organic compounds
Bis(tetraethylammonium) oxalate dihydrate
aDepartment of Chemistry, Loyola University Maryland, 4501 North Charles Street, Baltimore, MD 21210-2699, USA, and bDepartment of Chemistry, College of William and Mary, PO Box 8795, Williamsburg, VA 23187-8795, USA
*Correspondence e-mail: tmcneese@loyola.edu
The title compound, 2C8H20N+·C2O42−·2H2O, synthesized by neutralizing H2C2O4·2H2O with (C2H5)4NOH in a 1:2 molar ratio, is a deliquescent solid. The oxalate ion is nonplanar, with a dihedral angle between carboxylate groups of 64.37 (2)°. O—H⋯O hydrogen bonds of moderate strength link the O atoms of the water molecules and the oxalate ions into rings parallel to the c axis. The rings exhibit the graph-set motif R44(12). In addition, there are weak C—H⋯O interactions in the crystal structure.
Related literature
For related compounds containing planar and nonplanar oxalate ions, see: Beagley & Small (1964); Robertson (1965); Jeffrey & Parry (1954). For general syntheses of tetraalkylammonium salts and their uses, see: Barthel & Kunz (1988); Heck (1982); Markowitz (1957); McNeese et al. (1984); Starks (1971). For uses of [(C2H5)4N)2(C2O4)]·2H2O, see: Darensbourg et al. (1992); Demadis & Coucouvanis (1995); Diop et al. (1997); Engels et al. (1983). For classification of the graph-set motifs, see: Etter et al. (1990). For classification of the hydrogen bonds, see: Gilli & Gilli (2009). Oxalate was confirmed by the blue ring resorcinol test (Chernoff, 1920).
Experimental
Crystal data
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Refinement
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Data collection: APEX2 (Bruker, 2004); cell SAINT-Plus (Bruker, 2004); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXLE (Hübschle et al., 2011); molecular graphics: ORTEP-3 (Farrugia, 1997) and Mercury (Macrae et al., 2006); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).
Supporting information
https://doi.org/10.1107/S160053681203022X/fb2256sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S160053681203022X/fb2256Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S160053681203022X/fb2256Isup3.cml
An aqueous 35 weight percent solution of Et4NOH (6.69 g, 15.9 mmol OH-) was added by syringe to a 50-ml Schlenk tube containing a 20-ml CH3CN solution of H2C2O4.2H2O (1.00 g, 7.93 mmol). The colorless solution was stirred under argon for 15 min followed by solvent removal under reduced pressure. Hot tetrahydrofuran (25 ml) was added to the greasy solid, the mixture was stirred for 10 min, and the solution was decanted from the product. The deliquescent white solid was dried under vacuum and crystallized from CH3CN/ THF. Yield: 1.98 g (65%). IR (υ(CO), CH3CN) 1565(s) cm-1. Oxalate was confirmed by the blue ring resorcinol test (Chernoff, 1920). The analyzed crystal was rapidly transferred from vacuum to a 100 K stream of dry air for X-ray analysis.
Data were refined against F2. Because of the relatively high Rint the determination of the
turned out to be meaningless and therefore 1509 Friedel pairs have been merged. All the hydrogen atoms appeared in the difference nevertheless, those pertinent to the methyl and the methylene carbons were situated into the idealized positions and refined in the riding atom formalism. The positional parameters of the water hydrogens were refined freely. The applied constraints: Cmethyl-Hmethyl=0.98, Cmethylene-Hmethylene=0.99 Å. Uiso(Hmethylene) = 1.2Ueq(Cmethylene), Uiso(Hmethyl) = 1.5Ueq(Cmethyl), Uiso(Hwater) = 1.5Ueq(Owater).Tetraalkylammonium salts are important compounds as phase-transfer catalysts (Starks, 1971), as electrolytes in electrochemical studies (Barthel & Kunz, 1988), in organic Heck-type synthetic reactions (Heck, 1982), and in preparing and isolating polynuclear organometallic complexes (McNeese et al., 1984). A procedure for synthesizing quaternary ammonium salts involves neutralization of a tetraalkylammonium hydroxide with the acid of the desired anion (Markowitz, 1957).
