Products of the inter­action of (1-diamino­methyl­ene)thio­urea with hydro­fluoric acid

The salts 1-(diamino­methyl­ene)thio­uron-1-ium hydrogen di­fluoride, C₂H₇N₄S⁺·HF₂⁻, (I), and bis­[1-(diamino­methyl­ene)­thio­uron-1-ium] hexa­fluoridosilicate, 2C₂H₇N₄S⁺·SiF₆²⁻, (II), have both been obtained from the reaction of (1-diamino­methyl­ene)thio­urea (HATU) with hydro­fluoric acid. Both compounds contain extensive networks of N—H...F hydrogen bonds. The hydrogen difluoride salt contains four independent asymmetric [HF₂]⁻ anions. In the hexa­fluoridosilicate salt, the centrosymmetric [SiF₆]²⁻ anion is distorted, although this distortion is not clearly correlated with the N—H...F hydrogen-bonding network.

S1. Comment

(1-Diaminomethylene)thiourea (HATU) is known to be capable of participating in an extensive network of interactions (Janczak & Perpétuo, 2008a). This capability has been utilized in cage-like complexes, such as [Ni₆(ATU)₈Cl](ClO₄)₃ (Vilar et al., 1998), which could serve as sensors for the identification of chloride anions in solution. HATU also forms complex hydrogen-bonded systems in its simple salts, such as the hydrogen sulfate and dihydrogen phosphate (Janczak & Perpétuo, 2008b). The crystal structures of several halide salts of HATU are also known, namely the chloride, bromide and iodide, all obtained from the reaction of HATU with the corresponding hydrogen halide in aqueous solution (Perpétuo & Janczak, 2008). The products of the reaction of HATU with hydrogen fluoride have not been reported hitherto. The present work is thus a continuation of our studies on the reactivity and complexing properties of (1-diaminomethylene)thiourea (Hołyńska & Kubiak, 2008), in which HATU halides can also be used as substrates.

Compound (I), obtained in the reaction of either concentrated or dilute hydrofluoric acid with HATU in a Teflon reaction vessel, comprises 1-(diaminomethylene)thiouron-1-ium cations and hydrogen difluoride anions (see scheme and Fig. 1). A similar reaction using very dilute hydrofluoric acid in a quartz vessel gave compound (II), while recrystallization of (I) from water in a quartz vessel gave a third product, possibly [HATUH]₃[SiF₆]F.H₂O (see Experimental). The hydrogen difluoride anion is an important model for strong hydrogen bonding (Williams & Schneemeyer, 1973). Such hydrogen bonding has been widely investigated, e.g. for arylammonium (Harmon et al., 1974) or alkylammonium (Gennick, Harmon & Potvin, 1977; Gennick, Harmon & Hartwig, 1977) fluorides.

The [HF₂]^- anion can be either symmetric (Wilson et al., 1989; Rush et al., 1972) or asymmetric (Williams & Schneemeyer, 1973; Ramos Silva et al., 2000), depending on its local environment. Ramos Silva et al. (2000) reported the structure of L-argininium hydrogen difluoride, which has the shortest F···F distances observed so far for an asymmetric [HF₂]^- anion, at 2.233 (2) and 2.248 (3) Å in two independent anions [see also Ramos Silva et al. (2000) for a detailed discussion of F···F distances in other hydrogen-bonded compounds]. Recently, the hydrogen difluoride anion has been considered of importance in the description of the magnetism in a new antiferromagnet, [Cu(HF₂)(pyz)₂][BF₄] (pyz is pyrazine; Manson et al., 2006).

Compound (I) contains four independent [HF₂]^- anions all lying in general positions, with F···F distances in the range 2.287 (2)–2.291 (2) Å, although the degree of asymmetry varies markedly between them (Table 1, Fig. 1). The compound adopts a layered arrangement (Fig. 2a) and each layer is stabilized by N—H···F hydrogen bonds (Fig. 2b). Within each layer, two cation layers can be distinguished, linked by the anions (Fig. 2b). Hydrogen-bonding motifs characteristic of 1-(diaminomethylene)thiouron-1-ium salts (Janczak & Perpétuo, 2008b) are present, such as R¹₂(6) (Etter et al., 1990), with two ammine groups acting as donors and an F atom from an [HF₂]^- anion acting as acceptor.

Compound (II) comprises 1-(diaminomethylene)thiouron-1-ium cations, and hexafluoridosilicate anions which lie across inversion centres (Fig. 3). The anion is linked via N—H···F hydrogen bonds to six [HATUH]⁺ cations; the symmetry-independent cation and five cations are related by the following symmetry operations: (-x, 2 - y, -z), (1 - x, 1 - y, -z), (-x, 2 - y, 1 - z), (1 - x, 1 + y, z) and (x, y, z - 1). The distortion of the anion from ideal O_h symmetry can be rationalized in terms of hydrogen bonding (the F atom bonded to the Si atom with the shortest Si—F bond does not participate in any hydrogen bond). In the case of (II), the distortion of the anion is towards D_2h and its dependence on the hydrogen-bonding network (Table 3) is not as clear as in the case reported by Reiß (1998). The deformation in (II) affects the Si—F bond lengths, but not the F—Si—F bond angles. For comparison, in cubic K₂[SiF₆] no such anion distortion is observed and the Si—F distance is 1.683 (2) Å (Loehlin, 1984). The geometric parameters of the 1-(diaminomethylene)thiouron-1-ium cation in both (I) and (II) are normal and comparable with those previously reported for other salts (Janczak & Perpétuo, 2008 [a or b?]; Perpétuo & Janczak, 2008).

