 1 - y, -z). Hydrogen atoms not involved in hydrogen bonds (dashed lines) are omitted for clarity. |
NH4+·PF6−·C12H24O6 | F(000) = 896 |
Mr = 427.32 | Dx = 1.391 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yn | Cell parameters from 14970 reflections |
a = 12.559 (3) Å | θ = 3.0–27.8° |
b = 8.7352 (17) Å | µ = 0.21 mm−1 |
c = 18.6511 (17) Å | T = 298 K |
β = 94.097 (10)° | Block, colorless |
V = 2040.9 (7) Å3 | 0.40 × 0.36 × 0.30 mm |
Z = 4 |
Rigaku Mercury2 diffractometer | 4014 independent reflections |
Radiation source: fine-focus sealed tube | 2740 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.044 |
Detector resolution: 13.6612 pixels mm-1 | θmax = 26.0°, θmin = 3.0° |
CCD_Profile_fitting scans | h = −15→15 |
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005) | k = −10→10 |
Tmin = 0.920, Tmax = 0.940 | l = −23→23 |
18388 measured reflections |
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)] = 0.060 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.160 | H-atom parameters constrained |
S = 1.04 | w = 1/[σ2(Fo2) + (0.0668P)2 + 1.0944P] where P = (Fo2 + 2Fc2)/3 |
4014 reflections | (Δ/σ)max < 0.001 |
239 parameters | Δρmax = 0.35 e Å−3 |
0 restraints | Δρmin = −0.27 e Å−3 |
NH4+·PF6−·C12H24O6 | V = 2040.9 (7) Å3 |
Mr = 427.32 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 12.559 (3) Å | µ = 0.21 mm−1 |
b = 8.7352 (17) Å | T = 298 K |
c = 18.6511 (17) Å | 0.40 × 0.36 × 0.30 mm |
β = 94.097 (10)° |
Rigaku Mercury2 diffractometer | 4014 independent reflections |
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005) | 2740 reflections with I > 2σ(I) |
Tmin = 0.920, Tmax = 0.940 | Rint = 0.044 |
18388 measured reflections |
R[F2 > 2σ(F2)] = 0.060 | 0 restraints |
wR(F2) = 0.160 | H-atom parameters constrained |
S = 1.04 | Δρmax = 0.35 e Å−3 |
4014 reflections | Δρmin = −0.27 e Å−3 |
239 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 | ||
C1 | 0.9000 (3) | 0.5093 (4) | 0.18932 (18) | 0.0655 (9) | |
H1A | 0.9538 | 0.4465 | 0.2150 | 0.079* | |
H1B | 0.8914 | 0.4736 | 0.1400 | 0.079* | |
C2 | 0.7979 (3) | 0.4959 (3) | 0.22323 (17) | 0.0642 (9) | |
H2A | 0.7804 | 0.3888 | 0.2295 | 0.077* | |
H2B | 0.8038 | 0.5441 | 0.2702 | 0.077* | |
C3 | 0.6165 (3) | 0.5644 (4) | 0.20892 (18) | 0.0660 (9) | |
H3A | 0.6212 | 0.6175 | 0.2547 | 0.079* | |
H3B | 0.5959 | 0.4592 | 0.2171 | 0.079* | |
C4 | 0.5360 (3) | 0.6394 (4) | 0.1589 (2) | 0.0739 (10) | |
