1,1,3,3-tetramethylguanidinium dihydrogenorthophosphate

organic compounds 888 #2000 International Union of Crystallography Printed in Great Britain ± all rights reserved Acta Cryst. (2000). C56, 888±889 1,1,3,3-Tetramethylguanidinium dihydrogenorthophosphate A. Criado, a * M. J. Dia Ânez, a S. Pe Ârez-Garrido, a I. M. L. Fernandes, b M. Belsley b and E. de Matos Gomes b a Instituto de Ciencia de Materiales de Sevilla, Departamento de Fõ Âsica de la Materia Condensada, CSIC ± Universidad de Sevilla, Apartado 1065, 41080 Sevilla, Spain, and b Departamento de Fõ Âsica, Universidade do Minho, 4709 Braga, Portugal Correspondence e-mail: [email protected] Received 2 March 2000 Accepted 5 April 2000 In the title compound, C 5 H 14 N 3 + H 2 PO 4 ÿ , the cation has a central guanidinium fragment with a planar geometry, as expected for a central Csp 2 atom with a small charge delocalization along the three CÐN bonds. The crystal packing is governed by hydrogen bonds so that the phosphate anions are linked head to tail, forming chains running parallel to the cdirection. These chains in turn are interconnected by hydrogen bonds to intermediate tetramethylguanidinium cations forming hydrogen-bonded molecular layers stacked parallel to the bc crystal planes. Comment Inorganic salts of phosphoric acids form compounds that exhibit a wealth of interesting physical properties such as ferroelectricity and non-linear optical phenomena like second harmonic generation; a classical example is potassium dihydrogen orthophosphate (KDP) (Rafhkovich, 1991). A general synthetic route to obtain organo-dihydrogen orthophosphate crystals has been detailed (Masse & Zyss, 1991). In all these compounds, there is an inorganic subnetwork formed by the dihydrogen orthophosphate anions (H 2 PO 4 ) n . When the organic species are strongly dipolar, the anion sublattice is organized in a polar structure; examples are l-argininium dihydrogen orthophosphate monohydrate (Aoki et al., 1971), 2amino-5-nitropyridinium dihydrogen orthophosphate (Kotler et al., 1992) and sarcosine dihydrogen orthophosphate (Averbuch-Pouchot et al., 1988). In the case of a weakly dipolar organic species such as glycine, the anion sublattice will organize in a nonpolar structure (Averbuch-Pouchot et al., 1988). As part of a project to study new compounds with potentially interesting optical and dielectric properties, we have synthesized the title compound, (I). Similar to aminoguanidinium dihydrogen orthophosphate (Adams, 1977), we report here its crystal structure, as determined by singlecrystal X-ray diffraction. The compound crystallizes in a centrosymmetric space group; consequently, no non-linear optical effects are observed. Differential scanning calorimetry measurements performed from 93 to 673 K did not show any phase transition. The melting point occurs at about 493 K, followed by decomposition. The geometry of the guanidinium group in (I) is planar, as expected for sp 2 hybridization of the central C atom (Fig. 1). The delocalization along the three CÐN bonds gives rise to C1ÐN2 [1.344 (1) A Ê] and C1ÐN3 [1.346 (1) A Ê] bond lengths larger than the value expected for a Csp 2 N bond (1.295 A Ê) and