Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270109010919/gd3281sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270109010919/gd3281Isup2.hkl | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270109010919/gd3281IIsup3.hkl |
CCDC references: 735114; 735115
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.
In (I), the H-atom coordinates were freely refined, with Uiso(H) = 1.2Ueq(nearest F atom) or X.XUeq(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.
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).
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) Å3 |
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 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)] = 0.056 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.129 | Only H-atom coordinates refined |
S = 1.01 | w = 1/[σ2(Fo2) + (0.0671P)2] where P = (Fo2 + 2Fc2)/3 |
7461 reflections | (Δ/σ)max = 0.003 |
421 parameters | Δρmax = 0.41 e Å−3 |
0 restraints | Δρmin = −0.29 e Å−3 |
C2H7N4S+·HF2− | γ = 104.50 (3)° |
Mr = 158.18 | V = 1337.5 (8) Å3 |
Triclinic, P1 | Z = 8 |
a = 8.199 (3) Å | Mo Kα radiation |
b = 12.203 (4) Å | µ = 0.44 mm−1 |
c = 14.158 (4) Å | T = 100 K |
α = 100.78 (3)° | 0.19 × 0.09 × 0.07 mm |
β = 93.87 (3)° |
Oxford Diffraction KM4 CCD area-detector diffractometer | 7461 independent reflections |
Absorption correction: analytical (CrysAlis RED; Oxford Diffraction, 2006) | 5387 reflections with I > 2σ(I) |
Tmin = 0.897, Tmax = 0.979 | Rint = 0.051 |
20685 measured reflections |
R[F2 > 2σ(F2)] = 0.056 | 0 restraints |
wR(F2) = 0.129 | Only H-atom coordinates refined |
S = 1.01 | Δρmax = 0.41 e Å−3 |
7461 reflections | Δρmin = −0.29 e Å−3 |
421 parameters |
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) |
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* |
U11 | U22 | U33 | U12 | U13 | U23 | |
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) |
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) |
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···F21i | 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···F12ii | 0.83 (3) | 1.96 (3) | 2.744 (3) | 159 (3) |
N22—H212···F12ii | 0.86 (3) | 1.99 (3) | 2.768 (3) | 151 (3) |
N22—H222···F22iii | 0.80 (3) | 2.05 (3) | 2.847 (3) | 173 (3) |
N32—H312···F11ii | 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···F24iii | 0.86 (3) | 1.99 (3) | 2.851 (3) | 173 (3) |
N33—H323···F21ii | 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···F21ii | 0.82 (3) | 2.20 (3) | 2.928 (3) | 149 (3) |
N43—H423···F22ii | 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···F13iv | 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. |
2C2H7N4S+·SiF62− | 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) Å3 |
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 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)] = 0.026 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.071 | All H-atom parameters refined |
S = 1.01 | w = 1/[σ2(Fo2) + (0.0502P)2] where P = (Fo2 + 2Fc2)/3 |
1837 reflections | (Δ/σ)max = 0.001 |
125 parameters | Δρmax = 0.38 e Å−3 |
0 restraints | Δρmin = −0.28 e Å−3 |
2C2H7N4S+·SiF62− | γ = 66.15 (3)° |
Mr = 380.44 | V = 345.2 (3) Å3 |
Triclinic, P1 | Z = 1 |
a = 6.537 (3) Å | Mo Kα radiation |
b = 7.390 (3) Å | µ = 0.55 mm−1 |
c = 7.884 (4) Å | T = 100 K |
α = 83.65 (3)° | 0.25 × 0.23 × 0.09 mm |
β = 83.44 (3)° |
Oxford Diffraction KM4 CCD area-detector diffractometer | 1837 independent reflections |
Absorption correction: analytical (CrysAlis RED; Oxford Diffraction, 2006) | 1582 reflections with I > 2σ(I) |
Tmin = 0.870, Tmax = 0.953 | Rint = 0.021 |
4487 measured reflections |
R[F2 > 2σ(F2)] = 0.026 | 0 restraints |
wR(F2) = 0.071 | All H-atom parameters refined |
S = 1.01 | Δρmax = 0.38 e Å−3 |
1837 reflections | Δρmin = −0.28 e Å−3 |
125 parameters |
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) |
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)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
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) |