H4A | 0.5371 | 0.5935 | 0.1116 | 0.089* | |
H4B | 0.4654 | 0.6249 | 0.1757 | 0.089* | |
C5 | 0.4855 (3) | 0.8783 (5) | 0.1069 (2) | 0.0886 (12) | |
H5A | 0.4135 | 0.8634 | 0.1212 | 0.106* | |
H5B | 0.4889 | 0.8384 | 0.0586 | 0.106* | |
C6 | 0.5118 (3) | 1.0437 (5) | 0.1080 (2) | 0.0931 (14) | |
H6A | 0.4575 | 1.0999 | 0.0793 | 0.112* | |
H6B | 0.5138 | 1.0819 | 0.1569 | 0.112* | |
C7 | 0.6458 (4) | 1.2199 (4) | 0.0808 (2) | 0.0938 (15) | |
H7A | 0.6540 | 1.2563 | 0.1300 | 0.113* | |
H7B | 0.5920 | 1.2822 | 0.0547 | 0.113* | |
C8 | 0.7494 (5) | 1.2330 (4) | 0.0468 (2) | 0.0967 (16) | |
H8A | 0.7437 | 1.1844 | −0.0001 | 0.116* | |
H8B | 0.7670 | 1.3400 | 0.0403 | 0.116* | |
C9 | 0.9326 (4) | 1.1636 (4) | 0.0621 (2) | 0.0895 (14) | |
H9A | 0.9540 | 1.2689 | 0.0549 | 0.107* | |
H9B | 0.9277 | 1.1127 | 0.0158 | 0.107* | |
C10 | 1.0131 (3) | 1.0861 (4) | 0.1110 (2) | 0.0822 (12) | |
H10A | 1.0832 | 1.0972 | 0.0928 | 0.099* | |
H10B | 1.0150 | 1.1331 | 0.1582 | 0.099* | |
C11 | 1.0631 (3) | 0.8462 (5) | 0.1619 (2) | 0.0795 (11) | |
H11A | 1.0637 | 0.8851 | 0.2106 | 0.095* | |
H11B | 1.1341 | 0.8587 | 0.1453 | 0.095* | |
C12 | 1.0335 (3) | 0.6825 (5) | 0.1605 (2) | 0.0787 (11) | |
H12A | 1.0287 | 0.6452 | 0.1114 | 0.094* | |
H12B | 1.0876 | 0.6234 | 0.1880 | 0.094* | |
F1 | 0.17131 (17) | 0.4032 (3) | 0.03130 (14) | 0.1043 (8) | |
F2 | 0.18504 (19) | 0.3563 (3) | 0.14865 (13) | 0.1016 (8) | |
F3 | 0.26429 (15) | 0.2017 (2) | 0.07209 (11) | 0.0776 (6) | |
F4 | 0.36548 (17) | 0.3544 (2) | 0.14682 (12) | 0.0929 (7) | |
F5 | 0.34845 (19) | 0.4032 (3) | 0.02988 (13) | 0.1027 (8) | |
F6 | 0.27021 (16) | 0.5594 (2) | 0.10520 (12) | 0.0840 (6) | |
N1 | 0.7710 (2) | 0.8261 (3) | 0.09254 (14) | 0.0488 (6) | |
H1C | 0.7357 | 0.8983 | 0.0882 | 0.13 (2)* | |
H1E | 0.7676 | 0.7882 | 0.0543 | 0.096 (15)* | |
H1D | 0.8331 | 0.8534 | 0.1039 | 0.113 (16)* | |
H1F | 0.7393 | 0.7719 | 0.1167 | 0.14 (2)* | |
O1 | 0.93305 (15) | 0.6644 (2) | 0.19077 (11) | 0.0558 (5) | |
O2 | 0.71616 (16) | 0.5684 (2) | 0.17870 (10) | 0.0539 (5) | |
O3 | 0.55889 (15) | 0.7988 (3) | 0.15465 (11) | 0.0620 (6) | |
O4 | 0.6137 (2) | 1.0656 (2) | 0.07955 (12) | 0.0709 (7) | |
O5 | 0.8311 (2) | 1.1606 (2) | 0.09173 (11) | 0.0653 (6) | |
O6 | 0.98772 (17) | 0.9291 (2) | 0.11637 (11) | 0.0631 (6) | |
P1 | 0.26791 (6) | 0.38092 (9) | 0.09059 (4) | 0.0537 (3) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.080 (2) | 0.0483 (18) | 0.068 (2) | 0.0199 (16) | −0.0022 (18) | 0.0009 (15) |
