organic compounds
N-[Amino(imino)methyl]uronium tetrafluoroborate
aDepartment of Inorganic Chemistry, Faculty of Science, Charles University in Prague, Hlavova 2030, 12843 Prague 2, Czech Republic, and bInst. of Physics of the Czech Academy of Sciences, v. v. i., Na Slovance 2, 182 21 Praha 8, Czech Republic
*Correspondence e-mail: fabry@fzu.cz
In the title compound, C2H7N4O+·BF4−, intermolecular N—H⋯O hydrogen bonds connect the cations into chains parallel to the c axis, with graph-set motif C(4). These chains are in turn connected into a three-dimensional network by intermolecular N—H⋯F hydrogen bonds. The B—F distances distances in the anion are not equal.
Related literature
For the non-centrosymmetric structure, containing a 2-carbamoylguanidinium cation, that is promising for applications in non-linear optics, see: Fridrichová, Němec, Císařová & Chvostová (2010); Fridrichová, Němec, Císařová & Němec (2010); Kroupa & Fridrichová (2011). For related stuctures and a detailed description of the preparation of the title cation, see: Fábry et al. (2012a,b,c). For structures with rather strong N—H⋯F hydrogen bonds, see: Ali et al. (2007); Bardaji et al. (2002); Blue et al. (2003); Byrne et al. (2008); Zhao & Betley (2011). For information on fluorine as acceptor in organic hydrogen bonds, see: Dunitz & Taylor (1997). For hydrogen-bond classification and graph-set motifs, see: Desiraju & Steiner (1999); Etter et al. (1990). For a description of the Cambridge Structural Database (CSD), see: Allen (2002). For the extinction correction, see: Becker & Coppens (1974).
Experimental
Crystal data
|
Refinement
|
|
Data collection: CrysAlis PRO (Agilent, 2010); cell CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SIR97 (Altomare et al., 1997); program(s) used to refine structure: JANA2006 (Petříček et al., 2007); molecular graphics: DIAMOND (Brandenburg & Putz, 2005) and PLATON (Spek, 2009); software used to prepare material for publication: JANA2006.
Supporting information
10.1107/S1600536812010665/lh5427sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536812010665/lh5427Isup2.hkl
Supporting information file. DOI: 10.1107/S1600536812010665/lh5427Isup4.smi
Supporting information file. DOI: 10.1107/S1600536812010665/lh5427Isup4.cml
The structures were prepared by neutralization of equimolar amounts of solutions of 2-carbamoylguanidinium hydroxide and tetrafluoroborate acid HBF4 (Sigma-Aldrich). The solutions contained about 0.89 g of 2-carbamoylguanidinium hydroxide and about 1.36 g of 48% (weight) HBF4.
2-carbamoylguanidinium hydroxide was prepared from 2-carbamoylguanidinium hydrochloride hemihydrate by the exchange reaction on anex (Dowex Serva, type 2X8; ion exchange OI/OH, Entwicklungslabor, Heidelberg, Germany). The preparation of 2-carbamoylguanidinium chloride hemihydrate has been described in detail in the article by Fábry et al. (2012c).
The volume of the solution after neutralization was about 30 ml. Tiny crystals floating in the solution appeared in a few days. However, they disappeared in the course of time while being replaced by a white powder. The crystal used for the structure analysis was grown from a drop of the mother liquor on a glass. (The glass was not seemingly affected by the solution.) The powder is a different compound or phase because another grown crystal dissolved in a drop that contained the particles of the powder. The obtained crystals were colourless plates with dimensions of several tenths of mm.
The calorimetric experiments were performed on differential scanning calorimeters Perkin Elmer DSC 7 (93–323 K) and PerkinElmer Pyris Diamond DSC (298–493 K). Pyris Software (Version 4.02, PerkinElmer Instruments, 2001) was used for control and evaluation. The sample (m = 11 mg) was hermetically closed in an aluminium 30µl pan, the scanning rate was 10 K/min. The DSC sample holder was purged by helium (DSC 7) or nitrogen (Pyris Diamond). Below room temperature a tiny peak is observed at 267K on heating, probably because of a residue of water. Above room temperature, a distinct exothermic peak with an endothermic onset was found at about 463K on the first heating. This
obviously changed the composition of the sample because two peaks that had not been observed on the very first heating were observed in subsequent runs both on heating (at 422K and 477K) and on cooling (at 409K and 462K). The first peak indicated a solid state structural while the second one could be attributed to melting or solidification.All the hydrogen atoms were found in the difference
and their coordinates were refined independently. The isotropic atomic displacement parameters of the hydrogen atoms were set as 1.2×Ueq(Ncarrier).The title structure was synthesized as a part of a study of 2-carbamoylguanidinium salts with the goal of preparing non-centrosymmetric crystals which might be suitable as non-linear optical elements. 2-carbamoylguanidinium hydrogen phosphite (Fridrichová, Němec, Císařová & Chvostová, 2010; Fridrichová, Němec, Císařová & Němec, 2010; Kroupa & Fridrichová, 2011) can be given as such an example.