In (II), the hydrogen-bonded layers lie perpendicular to [110] (Fig. 4a). Within each such layer, [HATUH]⁺ cations interact with [SiF₆]^2- anions through N—H···F hydrogen bonds (Fig. 4b) with the formation of many specific graph-set motifs (Etter et al., 1990), such as R²₂(8), R¹₂(6) [also present in (I)] and R²₁(4) [absent from (I)].

It is suspected that the reaction of HATU with hydrofluoric acid carried out at different concentrations of the reagents and at different temperatures will yield further interesting hydrogen-bonded systems, although our preliminary investigations have so far invariably led to compound (I).

S2. Experimental

CAUTION! Hydrogen fluoride is extremely corrosive and harmful to human tissue, causing painful burns which heal with difficulty. All handling should be conducted in an efficient fume hood and suitable body protection should be worn. Suitable palliative preparations, such as calcium gluconate gel, should be to hand before work with HF commences.

For the synthesis of (I), HATU (Aldrich) (0.05 g) was dissolved in concentrated (40%) hydrofluoric acid in a Teflon vessel. On slow evaporation of the solution, crystals of (I) in the form of colourless plates were obtained. Compound (I) reacts readily with glass and if stored in air it readily loses hydrogen fluoride gas. Compound (I) is also obtained when 5% hydrofluoric acid is used as the substrate. [Please check rephrasing in this paragraph]

The same reaction with an excess of 5% hydrofluoric acid carried out in a quartz glass vessel yields crystalline (II) (colourless blocks). On recrystallization of (I) from water, carried out in a quartz glass vessel, a third crystalline compound, (III), is obtained in the form of colourless blocks. Compound (III) seems to be [HATUH]₃[SiF₆]F.H₂O [P2₁/n, a = 8.212 (3), b = 22.234 (5), c = 11.806 (4) Å, β = 100.81 (3)°]. Compound (III) comprises three symmetry-independent [HATUH]⁺ cations, one [SiF₆]^2- anion lying in a general position and apparently one water molecule along with one fluoride anion disordered over two sites with half-occupancy factors. The assumed structure model is arbitrary and it is difficult to prove it unambiguously using standard analytical methods.

ESI-MS spectra were collected on micrOTOF-Q device for samples prepared as solutions in methanol. Positive ions were analysed. For (I) and (II) the most intensive peak was observed at m/Z 119.0 (ascribed to the [HATUH]⁺ cation). For comparison purposes, spectra for HATU, (A), and other halides of HATU were also collected. Hydrogen chloride, (B), hydrogen bromide, (C), and hydrogen iodide, (D), were prepared according to the literature procedures of Perpétuo & Janczak (2008). As shown below, their MS spectra lead to some observations worth noting. In the MS spectrum collected for (A) a very weak peak [M+1] at m/Z 119.0 is detected. The highest peak is observed at m/Z 304.3. A similar peak at m/Z 304.3 is observed for (B). In the MS spectrum collected for (C)–(D) [A mixture of the two?] the peak at m/Z 119.0 is more visible than for (A). For (D) the most intense peak in the MS spectrum is at m/Z 365.0 (with characteristic isotope distribution), which is the sum of double the mass of a HATU molecule, a single H⁺ cation and a single I^- anion. Similarly for (C), the highest peak in the MS spectrum (with characteristic isotope distribution) corresponds to the sum of double the mass of a HATU molecule, a single H⁺ cation and a single Br^- anion.

S3. Refinement

In (I), the H-atom coordinates were freely refined, with U_iso(H) = 1.2U_eq(nearest F atom) or X.XU_eq(N) [Please complete]. The range of N—H bond lengths is 0.75 (3)–0.88 (3) Å for (I) and the highest peak in the difference map (0.41 e Å^-3) is located 0.82 Å from atom S4. In (II), all H-atom parameters were freely refined. The range of N—H bond lengths is 0.76 (2)–0.89 (2) Å, and the highest peak in the difference map (0.38 e Å^-3) is located 0.59 Å from atom N1 and 0.82 Å from atom C1.

