The structure of the title compound, C
5H
6N
5O
+·H
2PO
3−·2H
2O, consists of a layer arrangement in which the organic cations are sandwiched between H
2PO
3− inorganic sheets. In the crystal structure, the phosphite anions are linked together by short strong (P—O—H
O—P) hydrogen bonds to form a two-dimensional network. Strong hydrogen bonds are responsible for the cohesion between organic–inorganic layers and maintain the stability of the structure.
Supporting information
CCDC reference: 222911
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean (C-C) = 0.002 Å
- R factor = 0.032
- wR factor = 0.082
- Data-to-parameter ratio = 11.6
checkCIF/PLATON results
No syntax errors found
Alert level A
PLAT029_ALERT_3_A _diffrn_measured_fraction_theta_full Low ....... 0.94
Alert level C
REFLT03_ALERT_3_C Reflection count < 95% complete
From the CIF: _diffrn_reflns_theta_max 25.99
From the CIF: _diffrn_reflns_theta_full 0.00
From the CIF: _reflns_number_total 1978
TEST2: Reflns within _diffrn_reflns_theta_max
Count of symmetry unique reflns 2095
Completeness (_total/calc) 94.42%
PLAT022_ALERT_3_C Ratio Unique / Expected Reflections too Low .... 0.94
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ .... ?
PLAT242_ALERT_2_C Check Low U(eq) as Compared to Neighbors .... P
1 ALERT level A = In general: serious problem
0 ALERT level B = Potentially serious problem
4 ALERT level C = Check and explain
0 ALERT level G = General alerts; check
1 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
The title compound was prepared by slow evaporation at room temperature of a dilute aqueous solution containing guanine base and phosphorus acid in a stoichiometric ratio. A few days later, crystals had grown as white needles.
The H atoms were located in electron-density difference map. The H atoms of C—H and O—H groups were placed in calculated positions (C—H = 0.96 Å and O—H = 0.82 Å) and were allowed to refine as riding models, with displacement parameters fixed at 120% of those of their parent atoms. The H atoms of the water molecules were refined with O—H distances restrained to 0.84 (1) Å and H···H distances restrained to 1.37 (1) Å with displacement parameters fixed at 120% of those of their parent atoms. These restraints ensure a reasonable geometry for the water molecules. The coordinates of the H atom attached to phosporous were freely refined with displacement parameters fixed at 120% of those of the P atom.
Data collection: KappaCCD (Nonius, 1998); cell refinement: DENZO and SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO and SCALEPACK; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: WinGX publication routines (Farrugia, 1999).
Crystal data top
C5H6N5O+·H2O3P−·2H2O | F(000) = 560 |
Mr = 269.17 | Dx = 1.672 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 10263 reflections |
a = 4.7340 (2) Å | θ = 2.3–26.0° |
b = 24.0450 (3) Å | µ = 0.29 mm−1 |
c = 9.5050 (4) Å | T = 293 K |
β = 98.860 (4)° | Needle, white |
V = 1069.03 (7) Å3 | 0.60 × 0.10 × 0.10 mm |