Another goal of this study was consideration of influence of fluorine on the hydrogen-bond pattern. Usually, especially in presence of oxygen atoms as potential acceptors, fluorine avoids involvement in hydrogen bonds in organic compounds (Dunitz & Taylor, 1997). Poor involvement in hydrogen bonds is not, however, only limited to fluorine present in organic molecules but also in inorganic molecules. Recently synthesized compounds tris(2-carbamoylguanidinium) hydrogen fluorophosphonate fluorophosphonate monohydrate (Fábry et al., 2012a), two polymorphs of bis(2-carbamoylguanidinium) fluorophosphonate dihydrate (Fábry et al., 2012b) and mixed crystals of 2-carbamoylguanidinium with hydrogen fluorophosphonate and hydrogen phosphite in the ratios 1:0, 0.76 (2):0.24 (2) and 0.115 (7):0.885 (7) (Fábry et al., 2012c) exhibited weak N—H···F interactions which were weaker than the competing N—H···O hydrogen bonds in these structures.
On the other hand, inspection of the data in the Cambridge Structural Database (CSD; Version 5.32, October 2011 update; Allen, 2002) has shown that there is a number of structures which exhibit contacts N—H···F with the distances H···acceptor about 2.1 Å. It seems that majority of these structures contain highly symmetric anions with more F atoms as ligands such as [BF4]-, [PF6]-1, [SiF6]2-, [FeF6]3- etc. or organic molecules with a large number of fluorine substituents. ADOSIW, bis(2-ammonioethyl)ammonium hexafluoro-iron(III) monohydrate, Ali et al. (2007); AFUBIM, (2-aminothiazoline-N)-tris(pentafluorophenyl)-gold(III), Bardaji et al. (2002); AGOMEP, 3-(((4-methylphenyl)carbamoyl)amino)pyridinium hemikis(hexafluorosilicate, Byrne et al. (2008); AKEFEB, (1,2-bis(di-t-butylphosphino)ethane)-(aniline)-copper(I) tetrafluoroborate, Blue et al. (2003); ALIBED, (µ3–1,1,1-tris((2-aminoanilino)methyl)ethane)-tris(trimethylphosphino)- tri-iron hexafluorophosphate tetrahydrofuran solvate, Zhao et al. (2011) can be given as such examples. The reason for the involvement of F into the hydrogen-bond pattern in these structures seems to be steric: In whatever orientation fluorines get into a closer contact with the cationic H atoms.
This was also the case for the consideration of preparation of the title structure with a tetrahedral [BF4]- anion which would enhance a chance for the formation of a stronger N—H···F hydrogen bond even in presence of the competing carbonyl group in the 2-carbamoylguanidinium cation.
Indeed, a relatively strong N3—H1n3···F4i hydrogen bond appears in the title structure (Fig. 2) which is comparable by its geometric features to other present hydrogen bonds with the carbonyl oxygen involved, such as N2—H1n2···O1ii; N3—H2n3···O1; N4—H2n4···O1ii (Table 2). [The classification of the hydrogen bonds was taken from Desiraju & Steiner (1999); the symmetry codes i: -x + 1, y - 1/2, -z + 3/2; ii: x, -y + 1/2, z - 1/2.] The valence angle B1—F4···H1N3iii [the symmetry code iii: -x + 1, y + 1/2, -z + 3/2] equals to 109.2 (4)°. This angle would support the view that the N3—H1n3···F4i is indeed a true hydrogen bond.
The symmetry equivalent N1—H1n2···O1 hydrogen bonds form chains extended along the unit-cell axis c (Fig. 3). The pertinent graph set motif is C(4) (Etter et al., 1990). It is of interest that the secondary amine forms stronger N—H···O hydrogen bonds than the primary
also in tris(2-carbamoylguanidinium) hydrogen fluorophosphonate fluorophosphonate monohydrate (Fábry et al., 2012a), 2-carbamoylguanidinium with hydrogen fluorophosphonate (Fábry et al., 2012c) and in the first polymorph of bis(2-carbamoylguanidinium) fluorophosphonate dihydrate and the first independent cation of the second polymorph of bis(2-carbamoylguanidinium) fluorophosphonate dihydrate (Fábry et al., 2012b).In the title structure, in addition to the hydrogen bonds with the H···acceptor distances up to ~2.2 Å there are also present interactions with the H···acceptor distances up to ~2.6 Å with low N—H···acceptor angles.
