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The title compound, C2H7N4O+·HSeO3, contains a network of 1-carbamoyl­guanidinium cations and hydrogenselenite anions. The crystal packing is controlled by N—H...O [dav(H...O) = 1.89 Å, θav(N—H...O) = 167° and dav(N...O) = 2.760 (1) Å] and O—H...O [dav(H...O) = 1.86 Å, θav(O—H...O) = 175° and dav(O...O) = 2.712 (1) Å] hydrogen bonds, resulting in a layered structure.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536803017380/bt6323sup1.cif
Contains datablocks I, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536803017380/bt6323Isup2.hkl
Contains datablock I

CCDC reference: 222861

Key indicators

  • Single-crystal X-ray study
  • T = 293 K
  • Mean [sigma](Se-O) = 0.002 Å
  • R factor = 0.031
  • wR factor = 0.078
  • Data-to-parameter ratio = 25.9

checkCIF/PLATON results

No syntax errors found



Alert level A PLAT029_ALERT_3_A _diffrn_measured_fraction_theta_full Low ..... 0.96
Alert level C PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ .. ? PLAT125_ALERT_4_C No _symmetry_space_group_name_Hall Given ..... ?
1 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 2 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 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

Comment top

The title compound, (C2H7N4O)(HSeO3), (I) (Fig. 1), contains a hydrogen-bonded network of (C2H7N4O)+ (1-carbamoylguanidinium or guanylurea) cations and hydrogenselenite anions. It complements simple salt-like guanylurea compounds, including (C2H7N4O)(ClO4) (Begley et al., 1985), (C2H7N4O)(H2PO4) (Zaman & Darlow, 1986), (C2H7N4O)Cl·0.5H2O (Scoponi et al., 1991) and (C2H7N4O)(CH4PO3)·H2O (Brauer & Kottsieper, 2003)

In (I), the (C2H7N4O)+ cation has normal geometrical parameters (Begley et al., 1985), with dav(N—C) = 1.343 (3) Å, indicating significant delocalization of electrons over the non-H-atom skeleton (Scopoini et al., 1991) and is almost planar (for the non-H atoms, the root-mean-square deviation from the best least-squares plane = 0.031 Å). A non-linear (θ = 128.8°) intramolecular N3—H5···O4 hydrogen bond is present, which is typical for (C2H7N4O)+ (Bremner & Harrison, 2002). The (HSeO3) hydrogenselenite group shows its standard (Verma, 1999) pyramidal geometry [dav(Se—O) = 1.699 (2) Å and θav(O—Se—O) = 102.2 (1)°], with the protonated Se–O3 vertex showing its expected lengthening relative to the other Se—O bonds.

The component species in (I) interact by means of a network of N—H···O and O—H···O hydrogen bonds (see Table 2 for symmetry codes). The guanylurea cations form hydrogen-bonded chains (via N4—H7···O4v bonds) crosslinked by the hydrogenselenite groups to form hydrogen-bonded layers (Fig. 2) in the (011) plane. There are various intermolecular hydrogen-bonding motifs including N—H···OS, and bifurcated N—H···(OS,OS) and N—H···(OS,OG) (S = selenite, G = guanylurea) bonds. Based on the H···O separations, these N—H···O bonds vary in strength from fairly strong (1.98 Å) to very weak (2.53 Å). Atoms O1 and O2 accept three hydrogen bonds each, and atoms O3 and O4 accept two each.

The strong, short, inter-selenite O3—H8···O2i hydrogen bonds help to fuse the layers into double sheets (Fig. 3); when considered in isolation, pairs of (HSeO3) units form unusual, inversion-symmetry generated, dimers by way of two such bonds (Fig. 3). Pseudo-ππ-stacking interactions between adjacent guanylurea moieties [d(N2···C4i) = 3.295 (3) Å and d(N3···N1i) = 3.437 (3) Å] may also provide some coherence between the layers. The double sheets stack normal to (011), with bonding between the double sheets controlled by van der Waals forces.

Experimental top

5 ml of 0.1 M `H2SeO3' (dissolved SeO2) and 5 ml of 0.1 M cyanoguanidine (C2H4N4) were mixed, resulting in a clear solution. Rod- and block-shaped crystals of (I) grew as the water evaporated over the course of a few days. The cyanoguanidine was transformed to guanylurea by slow acid hydrolysis.

Refinement top

Atom H8 was found in a difference map and refined by riding in its as-found position. H atoms bonded to nitrogen were placed in calculated positions [d(N—H) = 0.86 Å] and refined by riding. The constraint Uiso(H) = 1.2Ueq(parent atom) was applied in all cases.

Computing details top

Data collection: SMART (Bruker, 1999); cell refinement: SAINT (Bruker, 1999); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97; molecular graphics: ORTEP-3 (Farrugia, 1997) and ATOMS (Shape Software, 1999); software used to prepare material for publication: SHELXL97.