Z = 4 | |
Data collection top
Nonius KappaCCD diffractometer | 1722 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.047 |
Graphite monochromator | θmax = 26.0°, θmin = 2.3° |
ϕ scans | h = −5→5 |
10263 measured reflections | k = −29→29 |
1978 independent reflections | l = −11→11 |
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)] = 0.032 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.082 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.06 | w = 1/[σ2(Fo2) + (0.0347P)2 + 0.3254P] where P = (Fo2 + 2Fc2)/3 |
1978 reflections | (Δ/σ)max < 0.001 |
170 parameters | Δρmax = 0.36 e Å−3 |
42 restraints | Δρmin = −0.30 e Å−3 |
Crystal data top
C5H6N5O+·H2O3P−·2H2O | V = 1069.03 (7) Å3 |
Mr = 269.17 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 4.7340 (2) Å | µ = 0.29 mm−1 |
b = 24.0450 (3) Å | T = 293 K |
c = 9.5050 (4) Å | 0.60 × 0.10 × 0.10 mm |
β = 98.860 (4)° | |
Data collection top
Nonius KappaCCD diffractometer | 1722 reflections with I > 2σ(I) |
10263 measured reflections | Rint = 0.047 |
1978 independent reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.032 | 42 restraints |
wR(F2) = 0.082 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.06 | Δρmax = 0.36 e Å−3 |
1978 reflections | Δρmin = −0.30 e Å−3 |
170 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 | |
O1W | 0.9614 (3) | 0.61374 (6) | −0.04030 (16) | 0.0408 (4) | |
H11 | 1.053 (5) | 0.5874 (7) | −0.068 (2) | 0.049* | |
H12 | 0.990 (5) | 0.6430 (7) | −0.079 (2) | 0.049* | |
O2W | 0.5546 (4) | 0.34824 (6) | 0.2851 (2) | 0.0607 (5) | |
H23 | 0.680 (5) | 0.3365 (12) | 0.344 (2) | 0.073* | |
H24 | 0.451 (5) | 0.3249 (11) | 0.246 (3) | 0.073* | |
O3 | −0.0226 (3) | 0.17958 (5) | 0.02070 (14) | 0.0377 (3) | |
O4 | 0.1122 (4) | 0.27195 (6) | 0.14601 (14) | 0.0460 (4) | |
O5 | 0.0257 (4) | 0.26826 (6) | −0.11604 (14) | 0.0453 (4) | |
H5 | 0.0635 | 0.2511 | −0.1853 | 0.068* | |
P | 0.12694 (10) | 0.234175 (19) | 0.02192 (5) | 0.02581 (15) | |
H | 0.398 (4) | 0.2231 (8) | 0.009 (2) | 0.031* | |
C2 | 0.2808 (3) | 0.47736 (7) | 0.35098 (17) | 0.0218 (3) | |
C4 | 0.3423 (3) | 0.56644 (7) | 0.29815 (17) | 0.0213 (3) | |
C5 | 0.5294 (3) | 0.55470 (7) | 0.20513 (17) | 0.0221 (3) | |
C6 | 0.6079 (3) | 0.49893 (7) | 0.18140 (17) | 0.0223 (3) | |
C8 | 0.4764 (4) | 0.64464 (7) | 0.20966 (19) | 0.0278 (4) | |
H8 | 0.4929 | 0.6824 | 0.1908 | 0.033* | |
N1 | 0.4691 (3) | 0.46262 (6) | 0.26186 (14) | 0.0233 (3) | |
H1 | 0.5049 | 0.4277 | 0.2550 | 0.028* | |
N2 | 0.1641 (3) | 0.43633 (6) | 0.41644 (16) | 0.0303 (3) | |
H2A | 0.0454 | 0.4438 | 0.4738 | 0.036* | |
H2B | 0.2075 | 0.4023 | 0.4014 | 0.036* | |
N3 | 0.2122 (3) | 0.52971 (6) | 0.37504 (14) | 0.0230 (3) | |
N7 | 0.6100 (3) | 0.60447 (6) | 0.15205 (15) | 0.0258 (3) | |
H7 | 0.7269 | 0.6087 | 0.0920 | 0.031* | |
N9 | 0.3129 (3) | 0.62305 (6) | 0.29956 (15) | 0.0255 (3) | |
H9 | 0.2082 | 0.6415 | 0.3493 | 0.031* | |
O6 | 0.7758 (3) | 0.48234 (5) | 0.10408 (13) | 0.0308 (3) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