The B—F distances within the anion show considerable spread. Such a distribution of the B—F distances in the tetrafluoroborate anions is, however, usual as it was checked in the structures stored in the Cambridge Structural database (CSD; Version 5.32, October 2011 update; Allen, 2002; Tab. 1).
The χ2 index through the cation's non-hydrogen atoms of the title structure equals to 4671.953. This is less than in the most probably less stable polymorph of bis(2-carbamoylguanidinium) fluorophosphonate dihydrate (Fábry et al., 2012b) with the χ2 index of 19477.0, and in 2-carbamoylguanidinium hydrogen phosphite with the χ2 index of 6515.041 (Fridrichová, Němec, Císařová & Němec, 2010; Fábry et al., 2012c). On the other hand, it is considerably more than e. g. the corresponding values regarding the two independent molecules in the presumably more stable polymorph of bis(2-carbamoylguanidinium) fluorophosphonate dihydrate (Fábry et al., 2012b) where the χ2 indices equal to 36.29 and 84.29.
For the non-centrosymmetric structure, containing a 2-carbamoylguanidinium cation, that is promising for applications in non-linear optics, see: Fridrichová, Němec, Císařová & Chvostová (2010); Fridrichová, Němec, Císařová & Němec (2010); Kroupa & Fridrichová (2011). For related stuctures and a detailed description of the preparation of the title cation, see: Fábry et al. (2012a,b,c). For structures with rather strong N—H···F hydrogen bonds, see: Ali et al. (2007); Bardaji et al. (2002); Blue et al. (2003); Byrne et al. (2008); Zhao & Betley (2011). For information on fluorine as acceptor in organic hydrogen bonds, see: Dunitz & Taylor (1997). For hydrogen-bond classification and graph-set motifs, see: Desiraju & Steiner (1999); Etter et al. (1990). For a description of the Cambridge Structural Database (CSD), see: Allen (2002). For the extinction correction, see: Becker & Coppens (1974).
Data collection: CrysAlis PRO (Agilent, 2010); cell
CrysAlis PRO (Agilent, 2010); data reduction: CrysAlis PRO (Agilent, 2010); program(s) used to solve structure: SIR97 (Altomare et al., 1997); program(s) used to refine structure: JANA2006 (Petříček et al., 2007); molecular graphics: DIAMOND (Brandenburg & Putz, 2005) and PLATON (Spek, 2009); software used to prepare material for publication: JANA2006 (Petříček et al., 2007).Fig. 1. The asymmetric unit of (I), the displacement ellipsoids are depicted at the 50% probability level (Spek, 2009). | |
Fig. 2. View of the unit cell of the title structure along the b axis. Colours: C (black), H (gray), B (khaki), F (green), N (blue), O (red). There are shown the strogenst hydrogen bonds in the structure N3—H1n3···F4i as well as N2—H1n2···O1ii hydrogen bonds - see Tab. 1 (Brandenburg & Putz, 2005). [Symmetry codes: i: -x + 1, y - 1/2, -z + 3/2; ii: x, -y + 1/2, z - 1/2.] | |
Fig. 3. The graph set motif C(4) (Etter et al., 1990) which involves the symmetry equivalent hydrogen bonds N2—H1n2···O1ii [Symmetry code: ii: x, -y + 1/2, z - 1/2)]. The colours are the same as in Fig. 2 (Brandenburg & Putz, 2005). |
C2H7N4O+·BF4− | F(000) = 384 |
Mr = 189.9 | Dx = 1.821 Mg m−3 |
