In the crystal structure of the title compound, C
9H
22N
22+·2H
2PO
4−·H
2O, the H
2PO
4− anions are hydrogen bonded to each other, forming a ribbon parallel to the
b axis. The water molecules connect these ribbons
via O—H

O hydrogen bonds. The organic cations are attached to the dihydrogen phosphate anions and water molecules through N—H

O and C—H

O hydrogen bonds, forming an infinite three-dimensional network.
Supporting information
CCDC reference: 726370
Key indicators
- Single-crystal X-ray study
- T = 298 K
- Mean
(C-C) = 0.004 Å
- R factor = 0.049
- wR factor = 0.128
- Data-to-parameter ratio = 18.3
checkCIF/PLATON results
No syntax errors found
Alert level C
Value of measurement temperature given = 298.000
Value of melting point given = 0.000
PLAT480_ALERT_4_C Long H...A H-Bond Reported H92 .. O4 .. 2.66 Ang.
PLAT731_ALERT_1_C Bond Calc 0.85(3), Rep 0.848(10) ...... 3.00 su-Ra
O9 -H91 1.555 1.555
PLAT735_ALERT_1_C D-H Calc 0.85(3), Rep 0.850(10) ...... 3.00 su-Ra
O9 -H91 1.555 1.555
PLAT736_ALERT_1_C H...A Calc 1.97(3), Rep 1.970(10) ...... 3.00 su-Ra
H91 -O5 1.555 1.555
Alert level G
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints ....... 3
0 ALERT level A = In general: serious problem
0 ALERT level B = Potentially serious problem
4 ALERT level C = Check and explain
1 ALERT level G = General alerts; check
3 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
0 ALERT type 2 Indicator that the structure model may be wrong or deficient
1 ALERT type 3 Indicator that the structure quality may be low
1 ALERT type 4 Improvement, methodology, query or suggestion
0 ALERT type 5 Informative message, check
Crystals of the title compound have been prepared in a Petri dish by adding 50 mmol of concentrated orthophosphoric acid (Fluka, 85%, d = 1.7) to 25 mmol of
4-Amino-2,2,6,6-tetramethylpiperidine (Acros) dissolved in ethanol. After
agitation, the resulting solution has been slowly evaporated at room
temperature until the formation of single crystals suitable for X-ray
structure analysis and these remained stable under
normal conditions of temperature
and humidity.
Hydrogen atoms were placed in calculated positions and refined as part of
a riding model except those of the water molecule which were located
in difference Fourier maps and their positions and isotropic displacement
parameters refined.
Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994); cell refinement: CAD-4 EXPRESS (Enraf–Nonius, 1994); data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).
4-Ammonio-2,2,6,6-tetramethylpiperidinium bis(dihydrogen phosphate) monohydrate
top
Crystal data top
C9H22N22+·2H2PO4−·H2O | F(000) = 792 |
Mr = 370.27 | Dx = 1.497 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 25 reflections |