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—F3i | 1.6789 (10) | N2—H21 | 0.87 (2) |
Si1—F1i | 1.6911 (11) | N2—H22 | 0.848 (17) |
Si1—F2i | 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—F3i | 180.0 | N3—C2—N1 | 116.59 (12) |
F3i—Si1—F1 | 90.23 (5) | C2—N1—C1 | 129.51 (11) |
F3—Si1—F1i | 90.23 (5) | C2—N1—H1 | 113.3 (12) |
F3i—Si1—F1i | 89.77 (5) | C1—N1—H1 | 116.3 (12) |
F1—Si1—F1i | 180.0 | C1—N2—H21 | 125.0 (14) |
F3i—Si1—F2 | 89.88 (5) | C1—N2—H22 | 119.6 (10) |
F1i—Si1—F2 | 89.98 (5) | H21—N2—H22 | 114.9 (16) |
F3—Si1—F2i | 89.88 (5) | C2—N3—H31 | 121.0 (14) |
F3i—Si1—F2i | 90.12 (5) | C2—N3—H32 | 116.4 (12) |
F1—Si1—F2i | 89.98 (5) | H31—N3—H32 | 120.7 (18) |
F1i—Si1—F2i | 90.02 (5) | C2—N4—H41 | 118.8 (14) |
F2—Si1—F2i | 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. |
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···F1ii | 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···F3iii | 0.89 (2) | 2.05 (2) | 2.873 (2) | 153 (2) |
N4—H42···F2iv | 0.76 (2) | 2.32 (2) | 2.978 (2) | 146 (2) |
N4—H42···F3iii | 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. |
Experimental details
(I) | (II) | |
Crystal data | ||
Chemical formula | C2H7N4S+·HF2− | 2C2H7N4S+·SiF62− |
Mr | 158.18 | 380.44 |
Crystal system, space group | Triclinic, P1 | Triclinic, P1 |
Temperature (K) | 100 | 100 |
a, b, c (Å) | 8.199 (3), 12.203 (4), 14.158 (4) | 6.537 (3), 7.390 (3), 7.884 (4) |
α, β, γ (°) | 100.78 (3), 93.87 (3), 104.50 (3) | 83.65 (3), 83.44 (3), 66.15 (3) |
V (Å3) | 1337.5 (8) | 345.2 (3) |
Z | 8 | 1 |
Radiation type | Mo Kα | Mo Kα |
µ (mm−1) | 0.44 | 0.55 |
Crystal size (mm) | 0.19 × 0.09 × 0.07 | 0.25 × 0.23 × 0.09 |
Data collection | ||
Diffractometer | Oxford Diffraction KM4 CCD area-detector diffractometer | Oxford Diffraction KM4 CCD area-detector diffractometer |
Absorption correction | Analytical (CrysAlis RED; Oxford Diffraction, 2006) | Analytical (CrysAlis RED; Oxford Diffraction, 2006) |
Tmin, Tmax | 0.897, 0.979 | 0.870, 0.953 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 20685, 7461, 5387 | 4487, 1837, 1582 |
Rint | 0.051 | 0.021 |
(sin θ/λ)max (Å−1) | 0.703 | 0.703 |
Refinement | ||
R[F2 > 2σ(F2)], wR(F2), S | 0.056, 0.129, 1.01 | 0.026, 0.071, 1.01 |
No. of reflections | 7461 | 1837 |
No. of parameters | 421 | 125 |
H-atom treatment | Only H-atom coordinates refined | All H-atom parameters refined |
Δρmax, Δρmin (e Å−3) | 0.41, −0.29 | 0.38, −0.28 |
Computer programs: CrysAlis CCD (Oxford Diffraction, 2006), CrysAlis RED (Oxford Diffraction, 2006), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg & Putz, 2005) and SHELXTL-NT (Sheldrick, 2008).
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···F21i | 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···F12ii | 0.83 (3) | 1.96 (3) | 2.744 (3) | 159 (3) |
N22—H212···F12ii | 0.86 (3) | 1.99 (3) | 2.768 (3) | 151 (3) |
N22—H222···F22iii | 0.80 (3) | 2.05 (3) | 2.847 (3) | 173 (3) |
N32—H312···F11ii | 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···F24iii | 0.86 (3) | 1.99 (3) | 2.851 (3) | 173 (3) |
N33—H323···F21ii | 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···F21ii | 0.82 (3) | 2.20 (3) | 2.928 (3) | 149 (3) |
N43—H423···F22ii | 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···F13iv | 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. |
Si1—F1 | 1.6911 (11) | Si1—F3 | 1.6788 (11) |
Si1—F2 | 1.7086 (10) | ||
F1—Si1—F2 | 90.02 (5) | F3—Si1—F2 | 90.12 (5) |
F3—Si1—F1 | 89.77 (5) |
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···F1i | 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···F3ii | 0.89 (2) | 2.05 (2) | 2.873 (2) | 153 (2) |
N4—H42···F2iii | 0.76 (2) | 2.32 (2) | 2.978 (2) | 146 (2) |
N4—H42···F3ii | 0.76 (2) | 2.38 (2) | 3.021 (2) | 143 (2) |
Symmetry codes: (i) x, y, z+1; (ii) −x+1, −y+1, −z; (iii) x+1, y−1, z. |
(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 Oh 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 D2h 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).