Monoclinic, P21/c | Cu Kα radiation, λ = 1.5418 Å |
Hall symbol: -P 2ybc | Cell parameters from 5746 reflections |
a = 7.8409 (3) Å | θ = 4.6–67° |
b = 9.6373 (4) Å | µ = 1.86 mm−1 |
c = 9.5199 (4) Å | T = 120 K |
β = 105.689 (3)° | Irregular shape, colourless |
V = 692.57 (5) Å3 | 0.51 × 0.30 × 0.17 mm |
Z = 4 |
Agilent Xcalibur diffractometer with an Atlas (Gemini ultra Cu) detector | 1230 independent reflections |
Radiation source: Enhance Ultra (Cu) X-ray Source | 1189 reflections with I > 3σ(I) |
Mirror monochromator | Rint = 0.020 |
Detector resolution: 10.3784 pixels mm-1 | θmax = 67.1°, θmin = 5.9° |
Rotation method data acquisition using ω scans | h = −9→9 |
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2010) | k = −11→11 |
Tmin = 0.534, Tmax = 0.733 | l = −11→10 |
7265 measured reflections |
Refinement on F2 | Only H-atom coordinates refined |
R[F > 3σ(F)] = 0.024 | Weighting scheme based on measured s.u.'s w = 1/(σ2(I) + 0.0016I2) |
wR(F) = 0.081 | (Δ/σ)max = 0.006 |
S = 1.74 | Δρmax = 0.13 e Å−3 |
1230 reflections | Δρmin = −0.15 e Å−3 |
131 parameters | Extinction correction: B-C type 1 Lorentzian isotropic (Becker & Coppens, 1974) |
0 restraints | Extinction coefficient: 1600 (300) |
7 constraints |
C2H7N4O+·BF4− | V = 692.57 (5) Å3 |
Mr = 189.9 | Z = 4 |
Monoclinic, P21/c | Cu Kα radiation |
a = 7.8409 (3) Å | µ = 1.86 mm−1 |
b = 9.6373 (4) Å | T = 120 K |
c = 9.5199 (4) Å | 0.51 × 0.30 × 0.17 mm |
β = 105.689 (3)° |
Agilent Xcalibur diffractometer with an Atlas (Gemini ultra Cu) detector | 1230 independent reflections |
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2010) | 1189 reflections with I > 3σ(I) |
Tmin = 0.534, Tmax = 0.733 | Rint = 0.020 |
7265 measured reflections |
R[F > 3σ(F)] = 0.024 | 0 restraints |
wR(F) = 0.081 | Only H-atom coordinates refined |
S = 1.74 | Δρmax = 0.13 e Å−3 |
1230 reflections | Δρmin = −0.15 e Å−3 |
131 parameters |
Experimental. CrysAlisPro (Agilent Technologies, 2010) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm. |
Refinement. The refinement was carried out against all reflections. The conventional R-factor is always based on F. The goodness of fit as well as the weighted R-factor are based on F and F2 for refinement carried out on F and F2, respectively. The threshold expression is used only for calculating R-factors etc. and it is not relevant to the choice of reflections for refinement. The program used for refinement, Jana2006, uses the weighting scheme based on the experimental expectations, see _refine_ls_weighting_details, that does not force S to be one. Therefore the values of S are usually larger than the ones from the SHELX program. |
x | y | z | Uiso*/Ueq | ||
B1 | 0.66007 (15) | 0.44707 (12) | 0.78507 (13) | 0.0190 (4) | |
F1 | 0.54351 (8) | 0.40448 (7) | 0.86358 (7) | 0.0295 (3) | |
F2 | 0.83067 (8) | 0.45670 (7) | 0.87576 (7) | 0.0254 (2) | |
F3 | 0.65411 (9) | 0.35814 (7) | 0.67085 (7) | 0.0304 (3) | |
F4 | 0.60448 (8) | 0.58120 (6) | 0.72842 (7) | 0.0242 (2) | |
N1 | 1.29213 (13) | 0.25144 (10) | 0.99490 (11) | 0.0230 (3) | |
H1n1 | 1.3573 (19) | 0.2796 (14) | 1.0783 (17) | 0.0276* | |