Figures top
[Figure 1] Fig. 1. The asymmetric unit of (I) (50% displacement ellipsoids). H atoms are drawn as small spheres of arbitrary radius and hydrogen bonds are indicated by dashed lines.
[Figure 2] Fig. 2. Detail of a (011) hydrogen-bonded sheet in (I) with the selenite groups represented by HSeO3E pseudo-tetrahedra (dummy atom E placed 1.0 Å from Se). Colour key: [HSeO3E] groups pink, O atoms red, C atoms blue, N atoms green, H atoms grey, E dummy atoms light blue (all radii arbitrary). The H···O portion of the intramolecular hydrogen bond is highlighted in light blue. The H···O portions of the N—H···O hydrogen bonds with 1.90 Å < d(H···O) < 2.30 Å and 2.30 Å < d(H···O) < 2.55 Å are highlighted in yellow and orange, respectively. Symmetry labels as in Table 2.
[Figure 3] Fig. 3. [010] projection of (I) showing the inter-selenite connectivity by way of hydrogen bonds. Colour key as in Fig. 1 and symmetry code as in Table 2. Guanylurea H atoms have been omitted for clarity.
(I) top
Crystal data top
C2H7N4O+·HSeO3Z = 2
Mr = 231.08F(000) = 228
Triclinic, P1Dx = 2.048 Mg m3
a = 6.7643 (4) ÅMo Kα radiation, λ = 0.71073 Å
b = 7.9045 (5) ÅCell parameters from 2368 reflections
c = 8.2612 (5) Åθ = 2.8–32.5°
α = 63.021 (1)°µ = 4.99 mm1
β = 81.414 (1)°T = 293 K
γ = 72.200 (1)°Block, colourless
V = 374.77 (4) Å30.45 × 0.35 × 0.30 mm
Data collection top
Bruker SMART1000 CCD
diffractometer
2591 independent reflections
Radiation source: fine-focus sealed tube2259 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.016
ω scansθmax = 32.5°, θmin = 2.8°
Absorption correction: multi-scan
(SADABS; Bruker, 1999)
h = 1010
Tmin = 0.143, Tmax = 0.224k = 117
3843 measured reflectionsl = 1212
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.031Hydrogen site location: geom (O-H) and calc (N-H)
wR(F2) = 0.078H-atom parameters constrained
S = 1.01 w = 1/[σ2(Fo2) + (0.0491P)2]
where P = (Fo2 + 2Fc2)/3
2591 reflections(Δ/σ)max = 0.001
100 parametersΔρmax = 1.00 e Å3
0 restraintsΔρmin = 0.66 e Å3
Crystal data top
C2H7N4O+·HSeO3γ = 72.200 (1)°
Mr = 231.08V = 374.77 (4) Å3
Triclinic, P1Z = 2
a = 6.7643 (4) ÅMo Kα radiation
b = 7.9045 (5) ŵ = 4.99 mm1
c = 8.2612 (5) ÅT = 293 K
α = 63.021 (1)°0.45 × 0.35 × 0.30 mm
β = 81.414 (1)°
Data collection top
Bruker SMART1000 CCD
diffractometer
2591 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 1999)
2259 reflections with I > 2σ(I)
Tmin = 0.143, Tmax = 0.224Rint = 0.016
3843 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0310 restraints
wR(F2) = 0.078H-atom parameters constrained
S = 1.01Δρmax = 1.00 e Å3
2591 reflectionsΔρmin = 0.66 e Å3
100 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
xyzUiso*/Ueq
Se10.46138 (3)0.22877 (3)0.59621 (3)0.02838 (8)
O10.5058 (3)0.3655 (3)0.3802 (2)0.0374 (4)
O20.2742 (3)0.1347 (2)0.5863 (2)0.0370 (3)
O30.6765 (3)0.0192 (3)0.6524 (3)0.0456 (4)
H80.68870.04480.57260.055*
O40.1792 (2)0.6594 (3)0.0737 (2)0.0421 (4)
N10.0675 (3)0.4162 (3)0.3471 (3)0.0375 (4)
H10.18530.38880.37560.045*
H20.03340.35030.42240.045*
N20.1542 (3)0.5944 (3)0.1572 (2)0.0311 (4)
H30.24310.52260.24300.037*
N30.0864 (3)0.8605 (3)0.1300 (3)0.0370 (4)
H40.12930.94780.22510.044*
H50.04060.85700.12210.044*
N40.4101 (3)0.7369 (3)0.0081 (3)0.0414 (5)
H60.45430.82370.10260.050*
H70.49310.65260.07970.050*
C10.2143 (3)0.7331 (3)0.0024 (3)0.0282 (4)
C20.0415 (3)0.5601 (3)0.1869 (3)0.0294 (4)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Se10.03106 (12)0.02730 (11)0.02449 (11)0.01114 (8)0.00084 (7)0.00710 (8)
O10.0357 (8)0.0368 (9)0.0298 (8)0.0181 (7)0.0015 (6)0.0006 (6)
O20.0345 (8)0.0369 (8)0.0381 (8)0.0193 (7)0.0035 (6)0.0101 (7)
O30.0421 (10)0.0418 (10)0.0448 (10)0.0037 (8)0.0196 (8)0.0158 (8)
O40.0246 (7)0.0523 (11)0.0352 (8)0.0151 (7)0.0062 (6)0.0024 (8)
N10.0312 (9)0.0384 (10)0.0322 (9)0.0159 (8)0.0016 (7)0.0019 (8)
N20.0226 (8)0.0364 (10)0.0249 (8)0.0104 (7)0.0044 (6)0.0025 (7)
N30.0285 (9)0.0403 (10)0.0299 (9)0.0143 (8)0.0052 (7)0.0002 (8)
N40.0257 (9)0.0519 (12)0.0376 (10)0.0176 (9)0.0023 (7)0.0066 (9)
C10.0247 (9)0.0321 (10)0.0257 (9)0.0104 (8)0.0014 (7)0.0086 (8)
C20.0253 (9)0.0320 (10)0.0272 (9)0.0103 (8)0.0002 (7)0.0081 (8)
Geometric parameters (Å, º) top
Se1—O11.6523 (15)N2—C21.396 (3)
Se1—O21.6807 (16)N2—H30.8600
Se1—O31.7626 (17)N3—C11.308 (3)
O3—H80.9787N3—H40.8600
O4—C21.227 (3)N3—H50.8600
N1—C21.328 (3)N4—C11.323 (3)
N1—H10.8600N4—H60.8600
N1—H20.8600N4—H70.8600
N2—C11.359 (3)
O1—Se1—O2103.10 (8)C1—N3—H5120.0
O1—Se1—O3102.92 (9)H4—N3—H5120.0
O2—Se1—O3100.48 (9)C1—N4—H6120.0
Se1—O3—H8111.7C1—N4—H7120.0
C2—N1—H1120.0H6—N4—H7120.0
C2—N1—H2120.0N3—C1—N4120.6 (2)
H1—N1—H2120.0N3—C1—N2122.58 (19)
C1—N2—C2124.68 (17)N4—C1—N2116.81 (19)
C1—N2—H3117.7O4—C2—N1123.2 (2)
C2—N2—H3117.7O4—C2—N2121.83 (19)
C1—N3—H4120.0N1—C2—N2114.98 (18)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O3—H8···O2i0.981.712.685 (3)173
N1—H1···O1ii0.862.152.990 (3)167
N1—H2···O20.862.062.903 (3)165
N2—H3···O10.861.992.824 (2)163
N3—H4···O2iii0.861.982.826 (2)169
N3—H5···O40.862.022.646 (3)129
N3—H5···O3iv0.862.483.132 (2)133
N4—H6···O3iii0.862.533.372 (3)165
N4—H7···O4v0.862.232.774 (2)122
N4—H7···O10.862.483.200 (3)142
Symmetry codes: (i) x+1, y, z+1; (ii) x1, y, z; (iii) x, y+1, z1; (iv) x1, y+1, z1; (v) x+1, y, z.

