organic compounds
N,N,N′,N′,N′′,N′′-hexamethylguanidinium cyanate 1.5-hydrate
ofaFakultät Chemie/Organische Chemie, Hochschule Aalen, Beethovenstrasse 1, D-73430 Aalen, Germany
*Correspondence e-mail: willi.kantlehner@hs-aalen.de
The title hydrated salt, C7H18N3+·OCN−.1.5H2O, was synthesized starting from N,N,N′,N′,N′′,N′′-hexamethylguanidinium chloride by a twofold anion-exchange reaction. The contains two cations, two cyanate anions and three water molecules. One cation shows orientational disorder and two sets of N-atom positions were found related by a 60° rotation, with an occupancy ratio of 0.852 (6):0.148 (6). The C—N bond lengths in both guanidinium ions range from 1.329 (2) to 1.358 (10) Å, indicating double-bond character, pointing towards charge delocalization within the NCN planes. Strong O—H⋯N hydrogen bonds between the crystal water molecules and the cyanate ions and strong O—H⋯O hydrogen bonds between the water molecules are present, resulting in a two-dimensional hydrogen bonded network running parallel to the (001) plane. The hexamethylguanidinium ions are packed in between the layers built up by water molecules and cyanate ions.
Keywords: crystal structure; cyanate; hexamethylguanidinium; salt; O—H⋯O hydrogen bonds; O—H⋯N hydrogen bonds.
CCDC reference: 867308
1. Related literature
For the synthesis of hexasubstituted guanidinium salts with different anions, see: Kantlehner et al. (1984). For the of N,N,N′,N′,N′′,N′′-hexamethylguanidinium chloride, see: Oelkers & Sundermeyer (2011). For the of N,N,N′,N′,N′′,N′′-hexamethylguanidinium difluorotrimethylsilicate, see: Röschenthaler et al. (2002). For the of N,N,N′,N′,N′′,N′′-hexamethylguanidinium tetraphenylborate, see: Frey et al. (1998). For the of N,N,N′,N′,N′′,N′′-hexamethylguanidinium fluoride, see: Kolomeitsev et al. (2000). For the of N,N,N′,N′,N′′,N′′-hexamethylguanidinium hexafluorosilicate hexahydrate, see: Zhang et al. (1999). For the crystal structures of [C(NMe2)3][Mn(CO)5] and [C(NMe2)3][Co(CO)4], see: Petz & Weller (1991). For a neutron diffraction studie of deuterated ammonium cyanate, see: MacLean et al. (2003). For the use of intensity quotients and differences in see: Parsons et al. (2013).
2. Experimental
2.1. Crystal data
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2.2. Data collection
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2.3. Refinement
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Data collection: APEX2 (Bruker, 2008); cell SAINT (Bruker, 2008); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: DIAMOND (Brandenburg & Putz, 2005); software used to prepare material for publication: SHELXL2014.
Supporting information
CCDC reference: 867308
https://doi.org/10.1107/S2056989015024317/rz5180sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989015024317/rz5180Isup2.hkl
To a solution of 10 g (0.043 mol) N,N,N',N',N'',N''-hexamethylguanidinium tetrafluoroborate in water, 3.51 g (0.043 mol) potassium cyanate in 20 ml water was added. The solution was kept for twelve hours at 273 K and the precipitated potassium tetrafluoroborate was removed by filtration. After removing of the water, the residue was redissolved in acetonitrile and the solution was filtered again to remove the insoluble residue. The title compound crystallized from a saturated acetonitrile solution after several days at 273 K, forming colorless single crystals. Yield: 7.05 g (88%).