H2n1 | 1.3380 (19) | 0.2346 (15) | 0.9280 (17) | 0.0276* | |
C1 | 1.12706 (13) | 0.21215 (10) | 0.98698 (11) | 0.0180 (3) | |
O1 | 1.05904 (10) | 0.21991 (8) | 1.08889 (8) | 0.0212 (3) | |
N2 | 1.03592 (11) | 0.16014 (9) | 0.85077 (9) | 0.0183 (3) | |
H1n2 | 1.0786 (18) | 0.1719 (14) | 0.7805 (17) | 0.022* | |
C2 | 0.86829 (13) | 0.10769 (10) | 0.81483 (11) | 0.0179 (3) | |
N3 | 0.77643 (12) | 0.10138 (10) | 0.91111 (10) | 0.0211 (3) | |
H1n3 | 0.666 (2) | 0.0746 (14) | 0.8846 (15) | 0.0253* | |
H2n3 | 0.8179 (18) | 0.1386 (15) | 0.9944 (17) | 0.0253* | |
N4 | 0.80477 (13) | 0.06150 (10) | 0.68075 (11) | 0.0221 (3) | |
H1n4 | 0.702 (2) | 0.0267 (15) | 0.6529 (15) | 0.0265* | |
H2n4 | 0.8632 (19) | 0.0642 (14) | 0.6222 (16) | 0.0265* |
U11 | U22 | U33 | U12 | U13 | U23 | |
B1 | 0.0181 (6) | 0.0208 (6) | 0.0181 (6) | 0.0008 (4) | 0.0052 (5) | 0.0009 (4) |
F1 | 0.0255 (4) | 0.0333 (4) | 0.0341 (4) | 0.0011 (3) | 0.0155 (3) | 0.0082 (3) |
F2 | 0.0189 (4) | 0.0318 (4) | 0.0229 (4) | 0.0015 (2) | 0.0015 (3) | 0.0031 (2) |
F3 | 0.0343 (4) | 0.0309 (4) | 0.0255 (4) | 0.0008 (3) | 0.0074 (3) | −0.0079 (3) |
F4 | 0.0228 (4) | 0.0227 (4) | 0.0254 (4) | 0.0021 (2) | 0.0033 (3) | 0.0046 (2) |
N1 | 0.0199 (5) | 0.0296 (5) | 0.0203 (5) | −0.0050 (4) | 0.0070 (4) | −0.0057 (4) |
C1 | 0.0203 (5) | 0.0156 (5) | 0.0177 (5) | 0.0015 (4) | 0.0048 (4) | 0.0008 (3) |
O1 | 0.0222 (4) | 0.0257 (4) | 0.0165 (4) | −0.0024 (3) | 0.0065 (3) | −0.0025 (3) |
N2 | 0.0188 (5) | 0.0231 (5) | 0.0141 (5) | −0.0012 (3) | 0.0060 (4) | 0.0003 (3) |
C2 | 0.0181 (5) | 0.0162 (5) | 0.0183 (5) | 0.0030 (4) | 0.0031 (4) | 0.0021 (4) |
N3 | 0.0174 (5) | 0.0262 (5) | 0.0196 (5) | −0.0025 (3) | 0.0052 (4) | −0.0031 (4) |
N4 | 0.0202 (5) | 0.0273 (5) | 0.0178 (5) | −0.0020 (4) | 0.0038 (4) | −0.0029 (4) |
B1—F1 | 1.3899 (15) | C2—N4 | 1.3159 (14) |
B1—F2 | 1.3852 (12) | N1—H1n1 | 0.863 (14) |
B1—F3 | 1.3754 (14) | N1—H2n1 | 0.828 (18) |
B1—F4 | 1.4229 (13) | N2—H1n2 | 0.833 (17) |
N1—C1 | 1.3309 (15) | N3—H1n3 | 0.873 (15) |
C1—O1 | 1.2293 (14) | N3—H2n3 | 0.850 (15) |
C1—N2 | 1.3936 (12) | N4—H1n4 | 0.844 (15) |
N2—C2 | 1.3627 (13) | N4—H2n4 | 0.812 (17) |
C2—N3 | 1.3113 (16) | ||
F1—B1—F2 | 110.44 (9) | N3—C2—N4 | 121.80 (10) |
F1—B1—F3 | 110.76 (9) | H1n1—N1—H2n1 | 119.8 (15) |
F1—B1—F4 | 107.07 (9) | H1n3—N3—H2n3 | 119.6 (15) |
F2—B1—F3 | 110.80 (9) | H1n4—N4—H2n4 | 117.5 (14) |
F2—B1—F4 | 108.70 (8) | H1n1—N1—C1 | 117.8 (11) |
F3—B1—F4 | 108.97 (9) | H2n1—N1—C1 | 121.3 (9) |
N1—C1—O1 | 124.11 (9) | C1—N2—H1n2 | 118.8 (9) |
N1—C1—N2 | 113.66 (10) | H1n2—N2—C2 | 114.7 (9) |
O1—C1—N2 | 122.24 (9) | C2—N3—H1n3 | 120.0 (10) |
C1—N2—C2 | 125.74 (10) | C2—N3—H2n3 | 119.2 (11) |
N2—C2—N3 | 121.10 (9) | C2—N4—H1n4 | 121.2 (11) |
N2—C2—N4 | 117.09 (11) | C2—N4—H2n4 | 121.3 (9) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1n1···F4i | 0.863 (14) | 2.231 (16) | 3.0069 (12) | 149.5 (13) |
N1—H2n1···F4ii | 0.828 (18) | 2.230 (16) | 2.9666 (13) | 148.5 (14) |
N2—H1n2···O1iii | 0.833 (17) | 2.070 (15) | 2.7981 (12) | 145.7 (12) |
N3—H1n3···F4iv | 0.873 (15) | 2.104 (14) | 2.9286 (11) | 157.4 (13) |
N3—H2n3···F3v | 0.850 (15) | 2.375 (17) | 2.9102 (13) | 121.5 (12) |