a = 12.604 (5) Å | θ = 9–11° |
b = 8.249 (2) Å | µ = 0.31 mm−1 |
c = 16.321 (2) Å | T = 298 K |
β = 104.56 (4)° | Prism, colorless |
V = 1642.4 (8) Å3 | 0.5 × 0.35 × 0.25 mm |
Z = 4 | |
Data collection top
Enraf–Nonius TurboCAD-4 diffractometer | Rint = 0.056 |
Radiation source: fine-focus sealed tube | θmax = 28.0°, θmin = 2.6° |
Graphite monochromator | h = −16→16 |
Nonprofiled ω scans | k = 0→10 |
6617 measured reflections | l = −10→21 |
3953 independent reflections | 2 standard reflections every 120 min |
2575 reflections with I > 2σ(I) | intensity decay: 8% |
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)] = 0.049 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.128 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.00 | w = 1/[σ2(Fo2) + (0.0646P)2] where P = (Fo2 + 2Fc2)/3 |
3953 reflections | (Δ/σ)max = 0.001 |
216 parameters | Δρmax = 0.32 e Å−3 |
3 restraints | Δρmin = −0.49 e Å−3 |
Crystal data top
C9H22N22+·2H2PO4−·H2O | V = 1642.4 (8) Å3 |
Mr = 370.27 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 12.604 (5) Å | µ = 0.31 mm−1 |
b = 8.249 (2) Å | T = 298 K |
c = 16.321 (2) Å | 0.5 × 0.35 × 0.25 mm |
β = 104.56 (4)° | |
Data collection top
Enraf–Nonius TurboCAD-4 diffractometer | Rint = 0.056 |
6617 measured reflections | 2 standard reflections every 120 min |
3953 independent reflections | intensity decay: 8% |
2575 reflections with I > 2σ(I) | |
Refinement top
R[F2 > 2σ(F2)] = 0.049 | 3 restraints |
wR(F2) = 0.128 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.00 | Δρmax = 0.32 e Å−3 |
3953 reflections | Δρmin = −0.49 e Å−3 |
216 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 | |
P1 | 0.52437 (5) | 0.19580 (8) | 0.19702 (4) | 0.02151 (17) | |
P2 | 0.79116 (5) | 0.36565 (8) | 0.37537 (4) | 0.02164 (17) | |
O1 | 0.57523 (14) | 0.0956 (2) | 0.27473 (12) | 0.0301 (4) | |
O2 | 0.42447 (15) | 0.2885 (2) | 0.21633 (14) | 0.0332 (5) | |
H2 | 0.4379 | 0.3859 | 0.2203 | 0.050* | |
O3 | 0.60240 (14) | 0.3112 (2) | 0.17133 (12) | 0.0279 (4) | |
O4 | 0.47608 (15) | 0.0832 (3) | 0.12059 (12) | 0.0372 (5) | |
H4 | 0.4155 | 0.0509 | 0.1233 | 0.056* | |
O5 | 0.70615 (14) | 0.4348 (2) | 0.41668 (12) | 0.0312 (5) | |
O6 | 0.77241 (16) | 0.4361 (3) | 0.28269 (12) | 0.0356 (5) | |
H6 | 0.7172 | 0.3954 | 0.2520 | 0.053* | |
O7 | 0.77502 (16) | 0.1773 (2) | 0.36442 (15) | 0.0380 (5) | |
H7 | 0.7113 | 0.1577 | 0.3394 | 0.057* | |
O8 | 0.90532 (14) | 0.3991 (3) | 0.42314 (13) | 0.0358 (5) | |
O9 | 0.59416 (18) | 0.2150 (3) | 0.49650 (14) | 0.0393 (5) | |
H91 | 0.626 (3) | 0.290 (3) | 0.476 (2) | 0.055 (11)* | |
H92 | 0.597 (4) | 0.226 (6) | 0.5489 (11) | 0.13 (2)* | |
N1 | 0.12655 (16) | 0.3672 (3) | 0.44120 (13) | 0.0195 (4) | |
H1A | 0.0535 | 0.3763 | 0.4329 | 0.023* | |