The O-bound H atoms of the water molecules were located in a difference Fourier map and were refined freely [O—H = 0.74 (4) - 0.86 (4) Å]. The atoms N6, N7 and N8 of one cation are disordered over two sets of sites (N6A, N7A and N8A; N6B, N7B and N8B) with refined occupancies of 0.862 (6):0.138 (6), 0.852 (6):0.148 (6) and 0.852 (6):0.148 (6). The title compound crystallizes in the non-centrosymmetric
Cc; however, in the absence of significant effects, the determined x = 0.2 (3) (Parsons et al., 2013) is essentially meaningless. The hydrogen atoms of the methyl groups were allowed to rotate with a fixed angle around the C–N bonds to best fit the experimental electron density, with Uiso(H) set to 1.5 Ueq(C) and d(C—H) = 0.98 Å.The reaction of phosgene with N,N,N',N'-tetramethylurea yields N,N,N',N'-tetramethylchloroformamidinium chloride, which can be transformed by a mixture of dimethylamine and triethylamine into a mixture of N,N,N',N',N'',N''-hexamethylguanidinium chloride and triethylamine hydrochloride. Treating the salt mixture with an aqueous sodium hydroxide solution leads after work up to the pure guanidinium chloride. Conversion of the chloride to the tetrafluoroborate salt occurs by heating it with BF3O(C2H5)2 (Kantlehner et al., 1984). A further
was possible by reacting N,N,N',N',N'',N''-hexamethylguanidinium tetrafluoroborate with potassium cyanate in water. According to the structure analysis of the title compound, the contains two N,N,N',N',N'',N''-hexamethylguanidinium (HMG+) ions, two cyanate ions and three water molecules (Fig. 1). One cation (cation I) shows an orientational disorder and two sets of N positions were found related by a 60° rotation, with an occupancy ratio of 0.852 (6):0.148 (6). This leads to the characteristic star-shaped appearance of the HMG+ ion (Fig. 2). The second cation (cation II) is not disordered. Searching for known crystal structures in literature of N,N,N',N',N'',N''-hexamethylguanidinium salts [see, for example: chloride salt (Oelkers & Sundermeyer, 2011), difluorotrimethylsilicate salt (Röschenthaler et al., 2002), tetraphenylborate salt (Frey et al., 1998), fluoride salt (Kolomeitsev et al., 2000), hexafluorosilicate hexahydrate salt (Zhang et al., 1999), [Mn(CO)5] and [Co(CO)4] salts (Petz & Weller, 1991)], it is obvious that in all those compounds the HMG+ ions are orientationally disordered too. In the title salt, the C–N bond lengths of both cations are in a range from 1.329 (2) and 1.358 (10) Å, indicating double bond character. The CN3 units are planar and the N–C–N angles are ranging from 118.0 (7)° to 121.8 (7)°. The positive charge is completely delocalized in the CN3 plane. The N–C bond lengths in the non-disordered guanidinium ion (cation II) are in a typical range from 1.453 (3) to 1.475 (2) Å, characteristic for a N–C single bond. In the disordered one (cation I), some N–C bond lengths deviate from their typical values and appear to be slightly longer [d(N–C) = 1.464 (3) - 1.655 (10) Å]. The N–C and C–O bond lengths in both cyanate ions [d(N–C) = 1.165 (3) and 1.172 (3) Å; d(C–O) = 1.213 (3) and 1.230 (3) Å] are in very good agreement with the data determined from a neutron diffraction study of deuterated ammonium cyanate (ND4OCN) at 14 K [d(N–C) = 1.191 (5) Å and d(C–O) =) 1.215 (5) Å (MacLean et al., 2003)]. Strong O–H···N hydrogen bonds between the crystal water molecules and the cyanate ions [d(H···N) = 2.00 (3) Å (Tab. 