O1W | 0.0530 (9) | 0.0256 (7) | 0.0504 (9) | 0.0056 (6) | 0.0291 (7) | 0.0034 (6) |
O2W | 0.0653 (12) | 0.0272 (9) | 0.0783 (13) | 0.0070 (7) | −0.0246 (9) | 0.0004 (8) |
O3 | 0.0537 (9) | 0.0276 (7) | 0.0344 (7) | −0.0116 (6) | 0.0149 (6) | 0.0001 (6) |
O4 | 0.0847 (11) | 0.0312 (8) | 0.0243 (7) | −0.0103 (7) | 0.0153 (7) | −0.0044 (6) |
O5 | 0.0869 (11) | 0.0274 (8) | 0.0238 (7) | 0.0122 (7) | 0.0155 (7) | 0.0040 (6) |
P | 0.0361 (3) | 0.0212 (3) | 0.0213 (3) | −0.00388 (17) | 0.00838 (18) | 0.00120 (17) |
C2 | 0.0192 (8) | 0.0251 (9) | 0.0209 (8) | 0.0013 (6) | 0.0019 (6) | −0.0016 (7) |
C4 | 0.0199 (8) | 0.0224 (9) | 0.0214 (8) | 0.0005 (6) | 0.0027 (6) | −0.0021 (6) |
C5 | 0.0201 (8) | 0.0251 (9) | 0.0216 (8) | 0.0012 (6) | 0.0050 (6) | −0.0011 (7) |
C6 | 0.0200 (8) | 0.0262 (9) | 0.0202 (8) | 0.0027 (6) | 0.0013 (6) | −0.0021 (7) |
C8 | 0.0293 (9) | 0.0226 (9) | 0.0325 (10) | −0.0017 (7) | 0.0074 (7) | −0.0002 (7) |
N1 | 0.0255 (7) | 0.0194 (7) | 0.0257 (8) | 0.0040 (5) | 0.0060 (6) | −0.0006 (6) |
N2 | 0.0342 (8) | 0.0239 (8) | 0.0358 (9) | −0.0004 (6) | 0.0149 (7) | 0.0012 (6) |
N3 | 0.0229 (7) | 0.0229 (7) | 0.0240 (7) | 0.0002 (5) | 0.0063 (6) | −0.0010 (6) |
N7 | 0.0248 (7) | 0.0268 (8) | 0.0274 (8) | 0.0001 (5) | 0.0088 (6) | 0.0017 (6) |
N9 | 0.0268 (8) | 0.0203 (7) | 0.0310 (8) | 0.0025 (5) | 0.0098 (6) | −0.0030 (6) |
O6 | 0.0318 (7) | 0.0343 (7) | 0.0292 (7) | 0.0091 (5) | 0.0137 (5) | −0.0023 (5) |
Geometric parameters (Å, º) top
O1W—H11 | 0.832 (15) | C4—C5 | 1.374 (2) |
O1W—H12 | 0.813 (15) | C5—N7 | 1.375 (2) |
O2W—H23 | 0.804 (17) | C5—C6 | 1.419 (2) |
O2W—H24 | 0.800 (17) | C6—O6 | 1.2293 (19) |
O3—P | 1.4905 (13) | C6—N1 | 1.391 (2) |
O4—P | 1.4989 (14) | C8—N7 | 1.319 (2) |
O5—P | 1.5580 (14) | C8—N9 | 1.342 (2) |
O5—H5 | 0.8200 | C8—H8 | 0.9300 |
P—H | 1.332 (19) | N1—H1 | 0.8600 |
C2—N3 | 1.329 (2) | N2—H2A | 0.8600 |
C2—N2 | 1.331 (2) | N2—H2B | 0.8600 |
C2—N1 | 1.368 (2) | N7—H7 | 0.8600 |
C4—N3 | 1.354 (2) | N9—H9 | 0.8600 |
C4—N9 | 1.368 (2) | | |
| | | |
H11—O1W—H12 | 112.8 (19) | O6—C6—C5 | 127.66 (16) |
H23—O2W—H24 | 114 (3) | N1—C6—C5 | 110.41 (14) |
P—O5—H5 | 109.5 | N7—C8—N9 | 109.97 (15) |
O3—P—O4 | 117.40 (8) | N7—C8—H8 | 125.0 |
O3—P—O5 | 111.87 (8) | N9—C8—H8 | 125.0 |
O4—P—O5 | 107.33 (8) | C2—N1—C6 | 125.89 (14) |
O3—P—H | 106.6 (9) | C2—N1—H1 | 117.1 |
O4—P—H | 110.8 (8) | C6—N1—H1 | 117.1 |
O5—P—H | 101.8 (8) | C2—N2—H2A | 120.0 |
N3—C2—N2 | 119.45 (15) | C2—N2—H2B | 120.0 |
N3—C2—N1 | 123.51 (15) | H2A—N2—H2B | 120.0 |
N2—C2—N1 | 117.04 (15) | C2—N3—C4 | 112.44 (14) |
N3—C4—N9 | 126.05 (14) | C8—N7—C5 | 107.87 (14) |
N3—C4—C5 | 127.26 (15) | C8—N7—H7 | 126.1 |
N9—C4—C5 | 106.69 (14) | C5—N7—H7 | 126.1 |
C4—C5—N7 | 107.46 (15) | C8—N9—C4 | 108.00 (14) |
C4—C5—C6 | 120.47 (15) | C8—N9—H9 | 126.0 |
N7—C5—C6 | 132.06 (15) | C4—N9—H9 | 126.0 |
O6—C6—N1 | 121.92 (16) | | |
| | | |
N3—C4—C5—N7 | −179.49 (15) | C5—C6—N1—C2 | 0.6 (2) |
N9—C4—C5—N7 | 0.04 (18) | N2—C2—N3—C4 | −178.41 (15) |
N3—C4—C5—C6 | −0.4 (3) | N1—C2—N3—C4 | 2.0 (2) |