close to the expected value for a delocalized C N double bond [1.339 (5) A Ê]. The C1ÐN1 bond length [1.320 (1) A Ê]is somewhat shorter and compares well with the average value for the guanidinium cation (1.321 A Ê) (Allen et al., 1987). The larger value for the C1ÐN2 and C1ÐN3 bond lengths must be ascribed to the methyl substitution which makes the three bonds non-equivalent. Indeed, simple molecular-orbital semiempirical calculations (extended Hu Èckel) give different atomic charges on N1 (ÿ0.376 e) and N2 and N3 (ÿ0.590 e). As may be expected, the two PÐO distances for the OH groups are signi®cantly longer than the other two PÐO distances. The basis of the molecular engineering interest in these salts is the obtention of structures with potential physical properties as a result of the hydrogen-bond crystal network, which tends to reinforce the properties exhibited by the isolated molecule by arranging them as linear or layered molecular patterns. In our case the hydrogen bonds also give rise to an interesting arrangement, which is best understood with the aid of the diagram corresponding to the crystal structure viewed perpendicular to the ab plane (Fig. 2). On one hand, each phosphate ion is connected by two hydrogen bonds to each phosphate ion related to it by a cglide plane with both positive and negative fractional ctranslations. Given that the central P atoms lie at a very close distance to the glide planes (0.32 A Ê), it results in approximately linear phosphate chains parallel to the cdirection. On the other hand, each tetramethylguanidinium ion is hydrogen-bonded to two phosphate ions related to each other by an inversion centre and belonging to different chains, giving rise to a framework of molecules Acta Crystallographica Section C Crystal Structure Communications ISSN 0108-2701 Figure 1 Structure of (I) showing 30% probability displacement ellipsoids. connected by hydrogen bonds in the form of layers parallel to the bc crystal planes and stacked according to the alattice translation period. Besides the above, two CÐHO contacts interrelating molecules within the same layer and not depicted in the diagram have been detected. Experimental The title compound was prepared by mixing equimolar portions of two reagents: 1,1,3,3-tetramethylguanidine (99%) and phosphoric acid (85%) in a 1:1 solution of ethanol and water at room temperature. Good quality, colourless single crystals of prism habit were grown from the solution by slow evaporation, one of which was selected and used for the X-ray analysis. Crystal data C 5 H 14 N 3 + H 2 PO 4 ÿ M r = 213.18 Monoclinic, P21=c a= 11.225 (3) A Ê b= 10.951 (1) A Ê c= 8.430 (2) A Ê = 103.50 (1) V= 1007.6 (4) A Ê 3 Z=4 D x = 1.405 Mg m ÿ3 D m = 1.40 Mg m ÿ3 D m measured by ¯otation in bromobenzene and acetone Mo Kradiation Cell parameters from 25 re¯ections = 7±12 = 0.264 mm ÿ1 T= 293 (2) K Prism, colourless 0.80 0.50 0.40 mm Data collection Enraf±Nonius CAD-4 diffractometer !