1)] and strong O–H···O hydrogen bonds between the water molecules are present [d(H···O) = 1.92 (3) - 2.10 (4) Å (Tab. 1)] (Fig. 3), resulting in a two-dimensional hydrogen bonded network parallel to the (0 0 1) plane (Fig. 4). Additionally, C–H···N and C–H···O interactions between the H atoms of the guanidinium –N(CH3)2 groups and the cyanate ions are present [d(H···N) = 2.52 – 2.61 Å; d(H···O) = 2.46 – 2.60 Å]. The hexamethylguanidinium ions are packed in between the layers build up by water molecules and cyanate ions (Fig. 5).For the synthesis of hexasubstituted guanidinium salts with different anions, see: Kantlehner et al. (1984). For the
of N,N,N',N',N'',N''-hexamethylguanidinium chloride, see: Oelkers & Sundermeyer (2011). For the of N,N,N',N',N'',N''-hexamethylguanidinium difluorotrimethylsilicate, see: Röschenthaler et al. (2002). For the of N,N,N',N',N'',N''-hexamethylguanidinium tetraphenylborate, see: Frey et al. (1998). For the of N,N,N',N',N'',N''-hexamethylguanidinium fluoride, see: Kolomeitsev et al. (2000). For the of N,N,N',N',N'',N''-hexamethylguanidinium hexafluorosilicate hexahydrate, see: Zhang et al. (1999). For the crystal structures of [C(NMe2)3][Mn(CO)5] and [C(NMe2)3][Co(CO)4], see: Petz & Weller (1991). For a neutron diffraction studie of deuterated ammonium cyanate, see: MacLean et al. (2003). For the use of intensity quotients and differences in see: Parsons et al. (2013).Data collection: APEX2 (Bruker, 2008); cell
SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: DIAMOND (Brandenburg & Putz, 2005); software used to prepare material for publication: SHELXL2014 (Sheldrick, 2015).Fig. 1. The structure of the title compound with displacement ellipsoids at the 50% probability level. All hydrogen atoms are omitted for clarity. Only the major component of the disordered cation is shown. | |
Fig. 2. The structure of the orientationally disordered cation. The nitrogen atoms are disordered between the opaque and dark positions. | |
Fig. 3. O—H···N and O—H···O hydrogen bonds (black dashed lines) between anions and water molecules and between the water molecules (view down the c axis). | |
Fig. 4. View down the c axis of the two-dimensional O—H···N and O—H···O hydrogen-bonding network (all hydrogen bonds are indicated by black dashed lines). | |
Fig. 5. Packing of the guanidinium ions in between the layers build up by water molecules and cyanate ions (down the a axis). |
2C7H18N3+·2CNO−·3H2O | F(000) = 936 |
Mr = 426.58 | Dx = 1.199 Mg m−3 |
Monoclinic, Cc | Mo Kα radiation, λ = 0.71073 Å |
a = 8.3245 (5) Å | Cell parameters from 19766 reflections |
b = 22.536 (2) Å | θ = 1.8–28.4° |
c = 13.2580 (12) Å | µ = 0.09 mm−1 |
β = 108.092 (7)° | T = 100 K |
V = 2364.2 (3) Å3 | Block, colorless |
Z = 4 | 0.40 × 0.25 × 0.10 mm |
Bruker Kappa APEXII DUO diffractometer | 5279 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.025 |
Triumph monochromator | θmax = 28.4°, θmin = 1.8° |
φ scans, and ω scans | h = −11→11 |
19766 measured reflections | k = −29→30 |
5588 independent reflections | l = −17→17 |
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)] = 0.034 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.089 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.02 | w = 1/[σ2(Fo2) + (0.0493P)2 + 0.9721P] where P = (Fo2 + 2Fc2)/3 |
5588 reflections | (Δ/σ)max < 0.001 |
328 parameters | Δρmax = 0.40 e Å−3 |
2 restraints | Δρmin = −0.19 e Å−3 |