Computing details

For both compounds, data collection: CrysAlis CCD (Oxford Diffraction, 2006); cell refinement: CrysAlis RED (Oxford Diffraction, 2006); data reduction: CrysAlis RED (Oxford Diffraction, 2006); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg & Putz, 2005) and SHELXTL-NT (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures

	Fig. 1. A view of the symmetry-independent part of (I), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level and H atoms are shown as small spheres of arbitrary radii. Hydrogen bonds are denoted by dashed lines.
	Fig. 2. (a) A view of the hydrogen-bonded layers in (I). (b) The building principle of one of the hydrogen-bonded layers in (I). Symmetry-independent atoms are coloured black. Hydrogen bonds are shown as dashed lines. [Symmetry codes: (ii) x + 1, y + 1, z; (iii) -x + 1, -y + 1, -z + 1.]
	Fig. 3. A view of the cation and anion in (II), showing the atom-labelling scheme. Unlabelled atoms are generated by the symmetry operation (-x, -y + 2, -z). Displacement ellipsoids are drawn at the 30% probability level. Hydrogen bonds are denoted by dashed lines. R^22(8) and R^12(6) graph-set motifs are formed (Etter et al., 1990).
	Fig. 4. Two different views, (a) and (b), of one of the hydrogen-bonded layers present in (II). Hydrogen bonds are denoted by dashed lines. [Symmetry codes: (i) x + 1, y - 1, z; (ii) -x + 1, -y + 1, -z; (iii) x, y, z + 1.]

(I) 1-(diaminomethylene)thiouron-1-ium hydrogen difluoride

Crystal data

C2H7N4S^+·HF2^−	Z = 8
Mr = 158.18	F(000) = 656
Triclinic, P1	Dx = 1.571 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 8.199 (3) Å	Cell parameters from 8334 reflections
b = 12.203 (4) Å	θ = 3.0–36.8°
c = 14.158 (4) Å	µ = 0.44 mm^−1
α = 100.78 (3)°	T = 100 K
β = 93.87 (3)°	Plate, colourless
γ = 104.50 (3)°	0.19 × 0.09 × 0.07 mm
V = 1337.5 (8) Å^3

Data collection

Oxford Diffraction KM4 CCD area-detector diffractometer	7461 independent reflections
Radiation source: fine-focus sealed tube	5387 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.051
ω scans	θmax = 30.0°, θmin = 3.0°
Absorption correction: analytical (CrysAlis RED; Oxford Diffraction, 2006)	h = −11→11
Tmin = 0.897, Tmax = 0.979	k = −17→12
20685 measured reflections	l = −19→19

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.056	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.129	Only H-atom coordinates refined
S = 1.01	w = 1/[σ^2(Fo^2) + (0.0671P)^2] where P = (Fo^2 + 2Fc^2)/3
7461 reflections	(Δ/σ)max = 0.003
421 parameters	Δρmax = 0.41 e Å^−3
0 restraints	Δρmin = −0.29 e Å^−3

Special details

Experimental. IR spectra were collected on BRUKER spectrometer for samples suspended in nujol mull (KBr windows). (I): 435.6 (w), 516.0 (vw), 560.2 (vw), 632.2 (w), 734.4 (m), 829.5 (vw), 910.6 (vw), 993.2 (vw), 1105.1 (w), 1180.5 (m), 1248.0 (s), 1338.7 (s), 1462.3 (m), 1511.5 (s), 1530.3 (s), 1607.5 (vs), 1647.3 (s), 1710.1 (vs), 2854.1 (s), 2924.6 (vs), 3118.0 (vs), 3351.6 (vs)