The title compound, (Et4N)2C2O4.2H2O, synthesized by reaction of Et4NOH and H2C2O4.2H2O in a 2:1 mole ratio, is deliquescent and rapidly absorbs moisture from air. Previously prepared and used in situ or as a noncrystalline solid, it has been employed as a reductant in aprotic electrochemical cells (Engels et al., 1983) and in the synthesis of oxalate-containing organometallic complexes (Diop et al., 1997; Demadis & Coucouvanis, 1995; Darensbourg et al., 1992).
Oxalate bond distances (C—C and C—O) and angles (O—C—O and O—C—C) are comparable to other reported oxalate salts containing NH4+ and alkali metal ions. The oxalate ion is planar in Li2C2O4 (Beagley & Small, 1964) and Na2C2O4 (Jeffrey & Parry, 1954), but the dihedral angle between planes of symmetrical carboxylate groups of the oxalate fragment is 26.6° in (NH4)2C2O4.H2O (Robertson, 1965). The directional character of the hydrogen bonding pattern in the monohydrate is believed responsible for the observed non-planar stereochemistry of the oxalate ion. A dihedral angle of 64.37 (2)° is present in the title compound (Fig. 1). The non-planarity of the oxalate ion is maintained by moderate hydrogen bonds (Table 1) that link the oxygen atoms of the oxalate ion and the water molecules into a ring motif R44(12) (Etter et al., 1990). (For the classification of the hydrogen bonds, see Gilli & Gilli, 2009). In addition, there are also present weak C-H···O interactions in the structure (Tab. 1). Fig. 2 illustrates the packing diagram for the structure of the title compound.
For related compounds containing planar and nonplanar oxalate ions, see: Beagley & Small (1964); Robertson (1965); Jeffrey & Parry (1954). For general syntheses of tetraalkylammonium salts and their uses, see: Barthel & Kunz (1988); Heck (1982); Markowitz (1957); McNeese et al. (1984); Starks (1971). For uses of [(C2H5)4N)2(C2O4)].2H2O, see: Darensbourg et al. (1992); Demadis & Coucouvanis (1995); Diop et al. (1997); Engels et al. (1983). For classification of the graph-set motifs, see: Etter et al. (1990). For classification of the hydrogen bonds, see: Gilli & Gilli (2009). Oxalate was confirmed by the blue ring resorcinol test (Chernoff, 1920).
Data collection: APEX2 (Bruker, 2004); cell
SAINT-Plus (Bruker, 2004); data reduction: SAINT-Plus (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXLE (Hübschle et al., 2011); molecular graphics: ORTEP-3 (Farrugia, 1997) and Mercury (Macrae et al., 2006); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).Fig. 1. Ellipsoid plot of the title molecules. Displacement ellipsoids are drawn at the 50% probability level. | |
Fig. 2. Mercury (Macrae et al., 2006) packing diagram of the title compound viewed down the b axis. |
2C8H20N+·C2O42−·2H2O | F(000) = 856 |
Mr = 384.55 | Dx = 1.168 Mg m−3 |