H1B | 0.1573 | 0.4360 | 0.4833 | 0.023* | |
N2 | 0.40484 (17) | 0.1521 (3) | 0.37758 (15) | 0.0301 (5) | |
H2A | 0.4183 | 0.1931 | 0.3307 | 0.045* | |
H2B | 0.4093 | 0.0445 | 0.3764 | 0.045* | |
H2C | 0.4540 | 0.1900 | 0.4226 | 0.045* | |
C1 | 0.15485 (19) | 0.4285 (3) | 0.36124 (16) | 0.0228 (5) | |
C2 | 0.2733 (2) | 0.3797 (3) | 0.36452 (18) | 0.0268 (6) | |
H22A | 0.2892 | 0.4053 | 0.3108 | 0.032* | |
H22B | 0.3231 | 0.4418 | 0.4083 | 0.032* | |
C3 | 0.29204 (19) | 0.2008 (3) | 0.38261 (17) | 0.0241 (5) | |
H3 | 0.2383 | 0.1395 | 0.3400 | 0.029* | |
C4 | 0.27523 (19) | 0.1613 (3) | 0.46967 (17) | 0.0233 (5) | |
H4A | 0.3253 | 0.2256 | 0.5121 | 0.028* | |
H4B | 0.2919 | 0.0478 | 0.4823 | 0.028* | |
C5 | 0.15786 (19) | 0.1958 (3) | 0.47367 (17) | 0.0221 (5) | |
C6 | 0.0747 (2) | 0.3618 (4) | 0.28233 (18) | 0.0404 (8) | |
H6A | 0.0866 | 0.2475 | 0.2781 | 0.061* | |
H6B | 0.0862 | 0.4155 | 0.2331 | 0.061* | |
H6C | 0.0010 | 0.3804 | 0.2862 | 0.061* | |
C7 | 0.1434 (2) | 0.6124 (3) | 0.36298 (19) | 0.0345 (7) | |
H7A | 0.0700 | 0.6401 | 0.3646 | 0.052* | |
H7B | 0.1589 | 0.6580 | 0.3131 | 0.052* | |
H7C | 0.1941 | 0.6550 | 0.4123 | 0.052* | |
C8 | 0.0775 (2) | 0.0728 (4) | 0.4223 (2) | 0.0339 (7) | |
H8A | 0.0875 | 0.0665 | 0.3660 | 0.051* | |
H8B | 0.0038 | 0.1062 | 0.4198 | 0.051* | |
H8C | 0.0908 | −0.0317 | 0.4488 | 0.051* | |
C9 | 0.1488 (2) | 0.1962 (3) | 0.56518 (17) | 0.0291 (6) | |
H9A | 0.1607 | 0.0885 | 0.5879 | 0.044* | |
H9B | 0.0771 | 0.2325 | 0.5670 | 0.044* | |
H9C | 0.2030 | 0.2679 | 0.5982 | 0.044* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
P1 | 0.0200 (3) | 0.0239 (3) | 0.0216 (3) | −0.0024 (3) | 0.0070 (3) | −0.0030 (3) |
P2 | 0.0183 (3) | 0.0229 (3) | 0.0226 (4) | 0.0007 (3) | 0.0032 (2) | −0.0014 (3) |
O1 | 0.0333 (10) | 0.0257 (10) | 0.0286 (11) | −0.0049 (8) | 0.0030 (8) | 0.0036 (8) |
O2 | 0.0323 (10) | 0.0254 (10) | 0.0473 (13) | 0.0010 (8) | 0.0203 (9) | −0.0007 (10) |
O3 | 0.0245 (9) | 0.0328 (10) | 0.0272 (10) | −0.0066 (8) | 0.0077 (8) | 0.0008 (9) |
O4 | 0.0286 (10) | 0.0517 (13) | 0.0333 (12) | −0.0120 (9) | 0.0115 (9) | −0.0202 (10) |
O5 | 0.0281 (9) | 0.0362 (11) | 0.0317 (11) | 0.0093 (8) | 0.0121 (8) | 0.0049 (9) |
O6 | 0.0392 (11) | 0.0427 (12) | 0.0228 (11) | −0.0127 (9) | 0.0037 (8) | 0.0015 (9) |
O7 | 0.0322 (10) | 0.0249 (10) | 0.0506 (14) | 0.0027 (8) | −0.0014 (10) | −0.0035 (10) |
O8 | 0.0209 (9) | 0.0438 (12) | 0.0382 (12) | −0.0010 (8) | −0.0009 (8) | −0.0108 (10) |
O9 | 0.0422 (12) | 0.0495 (14) | 0.0278 (12) | −0.0122 (10) | 0.0117 (10) | −0.0011 (11) |
N1 | 0.0193 (9) | 0.0214 (10) | 0.0183 (11) | 0.0005 (8) | 0.0059 (8) | 0.0003 (9) |
N2 | 0.0263 (11) | 0.0339 (13) | 0.0335 (13) | 0.0045 (9) | 0.0136 (10) | −0.0046 (11) |