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
S1	0.65033 (8)	0.34420 (5)	1.07733 (5)	0.02187 (15)
C11	0.4967 (3)	0.2312 (2)	1.01349 (17)	0.0168 (5)
C21	0.4187 (3)	0.3087 (2)	0.87042 (17)	0.0160 (5)
N11	0.4074 (3)	0.22647 (18)	0.92489 (15)	0.0165 (4)
H11	0.332 (4)	0.160 (3)	0.902 (2)	0.020*
N21	0.4466 (3)	0.13422 (19)	1.04580 (17)	0.0195 (4)
H211	0.378 (4)	0.078 (3)	1.012 (2)	0.023*
H221	0.501 (4)	0.129 (3)	1.100 (2)	0.023*
N31	0.3180 (3)	0.2799 (2)	0.78807 (16)	0.0207 (5)
H311	0.253 (4)	0.211 (3)	0.769 (2)	0.025*
H321	0.329 (4)	0.327 (3)	0.754 (2)	0.025*
N41	0.5254 (3)	0.41215 (19)	0.89735 (18)	0.0224 (5)
H411	0.582 (4)	0.423 (3)	0.948 (2)	0.027*
H421	0.520 (4)	0.455 (3)	0.862 (2)	0.027*
S2	0.58023 (8)	0.77907 (6)	0.56529 (5)	0.02171 (15)
C12	0.7568 (3)	0.8815 (2)	0.61651 (17)	0.0165 (5)
C22	0.8175 (3)	0.8187 (2)	0.77058 (17)	0.0159 (5)
N12	0.8497 (3)	0.88734 (18)	0.70460 (15)	0.0161 (4)
H12	0.935 (4)	0.943 (3)	0.717 (2)	0.019*
N22	0.8237 (3)	0.9687 (2)	0.57484 (17)	0.0209 (5)
H212	0.919 (4)	1.017 (3)	0.600 (2)	0.025*
H222	0.777 (4)	0.967 (3)	0.523 (2)	0.025*
N32	0.9254 (3)	0.84630 (19)	0.85032 (16)	0.0199 (4)
H312	1.015 (4)	0.904 (3)	0.856 (2)	0.024*
H322	0.916 (4)	0.802 (3)	0.889 (2)	0.024*
N42	0.6839 (3)	0.72842 (19)	0.75633 (17)	0.0205 (5)
H412	0.610 (4)	0.715 (3)	0.702 (2)	0.025*
H422	0.679 (4)	0.693 (3)	0.796 (2)	0.025*
S3	0.94092 (8)	0.68826 (6)	0.40442 (5)	0.02431 (16)
C13	0.8619 (3)	0.6004 (2)	0.47814 (17)	0.0158 (5)
C23	1.0729 (3)	0.6814 (2)	0.62613 (17)	0.0151 (5)
N13	0.9309 (3)	0.60576 (18)	0.57172 (15)	0.0155 (4)
H13	0.869 (4)	0.554 (3)	0.599 (2)	0.019*
N23	0.7215 (3)	0.51430 (18)	0.44971 (17)	0.0180 (4)
H213	0.681 (4)	0.475 (3)	0.491 (2)	0.022*
H223	0.664 (4)	0.512 (2)	0.396 (2)	0.022*
N33	1.1119 (3)	0.6634 (2)	0.71263 (16)	0.0205 (5)
H313	1.050 (4)	0.613 (3)	0.732 (2)	0.025*
H323	1.196 (4)	0.713 (3)	0.747 (2)	0.025*
N43	1.1657 (3)	0.76801 (19)	0.59415 (18)	0.0216 (5)
H413	1.139 (4)	0.773 (3)	0.535 (2)	0.026*
H423	1.248 (4)	0.810 (3)	0.631 (2)	0.026*
S4	0.89831 (9)	0.13769 (6)	0.91483 (5)	0.02482 (16)
C14	0.9121 (3)	0.2595 (2)	0.87298 (17)	0.0176 (5)
C24	0.6875 (3)	0.1886 (2)	0.73083 (18)	0.0161 (5)
N14	0.8184 (3)	0.26871 (18)	0.79072 (15)	0.0175 (4)
H14	0.838 (4)	0.334 (3)	0.779 (2)	0.021*
N24	1.0205 (3)	0.35896 (19)	0.91640 (16)	0.0204 (5)
H214	1.025 (4)	0.421 (3)	0.893 (2)	0.024*
H224	1.077 (4)	0.359 (3)	0.970 (2)	0.024*
N44	0.6221 (3)	0.08607 (19)	0.74982 (17)	0.0206 (5)
H314	0.667 (4)	0.286 (3)	0.642 (2)	0.025*
H324	0.547 (4)	0.174 (3)	0.618 (2)	0.025*
N34	0.6283 (3)	0.2179 (2)	0.65343 (17)	0.0212 (5)
H414	0.663 (4)	0.066 (3)	0.800 (2)	0.025*
H424	0.553 (4)	0.046 (3)	0.713 (2)	0.025*
F11	0.24069 (19)	−0.00178 (12)	0.87552 (11)	0.0228 (3)
F21	0.37400 (19)	−0.11575 (13)	0.77898 (11)	0.0221 (3)
H11F	0.318 (4)	−0.075 (3)	0.820 (2)	0.027*
F12	0.12625 (19)	0.06459 (13)	0.69533 (11)	0.0258 (3)
F22	0.3311 (2)	0.01618 (13)	0.60668 (11)	0.0243 (3)
H12F	0.230 (4)	0.037 (3)	0.648 (2)	0.029*