2C7H18N3+·2CNO−·3H2O | V = 2364.2 (3) Å3 |
Mr = 426.58 | Z = 4 |
Monoclinic, Cc | Mo Kα radiation |
a = 8.3245 (5) Å | µ = 0.09 mm−1 |
b = 22.536 (2) Å | T = 100 K |
c = 13.2580 (12) Å | 0.40 × 0.25 × 0.10 mm |
β = 108.092 (7)° |
Bruker Kappa APEXII DUO diffractometer | 5279 reflections with I > 2σ(I) |
19766 measured reflections | Rint = 0.025 |
5588 independent reflections |
R[F2 > 2σ(F2)] = 0.034 | 2 restraints |
wR(F2) = 0.089 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.02 | Δρmax = 0.40 e Å−3 |
5588 reflections | Δρmin = −0.19 e Å−3 |
328 parameters |
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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. |
x | y | z | Uiso*/Ueq | Occ. (<1) | |
O1 | 0.3316 (2) | 0.36058 (8) | 0.23689 (17) | 0.0409 (4) | |
C1 | 0.2204 (3) | 0.32390 (9) | 0.22404 (19) | 0.0269 (4) | |
N1 | 0.1126 (3) | 0.28850 (9) | 0.2104 (2) | 0.0397 (5) | |
C2 | 0.4331 (2) | 0.02149 (8) | 0.32420 (15) | 0.0181 (4) | |
O2 | 0.5548 (2) | −0.00567 (8) | 0.38261 (13) | 0.0316 (4) | |
N2 | 0.3167 (2) | 0.04653 (9) | 0.26863 (17) | 0.0300 (4) | |
C3 | 0.1363 (2) | 0.09910 (8) | 0.52739 (14) | 0.0150 (3) | |
N3 | 0.2570 (2) | 0.05814 (7) | 0.54024 (13) | 0.0194 (3) | |
N4 | −0.0178 (2) | 0.08430 (7) | 0.52842 (14) | 0.0200 (3) | |
N5 | 0.1730 (2) | 0.15661 (7) | 0.51504 (14) | 0.0206 (3) | |
C4 | 0.0955 (3) | 0.20481 (9) | 0.55702 (18) | 0.0258 (4) | |
H4A | 0.0156 | 0.2262 | 0.4982 | 0.039* | |
H4B | 0.1835 | 0.2322 | 0.5974 | 0.039* | |
H4C | 0.0355 | 0.1885 | 0.6037 | 0.039* | |
C5 | 0.2881 (3) | 0.17368 (10) | 0.45722 (18) | 0.0245 (4) | |
H5A | 0.3885 | 0.1925 | 0.5060 | 0.037* | |
H5B | 0.2316 | 0.2017 | 0.4008 | 0.037* | |
H5C | 0.3221 | 0.1383 | 0.4258 | 0.037* | |
C6 | 0.2163 (3) | −0.00338 (8) | 0.50317 (16) | 0.0208 (4) | |
H6A | 0.2274 | −0.0294 | 0.5642 | 0.031* | |
H6B | 0.2943 | −0.0165 | 0.4655 | 0.031* | |
H6C | 0.1001 | −0.0052 | 0.4551 | 0.031* | |
C7 | 0.4348 (2) | 0.07080 (9) | 0.59433 (16) | 0.0198 (4) | |
H7A | 0.4983 | 0.0686 | 0.5433 | 0.030* | |
H7B | 0.4799 | 0.0416 | 0.6508 | 0.030* | |
H7C | 0.4458 | 0.1107 | 0.6251 | 0.030* | |
C8 | −0.0467 (3) | 0.03409 (10) | 0.59113 (17) | 0.0243 (4) | |
H8A | −0.0926 | 0.0005 | 0.5440 | 0.036* | |
H8B | −0.1274 | 0.0458 | 0.6279 | 0.036* | |
H8C | 0.0604 | 0.0225 | 0.6434 | 0.036* | |
C9 | −0.1698 (2) | 0.11617 (9) | 0.46464 (17) | 0.0216 (4) | |
H9A | −0.2186 | 0.1382 | 0.5118 | 0.032* | |
H9B | −0.2528 | 0.0876 | 0.4229 | 0.032* | |
H9C | −0.1391 | 0.1439 | 0.4167 | 0.032* | |
N6A | 0.3149 (2) | 0.16312 (8) | 0.08657 (15) | 0.0176 (5) | 0.862 (6) |
N7A | 0.2872 (2) | 0.16823 (8) | −0.09169 (15) | 0.0176 (5) | 0.852 (6) |
N8A | 0.5332 (2) | 0.13023 (8) | 0.02745 (15) | 0.0165 (5) | 0.852 (6) |
N6B | 0.4372 (13) | 0.1485 (5) | −0.0765 (8) | 0.011 (3) | 0.138 (6) |
N7B | 0.2238 (14) | 0.1787 (5) | −0.0095 (9) | 0.017 (3) | 0.148 (6) |
N8B | 0.4759 (12) | 0.1399 (4) | 0.1027 (7) | 0.011 (3) | 0.148 (6) |
C10 | 0.3786 (2) | 0.15393 (7) | 0.00727 (15) | 0.0140 (3) | |
C11 | 0.1322 (3) | 0.15698 (9) | 0.0706 (2) | 0.0257 (4) | |
H11A | 0.0761 | 0.1414 | −0.0007 | 0.038* | |
H11B | 0.0846 | 0.1959 | 0.0784 | 0.038* | |
H11C | 0.1146 | 0.1295 | 0.1236 | 0.038* | |
C12 | 0.4256 (3) | 0.18015 (10) | 0.19285 (17) | 0.0286 (5) | |
H12A | 0.5401 | 0.1874 | 0.1900 | 0.043* | |
H12B | 0.4282 | 0.1480 | 0.2431 | 0.043* | |
H12C | 0.3818 | 0.2163 | 0.2160 | 0.043* | |
C13 | 0.6009 (2) | 0.08765 (9) | 0.11404 (17) | 0.0218 (4) | |