C1 | 0.0231 (12) | 0.0300 (13) | 0.0154 (12) | 0.0004 (11) | 0.0051 (10) | 0.0048 (11) |
C2 | 0.0252 (12) | 0.0308 (14) | 0.0275 (15) | −0.0008 (11) | 0.0122 (11) | 0.0038 (12) |
C3 | 0.0194 (11) | 0.0283 (13) | 0.0268 (14) | −0.0006 (10) | 0.0100 (10) | −0.0038 (12) |
C4 | 0.0227 (11) | 0.0209 (13) | 0.0263 (14) | 0.0032 (10) | 0.0064 (10) | 0.0010 (11) |
C5 | 0.0226 (11) | 0.0194 (11) | 0.0255 (14) | −0.0010 (10) | 0.0082 (10) | −0.0001 (11) |
C6 | 0.0330 (15) | 0.061 (2) | 0.0229 (15) | 0.0037 (14) | −0.0001 (12) | −0.0019 (15) |
C7 | 0.0391 (15) | 0.0298 (15) | 0.0374 (17) | 0.0078 (12) | 0.0148 (13) | 0.0118 (13) |
C8 | 0.0284 (13) | 0.0279 (14) | 0.0482 (19) | −0.0110 (11) | 0.0146 (13) | −0.0081 (14) |
C9 | 0.0350 (14) | 0.0278 (14) | 0.0280 (15) | 0.0019 (11) | 0.0143 (12) | 0.0071 (12) |
Geometric parameters (Å, º) top
P1—O3 | 1.5020 (19) | C1—C2 | 1.534 (3) |
P1—O1 | 1.515 (2) | C2—C3 | 1.512 (4) |
P1—O4 | 1.552 (2) | C2—H22A | 0.9700 |
P1—O2 | 1.5713 (19) | C2—H22B | 0.9700 |
P2—O8 | 1.480 (2) | C3—C4 | 1.524 (4) |
P2—O5 | 1.5137 (19) | C3—H3 | 0.9800 |
P2—O7 | 1.572 (2) | C4—C5 | 1.524 (3) |
P2—O6 | 1.582 (2) | C4—H4A | 0.9700 |
O2—H2 | 0.8200 | C4—H4B | 0.9700 |
O4—H4 | 0.8200 | C5—C9 | 1.526 (4) |
O6—H6 | 0.8200 | C5—C8 | 1.527 (4) |
O7—H7 | 0.8200 | C6—H6A | 0.9600 |
O9—H91 | 0.848 (10) | C6—H6B | 0.9600 |
O9—H92 | 0.852 (10) | C6—H6C | 0.9600 |
N1—C1 | 1.523 (3) | C7—H7A | 0.9600 |
N1—C5 | 1.527 (3) | C7—H7B | 0.9600 |
N1—H1A | 0.9000 | C7—H7C | 0.9600 |
N1—H1B | 0.9000 | C8—H8A | 0.9600 |
N2—C3 | 1.499 (3) | C8—H8B | 0.9600 |
N2—H2A | 0.8900 | C8—H8C | 0.9600 |
N2—H2B | 0.8900 | C9—H9A | 0.9600 |
N2—H2C | 0.8900 | C9—H9B | 0.9600 |
C1—C7 | 1.525 (4) | C9—H9C | 0.9600 |
C1—C6 | 1.526 (4) | | |
| | | |
O3—P1—O1 | 114.23 (11) | N2—C3—C4 | 110.5 (2) |
O3—P1—O4 | 107.88 (11) | C2—C3—C4 | 109.8 (2) |
O1—P1—O4 | 110.16 (13) | N2—C3—H3 | 108.6 |
O3—P1—O2 | 111.20 (12) | C2—C3—H3 | 108.6 |
O1—P1—O2 | 106.82 (12) | C4—C3—H3 | 108.6 |
O4—P1—O2 | 106.28 (12) | C3—C4—C5 | 111.4 (2) |
O8—P2—O5 | 113.48 (12) | C3—C4—H4A | 109.4 |
O8—P2—O7 | 108.97 (11) | C5—C4—H4A | 109.4 |
O5—P2—O7 | 109.72 (12) | C3—C4—H4B | 109.4 |
O8—P2—O6 | 109.09 (13) | C5—C4—H4B | 109.4 |
O5—P2—O6 | 109.58 (12) | H4A—C4—H4B | 108.0 |
O7—P2—O6 | 105.71 (12) | C4—C5—C9 | 110.8 (2) |
P1—O2—H2 | 109.5 | C4—C5—N1 | 109.09 (19) |
P1—O4—H4 | 109.5 | C9—C5—N1 | 105.1 (2) |
P2—O6—H6 | 109.5 | C4—C5—C8 | 111.7 (2) |
P2—O7—H7 | 109.5 | C9—C5—C8 | 109.7 (2) |
H91—O9—H92 | 114 (3) | N1—C5—C8 | 110.3 (2) |
C1—N1—C5 | 120.63 (19) | C1—C6—H6A | 109.5 |
C1—N1—H1A | 107.2 | C1—C6—H6B | 109.5 |
C5—N1—H1A | 107.2 | H6A—C6—H6B | 109.5 |
C1—N1—H1B | 107.2 | C1—C6—H6C | 109.5 |
C5—N1—H1B | 107.2 | H6A—C6—H6C | 109.5 |
H1A—N1—H1B | 106.8 | H6B—C6—H6C | 109.5 |