C2 | 0.094 (3) | 0.0443 (17) | 0.0532 (18) | −0.0058 (17) | −0.0063 (17) | 0.0113 (14) |
C3 | 0.076 (2) | 0.0564 (19) | 0.068 (2) | −0.0250 (17) | 0.0198 (18) | −0.0071 (16) |
C4 | 0.056 (2) | 0.080 (2) | 0.087 (2) | −0.0299 (18) | 0.0119 (18) | −0.030 (2) |
C5 | 0.0465 (19) | 0.129 (4) | 0.087 (3) | 0.008 (2) | −0.0148 (18) | −0.012 (3) |
C6 | 0.073 (3) | 0.110 (3) | 0.092 (3) | 0.054 (2) | −0.021 (2) | −0.008 (2) |
C7 | 0.135 (4) | 0.049 (2) | 0.089 (3) | 0.032 (2) | −0.054 (3) | −0.0103 (19) |
C8 | 0.179 (5) | 0.045 (2) | 0.060 (2) | −0.015 (3) | −0.035 (3) | 0.0138 (17) |
C9 | 0.156 (4) | 0.049 (2) | 0.070 (2) | −0.025 (2) | 0.055 (3) | −0.0036 (17) |
C10 | 0.084 (3) | 0.070 (2) | 0.099 (3) | −0.039 (2) | 0.052 (2) | −0.025 (2) |
C11 | 0.0392 (17) | 0.115 (3) | 0.086 (3) | −0.0054 (19) | 0.0125 (17) | −0.009 (2) |
C12 | 0.054 (2) | 0.096 (3) | 0.088 (3) | 0.029 (2) | 0.0155 (18) | 0.001 (2) |
F1 | 0.0796 (15) | 0.1011 (18) | 0.1247 (19) | 0.0091 (12) | −0.0443 (14) | −0.0083 (14) |
F2 | 0.1082 (17) | 0.0858 (15) | 0.1183 (18) | −0.0139 (13) | 0.0598 (15) | −0.0182 (13) |
F3 | 0.0747 (13) | 0.0560 (12) | 0.1020 (15) | −0.0021 (9) | 0.0051 (11) | −0.0175 (10) |
F4 | 0.0879 (15) | 0.0858 (15) | 0.0988 (16) | 0.0013 (12) | −0.0361 (12) | −0.0043 (12) |
F5 | 0.0939 (16) | 0.1138 (19) | 0.1056 (17) | −0.0110 (14) | 0.0442 (14) | 0.0028 (14) |
F6 | 0.0805 (14) | 0.0547 (11) | 0.1155 (17) | −0.0061 (10) | −0.0009 (12) | −0.0113 (11) |
N1 | 0.0531 (16) | 0.0445 (13) | 0.0488 (15) | −0.0016 (13) | 0.0033 (11) | −0.0026 (12) |
O1 | 0.0524 (12) | 0.0529 (12) | 0.0626 (13) | 0.0132 (9) | 0.0082 (10) | 0.0004 (10) |
O2 | 0.0625 (13) | 0.0496 (11) | 0.0503 (11) | −0.0075 (10) | 0.0083 (10) | 0.0056 (9) |
O3 | 0.0420 (11) | 0.0733 (15) | 0.0690 (14) | −0.0032 (10) | −0.0083 (10) | −0.0175 (11) |
O4 | 0.0833 (17) | 0.0540 (13) | 0.0717 (15) | 0.0239 (12) | −0.0210 (13) | −0.0119 (11) |
O5 | 0.1022 (18) | 0.0461 (12) | 0.0478 (12) | −0.0099 (12) | 0.0068 (12) | 0.0064 (9) |
O6 | 0.0569 (13) | 0.0651 (13) | 0.0689 (14) | −0.0166 (11) | 0.0165 (11) | −0.0052 (11) |
P1 | 0.0441 (4) | 0.0524 (5) | 0.0643 (5) | −0.0032 (4) | 0.0011 (3) | −0.0086 (4) |
C1—O1 | 1.416 (4) | C8—H8A | 0.9700 |
C1—C2 | 1.475 (5) | C8—H8B | 0.9700 |
C1—H1A | 0.9700 | C9—O5 | 1.424 (5) |
C1—H1B | 0.9700 | C9—C10 | 1.477 (6) |
C2—O2 | 1.422 (4) | C9—H9A | 0.9700 |
C2—H2A | 0.9700 | C9—H9B | 0.9700 |