H13A | 0.5138 | 0.0783 | 0.1471 | 0.033* | |
H13B | 0.6992 | 0.1050 | 0.1672 | 0.033* | |
H13C | 0.6349 | 0.0513 | 0.0857 | 0.033* | |
C14 | 0.6438 (3) | 0.14659 (10) | −0.0358 (2) | 0.0318 (5) | |
H14A | 0.5891 | 0.1775 | −0.0868 | 0.048* | |
H14B | 0.6643 | 0.1116 | −0.0740 | 0.048* | |
H14C | 0.7516 | 0.1615 | 0.0113 | 0.048* | |
C15 | 0.2985 (3) | 0.13442 (10) | −0.18353 (16) | 0.0274 (4) | |
H15A | 0.3685 | 0.0991 | −0.1591 | 0.041* | |
H15B | 0.3495 | 0.1592 | −0.2261 | 0.041* | |
H15C | 0.1849 | 0.1223 | −0.2268 | 0.041* | |
C16 | 0.1731 (3) | 0.22027 (9) | −0.1124 (2) | 0.0296 (5) | |
H16A | 0.1823 | 0.2404 | −0.0453 | 0.044* | |
H16B | 0.0563 | 0.2071 | −0.1455 | 0.044* | |
H16C | 0.2051 | 0.2478 | −0.1602 | 0.044* | |
O3 | 0.0041 (2) | 0.08290 (7) | 0.28078 (13) | 0.0251 (3) | |
H31 | 0.090 (4) | 0.0710 (12) | 0.277 (2) | 0.025 (7)* | |
H32 | −0.055 (4) | 0.0523 (16) | 0.285 (3) | 0.044 (9)* | |
O4 | 0.8891 (2) | 0.20268 (8) | 0.24797 (15) | 0.0327 (4) | |
H41 | 0.962 (4) | 0.2257 (13) | 0.237 (2) | 0.027 (7)* | |
H42 | 0.934 (5) | 0.1695 (18) | 0.250 (3) | 0.054 (10)* | |
O5 | 0.8322 (2) | 0.02166 (9) | 0.81332 (15) | 0.0330 (4) | |
H51 | 0.747 (4) | 0.0190 (13) | 0.835 (2) | 0.031 (7)* | |
H52 | 0.833 (4) | 0.0529 (16) | 0.795 (3) | 0.039 (9)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0293 (9) | 0.0276 (8) | 0.0665 (13) | −0.0008 (7) | 0.0161 (9) | 0.0045 (8) |
C1 | 0.0280 (10) | 0.0187 (9) | 0.0352 (12) | 0.0088 (8) | 0.0114 (9) | 0.0042 (8) |
N1 | 0.0375 (11) | 0.0197 (9) | 0.0630 (15) | −0.0025 (8) | 0.0172 (11) | −0.0015 (9) |
C2 | 0.0195 (9) | 0.0180 (8) | 0.0223 (9) | −0.0058 (7) | 0.0147 (7) | −0.0039 (7) |
O2 | 0.0260 (8) | 0.0351 (9) | 0.0356 (9) | 0.0022 (7) | 0.0123 (7) | 0.0047 (7) |
N2 | 0.0277 (9) | 0.0340 (10) | 0.0329 (10) | 0.0041 (8) | 0.0162 (8) | 0.0065 (8) |
C3 | 0.0180 (8) | 0.0153 (8) | 0.0111 (8) | −0.0003 (6) | 0.0038 (6) | −0.0008 (6) |
N3 | 0.0186 (8) | 0.0171 (7) | 0.0222 (8) | −0.0009 (6) | 0.0061 (6) | −0.0008 (6) |
N4 | 0.0209 (8) | 0.0191 (8) | 0.0218 (8) | −0.0010 (6) | 0.0090 (6) | 0.0019 (6) |
N5 | 0.0226 (8) | 0.0166 (7) | 0.0230 (8) | −0.0009 (6) | 0.0080 (6) | 0.0006 (6) |
C4 | 0.0331 (11) | 0.0153 (9) | 0.0274 (10) | 0.0048 (7) | 0.0069 (8) | −0.0030 (8) |
C5 | 0.0249 (10) | 0.0244 (10) | 0.0262 (10) | −0.0068 (8) | 0.0108 (8) | 0.0029 (8) |
C6 | 0.0278 (10) | 0.0142 (8) | 0.0219 (9) | 0.0022 (7) | 0.0102 (7) | −0.0001 (7) |
C7 | 0.0154 (8) | 0.0209 (9) | 0.0218 (9) | −0.0004 (7) | 0.0039 (7) | −0.0006 (7) |
C8 | 0.0252 (10) | 0.0275 (10) | 0.0247 (10) | −0.0029 (8) | 0.0142 (8) | 0.0060 (8) |
C9 | 0.0178 (9) | 0.0231 (9) | 0.0246 (10) | 0.0021 (7) | 0.0073 (7) | −0.0004 (8) |
N6A | 0.0164 (10) | 0.0201 (9) | 0.0175 (10) | −0.0003 (7) | 0.0068 (7) | −0.0014 (7) |
N7A | 0.0198 (9) | 0.0179 (10) | 0.0149 (9) | 0.0020 (7) | 0.0050 (7) | 0.0007 (7) |
N8A | 0.0145 (9) | 0.0168 (9) | 0.0181 (9) | 0.0002 (7) | 0.0050 (7) | −0.0002 (7) |
N6B | 0.013 (5) | 0.017 (6) | 0.006 (5) | −0.001 (4) | 0.006 (4) | −0.001 (4) |
N7B | 0.016 (5) | 0.016 (5) | 0.024 (6) | 0.006 (4) | 0.014 (4) | 0.005 (4) |
N8B | 0.016 (5) | 0.012 (5) | 0.003 (4) | 0.000 (4) | 0.003 (3) | −0.001 (3) |
C10 | 0.0148 (7) | 0.0102 (7) | 0.0163 (8) | −0.0019 (6) | 0.0038 (6) | −0.0013 (6) |
C11 | 0.0200 (9) | 0.0248 (10) | 0.0379 (12) | 0.0004 (8) | 0.0173 (9) | −0.0008 (9) |
C12 | 0.0421 (13) | 0.0267 (11) | 0.0163 (9) | −0.0055 (9) | 0.0084 (9) | −0.0055 (8) |