C3—N2—H2A | 109.5 | C1—C7—H7A | 109.5 |
C3—N2—H2B | 109.5 | C1—C7—H7B | 109.5 |
H2A—N2—H2B | 109.5 | H7A—C7—H7B | 109.5 |
C3—N2—H2C | 109.5 | C1—C7—H7C | 109.5 |
H2A—N2—H2C | 109.5 | H7A—C7—H7C | 109.5 |
H2B—N2—H2C | 109.5 | H7B—C7—H7C | 109.5 |
N1—C1—C7 | 105.7 (2) | C5—C8—H8A | 109.5 |
N1—C1—C6 | 110.8 (2) | C5—C8—H8B | 109.5 |
C7—C1—C6 | 109.2 (2) | H8A—C8—H8B | 109.5 |
N1—C1—C2 | 108.6 (2) | C5—C8—H8C | 109.5 |
C7—C1—C2 | 110.9 (2) | H8A—C8—H8C | 109.5 |
C6—C1—C2 | 111.5 (2) | H8B—C8—H8C | 109.5 |
C3—C2—C1 | 111.4 (2) | C5—C9—H9A | 109.5 |
C3—C2—H22A | 109.3 | C5—C9—H9B | 109.5 |
C1—C2—H22A | 109.3 | H9A—C9—H9B | 109.5 |
C3—C2—H22B | 109.3 | C5—C9—H9C | 109.5 |
C1—C2—H22B | 109.3 | H9A—C9—H9C | 109.5 |
H22A—C2—H22B | 108.0 | H9B—C9—H9C | 109.5 |
N2—C3—C2 | 110.7 (2) | | |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2···O1i | 0.82 | 1.74 | 2.537 (3) | 163 |
O4—H4···O5ii | 0.82 | 1.79 | 2.538 (3) | 152 |
O6—H6···O3 | 0.82 | 1.83 | 2.646 (3) | 172 |
O7—H7···O1 | 0.82 | 1.85 | 2.662 (3) | 173 |
O9—H91···O5 | 0.85 (1) | 1.97 (1) | 2.811 (3) | 170 (3) |
O9—H92···O3iii | 0.85 (1) | 2.00 (1) | 2.837 (3) | 165 (5) |
O9—H92···O4iii | 0.85 (1) | 2.66 (5) | 3.256 (3) | 128 (5) |
N1—H1A···O8iv | 0.90 | 1.84 | 2.742 (3) | 176 |
N1—H1B···O5v | 0.90 | 2.31 | 3.168 (3) | 159 |
N1—H1B···O8v | 0.90 | 2.33 | 3.038 (3) | 136 |
N2—H2A···O2 | 0.89 | 2.05 | 2.929 (3) | 172 |
N2—H2A···O1 | 0.89 | 2.51 | 3.076 (3) | 122 |
N2—H2B···O3ii | 0.89 | 2.07 | 2.919 (3) | 160 |
N2—H2C···O9 | 0.89 | 1.88 | 2.721 (4) | 156 |
C3—H3···O6ii | 0.98 | 2.59 | 3.406 (3) | 141 |
C4—H4B···O9vi | 0.97 | 2.58 | 3.492 (4) | 158 |
C9—H9A···O7vi | 0.96 | 2.40 | 3.343 (3) | 168 |
Symmetry codes: (i) −x+1, y+1/2, −z+1/2; (ii) −x+1, y−1/2, −z+1/2; (iii) x, −y+1/2, z+1/2; (iv) x−1, y, z; (v) −x+1, −y+1, −z+1; (vi) −x+1, −y, −z+1. |
Experimental details
Crystal data |
Chemical formula | C9H22N22+·2H2PO4−·H2O |
Mr | 370.27 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 298 |
a, b, c (Å) | 12.604 (5), 8.249 (2), 16.321 (2) |
β (°) | 104.56 (4) |
V (Å3) | 1642.4 (8) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.31 |
Crystal size (mm) | 0.5 × 0.35 × 0.25 |
|
Data collection |
Diffractometer | Enraf–Nonius TurboCAD-4 diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 6617, 3953, 2575 |
Rint | 0.056 |
(sin θ/λ)max (Å−1) | 0.660 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.049, 0.128, 1.00 |
No. of reflections | 3953 |
No. of parameters | 216 |
No. of restraints | 3 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.32, −0.49 |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2···O1i | 0.82 | 1.74 | 2.537 (3) | 163.1 |
O4—H4···O5ii | 0.82 | 1.79 | 2.538 (3) | 151.6 |
O6—H6···O3 | 0.82 | 1.83 | 2.646 (3) | 172.1 |