F13	0.78898 (19)	0.62194 (12)	0.90490 (11)	0.0227 (3)
F23	0.92486 (19)	0.50839 (12)	0.81046 (11)	0.0235 (3)
H13F	0.866 (4)	0.568 (3)	0.860 (2)	0.028*
F14	0.68870 (18)	0.44053 (12)	0.62464 (11)	0.0222 (3)
F24	0.49078 (19)	0.48832 (12)	0.71916 (10)	0.0217 (3)
H14F	0.584 (4)	0.469 (3)	0.675 (2)	0.026*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0207 (3)	0.0180 (3)	0.0223 (3)	−0.0009 (2)	−0.0049 (2)	0.0036 (2)
C11	0.0149 (11)	0.0184 (12)	0.0171 (11)	0.0053 (9)	0.0032 (9)	0.0023 (9)
C21	0.0151 (11)	0.0150 (11)	0.0181 (11)	0.0038 (9)	0.0042 (9)	0.0032 (9)
N11	0.0179 (10)	0.0119 (9)	0.0172 (10)	−0.0004 (8)	−0.0020 (8)	0.0038 (8)
N21	0.0199 (11)	0.0174 (11)	0.0174 (10)	−0.0019 (9)	−0.0031 (9)	0.0052 (8)
N31	0.0231 (11)	0.0188 (11)	0.0184 (11)	0.0002 (9)	0.0006 (9)	0.0073 (9)
N41	0.0296 (12)	0.0162 (11)	0.0186 (11)	−0.0004 (9)	−0.0013 (9)	0.0074 (9)
S2	0.0169 (3)	0.0234 (3)	0.0202 (3)	−0.0019 (2)	−0.0036 (2)	0.0055 (2)
C12	0.0184 (11)	0.0159 (11)	0.0155 (11)	0.0056 (9)	0.0033 (9)	0.0021 (9)
C22	0.0171 (11)	0.0132 (11)	0.0180 (11)	0.0059 (9)	0.0044 (9)	0.0015 (9)
N12	0.0146 (10)	0.0143 (10)	0.0164 (10)	−0.0013 (8)	−0.0010 (8)	0.0041 (8)
N22	0.0199 (11)	0.0211 (11)	0.0186 (11)	−0.0005 (9)	−0.0020 (9)	0.0064 (9)
N32	0.0194 (11)	0.0162 (11)	0.0214 (11)	−0.0003 (9)	−0.0031 (9)	0.0062 (9)
N42	0.0203 (11)	0.0192 (11)	0.0206 (11)	0.0000 (9)	−0.0012 (9)	0.0095 (9)
S3	0.0200 (3)	0.0306 (4)	0.0223 (3)	0.0002 (3)	0.0021 (3)	0.0146 (3)
C13	0.0153 (11)	0.0173 (11)	0.0160 (11)	0.0060 (9)	0.0021 (9)	0.0039 (9)
C23	0.0133 (11)	0.0135 (11)	0.0179 (11)	0.0041 (9)	0.0020 (9)	0.0015 (9)
N13	0.0147 (10)	0.0148 (10)	0.0153 (10)	0.0000 (8)	0.0009 (8)	0.0049 (8)
N23	0.0157 (10)	0.0182 (10)	0.0174 (10)	−0.0002 (8)	−0.0023 (8)	0.0055 (8)
N33	0.0225 (11)	0.0180 (11)	0.0164 (10)	−0.0016 (9)	−0.0019 (9)	0.0036 (9)
N43	0.0183 (11)	0.0186 (11)	0.0228 (11)	−0.0049 (9)	−0.0015 (9)	0.0067 (9)
S4	0.0347 (4)	0.0173 (3)	0.0218 (3)	0.0058 (3)	−0.0042 (3)	0.0067 (2)
C14	0.0173 (12)	0.0206 (12)	0.0151 (11)	0.0057 (10)	0.0046 (9)	0.0027 (9)
C24	0.0149 (11)	0.0159 (11)	0.0180 (11)	0.0044 (9)	0.0050 (9)	0.0032 (9)
N14	0.0191 (10)	0.0140 (10)	0.0178 (10)	0.0008 (8)	−0.0030 (8)	0.0063 (8)
N24	0.0231 (11)	0.0175 (11)	0.0182 (11)	0.0007 (9)	−0.0036 (9)	0.0067 (9)
N44	0.0216 (11)	0.0152 (11)	0.0215 (11)	−0.0019 (9)	−0.0032 (9)	0.0063 (9)
N34	0.0179 (11)	0.0186 (11)	0.0244 (11)	−0.0015 (9)	−0.0038 (9)	0.0088 (9)
F11	0.0217 (7)	0.0177 (7)	0.0246 (8)	−0.0007 (6)	−0.0036 (6)	0.0038 (6)
F21	0.0247 (8)	0.0187 (7)	0.0201 (7)	0.0012 (6)	−0.0002 (6)	0.0043 (6)
F12	0.0236 (8)	0.0258 (8)	0.0221 (8)	−0.0050 (6)	−0.0009 (6)	0.0071 (6)
F22	0.0235 (8)	0.0229 (8)	0.0238 (8)	−0.0005 (6)	−0.0018 (6)	0.0092 (6)
F13	0.0238 (8)	0.0198 (7)	0.0228 (8)	0.0023 (6)	−0.0021 (6)	0.0066 (6)
F23	0.0284 (8)	0.0174 (7)	0.0232 (8)	0.0019 (6)	−0.0005 (6)	0.0073 (6)
F14	0.0221 (7)	0.0210 (7)	0.0224 (8)	0.0007 (6)	0.0031 (6)	0.0090 (6)
F24	0.0220 (7)	0.0219 (8)	0.0193 (7)	0.0013 (6)	0.0008 (6)	0.0070 (6)