C13 | 0.0167 (8) | 0.0183 (9) | 0.0267 (10) | 0.0021 (7) | 0.0011 (7) | 0.0037 (8) |
C14 | 0.0263 (11) | 0.0293 (11) | 0.0492 (14) | −0.0076 (9) | 0.0251 (10) | −0.0115 (10) |
C15 | 0.0394 (12) | 0.0268 (10) | 0.0144 (9) | −0.0007 (9) | 0.0060 (8) | −0.0044 (8) |
C16 | 0.0240 (10) | 0.0211 (9) | 0.0356 (12) | 0.0016 (8) | −0.0026 (9) | 0.0095 (9) |
O3 | 0.0214 (7) | 0.0235 (7) | 0.0314 (8) | 0.0013 (6) | 0.0097 (6) | 0.0028 (6) |
O4 | 0.0283 (8) | 0.0272 (8) | 0.0483 (10) | 0.0062 (7) | 0.0200 (7) | 0.0074 (7) |
O5 | 0.0313 (9) | 0.0332 (9) | 0.0414 (10) | 0.0117 (7) | 0.0211 (8) | 0.0132 (8) |
O1—C1 | 1.213 (3) | N8A—C10 | 1.341 (3) |
C1—N1 | 1.172 (3) | N8A—C13 | 1.468 (3) |
C2—N2 | 1.165 (3) | N8A—C14 | 1.472 (3) |
C2—O2 | 1.230 (3) | N6B—C10 | 1.350 (10) |
C3—N4 | 1.329 (2) | N6B—C15 | 1.558 (10) |
C3—N3 | 1.336 (2) | N6B—C14 | 1.635 (11) |
C3—N5 | 1.353 (2) | N7B—C10 | 1.358 (10) |
N3—C7 | 1.459 (2) | N7B—C11 | 1.566 (11) |
N3—C6 | 1.475 (2) | N7B—C16 | 1.600 (11) |
N4—C8 | 1.468 (3) | N8B—C10 | 1.311 (9) |
N4—C9 | 1.472 (3) | N8B—C13 | 1.548 (10) |
N5—C5 | 1.453 (3) | N8B—C12 | 1.655 (10) |
N5—C4 | 1.459 (3) | C11—H11A | 0.9800 |
C4—H4A | 0.9800 | C11—H11B | 0.9800 |
C4—H4B | 0.9800 | C11—H11C | 0.9800 |
C4—H4C | 0.9800 | C12—H12A | 0.9800 |
C5—H5A | 0.9800 | C12—H12B | 0.9800 |
C5—H5B | 0.9800 | C12—H12C | 0.9800 |
C5—H5C | 0.9800 | C13—H13A | 0.9800 |
C6—H6A | 0.9800 | C13—H13B | 0.9800 |
C6—H6B | 0.9800 | C13—H13C | 0.9800 |
C6—H6C | 0.9800 | C14—H14A | 0.9800 |
C7—H7A | 0.9800 | C14—H14B | 0.9800 |
C7—H7B | 0.9800 | C14—H14C | 0.9800 |
C7—H7C | 0.9800 | C15—H15A | 0.9800 |
C8—H8A | 0.9800 | C15—H15B | 0.9800 |
C8—H8B | 0.9800 | C15—H15C | 0.9800 |
C8—H8C | 0.9800 | C16—H16A | 0.9800 |
C9—H9A | 0.9800 | C16—H16B | 0.9800 |
C9—H9B | 0.9800 | C16—H16C | 0.9800 |
C9—H9C | 0.9800 | O3—H31 | 0.78 (3) |
N6A—C10 | 1.333 (3) | O3—H32 | 0.86 (4) |
N6A—C12 | 1.475 (3) | O4—H41 | 0.84 (3) |
N6A—C11 | 1.475 (3) | O4—H42 | 0.83 (4) |
N7A—C10 | 1.336 (3) | O5—H51 | 0.85 (3) |
N7A—C15 | 1.464 (3) | O5—H52 | 0.74 (4) |
N7A—C16 | 1.480 (3) | ||
N1—C1—O1 | 179.2 (3) | C10—N8A—C14 | 121.18 (18) |
N2—C2—O2 | 179.1 (2) | C13—N8A—C14 | 116.95 (18) |
N4—C3—N3 | 121.01 (16) | C10—N6B—C15 | 114.4 (7) |
N4—C3—N5 | 119.77 (17) | C10—N6B—C14 | 110.0 (7) |
N3—C3—N5 | 119.21 (17) | C15—N6B—C14 | 134.5 (7) |
C3—N3—C7 | 122.40 (16) | C10—N7B—C11 | 113.4 (7) |
C3—N3—C6 | 121.41 (16) | C10—N7B—C16 | 111.5 (7) |
C7—N3—C6 | 116.15 (16) | C11—N7B—C16 | 135.0 (7) |
C3—N4—C8 | 121.87 (17) | C10—N8B—C13 | 118.2 (7) |
C3—N4—C9 | 122.10 (16) | C10—N8B—C12 | 110.3 (6) |
C8—N4—C9 | 116.01 (16) | C13—N8B—C12 | 131.3 (6) |
C3—N5—C5 | 121.89 (17) | N6A—C10—N7A | 119.49 (18) |
C3—N5—C4 | 121.58 (18) | N6A—C10—N8A | 119.80 (18) |
C5—N5—C4 | 116.52 (17) | N7A—C10—N8A | 120.72 (18) |
N5—C4—H4A | 109.5 | N8B—C10—N6B | 120.0 (6) |
N5—C4—H4B | 109.5 | N8B—C10—N7B | 121.8 (7) |
H4A—C4—H4B | 109.5 | N6B—C10—N7B | 118.0 (7) |
N5—C4—H4C | 109.5 | N6A—C11—H11A | 109.5 |
H4A—C4—H4C | 109.5 | N6A—C11—H11B | 109.5 |
H4B—C4—H4C | 109.5 | H11A—C11—H11B | 109.5 |
N5—C5—H5A | 109.5 | N6A—C11—H11C | 109.5 |
N5—C5—H5B | 109.5 | H11A—C11—H11C | 109.5 |
H5A—C5—H5B | 109.5 | H11B—C11—H11C | 109.5 |
N5—C5—H5C | 109.5 | N6A—C12—H12A | 109.5 |
H5A—C5—H5C | 109.5 | N6A—C12—H12B | 109.5 |
H5B—C5—H5C | 109.5 | H12A—C12—H12B | 109.5 |
N3—C6—H6A | 109.5 | N6A—C12—H12C | 109.5 |
N3—C6—H6B | 109.5 | H12A—C12—H12C | 109.5 |
H6A—C6—H6B | 109.5 | H12B—C12—H12C | 109.5 |