C2—H2B | 0.9700 | C10—O6 | 1.413 (4) |
C3—O2 | 1.410 (4) | C10—H10A | 0.9700 |
C3—C4 | 1.478 (5) | C10—H10B | 0.9700 |
C3—H3A | 0.9700 | C11—O6 | 1.423 (4) |
C3—H3B | 0.9700 | C11—C12 | 1.478 (5) |
C4—O3 | 1.425 (4) | C11—H11A | 0.9700 |
C4—H4A | 0.9700 | C11—H11B | 0.9700 |
C4—H4B | 0.9700 | C12—O1 | 1.426 (4) |
C5—O3 | 1.417 (4) | C12—H12A | 0.9700 |
C5—C6 | 1.482 (6) | C12—H12B | 0.9700 |
C5—H5A | 0.9700 | F1—P1 | 1.594 (2) |
C5—H5B | 0.9700 | F2—P1 | 1.569 (2) |
C6—O4 | 1.432 (5) | F3—P1 | 1.6029 (19) |
C6—H6A | 0.9700 | F4—P1 | 1.572 (2) |
C6—H6B | 0.9700 | F5—P1 | 1.583 (2) |
C7—O4 | 1.407 (4) | F6—P1 | 1.583 (2) |
C7—C8 | 1.492 (6) | N1—H1C | 0.7721 |
C7—H7A | 0.9700 | N1—H1E | 0.7840 |
C7—H7B | 0.9700 | N1—H1D | 0.8282 |
C8—O5 | 1.427 (5) | N1—H1F | 0.7827 |
O1—C1—C2 | 109.3 (2) | C10—C9—H9A | 109.6 |
O1—C1—H1A | 109.8 | O5—C9—H9B | 109.6 |
C2—C1—H1A | 109.8 | C10—C9—H9B | 109.6 |
O1—C1—H1B | 109.8 | H9A—C9—H9B | 108.1 |
C2—C1—H1B | 109.8 | O6—C10—C9 | 109.9 (3) |
H1A—C1—H1B | 108.3 | O6—C10—H10A | 109.7 |
O2—C2—C1 | 109.1 (2) | C9—C10—H10A | 109.7 |
O2—C2—H2A | 109.9 | O6—C10—H10B | 109.7 |
C1—C2—H2A | 109.9 | C9—C10—H10B | 109.7 |
O2—C2—H2B | 109.9 | H10A—C10—H10B | 108.2 |
C1—C2—H2B | 109.9 | O6—C11—C12 | 109.0 (3) |
H2A—C2—H2B | 108.3 | O6—C11—H11A | 109.9 |
O2—C3—C4 | 108.9 (3) | C12—C11—H11A | 109.9 |
O2—C3—H3A | 109.9 | O6—C11—H11B | 109.9 |
C4—C3—H3A | 109.9 | C12—C11—H11B | 109.9 |
O2—C3—H3B | 109.9 | H11A—C11—H11B | 108.3 |
C4—C3—H3B | 109.9 | O1—C12—C11 | 109.2 (3) |
H3A—C3—H3B | 108.3 | O1—C12—H12A | 109.8 |
O3—C4—C3 | 109.7 (2) | C11—C12—H12A | 109.8 |
O3—C4—H4A | 109.7 | O1—C12—H12B | 109.8 |
C3—C4—H4A | 109.7 | C11—C12—H12B | 109.8 |
O3—C4—H4B | 109.7 | H12A—C12—H12B | 108.3 |
C3—C4—H4B | 109.7 | H1C—N1—H1E | 104.9 |
H4A—C4—H4B | 108.2 | H1C—N1—H1D | 108.4 |
O3—C5—C6 | 109.5 (3) | H1E—N1—H1D | 110.2 |
O3—C5—H5A | 109.8 | H1C—N1—H1F | 104.0 |
C6—C5—H5A | 109.8 | H1E—N1—H1F | 105.7 |
O3—C5—H5B | 109.8 | H1D—N1—H1F | 122.3 |
C6—C5—H5B | 109.8 | C1—O1—C12 | 111.4 (2) |
H5A—C5—H5B | 108.2 | C3—O2—C2 | 112.3 (2) |
O4—C6—C5 | 109.3 (3) | C5—O3—C4 | 112.9 (3) |
O4—C6—H6A | 109.8 | C7—O4—C6 | 112.6 (3) |
C5—C6—H6A | 109.8 | C9—O5—C8 | 112.9 (3) |
O4—C6—H6B | 109.8 | C10—O6—C11 | 113.1 (3) |
C5—C6—H6B | 109.8 | F2—P1—F4 | 92.48 (14) |
H6A—C6—H6B | 108.3 | F2—P1—F6 | 91.19 (12) |
O4—C7—C8 | 108.9 (3) | F4—P1—F6 | 91.52 (12) |
O4—C7—H7A | 109.9 | F2—P1—F5 | 177.92 (14) |