N3—H2n3···O1 | 0.850 (15) | 2.020 (13) | 2.6555 (11) | 130.9 (15) |
N4—H1n4···F1iv | 0.844 (15) | 2.229 (16) | 3.0499 (12) | 164.5 (13) |
N4—H2n4···F2iii | 0.812 (17) | 2.299 (15) | 2.9700 (13) | 140.4 (12) |
N1—H2n1···F1vi | 0.828 (18) | 2.488 (16) | 2.9927 (13) | 120.4 (12) |
N3—H2n3···F3v | 0.850 (15) | 2.375 (17) | 2.9102 (13) | 121.5 (12) |
N4—H2n4···O1iii | 0.812 (17) | 2.655 (15) | 3.1813 (13) | 123.9 (11) |
Symmetry codes: (i) −x+2, −y+1, −z+2; (ii) −x+2, y−1/2, −z+3/2; (iii) x, −y+1/2, z−1/2; (iv) −x+1, y−1/2, −z+3/2; (v) x, −y+1/2, z+1/2; (vi) x+1, y, z. |
Experimental details
Crystal data | |
Chemical formula | C2H7N4O+·BF4− |
Mr | 189.9 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 120 |
a, b, c (Å) | 7.8409 (3), 9.6373 (4), 9.5199 (4) |
β (°) | 105.689 (3) |
V (Å3) | 692.57 (5) |
Z | 4 |
Radiation type | Cu Kα |
µ (mm−1) | 1.86 |
Crystal size (mm) | 0.51 × 0.30 × 0.17 |
Data collection | |
Diffractometer | Agilent Xcalibur diffractometer with an Atlas (Gemini ultra Cu) detector |
Absorption correction | Multi-scan (CrysAlis PRO; Agilent, 2010) |
Tmin, Tmax | 0.534, 0.733 |
No. of measured, independent and observed [I > 3σ(I)] reflections | 7265, 1230, 1189 |
Rint | 0.020 |
(sin θ/λ)max (Å−1) | 0.597 |
Refinement | |
R[F > 3σ(F)], wR(F), S | 0.024, 0.081, 1.74 |
No. of reflections | 1230 |
No. of parameters | 131 |
H-atom treatment | Only H-atom coordinates refined |
Δρmax, Δρmin (e Å−3) | 0.13, −0.15 |
Computer programs: CrysAlis PRO (Agilent, 2010), SIR97 (Altomare et al., 1997), JANA2006 (Petříček et al., 2007), DIAMOND (Brandenburg & Putz, 2005) and PLATON (Spek, 2009).
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1n1···F4i | 0.863 (14) | 2.231 (16) | 3.0069 (12) | 149.5 (13) |
N1—H2n1···F4ii | 0.828 (18) | 2.230 (16) | 2.9666 (13) | 148.5 (14) |
N2—H1n2···O1iii | 0.833 (17) | 2.070 (15) | 2.7981 (12) | 145.7 (12) |
N3—H1n3···F4iv | 0.873 (15) | 2.104 (14) | 2.9286 (11) | 157.4 (13) |
N3—H2n3···F3v | 0.850 (15) | 2.375 (17) | 2.9102 (13) | 121.5 (12) |
N3—H2n3···O1 | 0.850 (15) | 2.020 (13) | 2.6555 (11) | 130.9 (15) |
N4—H1n4···F1iv | 0.844 (15) | 2.229 (16) | 3.0499 (12) | 164.5 (13) |
N4—H2n4···F2iii | 0.812 (17) | 2.299 (15) | 2.9700 (13) | 140.4 (12) |
N1—H2n1···F1vi | 0.828 (18) | 2.488 (16) | 2.9927 (13) | 120.4 (12) |
N3—H2n3···F3v | 0.850 (15) | 2.375 (17) | 2.9102 (13) | 121.5 (12) |
N4—H2n4···O1iii | 0.812 (17) | 2.655 (15) | 3.1813 (13) | 123.9 (11) |
Symmetry codes: (i) −x+2, −y+1, −z+2; (ii) −x+2, y−1/2, −z+3/2; (iii) x, −y+1/2, z−1/2; (iv) −x+1, y−1/2, −z+3/2; (v) x, −y+1/2, z+1/2; (vi) x+1, y, z. |
Acknowledgements
The authors also gratefully acknowledge support of this work by the Praemium Academiae project of the Academy of Sciences of the Czech Republic, by grant No. 58608 of the Grant Agency of the Charles University in Prague, and the Czech Science Foundation (grant No. 203/09/0878) as part of the long-term Research Plan of the Ministry of Education of the Czech Republic (grant No. MSM0021620857). Dr Michal Dušek from the Institute of Physics of the Czech Academy of Sciences is gratefully thanked for careful reading of the manuscript.