Orthorhombic, Pca21 | Cu Kα radiation, λ = 1.54178 Å |
Hall symbol: P 2c -2ac | Cell parameters from 6094 reflections |
a = 19.9302 (4) Å | θ = 3.8–68.4° |
b = 7.6627 (1) Å | µ = 0.70 mm−1 |
c = 14.3253 (3) Å | T = 100 K |
V = 2187.75 (7) Å3 | Plate, colorless |
Z = 4 | 0.32 × 0.25 × 0.05 mm |
Bruker SMART APEXII CCD diffractometer | 2026 independent reflections |
Radiation source: fine-focus sealed tube | 1953 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.067 |
ω and ψ scans | θmax = 67.0°, θmin = 4.4° |
Absorption correction: multi-scan (SADABS; Sheldrick, 2004) | h = −23→23 |
Tmin = 0.808, Tmax = 0.966 | k = −8→9 |
17374 measured reflections | l = −16→16 |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.031 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.081 | w = 1/[σ2(Fo2) + (0.0468P)2 + 0.3359P] where P = (Fo2 + 2Fc2)/3 |
S = 1.07 | (Δ/σ)max < 0.001 |
2026 reflections | Δρmax = 0.20 e Å−3 |
256 parameters | Δρmin = −0.16 e Å−3 |
1 restraint | Extinction correction: SHELXLE (Hübschle et al., 2011), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
152 constraints | Extinction coefficient: 0.0018 (3) |
Primary atom site location: structure-invariant direct methods |
2C8H20N+·C2O42−·2H2O | V = 2187.75 (7) Å3 |
Mr = 384.55 | Z = 4 |
Orthorhombic, Pca21 | Cu Kα radiation |
a = 19.9302 (4) Å | µ = 0.70 mm−1 |
b = 7.6627 (1) Å | T = 100 K |
c = 14.3253 (3) Å | 0.32 × 0.25 × 0.05 mm |
Bruker SMART APEXII CCD diffractometer | 2026 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 2004) | 1953 reflections with I > 2σ(I) |
Tmin = 0.808, Tmax = 0.966 | Rint = 0.067 |
17374 measured reflections |
R[F2 > 2σ(F2)] = 0.031 | 1 restraint |
wR(F2) = 0.081 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.07 | Δρmax = 0.20 e Å−3 |
2026 reflections | Δρmin = −0.16 e Å−3 |
256 parameters |
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 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 > σ(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 | ||
O1 | 0.44416 (8) | 0.9370 (2) | 0.66940 (11) | 0.0260 (4) | |
O2 | 0.54192 (8) | 1.0741 (2) | 0.69474 (11) | 0.0245 (4) | |
O3 | 0.53292 (7) | 0.8233 (2) | 0.84977 (11) | 0.0263 (4) | |
O4 | 0.44453 (8) | 0.9997 (2) | 0.87126 (11) | 0.0254 (4) | |
C1 | 0.49202 (10) | 0.9852 (3) | 0.71976 (14) | 0.0162 (4) | |
C2 | 0.48956 (10) | 0.9310 (3) | 0.82269 (14) | 0.0167 (4) | |
N1 | 0.52560 (8) | 0.5362 (2) | 0.52871 (12) | 0.0155 (4) | |
C3 | 0.48056 (10) | 0.3892 (3) | 0.56294 (15) | 0.0191 (4) | |
H3A | 0.4527 | 0.3484 | 0.5100 | 0.023* | |
H3B | 0.5092 | 0.2903 | 0.5826 | 0.023* | |
C4 | 0.43481 (12) | 0.4368 (3) | 0.64282 (19) | 0.0321 (6) | |
H4A | 0.4618 | 0.4682 | 0.6975 | 0.048* | |
H4B | 0.4061 | 0.3369 | 0.6581 | 0.048* | |
H4C | 0.4067 | 0.5363 | 0.6248 | 0.048* | |
C5 | 0.48413 (10) | 0.6851 (3) | 0.48890 (15) | 0.0194 (4) | |