C8—C7—H7A | 109.9 | F4—P1—F5 | 89.31 (14) |
O4—C7—H7B | 109.9 | F6—P1—F5 | 89.83 (13) |
C8—C7—H7B | 109.9 | F2—P1—F1 | 89.19 (15) |
H7A—C7—H7B | 108.3 | F4—P1—F1 | 177.60 (14) |
O5—C8—C7 | 109.2 (3) | F6—P1—F1 | 90.16 (12) |
O5—C8—H8A | 109.8 | F5—P1—F1 | 88.99 (15) |
C7—C8—H8A | 109.8 | F2—P1—F3 | 90.29 (11) |
O5—C8—H8B | 109.8 | F4—P1—F3 | 90.49 (11) |
C7—C8—H8B | 109.8 | F6—P1—F3 | 177.45 (13) |
H8A—C8—H8B | 108.3 | F5—P1—F3 | 88.63 (12) |
O5—C9—C10 | 110.1 (3) | F1—P1—F3 | 87.78 (12) |
O5—C9—H9A | 109.6 |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1D···O1 | 0.83 | 2.58 | 2.993 (3) | 113 |
N1—H1F···O2 | 0.78 | 2.15 | 2.878 (3) | 155 |
N1—H1F···O3 | 0.78 | 2.43 | 2.990 (3) | 129 |
N1—H1C···O4 | 0.77 | 2.12 | 2.876 (3) | 169 |
N1—H1C···O5 | 0.77 | 2.58 | 3.018 (3) | 117 |
N1—H1D···O6 | 0.83 | 2.05 | 2.871 (3) | 172 |
N1—H1E···F1i | 0.78 | 2.47 | 3.179 (4) | 151 |
N1—H1E···F3i | 0.78 | 2.37 | 3.080 (3) | 152 |
Symmetry code: (i) −x+1, −y+1, −z. |
Experimental details
Crystal data | |
Chemical formula | NH4+·PF6−·C12H24O6 |
Mr | 427.32 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 298 |
a, b, c (Å) | 12.559 (3), 8.7352 (17), 18.6511 (17) |
β (°) | 94.097 (10) |
V (Å3) | 2040.9 (7) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.21 |
Crystal size (mm) | 0.40 × 0.36 × 0.30 |
Data collection | |
Diffractometer | Rigaku Mercury2 |
Absorption correction | Multi-scan (CrystalClear; Rigaku, 2005) |
Tmin, Tmax | 0.920, 0.940 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 18388, 4014, 2740 |
Rint | 0.044 |
(sin θ/λ)max (Å−1) | 0.617 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.060, 0.160, 1.04 |
No. of reflections | 4014 |
No. of parameters | 239 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.35, −0.27 |
Computer programs: CrystalClear (Rigaku, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1D···O1 | 0.83 | 2.58 | 2.993 (3) | 112.6 |
N1—H1F···O2 | 0.78 | 2.15 | 2.878 (3) | 154.6 |
N1—H1F···O3 | 0.78 | 2.43 | 2.990 (3) | 129.2 |
N1—H1C···O4 | 0.77 | 2.12 | 2.876 (3) | 168.6 |
N1—H1C···O5 | 0.77 | 2.58 | 3.018 (3) | 117.3 |
N1—H1D···O6 | 0.83 | 2.05 | 2.871 (3) | 171.5 |
N1—H1E···F1i | 0.78 | 2.47 | 3.179 (4) | 150.9 |
N1—H1E···F3i | 0.78 | 2.37 | 3.080 (3) | 152.2 |
Symmetry code: (i) −x+1, −y+1, −z. |
Acknowledgements
DHW thanks the China Postdoctoral Science Foundation funded project (20090451147), Jiangsu Planned Projects for Postdoctoral Research Funds (0802003B) and the SEU Major Postdoctoral Research Funds (3212000901) for financial support.