N3—C6—H6C | 109.5 | N8A—C13—H13A | 109.5 |
H6A—C6—H6C | 109.5 | N8A—C13—H13B | 109.5 |
H6B—C6—H6C | 109.5 | H13A—C13—H13B | 109.5 |
N3—C7—H7A | 109.5 | N8A—C13—H13C | 109.5 |
N3—C7—H7B | 109.5 | H13A—C13—H13C | 109.5 |
H7A—C7—H7B | 109.5 | H13B—C13—H13C | 109.5 |
N3—C7—H7C | 109.5 | N8A—C14—H14A | 109.5 |
H7A—C7—H7C | 109.5 | N8A—C14—H14B | 109.5 |
H7B—C7—H7C | 109.5 | H14A—C14—H14B | 109.5 |
N4—C8—H8A | 109.5 | N8A—C14—H14C | 109.5 |
N4—C8—H8B | 109.5 | H14A—C14—H14C | 109.5 |
H8A—C8—H8B | 109.5 | H14B—C14—H14C | 109.5 |
N4—C8—H8C | 109.5 | N7A—C15—H15A | 109.5 |
H8A—C8—H8C | 109.5 | N7A—C15—H15B | 109.5 |
H8B—C8—H8C | 109.5 | H15A—C15—H15B | 109.5 |
N4—C9—H9A | 109.5 | N7A—C15—H15C | 109.5 |
N4—C9—H9B | 109.5 | H15A—C15—H15C | 109.5 |
H9A—C9—H9B | 109.5 | H15B—C15—H15C | 109.5 |
N4—C9—H9C | 109.5 | N7A—C16—H16A | 109.5 |
H9A—C9—H9C | 109.5 | N7A—C16—H16B | 109.5 |
H9B—C9—H9C | 109.5 | H16A—C16—H16B | 109.5 |
C10—N6A—C12 | 120.70 (18) | N7A—C16—H16C | 109.5 |
C10—N6A—C11 | 121.16 (18) | H16A—C16—H16C | 109.5 |
C12—N6A—C11 | 118.14 (19) | H16B—C16—H16C | 109.5 |
C10—N7A—C15 | 121.83 (18) | H31—O3—H32 | 106 (3) |
C10—N7A—C16 | 120.70 (19) | H41—O4—H42 | 102 (3) |
C15—N7A—C16 | 117.45 (18) | H51—O5—H52 | 105 (3) |
C10—N8A—C13 | 121.86 (18) | ||
N4—C3—N3—C7 | −146.45 (19) | C12—N6A—C10—N8A | 34.3 (3) |
N5—C3—N3—C7 | 32.4 (3) | C11—N6A—C10—N8A | −146.11 (19) |
N4—C3—N3—C6 | 31.5 (3) | C15—N7A—C10—N6A | −147.2 (2) |
N5—C3—N3—C6 | −149.64 (18) | C16—N7A—C10—N6A | 34.4 (3) |
N3—C3—N4—C8 | 30.4 (3) | C15—N7A—C10—N8A | 32.5 (3) |
N5—C3—N4—C8 | −148.39 (19) | C16—N7A—C10—N8A | −145.9 (2) |
N3—C3—N4—C9 | −147.87 (18) | C13—N8A—C10—N6A | 31.7 (3) |
N5—C3—N4—C9 | 33.3 (3) | C14—N8A—C10—N6A | −147.48 (19) |
N4—C3—N5—C5 | −145.34 (19) | C13—N8A—C10—N7A | −148.04 (19) |
N3—C3—N5—C5 | 35.8 (3) | C14—N8A—C10—N7A | 32.8 (3) |
N4—C3—N5—C4 | 33.1 (3) | C15—N6B—C10—N8B | 150.1 (7) |
N3—C3—N5—C4 | −145.71 (19) | C14—N6B—C10—N8B | −19.7 (10) |
C13—N8B—C10—N6B | −34.6 (10) | C15—N6B—C10—N7B | −35.3 (10) |
C12—N8B—C10—N6B | 150.7 (6) | C14—N6B—C10—N7B | 154.9 (6) |
C13—N8B—C10—N7B | 151.0 (7) | C11—N7B—C10—N8B | −32.9 (10) |
C12—N8B—C10—N7B | −23.7 (9) | C16—N7B—C10—N8B | 150.9 (7) |
C12—N6A—C10—N7A | −146.0 (2) | C11—N7B—C10—N6B | 152.6 (7) |
C11—N6A—C10—N7A | 33.6 (3) | C16—N7B—C10—N6B | −23.6 (10) |
D—H···A | D—H | H···A | D···A | D—H···A |
O3—H31···N2 | 0.78 (3) | 2.00 (3) | 2.780 (3) | 176 (3) |
O3—H32···O5i | 0.86 (4) | 2.00 (4) | 2.858 (4) | 172 (3) |
O4—H42···O3ii | 0.83 (4) | 2.04 (4) | 2.852 (4) | 164 (3) |
O4—H41···N1ii | 0.84 (3) | 2.00 (3) | 2.833 (3) | 173 (3) |
O5—H51···O2iii | 0.85 (3) | 1.92 (3) | 2.761 (3) | 175 (3) |
O5—H52···O1iv | 0.74 (4) | 2.10 (4) | 2.840 (4) | 177 (3) |
Symmetry codes: (i) x−1, −y, z−1/2; (ii) x+1, y, z; (iii) x, −y, z+1/2; (iv) x+1/2, −y+1/2, z+1/2. |
D—H···A | D—H | H···A | D···A | D—H···A |
O3—H31···N2 | 0.78 (3) | 2.00 (3) | 2.780 (3) | 176 (3) |
O3—H32···O5i | 0.86 (4) | 2.00 (4) | 2.858 (4) | 172 (3) |
O4—H42···O3ii | 0.83 (4) | 2.04 (4) | 2.852 (4) | 164 (3) |
O4—H41···N1ii | 0.84 (3) | 2.00 (3) | 2.833 (3) | 173 (3) |
O5—H51···O2iii | 0.85 (3) | 1.92 (3) | 2.761 (3) | 175 (3) |
O5—H52···O1iv | 0.74 (4) | 2.10 (4) | 2.840 (4) | 177 (3) |
Symmetry codes: (i) x−1, −y, z−1/2; (ii) x+1, y, z; (iii) x, −y, z+1/2; (iv) x+1/2, −y+1/2, z+1/2. |
Acknowledgements
The authors thank Dr W. Frey (Institut für Organische Chemie, Universität Stuttgart) for measuring the diffraction data.