N9—C4—C5—C6 | 179.14 (14) | N9—C4—N3—C2 | 179.69 (15) |
C4—C5—C6—O6 | −178.47 (17) | C5—C4—N3—C2 | −0.9 (2) |
N7—C5—C6—O6 | 0.4 (3) | N9—C8—N7—C5 | 0.5 (2) |
C4—C5—C6—N1 | 0.5 (2) | C4—C5—N7—C8 | −0.35 (19) |
N7—C5—C6—N1 | 179.37 (16) | C6—C5—N7—C8 | −179.30 (17) |
N3—C2—N1—C6 | −2.0 (3) | N7—C8—N9—C4 | −0.5 (2) |
N2—C2—N1—C6 | 178.37 (15) | N3—C4—N9—C8 | 179.81 (16) |
O6—C6—N1—C2 | 179.65 (15) | C5—C4—N9—C8 | 0.28 (18) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O5—H5···O4i | 0.82 | 1.74 | 2.5501 (19) | 167 |
N1—H1···O2W | 0.86 | 1.94 | 2.784 (2) | 166 |
N2—H2A···N3ii | 0.86 | 2.12 | 2.976 (2) | 173 |
N2—H2B···O2W | 0.86 | 2.48 | 3.189 (2) | 140 |
N2—H2B···O3iii | 0.86 | 2.59 | 3.131 (2) | 122 |
N7—H7···O1W | 0.86 | 1.81 | 2.6639 (19) | 176 |
N9—H9···O3iv | 0.86 | 1.86 | 2.7165 (19) | 172 |
O1W—H11···O6v | 0.83 (2) | 1.92 (2) | 2.7359 (18) | 168 (2) |
O1W—H12···O4vi | 0.81 (2) | 2.18 (2) | 2.929 (2) | 154 (2) |
O2W—H23···O3vii | 0.80 (2) | 2.05 (2) | 2.844 (2) | 168 (3) |
O2W—H24···O4 | 0.80 (2) | 2.15 (2) | 2.940 (2) | 170 (3) |
Symmetry codes: (i) x, −y+1/2, z−1/2; (ii) −x, −y+1, −z+1; (iii) x, −y+1/2, z+1/2; (iv) −x, y+1/2, −z+1/2; (v) −x+2, −y+1, −z; (vi) −x+1, −y+1, −z; (vii) x+1, −y+1/2, z+1/2. |
Experimental details
Crystal data |
Chemical formula | C5H6N5O+·H2O3P−·2H2O |
Mr | 269.17 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 293 |
a, b, c (Å) | 4.7340 (2), 24.0450 (3), 9.5050 (4) |
β (°) | 98.860 (4) |
V (Å3) | 1069.03 (7) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.29 |
Crystal size (mm) | 0.60 × 0.10 × 0.10 |
|
Data collection |
Diffractometer | Nonius KappaCCD diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 10263, 1978, 1722 |
Rint | 0.047 |
(sin θ/λ)max (Å−1) | 0.617 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.032, 0.082, 1.06 |
No. of reflections | 1978 |
No. of parameters | 170 |
No. of restraints | 42 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.36, −0.30 |
Selected geometric parameters (Å, º) topO3—P | 1.4905 (13) | O5—P | 1.5580 (14) |
O4—P | 1.4989 (14) | P—H | 1.332 (19) |
| | | |
O3—P—O4 | 117.40 (8) | O3—P—H | 106.6 (9) |
O3—P—O5 | 111.87 (8) | O4—P—H | 110.8 (8) |
O4—P—O5 | 107.33 (8) | O5—P—H | 101.8 (8) |
| | | |
N3—C4—C5—N7 | −179.49 (15) | C4—C5—C6—O6 | −178.47 (17) |
N9—C4—C5—N7 | 0.04 (18) | N7—C5—C6—N1 | 179.37 (16) |
N3—C4—C5—C6 | −0.4 (3) | O6—C6—N1—C2 | 179.65 (15) |
N9—C4—C5—C6 | 179.14 (14) | N3—C4—N9—C8 | 179.81 (16) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O5—H5···O4i | 0.82 | 1.74 | 2.5501 (19) | 167 |
N1—H1···O2W | 0.86 | 1.94 | 2.784 (2) | 166 |
N2—H2A···N3ii | 0.86 | 2.12 | 2.976 (2) | 173 |
N2—H2B···O2W | 0.86 | 2.48 | 3.189 (2) | 140 |
N2—H2B···O3iii | 0.86 | 2.59 | 3.131 (2) | 122 |
N7—H7···O1W | 0.86 | 1.81 | 2.6639 (19) | 176 |
N9—H9···O3iv | 0.86 | 1.86 | 2.7165 (19) | 172 |
O1W—H11···O6v | 0.832 (15) | 1.917 (15) | 2.7359 (18) | 168 (2) |
O1W—H12···O4vi | 0.813 (15) | 2.175 (16) | 2.929 (2) | 154 (2) |
O2W—H23···O3vii | 0.804 (17) | 2.053 (17) | 2.844 (2) | 168 (3) |