Experimental details

Crystal data
Chemical formulaC2H7N4O+·HSeO3
Mr231.08
Crystal system, space groupTriclinic, P1
Temperature (K)293
a, b, c (Å)6.7643 (4), 7.9045 (5), 8.2612 (5)
α, β, γ (°)63.021 (1), 81.414 (1), 72.200 (1)
V3)374.77 (4)
Z2
Radiation typeMo Kα
µ (mm1)4.99
Crystal size (mm)0.45 × 0.35 × 0.30
Data collection
DiffractometerBruker SMART1000 CCD
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 1999)
Tmin, Tmax0.143, 0.224
No. of measured, independent and
observed [I > 2σ(I)] reflections
3843, 2591, 2259
Rint0.016
(sin θ/λ)max1)0.756
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.031, 0.078, 1.01
No. of reflections2591
No. of parameters100
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)1.00, 0.66

Computer programs: SMART (Bruker, 1999), SAINT (Bruker, 1999), SAINT, SHELXS97 (Sheldrick, 1997), SHELXL97, ORTEP-3 (Farrugia, 1997) and ATOMS (Shape Software, 1999).

Selected bond lengths (Å) top
Se1—O11.6523 (15)N2—C11.359 (3)
Se1—O21.6807 (16)N2—C21.396 (3)
Se1—O31.7626 (17)N3—C11.308 (3)
O4—C21.227 (3)N4—C11.323 (3)
N1—C21.328 (3)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O3—H8···O2i0.981.712.685 (3)173
N1—H1···O1ii0.862.152.990 (3)167
N1—H2···O20.862.062.903 (3)165
N2—H3···O10.861.992.824 (2)163
N3—H4···O2iii0.861.982.826 (2)169
N3—H5···O40.862.022.646 (3)129
N3—H5···O3iv0.862.483.132 (2)133
N4—H6···O3iii0.862.533.372 (3)165
N4—H7···O4v0.862.232.774 (2)122
N4—H7···O10.862.483.200 (3)142
Symmetry codes: (i) x+1, y, z+1; (ii) x1, y, z; (iii) x, y+1, z1; (iv) x1, y+1, z1; (v) x+1, y, z.
 

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