±2scans 3777 measured re¯ections 3777 independent re¯ections 3257 re¯ections with I>2(I)  max = 32.96 h=0!17 k=0!16 l=ÿ12 !12 3 standard re¯ections frequency: 60 min intensity decay: none Re®nement Re®nement on F 2 R[F 2 >2(F 2 )] = 0.034 wR(F 2 ) = 0.105 S= 1.080 3777 re¯ections 124 parameters H-atom parameters constrained w= 1/[ 2 (F o 2 ) + (0.0639P) 2 + 0.1114P] where P=(F o 2 +2F c 2 )/3 (/) max < 0.001  max = 0.46 e A Ê ÿ3  min =ÿ0.37 e A Ê ÿ3 Data collection and cell re®nement: CAD-4 Software (Enraf± Nonius, 1989); data reduction: XRAY76 (Stewart et al., 1976); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to re®ne structure: SHELXL93 (Sheldrick, 1993); molecular graphics: PLATON (Spek, 1994); software used to prepare material for publication: PARST (Nardelli, 1995) and PARSTCIF (Nardelli, 1991). This work was supported by the Spanish CICYT project PB98-1126. We also acknowledge travel support from Accion Integrada Hispano-Portuguesa HP 1999-0070. Supplementary data for this paper are available from the IUCr electronic archives (Reference: NA1466). Services for accessing these data are described at the back of the journal. References Adams, J. M. (1977). Acta Cryst. B33, 1513±1515. Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1±19. Altomare, A., Cascarano, G., Giacovazzo, C., Guagliardi, A., Burla, M. C., Polidori, G. & Camalli, M. (1994). J. Appl. Cryst. 27, 435. Aoki, K., Nagano, K. & Iitaka, Y. (1971). Acta Cryst. B27, 11±23. Averbuch-Pouchot, A. T., Durif, A. & Guitel, J. C. (1988). Acta Cryst. C44, 99± 102. Enraf±Nonius (1989). CAD-4 Software. Version 5.0. Enraf±Nonius, Delft, The Netherlands. Kotler, Z., Hierle, R., Josse, D., Zyss, J. & Masse, R. (1992). J. Opt. Soc. Am. B9, 534±547. Masse, R. & Zyss, J. (1991). Mol. Eng. 1, 141±152. Nardelli, M. (1991). PARSTCIF. University of Parma, Italy. Nardelli, M. (1995). J. Appl. Cryst. 28, 659. Rafhkovich,L.N.(1991).KDP-Family Single Crystals. Bristol: IOP Publishing. Sheldrick, G. M. (1993). SHELXL93. University of Go Èttingen, Germany. Spek, A. L. (1994). PLATON. University of Utrecht, The Netherlands. Stewart, J. M., Machin, P. A., Dickinson, C. W., Ammon, H. L., Heck, H. & Flack, H. (1976). The XRAY76 System. Technical Report TR-446. Computer Science Center, University of Maryland, USA. Acta Cryst. (2000). C56, 888±889 A. Criado et al. C 5 H 14 N 3 + H 2 PO 4 ÿ 889 organic compounds Table 1 Selected geometric parameters (A Ê,). P1ÐO4 1.4968 (7) P1ÐO3 1.5148 (7) P1ÐO1 1.5629 (8) P1ÐO2 1.5800 (8) N1ÐC1 1.3198 (13) N3ÐC1 1.3451 (14) N3ÐC5 1.461 (2) N3ÐC4 1.458 (2) N2ÐC1 1.3447 (15) N2ÐC3 1.466 (2) N2ÐC2 1.455 (2) O4ÐP1ÐO3 114.78 (5) O4ÐP1ÐO1 108.64 (5) O3ÐP1ÐO1 109.11 (4) O4ÐP1ÐO2 110.24 (4) O3ÐP1ÐO2 108.20 (5) O1ÐP1ÐO2 105.47 (5) C1ÐN3ÐC5 120.91 (10) C1ÐN3ÐC4 121.53 (12) C5ÐN3ÐC4 114.50 (12) C1ÐN2ÐC3 121.02 (12) C1ÐN2ÐC2 121.27 (11) C3ÐN2ÐC2 115.34 (12) N1ÐC1ÐN2 120.78 (11) N1ÐC1ÐN3 120.22 (10) N2ÐC1ÐN3 119.01 (10) Table 2 Hydrogen-bonding geometry (A Ê,). DÐHADÐH HADADÐHA N1ÐH1AO3 0.88 2.08 2.924 (1) 161 O2ÐH2O3 i 0.84 1.79 2.616 (1) 167 O1ÐH1O4 ii 0.84 1.71 2.541 (1) 169 N1ÐH1BO3 iii 0.88 2.07 2.894 (1) 155 C5ÐH5BO2 iii 0.98 2.56 3.521 (2) 167 C5ÐH5AO2 iv 0.98 2.67 3.607 (2) 159 Symmetry codes: (i) x;ÿ1 2ÿy;zÿ1 2; (ii) x;ÿ1 2ÿy;1 2z; (iii) ÿx;ÿy;1ÿz; (iv) x;1y;z. Figure 2 The molecular packing viewed along an axis perpendicular to the ab plane showing the hydrogen bonding. supporting