Geometric parameters (Å, º)

S1—C11	1.678 (3)	C23—N33	1.317 (3)
C11—N21	1.328 (3)	C23—N13	1.369 (3)
C11—N11	1.393 (3)	N13—H13	0.87 (3)
C21—N41	1.314 (3)	N23—H213	0.86 (3)
C21—N31	1.318 (3)	N23—H223	0.86 (3)
C21—N11	1.365 (3)	N33—H313	0.80 (3)
N11—H11	0.87 (3)	N33—H323	0.84 (3)
N21—H211	0.82 (3)	N43—H413	0.87 (3)
N21—H221	0.88 (3)	N43—H423	0.82 (3)
N31—H311	0.86 (3)	S4—C14	1.681 (3)
N31—H321	0.81 (3)	C14—N24	1.322 (3)
N41—H411	0.79 (3)	C14—N14	1.389 (3)
N41—H421	0.79 (3)	C24—N34	1.313 (3)
S2—C12	1.673 (3)	C24—N44	1.317 (3)
C12—N22	1.329 (3)	C24—N14	1.367 (3)
C12—N12	1.397 (3)	N14—H14	0.82 (3)
C22—N42	1.318 (3)	N24—H214	0.87 (3)
C22—N32	1.321 (3)	N24—H224	0.86 (3)
C22—N12	1.364 (3)	N44—H414	0.87 (3)
N12—H12	0.83 (3)	N44—H424	0.75 (3)
N22—H212	0.86 (3)	N34—H314	0.86 (3)
N22—H222	0.80 (3)	N34—H324	0.81 (3)
N32—H312	0.87 (3)	F11—H11F	1.38 (3)
N32—H322	0.83 (3)	F21—H11F	0.92 (3)
N42—H412	0.91 (3)	F12—H12F	1.20 (3)
N42—H422	0.76 (3)	F22—H12F	1.10 (3)
S3—C13	1.680 (3)	F13—H13F	1.16 (3)
C13—N23	1.328 (3)	F23—H13F	1.14 (3)
C13—N13	1.388 (3)	F14—H14F	1.23 (3)
C23—N43	1.313 (3)	F24—H14F	1.06 (3)
N21—C11—N11	112.6 (2)	N23—C13—N13	112.4 (2)
N21—C11—S1	121.2 (2)	N23—C13—S3	121.35 (19)
N11—C11—S1	126.21 (19)	N13—C13—S3	126.24 (19)
N41—C21—N31	120.6 (2)	N43—C23—N33	121.4 (2)
N41—C21—N11	122.3 (2)	N43—C23—N13	121.9 (2)
N31—C21—N11	117.1 (2)	N33—C23—N13	116.7 (2)
C21—N11—C11	130.0 (2)	C23—N13—C13	129.9 (2)
C21—N11—H11	116.4 (19)	C23—N13—H13	117.5 (19)
C11—N11—H11	113.5 (19)	C13—N13—H13	112.6 (19)
C11—N21—H211	120 (2)	C13—N23—H213	118 (2)
C11—N21—H221	118 (2)	C13—N23—H223	117 (2)
H211—N21—H221	121 (3)	H213—N23—H223	123 (3)
C21—N31—H311	121 (2)	C23—N33—H313	120 (2)
C21—N31—H321	117 (2)	C23—N33—H323	117 (2)
H311—N31—H321	121 (3)	H313—N33—H323	123 (3)
C21—N41—H411	115 (2)	C23—N43—H413	118 (2)
C21—N41—H421	115 (2)	C23—N43—H423	117 (2)
H411—N41—H421	130 (3)	H413—N43—H423	125 (3)
N22—C12—N12	112.5 (2)	N24—C14—N14	112.4 (2)
N22—C12—S2	121.5 (2)	N24—C14—S4	121.7 (2)
N12—C12—S2	125.90 (19)	N14—C14—S4	125.84 (19)
N42—C22—N32	120.8 (2)	N34—C24—N44	121.0 (2)
N42—C22—N12	121.8 (2)	N34—C24—N14	117.4 (2)
N32—C22—N12	117.4 (2)	N44—C24—N14	121.6 (2)
C22—N12—C12	130.1 (2)	C24—N14—C14	130.0 (2)
C22—N12—H12	118 (2)	C24—N14—H14	115 (2)
C12—N12—H12	112 (2)	C14—N14—H14	115 (2)
C12—N22—H212	120 (2)	C14—N24—H214	120 (2)
C12—N22—H222	116 (2)	C14—N24—H224	116 (2)
H212—N22—H222	124 (3)	H214—N24—H224	124 (3)
C22—N32—H312	119 (2)	C24—N44—H414	121 (2)
C22—N32—H322	120 (2)	C24—N44—H424	115 (2)
H312—N32—H322	120 (3)	H414—N44—H424	124 (3)
C22—N42—H412	117.6 (19)	C24—N34—H314	121 (2)
C22—N42—H422	115 (2)	C24—N34—H324	120 (2)
H412—N42—H422	128 (3)	H314—N34—H324	119 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
F21—H11F···F11	0.92 (3)	1.38 (3)	2.291 (2)	172 (3)
F22—H12F···F12	1.10 (3)	1.20 (3)	2.291 (2)	177 (3)
F23—H13F···F13	1.14 (3)	1.16 (3)	2.287 (2)	172 (3)
F24—H14F···F14	1.06 (3)	1.23 (3)	2.289 (2)	177 (3)
N11—H11···F11	0.87 (3)	1.89 (3)	2.711 (3)	157 (3)
N21—H211···F11	0.82 (3)	2.10 (3)	2.823 (3)	148 (3)
N21—H221···F21^i	0.88 (3)	2.00 (3)	2.873 (3)	179 (3)
N31—H311···F12	0.86 (3)	1.90 (3)	2.732 (3)	166 (3)
N31—H321···F24	0.81 (3)	2.24 (3)	2.955 (3)	147 (3)
N41—H421···F24	0.79 (3)	2.14 (3)	2.867 (3)	152 (3)
N12—H12···F12^ii	0.83 (3)	1.96 (3)	2.744 (3)	159 (3)
N22—H212···F12^ii	0.86 (3)	1.99 (3)	2.768 (3)	151 (3)
N22—H222···F22^iii	0.80 (3)	2.05 (3)	2.847 (3)	173 (3)
N32—H312···F11^ii	0.87 (3)	1.89 (3)	2.734 (3)	165 (3)
N32—H322···F13	0.83 (3)	2.24 (3)	2.953 (3)	144 (3)
N42—H422···F13	0.76 (3)	2.16 (3)	2.862 (3)	153 (3)
N13—H13···F14	0.87 (3)	1.87 (3)	2.708 (3)	162 (3)
N23—H213···F14	0.86 (3)	2.01 (3)	2.796 (3)	151 (3)
N23—H223···F24^iii	0.86 (3)	1.99 (3)	2.851 (3)	173 (3)
N33—H323···F21^ii	0.84 (3)	2.18 (3)	2.940 (3)	150 (3)
N33—H313···F23	0.80 (3)	1.98 (3)	2.768 (3)	166 (3)
N43—H423···F21^ii	0.82 (3)	2.20 (3)	2.928 (3)	149 (3)
N43—H423···F22^ii	0.82 (3)	2.53 (3)	2.958 (3)	114 (3)
N14—H14···F23	0.82 (3)	2.02 (3)	2.789 (3)	156 (3)
N24—H214···F23	0.87 (3)	1.99 (3)	2.788 (3)	151 (3)
N24—H224···F13^iv	0.86 (3)	1.96 (3)	2.821 (3)	174 (3)
N34—H324···F22	0.81 (3)	2.24 (3)	2.933 (3)	145 (3)
N34—H314···F14	0.86 (3)	1.92 (3)	2.750 (3)	163 (3)
N44—H424···F21	0.75 (3)	2.52 (3)	2.891 (3)	112 (3)
N44—H424···F22	0.75 (3)	2.19 (3)	2.865 (3)	151 (3)