References
Bajaj, A. V. & Poonia, N. S. (1988). Coord. Chem. Rev. 87, 55–213. CrossRef CAS Web of Science Google Scholar
Dapporto, P., Paoli, P., Matijasic, I. & Tusek-Bozic, L. (1996). Inorg. Chim. Acta, 252, 383–389. CSD CrossRef CAS Web of Science Google Scholar
Fender, N. S., Kahwa, I. A. & Fronczek, F. R. (2002). J. Solid State Chem. 163, 286–293. Web of Science CSD CrossRef CAS Google Scholar
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Recently much attention has been devoted to crown ethers due to their ability to form non-covalent, H-bonding complexes with ammonium cations both in solid and in solution (Bajaj et al., 1988; Fender et al., 2002; Kryatova et al., 2004). Both the nature of the ammonium cation (NH4+,RNH3+, R2NH2+, etc.) and the size of the crown ether can work on the stability and stoichiometry of these host–guest complexes. The host molecules combine with the guest species by intermolecular interaction, 18-Crown-6 has a high affinity for RNH3+cations and most studies of 18-crown-6 and its derivatives invariably showed a 1:1 stoichiometry with RNH3+ cations. For similar structures, see: Dapporto et al., 1996; Pears et al., 1988. In our laboratory, the title compound has been synthesized and its crystal structure is herein reported.
The title compound crystallizes in the P21/n space group with an asymmetric unit consisting of a cationic [(NH4)(18-crown-6)]+ moiety and an isolated anionic PF6-(Fig 1). The NH4+ nests in the 18-crown-6 ring to form a superamolecular rotator-stator-like structure by intramolecular N—H···O hydrogen-bonded interactions between the NH4+ (H1C, H1D and H1F)and the six oxygen atoms of the crown ether (Fig 2). Intramolecular N—H···O hydrogen distances fall within the normal range: 2.871 (3) and 3.018 (3) Å (Table 1). The six oxygen atoms of the crown ether lie approximately in a plane with the mean deviation of 0.2129 Å, the N atom aparts from the center of the crown ring about 0.864 Å. The slightly distorted tetrahedralcations NH4+ further interact with F1i and F3i (symmetry code, i: 1 - x, 1 - y, -z) of the slightly distorted octahedral anions PF6- (The P—F bond lengths are within the range of 1.51 - 1.60 Å, the F—P—F bond angles are within the range of 87.78 - 92.48°) by intermolecular N—H···F hydrogen bonds (Table 1 and Fig 2).