information sup-1 Acta Cryst. (2000). C56, 888-889 supporting information Acta Cryst. (2000). C56, 888-889 [doi:10.1107/S0108270100005187] 1,1,3,3-Tetramethylguanidinium dihydrogenorthophosphate A. Criado, M. J. Diánez, S. Pérez-Garrido, I. M. L. Fernandes, M. Belsley and E. de Matos Gomes Computing details Data collection: CAD-4 Software (Enraf-Nonius, 1989); cell refinement: SET4 (de Boer & Duissenberg, 1984) and CELDIM (CAD4, Retting, 1989); data reduction: XRAY76 System (Stewart et al., 1976); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: SHELXL93 (Sheldrick, 1993); molecular graphics: PLATON (Spek, 1994); software used to prepare material for publication: PARST (Nardelli, 1995) and PARSTCIF (Nardelli, 1991). 1,1,3,3-tetramethyl guanidinium phosphate Crystal data C5H14N3+·H2PO4− Mr = 213.18 Monoclinic, P21/c a = 11.225 (3) Å b = 10.951 (1) Å c = 8.430 (2) Å β = 103.50 (1)° V = 1007.6 (4) Å3 Z = 4 F(000) = 456 Dx = 1.405 Mg m−3 Dm = 1.40 Mg m−3 Dm measured by flotation in bromobenzene and acetone Melting point: 493 K Mo Kα radiation, λ = 0.71069 Å Cell parameters from 25 reflections θ = 7–12° µ = 0.26 mm−1 T = 293 K Prism, colourless 0.80 × 0.50 × 0.40 mm Data collection Enraf-Nonius CAD4 diffractometer Radiation source: fine-focus sealed tube Graphite monochromator ω–2θ scans 3777 measured reflections 3777 independent reflections 3257 reflections with I > 2σ(I) Rint = 0.000 θmax = 33.0°, θmin = 2.6° h = 0→17 k = 0→16 l = −12→12 3 standard reflections every 60 min min intensity decay: none Refinement Refinement on F2 Least-squares matrix: full R[F2 > 2σ(F2)] = 0.034 wR(F2) = 0.105 S = 1.08 3777 reflections 124 parameters 0 restraints Primary atom site location: structure-invariant direct methods Secondary atom site location: difference Fourier map supporting information sup-2 Acta Cryst. (2000). C56, 888-889 Hydrogen site location: inferred from neighbouring sites H-atom parameters constrained Calculated w = 1/[σ2(Fo2) + (0.0639P)2 + 0.1114P] where P = (Fo2 + 2Fc2)/3 (Δ/σ)max < 0.001 Δρmax = 0.46 e Å−3 Δρmin = −0.37 e Å−3 Special details Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. Refinement. Refinement on F2 for ALL reflections except for 0 with very negative F2 or flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The observed criterion of F2 > σ(F2) is used only for calculating R_factor_obs 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 Rfactors based on ALL data will be even larger. Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) xyzU iso*/Ueq P1 0.21200 (2) −0.22099 (2) 0.44607 (3) 0.02297 (8) O4 0.26662 (8) −0.14310 (7) 0.33544 (9) 0.0318 (2) O3 0.12944 (7) −0.15363 (7) 0.53532 (9) 0.0296 (2) O2 0.13625 (9) −0.32927 (8) 0.34687 (10) 0.0384 (2) H2 0.1421 −0.3263 0.2494 0.058* O1 0.31819 (7) −0.28321 (8) 0.57362 (10) 0.0348 (2) H1 0.2919 −0.3067 0.6540 0.052* N1 0.13166 (8) 0.11300 (8) 0.51765 (13) 0.0358 (2) H1A 0.14840 0.03517 0.53720 0.043* H1B 0.05591 0.13620 0.47485 0.043* N3 0.19506 (10) 0.31397 (9) 0.52252 (13) 0.0386 (2) N2 0.33639 (9) 0.16108 (10) 0.61799 (14) 0.0415 (2) C1 0.22015 (10) 0.19494 (10) 0.55254 (13) 0.0309 (2) C5 0.08049 (12) 0.35246 (12) 0.4126 (2) 0.0459 (3) H5A 0.0924 0.4317 0.3645 