Symmetry codes: (i) −x+1, −y, −z+2; (ii) x+1, y+1, z; (iii) −x+1, −y+1, −z+1; (iv) −x+2, −y+1, −z+2.

(II) bis[1-(diaminomethylene)thiouron-1-ium] hexafluoridosilicate

Crystal data

2C2H7N4S^+·SiF6^2^−	Z = 1
Mr = 380.44	F(000) = 194
Triclinic, P1	Dx = 1.830 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 6.537 (3) Å	Cell parameters from 3979 reflections
b = 7.390 (3) Å	θ = 3.4–36.7°
c = 7.884 (4) Å	µ = 0.55 mm^−1
α = 83.65 (3)°	T = 100 K
β = 83.44 (3)°	Plate, colourless
γ = 66.15 (3)°	0.25 × 0.23 × 0.09 mm
V = 345.2 (3) Å^3

Data collection

Oxford Diffraction KM4 CCD area-detector diffractometer	1837 independent reflections
Radiation source: fine-focus sealed tube	1582 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.021
ω scans	θmax = 30.0°, θmin = 3.4°
Absorption correction: analytical (CrysAlis RED; Oxford Diffraction, 2006)	h = −9→8
Tmin = 0.870, Tmax = 0.953	k = −10→10
4487 measured reflections	l = −10→7

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.026	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.071	All H-atom parameters refined
S = 1.01	w = 1/[σ^2(Fo^2) + (0.0502P)^2] where P = (Fo^2 + 2Fc^2)/3
1837 reflections	(Δ/σ)max = 0.001
125 parameters	Δρmax = 0.38 e Å^−3
0 restraints	Δρmin = −0.28 e Å^−3

Special details

Experimental. IR spectra were collected on BRUKER spectrometer for samples suspended in nujol mull (KBr windows). (2): 431.3 (w), 466.3 (w), 475.8 (w), 557.5 (w), 672.9 (m), 724.3 (m), 781.4 (w), 911.0 (vw), 990.8 (vw), 1103.8 (w), 1153.3 (w), 1180.6 (w), 1248.5 (m), 1341.1 (s), 1376.6 (s), 1462.6 (s), 1516.1 (m), 1611.3 (vs), 1711.5 (s), 2854.0 (vs), 2923.9 (vs), 3106.4 (s), 3241.6 (s), 3336.2 (s), 3423.6 (s)