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The reaction of phosgene with N,N,N',N'-tetramethylurea yields N,N,N',N'-tetramethylchloroformamidinium chloride, which can be transformed by a mixture of dimethylamine and triethylamine into a mixture of N,N,N',N',N'',N''-hexamethylguanidinium chloride and triethylamine hydrochloride. Treating the salt mixture with an aqueous sodium hydroxide solution leads after work up to the pure guanidinium chloride. Conversion of the chloride to the tetrafluoroborate salt occurs by heating it with BF3O(C2H5)2 (Kantlehner et al., 1984). A further anion exchange was possible by reacting N,N,N',N',N'',N''-hexamethylguanidinium tetrafluoroborate with potassium cyanate in water. According to the structure analysis of the title compound, the asymmetric unit contains two N,N,N',N',N'',N''-hexamethylguanidinium (HMG+) ions, two cyanate ions and three water molecules (Fig. 1). One cation (cation I) shows an orientational disorder and two sets of N positions were found related by a 60° rotation, with an occupancy ratio of 0.852 (6):0.148 (6). This leads to the characteristic star-shaped appearance of the HMG+ ion (Fig. 2). The second cation (cation II) is not disordered. Searching for known crystal structures in literature of N,N,N',N',N'',N''-hexamethylguanidinium salts [see, for example: chloride salt (Oelkers & Sundermeyer, 2011), difluorotrimethylsilicate salt (Röschenthaler et al., 2002), tetraphenylborate salt (Frey et al., 1998), fluoride salt (Kolomeitsev et al., 2000), hexafluorosilicate hexahydrate salt (Zhang et al., 1999), [Mn(CO)5] and [Co(CO)4] salts (Petz & Weller, 1991)], it is obvious that in all those compounds the HMG+ ions are orientationally disordered too. In the title salt, the C–N bond lengths of both cations are in a range from 1.329 (2) and 1.358 (10) Å, indicating double bond character. The CN3 units are planar and the N–C–N angles are ranging from 118.0 (7)° to 121.8 (7)°. The positive charge is completely delocalized in the CN3 plane. The N–C bond lengths in the non-disordered guanidinium ion (cation II) are in a typical range from 1.453 (3) to 1.475 (2) Å, characteristic for a N–C single bond. In the disordered one (cation I), some N–C bond lengths deviate from their typical values and appear to be slightly longer [d(N–C) = 1.464 (3) - 1.655 (10) Å]. The N–C and C–O bond lengths in both cyanate ions [d(N–C) = 1.165 (3) and 1.172 (3) Å; d(C–O) = 1.213 (3) and 1.230 (3) Å] are in very good agreement with the data determined from a neutron diffraction study of deuterated ammonium cyanate (ND4OCN) at 14 K [d(N–C) = 1.191 (5) Å and d(C–O) =) 1.215 (5) Å (MacLean et al., 2003)]. Strong O–H···N hydrogen bonds between the crystal water molecules and the cyanate ions [d(H···N) = 2.00 (3) Å (Tab. 1)] and strong O–H···O hydrogen bonds between the water molecules are present [d(H···O) = 1.92 (3) - 2.10 (4) Å (Tab. 1)] (Fig. 3), resulting in a two-dimensional hydrogen bonded network parallel to the (0 0 1) plane (Fig. 4). Additionally, C–H···N and C–H···O interactions between the H atoms of the guanidinium –N(CH3)2 groups and the cyanate ions are present [d(H···N) = 2.52 – 2.61 Å; d(H···O) = 2.46 – 2.60 Å]. The hexamethylguanidinium ions are packed in between the layers build up by water molecules and cyanate ions (Fig. 5).