References
Agilent (2010). CrysAlis PRO. Agilent Technologies, Yarnton, Oxfordshire, England. Google Scholar
Ali, A. B., Dang, M. T., Greneche, J.-M., Hemon-Ribaud, A., Leblanc, M. & Maisonneuve, V. (2007). J. Solid State Chem. 180, 1911–1917. Google Scholar
Allen, F. H. (2002). Acta Cryst. B58, 380–388. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Altomare, A., Burla, M. C., Camalli, M., Cascarano, G., Giacovazzo, C., Guagliardi, A., Moliterni, A. G. G., Polidori, G. & Spagna, R. (1997). SIR97. University of Bari, Rome, Italy. Google Scholar
Bardaji, M., Laguna, A., Perez, M. R. & Jones, P. G. (2002). Organometallics, 21, 1877–1881. CAS Google Scholar
Becker, P. J. & Coppens, P. (1974). Acta Cryst. A30, 129–147. CrossRef IUCr Journals Web of Science Google Scholar
Blue, E. D., Davis, A., Conner, D., Gunnoe, T. B., Boyle, P. D. & White, P. S. (2003). J. Am. Chem. Soc. 125, 9435–9441. Web of Science CSD CrossRef PubMed CAS Google Scholar
Brandenburg, K. & Putz, H. (2005). DIAMOND. Crystal Impact GbR, D-53002 Bonn, Germany. Google Scholar
Byrne, P., Turner, D. R., Lloyd, G. O., Clarke, N. & Steed, J. W. (2008). Cryst. Growth Des. 8, 3335–3344. Web of Science CSD CrossRef CAS Google Scholar
Desiraju, G. R. & Steiner, T. (1999). The Weak Hydrogen Bond in Structural Chemistry and Biology, p. 13. New York: Oxford University Press Inc. Google Scholar
Dunitz, J. D. & Taylor, R. (1997). Chem. Eur. J. 3, 89–98. CrossRef CAS Web of Science Google Scholar
Etter, M. C., MacDonald, J. C. & Bernstein, J. (1990). Acta Cryst. B46, 256–262. CrossRef CAS Web of Science IUCr Journals Google Scholar
Fábry, J., Fridrichová, M., Dušek, M., Fejfarová, K. & Krupková, R. (2012a). Acta Cryst. E68, o47–o48. Web of Science CSD CrossRef IUCr Journals Google Scholar
Fábry, J., Fridrichová, M., Dušek, M., Fejfarová, K. & Krupková, R. (2012b). Acta Cryst. C68, o71–o75. Web of Science CSD CrossRef IUCr Journals Google Scholar
Fábry, J., Fridrichová, M., Dušek, M., Fejfarová, K. & Krupková, R. (2012c). Acta Cryst. C68, o76–o83. Web of Science CSD CrossRef IUCr Journals Google Scholar
Fridrichová, M., Němec, I., Císařová, I. & Chvostová, D. (2010). Phase Trans. 83, 761–767. Google Scholar
Fridrichová, M., Němec, I., Císařová, I. & Němec, P. (2010). CrystEngComm, 12, 2054–2056. Google Scholar
Kroupa, J. & Fridrichová, M. (2011). J. Opt. 13, 035204 (7 pp.) Web of Science CrossRef Google Scholar
Petříček, V., Dušek, M. & Palatinus, L. (2007). JANA2006. Institute of Physics, Praha, Czech Republic. Google Scholar
Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar
Zhao, Q. & Betley, T. A. (2011). Angew. Chem. Int. Ed. 50, 709–712. Web of Science CSD CrossRef CAS Google Scholar
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
The title structure was synthesized as a part of a study of 2-carbamoylguanidinium salts with the goal of preparing non-centrosymmetric crystals which might be suitable as non-linear optical elements. 2-carbamoylguanidinium hydrogen phosphite (Fridrichová, Němec, Císařová & Chvostová, 2010; Fridrichová, Němec, Císařová & Němec, 2010; Kroupa & Fridrichová, 2011) can be given as such an example.
Another goal of this study was consideration of influence of fluorine on the hydrogen-bond pattern. Usually, especially in presence of oxygen atoms as potential acceptors, fluorine avoids involvement in hydrogen bonds in organic compounds (Dunitz & Taylor, 1997). Poor involvement in hydrogen bonds is not, however, only limited to fluorine present in organic molecules but also in inorganic molecules. Recently synthesized compounds tris(2-carbamoylguanidinium) hydrogen fluorophosphonate fluorophosphonate monohydrate (Fábry et al., 2012a), two polymorphs of bis(2-carbamoylguanidinium) fluorophosphonate dihydrate (Fábry et al., 2012b) and mixed crystals of 2-carbamoylguanidinium with hydrogen fluorophosphonate and hydrogen phosphite in the ratios 1:0, 0.76 (2):0.24 (2) and 0.115 (7):0.885 (7) (Fábry et al., 2012c) exhibited weak N—H···F interactions which were weaker than the competing N—H···O hydrogen bonds in these structures.