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Si1	0.0000	1.0000	0.0000	0.01013 (12)
F1	0.24934 (12)	0.95426 (11)	−0.11350 (10)	0.01524 (18)
F2	0.10377 (12)	1.04449 (11)	0.17299 (10)	0.01523 (18)
F3	0.08812 (13)	0.75883 (11)	0.06702 (10)	0.01587 (18)
S1	0.68023 (5)	0.61828 (5)	0.59622 (4)	0.01390 (10)
C1	0.4908 (2)	0.76695 (18)	0.46135 (16)	0.0112 (2)
C2	0.6659 (2)	0.61699 (19)	0.18499 (16)	0.0112 (2)
N1	0.51467 (18)	0.76054 (16)	0.28476 (14)	0.0117 (2)
H1	0.409 (3)	0.847 (3)	0.230 (2)	0.019 (4)*
N2	0.29919 (18)	0.90823 (17)	0.51676 (15)	0.0136 (2)
H21	0.204 (3)	0.998 (3)	0.451 (3)	0.035 (5)*
H22	0.272 (2)	0.926 (2)	0.623 (2)	0.008 (4)*
N3	0.6347 (2)	0.63905 (18)	0.02024 (15)	0.0144 (2)
H31	0.518 (3)	0.734 (3)	−0.020 (3)	0.037 (6)*
H32	0.717 (3)	0.537 (3)	−0.041 (2)	0.028 (5)*
N4	0.83427 (19)	0.46546 (17)	0.24824 (16)	0.0135 (2)
H41	0.849 (4)	0.453 (3)	0.363 (3)	0.038 (5)*
H42	0.906 (3)	0.383 (3)	0.190 (2)	0.015 (4)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Si1	0.0101 (2)	0.0095 (2)	0.0082 (2)	−0.00097 (17)	−0.00135 (17)	−0.00098 (17)
F1	0.0119 (4)	0.0166 (4)	0.0138 (4)	−0.0025 (3)	0.0008 (3)	−0.0014 (3)
F2	0.0147 (4)	0.0156 (4)	0.0126 (4)	−0.0015 (3)	−0.0048 (3)	−0.0033 (3)
F3	0.0182 (4)	0.0095 (4)	0.0156 (4)	−0.0013 (3)	−0.0018 (3)	0.0004 (3)
S1	0.01318 (16)	0.01599 (17)	0.00995 (17)	−0.00279 (12)	−0.00338 (11)	0.00034 (12)
C1	0.0129 (5)	0.0116 (6)	0.0104 (6)	−0.0063 (4)	−0.0012 (4)	−0.0002 (5)
C2	0.0110 (5)	0.0124 (6)	0.0116 (6)	−0.0061 (4)	−0.0007 (4)	−0.0010 (5)
N1	0.0117 (5)	0.0114 (5)	0.0092 (5)	−0.0015 (4)	−0.0022 (4)	0.0002 (4)
N2	0.0137 (5)	0.0140 (5)	0.0094 (6)	−0.0018 (4)	0.0000 (4)	−0.0016 (4)
N3	0.0146 (5)	0.0150 (5)	0.0107 (5)	−0.0026 (4)	−0.0018 (4)	−0.0015 (4)
N4	0.0128 (5)	0.0123 (5)	0.0119 (6)	−0.0006 (4)	−0.0015 (4)	−0.0031 (4)

Geometric parameters (Å, º)

Si1—F1	1.6911 (11)	C2—N3	1.3198 (18)
Si1—F2	1.7086 (10)	C2—N1	1.3711 (18)
Si1—F3	1.6788 (11)	N1—H1	0.848 (18)
Si1—F3^i	1.6789 (10)	N2—H21	0.87 (2)
Si1—F1^i	1.6911 (11)	N2—H22	0.848 (17)
Si1—F2^i	1.7086 (10)	N3—H31	0.86 (2)
S1—C1	1.6774 (14)	N3—H32	0.89 (2)
C1—N2	1.3296 (18)	N4—H41	0.91 (2)
C1—N1	1.3870 (18)	N4—H42	0.763 (19)
C2—N4	1.3113 (17)
F1—Si1—F2	90.02 (5)	N1—C1—S1	125.24 (10)
F3—Si1—F1	89.77 (5)	N4—C2—N3	121.12 (13)
F3—Si1—F2	90.12 (5)	N4—C2—N1	122.29 (12)
F3—Si1—F3^i	180.0	N3—C2—N1	116.59 (12)
F3^i—Si1—F1	90.23 (5)	C2—N1—C1	129.51 (11)
F3—Si1—F1^i	90.23 (5)	C2—N1—H1	113.3 (12)
F3^i—Si1—F1^i	89.77 (5)	C1—N1—H1	116.3 (12)
F1—Si1—F1^i	180.0	C1—N2—H21	125.0 (14)
F3^i—Si1—F2	89.88 (5)	C1—N2—H22	119.6 (10)
F1^i—Si1—F2	89.98 (5)	H21—N2—H22	114.9 (16)
F3—Si1—F2^i	89.88 (5)	C2—N3—H31	121.0 (14)
F3^i—Si1—F2^i	90.12 (5)	C2—N3—H32	116.4 (12)
F1—Si1—F2^i	89.98 (5)	H31—N3—H32	120.7 (18)
F1^i—Si1—F2^i	90.02 (5)	C2—N4—H41	118.8 (14)
F2—Si1—F2^i	180.0	C2—N4—H42	118.8 (13)
N2—C1—N1	112.97 (11)	H41—N4—H42	121.8 (18)
N2—C1—S1	121.79 (11)

Symmetry code: (i) −x, −y+2, −z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···F2	0.85 (2)	2.01 (2)	2.823 (2)	162 (2)
N2—H22···F1^ii	0.85 (2)	2.10 (2)	2.938 (2)	173 (2)
N2—H21···F2	0.87 (2)	2.31 (2)	3.023 (2)	139 (2)
N3—H31···F1	0.86 (2)	2.00 (2)	2.864 (2)	179 (2)
N3—H32···F3^iii	0.89 (2)	2.05 (2)	2.873 (2)	153 (2)
N4—H42···F2^iv	0.76 (2)	2.32 (2)	2.978 (2)	146 (2)
N4—H42···F3^iii	0.76 (2)	2.38 (2)	3.021 (2)	143 (2)

Symmetry codes: (ii) x, y, z+1; (iii) −x+1, −y+1, −z; (iv) x+1, y−1, z.