O2W—H24···O4 | 0.800 (17) | 2.150 (17) | 2.940 (2) | 170 (3) |
Symmetry codes: (i) x, −y+1/2, z−1/2; (ii) −x, −y+1, −z+1; (iii) x, −y+1/2, z+1/2; (iv) −x, y+1/2, −z+1/2; (v) −x+2, −y+1, −z; (vi) −x+1, −y+1, −z; (vii) x+1, −y+1/2, z+1/2. |
The crystal structures of organic–inorganic hybrid materials have been investigated over the past few decades (Bagieu-Beucher, 1990; Ravikumar et al., 2002). As part of our continuing interest in this field, we report here the crystal structure of guaninium monohydrogenphosphite dihydrate, (I).
The asymmetric unit contains one guaninium cation, one monohydrogenphosphite anion and two water molecules (Fig. 1)·The main feature of the alkyl or aryl ammonium monohydrogenphosphite is that the anionic subnetwork is built up through short strong hydrogen bonds (Blessing, 1986) and the organic cations are bonded to the phosphite layers by weaker hydrogen bonds (Masse et al., 1991). The inorganic moiety is a network of H2PO3− tetrahedra connected by short and strong hydrogen bonds. Inside this chains each H2PO3− group is connected with its two adjacent neighbours by strong hydrogen bonds (O5—H5···O4) to build a two-dimensional network along the c direction. Some similarities may be observed between the present atomic arrangement and the corresponding monophosphite previously investigated (Bendheif et al., 2003; William &Harrison, 2003). The guanine base occurs as the guaninium cation, [C5H6N5O]+, we observe that only the imino group of the imidazolyl portion (N7) has been protonated in the reaction with the phosphorus acid, while the imino group of the pyrimidine moity (N3) is not protonated, as was observed in guaninium dinitrate dihydrate (Bouchouit et al., 2002) and guaninium sulfate monohydrate (Cherouana et al., 2003). The guaninium organic cations are connected to H2PO3− anions by two means: (i) via a strong hydrogen bond nearly situated in their plane (N9—N9···O3) and (ii) via a large hydrogen bond (N2—H22···O3). When cations possess hydrogen-donor and hydrogen-acceptor functional groups, large hydrogen bonds occur between them; they are joined through only one hydrogen bond from the amino group N2 towards the imino group N3 (N2—H21···N3), so as to form infinite layers spreading along the [101] direction. A deformation electron-density map calculated from the observed X-ray structure factors (Fig. 2) showed significantly that the imidazolyl and pyrimidine rings are closely coplanar their deviation from planarity are given by the torsion angles. Water molecules play an important role in the cohesion and the stability of the crystal structure, the first water molecule (O1W) is involved in three hydrogen bonds connecting two guaninium cations via O1W···H7—N7 and O1W—H11···O6, and one phosphite anion via O1W—H12···O4, while the second water molecule (O2W) is bonded to two phosphite anions via O2W—H24···04 and O2W—H23···O3 and to the guaninium base via O2W···H1—N1 and O2W···H22···N22. No hydrogen bonds between water molecules were observed.