On the other hand, inspection of the data in the Cambridge Structural Database (CSD; Version 5.32, October 2011 update; Allen, 2002) has shown that there is a number of structures which exhibit contacts N—H···F with the distances H···acceptor about 2.1 Å. It seems that majority of these structures contain highly symmetric anions with more F atoms as ligands such as [BF4]-, [PF6]-1, [SiF6]2-, [FeF6]3- etc. or organic molecules with a large number of fluorine substituents. ADOSIW, bis(2-ammonioethyl)ammonium hexafluoro-iron(III) monohydrate, Ali et al. (2007); AFUBIM, (2-aminothiazoline-N)-tris(pentafluorophenyl)-gold(III), Bardaji et al. (2002); AGOMEP, 3-(((4-methylphenyl)carbamoyl)amino)pyridinium hemikis(hexafluorosilicate, Byrne et al. (2008); AKEFEB, (1,2-bis(di-t-butylphosphino)ethane)-(aniline)-copper(I) tetrafluoroborate, Blue et al. (2003); ALIBED, (µ3–1,1,1-tris((2-aminoanilino)methyl)ethane)-tris(trimethylphosphino)- tri-iron hexafluorophosphate tetrahydrofuran solvate, Zhao et al. (2011) can be given as such examples. The reason for the involvement of F into the hydrogen-bond pattern in these structures seems to be steric: In whatever orientation fluorines get into a closer contact with the cationic H atoms.
This was also the case for the consideration of preparation of the title structure with a tetrahedral [BF4]- anion which would enhance a chance for the formation of a stronger N—H···F hydrogen bond even in presence of the competing carbonyl group in the 2-carbamoylguanidinium cation.
Indeed, a relatively strong N3—H1n3···F4i hydrogen bond appears in the title structure (Fig. 2) which is comparable by its geometric features to other present hydrogen bonds with the carbonyl oxygen involved, such as N2—H1n2···O1ii; N3—H2n3···O1; N4—H2n4···O1ii (Table 2). [The classification of the hydrogen bonds was taken from Desiraju & Steiner (1999); the symmetry codes i: -x + 1, y - 1/2, -z + 3/2; ii: x, -y + 1/2, z - 1/2.] The valence angle B1—F4···H1N3iii [the symmetry code iii: -x + 1, y + 1/2, -z + 3/2] equals to 109.2 (4)°. This angle would support the view that the N3—H1n3···F4i is indeed a true hydrogen bond.
The symmetry equivalent N1—H1n2···O1 hydrogen bonds form chains extended along the unit-cell axis c (Fig. 3). The pertinent graph set motif is C(4) (Etter et al., 1990). It is of interest that the secondary amine forms stronger N—H···O hydrogen bonds than the primary amines also in tris(2-carbamoylguanidinium) hydrogen fluorophosphonate fluorophosphonate monohydrate (Fábry et al., 2012a), 2-carbamoylguanidinium with hydrogen fluorophosphonate (Fábry et al., 2012c) and in the first polymorph of bis(2-carbamoylguanidinium) fluorophosphonate dihydrate and the first independent cation of the second polymorph of bis(2-carbamoylguanidinium) fluorophosphonate dihydrate (Fábry et al., 2012b).
In the title structure, in addition to the hydrogen bonds with the H···acceptor distances up to ~2.2 Å there are also present interactions with the H···acceptor distances up to ~2.6 Å with low N—H···acceptor angles.
The B—F distances within the anion show considerable spread. Such a distribution of the B—F distances in the tetrafluoroborate anions is, however, usual as it was checked in the structures stored in the Cambridge Structural database (CSD; Version 5.32, October 2011 update; Allen, 2002; Tab. 1).
The χ2 index through the cation's non-hydrogen atoms of the title structure equals to 4671.953. This is less than in the most probably less stable polymorph of bis(2-carbamoylguanidinium) fluorophosphonate dihydrate (Fábry et al., 2012b) with the χ2 index of 19477.0, and in 2-carbamoylguanidinium hydrogen phosphite with the χ2 index of 6515.041 (Fridrichová, Němec, Císařová & Němec, 2010; Fábry et al., 2012c). On the other hand, it is considerably more than e. g. the corresponding values regarding the two independent molecules in the presumably more stable polymorph of bis(2-carbamoylguanidinium) fluorophosphonate dihydrate (Fábry et al., 2012b) where the χ2 indices equal to 36.29 and 84.29.