0.069* H5B 0.0166 0.3597 0.4739 0.069* H5C 0.0556 0.2918 0.3257 0.069* C2 0.36472 (13) 0.04187 (13) 0.6937 (2) 0.0530 (4) H2A 0.4411 0.0469 0.7782 0.080* H2B 0.3742 −0.0177 0.6108 0.080* H2C 0.2979 0.0162 0.7430 0.080* C4 0.2563 (2) 0.40878 (13) 0.6335 (2) 0.0626 (4) H4A 0.1968 0.4485 0.6851 0.094* H4B 0.2915 0.4695 0.5723 0.094* H4C 0.3216 0.3721 0.7177 0.094* C3 0.43961 (13) 0.2244 (2) 0.5750 (2) 0.0630 (5) H3A 0.4925 0.1646 0.5386 0.094* H3B 0.4867 0.2681 0.6707 0.094* H3C 0.40852 0.2828 0.4870 0.094* supporting information sup-3 Acta Cryst. (2000). C56, 888-889 Atomic displacement parameters (Å2) U11 U22 U33 U12 U13 U23 P1 0.02584 (12) 0.02308 (12) 0.02056 (11) 0.00027 (7) 0.00656 (8) 0.00083 (7) O4 0.0431 (4) 0.0283 (3) 0.0264 (3) −0.0075 (3) 0.0125 (3) 0.0006 (3) O3 0.0303 (3) 0.0317 (3) 0.0277 (3) 0.0081 (3) 0.0087 (3) 0.0015 (3) O2 0.0539 (5) 0.0356 (4) 0.0279 (3) −0.0179 (4) 0.0137 (3) −0.0048 (3) O1 0.0294 (3) 0.0464 (5) 0.0301 (3) 0.0121 (3) 0.0100 (3) 0.0092 (3) N1 0.0266 (4) 0.0261 (4) 0.0535 (6) 0.0007 (3) 0.0072 (4) −0.0021 (4) N3 0.0430 (5) 0.0271 (4) 0.0458 (5) −0.0043 (4) 0.0105 (4) −0.0041 (4) N2 0.0282 (4) 0.0438 (5) 0.0496 (6) −0.0022 (4) 0.0032 (4) −0.0042 (4) C1 0.0300 (4) 0.0297 (4) 0.0339 (5) −0.0012 (3) 0.0093 (4) −0.0058 (4) C5 0.0426 (6) 0.0347 (6) 0.0626 (8) 0.0028 (5) 0.0168 (6) 0.0122 (5) C2 0.0417 (6) 0.0429 (7) 0.0653 (9) 0.0081 (5) −0.0059 (6) −0.0054 (6) C4 0.0952 (13) 0.0332 (6) 0.0558 (8) −0.0164 (7) 0.0105 (8) −0.0130 (6) C3 0.0298 (6) 0.0859 (13) 0.0708 (10) −0.0132 (7) 0.0071 (6) 0.0034 (9) Geometric parameters (Å, º) P1—O4 1.4968 (7) N2—C2 1.455 (2) P1—O3 1.5148 (7) C5—H5A 0.98 P1—O1 1.5629 (8) C5—H5B 0.98 P1—O2 1.5800 (8) C5—H5C 0.98 O2—H2 0.84 C2—H2A 0.98 O1—H1 0.84 C2—H2B 0.98 N1—C1 1.3198 (13) C2—H2C 0.98 N1—H1A 0.88 C4—H4A 0.98 N1—H1B 0.88 C4—H4B 0.98 N3—C1 1.3451 (14) C4—H4C 0.98 N3—C5 1.461 (2) C3—H3A 0.98 N3—C4 1.458 (2) C3—H3B 0.98 N2—C1 1.3447 (15) C3—H3C 0.98 N2—C3 1.466 (2) O4—P1—O3 114.78 (5) H5A—C5—H5B 109.5 O4—P1—O1 108.64 (5) N3—C5—H5C 109.47 O3—P1—O1 109.11 (4) H5A—C5—H5C 109.5 O4—P1—O2 110.24 (4) H5B—C5—H5C 109.5 O3—P1—O2 108.20 (5) N2—C2—H2A 109.47 O1—P1—O2 105.47 (5) N2—C2—H2B 109.47 P1—O2—H2 109.47 H2A—C2—H2B 109.5 P1—O1—H1 109.47 N2—C2—H2C 109.47 C1—N1—H1A 120.00 H2A—C2—H2C 109.5 C1—N1—H1B 120.00 H2B—C2—H2C 109.5 H1A—N1—H1B 120.0 N3—C4—H4A 109.47 C1—N3—C5 120.91 (10) N3—C4—H4B 109.47 C1—N3—C4 121.53 (12) H4A—C4—H4B 109.5 C5—N3—C4 114.50 (12) N3—C4—H4C 109.47 supporting information sup-4 Acta Cryst. (2000). C56, 888-889 C1—N2—C3 121.02 (12) H4A—C4—H4C 109.5 C1—N2—C2 121.27 (11) H4B—C4—H4C 109.5 C3—N2—C2 115.34 (12) N2—C3—H3A 109.47 N1—C1—N2 120.78 (11) N2—C3—H3B 109.47 N1—C1—N3 120.22 (10) H3A—C3—H3B 109.5 N2—C1—N3 119.01 (10) N2—C3—H3C 109.47 N3—C5—H5A 109.47 H3A—C3—H3C 109.5 N3—C5—H5B 109.47 H3B—C3—H3C 109.5 Hydrogen-bond geometry (Å, º) D—H···AD—H H···AD···AD—H···A N1—H1A···O3 0.88 2.08 2.924 (1) 161 O2—H2···O3i0.84 1.79 2.616 (1) 167 O1—H1···O4ii 0.84 1.71 2.541 (1) 169 N1—H1B···O3iii 0.88 2.07 2.894 (1) 155 C5—H5B···O2iii 0.98 2.56 3.521 (2) 167 C5—H5A···O2iv 0.98 2.67 3.607 (2) 159 Symmetry codes: (i) x, −y−1/2, z−1/2; (ii) x, −y−1/2, z+1/2; (iii) −x, −y, −z+1; (iv) x, y+1, z.