O7—H7···O1 | 0.82 | 1.85 | 2.662 (3) | 172.6 |
O9—H91···O5 | 0.85 (1) | 1.97 (1) | 2.811 (3) | 170 (3) |
O9—H92···O3iii | 0.85 (1) | 2.00 (1) | 2.837 (3) | 165 (5) |
O9—H92···O4iii | 0.85 (1) | 2.66 (5) | 3.256 (3) | 128 (5) |
N1—H1A···O8iv | 0.90 | 1.84 | 2.742 (3) | 176.4 |
N1—H1B···O5v | 0.90 | 2.31 | 3.168 (3) | 158.5 |
N1—H1B···O8v | 0.90 | 2.33 | 3.038 (3) | 135.8 |
N2—H2A···O2 | 0.89 | 2.05 | 2.929 (3) | 171.5 |
N2—H2A···O1 | 0.89 | 2.51 | 3.076 (3) | 121.9 |
N2—H2B···O3ii | 0.89 | 2.07 | 2.919 (3) | 159.7 |
N2—H2C···O9 | 0.89 | 1.88 | 2.721 (4) | 155.9 |
C3—H3···O6ii | 0.98 | 2.59 | 3.406 (3) | 140.8 |
C4—H4B···O9vi | 0.97 | 2.58 | 3.492 (4) | 157.6 |
C9—H9A···O7vi | 0.96 | 2.40 | 3.343 (3) | 168.2 |
Symmetry codes: (i) −x+1, y+1/2, −z+1/2; (ii) −x+1, y−1/2, −z+1/2; (iii) x, −y+1/2, z+1/2; (iv) x−1, y, z; (v) −x+1, −y+1, −z+1; (vi) −x+1, −y, −z+1. |
The combination of organic molecules and inorganic materials was the starting point for the development of new hybrid compounds having many practical and potential applications in various fields, such as biomolecular sciences, catalysis, fuel cells, liquid crystal-material development and quadratic nonlinear optics (Wang et al., 1996; Coombs et al., 1997; Masse et al., 1993). Among these hybrid compounds, organic phosphates are particularly interesting owing to the specific H-bond schemes that they can present in their infinite networks (Baoub & Jouini, 1998). We report here the synthesis and the crystal structure of a new member of this family, the compound (C9H28N2O9P2). As shown in Fig. 1, to ensure charge equilibrium the organic species is doubly protonated at N1 and N2 nitrogen atoms. Thus, the structure associates to each 4-ammonio-2,2,6,6,-tetramethylpiperidinium cation two dihydrogen phosphate anions and one water molecule. The two H2PO4- are crystallographically independent. They form, via H-bonds a repetitive motif of four member (H2PO4-)4 (Fig. 2). The organic cations and the water molecules are attached to these units via (O—H···O), N—H···O and C—H···O hydrogen bonds to perform a three dimensional infinite network. An examination of the anionic entity shows that the O···O distances involved in hydrogen bonds [2.537 (3) to 2.662 (3) A°] are close to the O···O distances in the H2PO4- tetrahedra [2.469 (3) to 2.536 (3) A°], so one could consider the [(H2PO4-)4]n subnetwork as a polyanion (Kefi et al., 2OO6). The detailed geometries of H2P(1)O4- and H2P(2)O4- entities show that the P···O distances significantly are shorter [1.480 (2) to 1.515 (2) A°] than the P···OH distances [1.552 (2) to 1.582 (2) A°], which is in full agreement with those observed in such anions in other organic dihydrogenomonophosphates [Oueslati and Ben Nasr, 2006].