H5A | 0.4561 | 0.7342 | 0.5396 | 0.023* | |
H5B | 0.5151 | 0.7782 | 0.4678 | 0.023* | |
C6 | 0.43882 (13) | 0.6362 (3) | 0.40826 (19) | 0.0331 (6) | |
H6A | 0.4200 | 0.7423 | 0.3804 | 0.050* | |
H6B | 0.4023 | 0.5620 | 0.4310 | 0.050* | |
H6C | 0.4648 | 0.5726 | 0.3612 | 0.050* | |
C7 | 0.57042 (10) | 0.4560 (3) | 0.45509 (15) | 0.0191 (4) | |
H7A | 0.5418 | 0.4061 | 0.4053 | 0.023* | |
H7B | 0.5958 | 0.3587 | 0.4837 | 0.023* | |
C8 | 0.61999 (11) | 0.5824 (3) | 0.41095 (17) | 0.0267 (5) | |
H8A | 0.6519 | 0.6226 | 0.4584 | 0.040* | |
H8B | 0.5956 | 0.6828 | 0.3854 | 0.040* | |
H8C | 0.6444 | 0.5233 | 0.3606 | 0.040* | |
C9 | 0.56591 (10) | 0.6129 (3) | 0.60804 (14) | 0.0180 (4) | |
H9A | 0.5347 | 0.6644 | 0.6542 | 0.022* | |
H9B | 0.5943 | 0.7084 | 0.5833 | 0.022* | |
C10 | 0.61047 (11) | 0.4815 (3) | 0.65726 (16) | 0.0231 (5) | |
H10A | 0.5836 | 0.3801 | 0.6759 | 0.035* | |
H10B | 0.6303 | 0.5355 | 0.7128 | 0.035* | |
H10C | 0.6463 | 0.4440 | 0.6149 | 0.035* | |
N2 | 0.74829 (8) | 0.0031 (2) | 0.76685 (12) | 0.0164 (4) | |
C11 | 0.72670 (10) | 0.1585 (3) | 0.70941 (15) | 0.0189 (4) | |
H11A | 0.6954 | 0.2301 | 0.7470 | 0.023* | |
H11B | 0.7019 | 0.1160 | 0.6540 | 0.023* | |
C12 | 0.78410 (11) | 0.2737 (3) | 0.67665 (17) | 0.0257 (5) | |
H12A | 0.8076 | 0.3218 | 0.7310 | 0.039* | |
H12B | 0.7663 | 0.3694 | 0.6386 | 0.039* | |
H12C | 0.8154 | 0.2043 | 0.6392 | 0.039* | |
C13 | 0.79440 (10) | −0.1148 (3) | 0.71088 (15) | 0.0195 (4) | |
H13A | 0.8343 | −0.0467 | 0.6918 | 0.023* | |
H13B | 0.8100 | −0.2106 | 0.7518 | 0.023* | |
C14 | 0.76283 (11) | −0.1938 (3) | 0.62449 (16) | 0.0243 (5) | |
H14A | 0.7287 | −0.2792 | 0.6430 | 0.036* | |
H14B | 0.7975 | −0.2519 | 0.5873 | 0.036* | |
H14C | 0.7418 | −0.1014 | 0.5873 | 0.036* | |
C15 | 0.78792 (10) | 0.0602 (3) | 0.85239 (15) | 0.0204 (4) | |
H15A | 0.8001 | −0.0449 | 0.8888 | 0.024* | |
H15B | 0.8302 | 0.1154 | 0.8312 | 0.024* | |
C16 | 0.75169 (11) | 0.1864 (3) | 0.91622 (15) | 0.0247 (5) | |
H16A | 0.7430 | 0.2955 | 0.8827 | 0.037* | |
H16B | 0.7796 | 0.2103 | 0.9711 | 0.037* | |
H16C | 0.7090 | 0.1349 | 0.9362 | 0.037* | |
C17 | 0.68437 (10) | −0.0925 (3) | 0.79498 (14) | 0.0177 (4) | |
H17A | 0.6562 | −0.0122 | 0.8324 | 0.021* | |
H17B | 0.6590 | −0.1220 | 0.7377 | 0.021* | |
C18 | 0.69534 (10) | −0.2576 (3) | 0.85037 (15) | 0.0213 (4) | |
H18A | 0.6519 | −0.3112 | 0.8646 | 0.032* | |
H18B | 0.7187 | −0.2296 | 0.9087 | 0.032* | |
H18C | 0.7226 | −0.3391 | 0.8138 | 0.032* | |
O5 | 0.38115 (7) | 0.9648 (2) | 0.03930 (11) | 0.0216 (3) | |
H1W | 0.4148 (16) | 0.023 (4) | 0.547 (3) | 0.032* | |
H2W | 0.4216 (17) | 0.071 (4) | 0.461 (3) | 0.032* | |
O6 | 0.39111 (7) | 0.0424 (2) | 0.50150 (12) | 0.0235 (3) | |
H3W | 0.4112 (17) | 0.951 (4) | 0.082 (3) | 0.035* | |
H4W | 0.4061 (16) | 0.968 (4) | −0.009 (3) | 0.035* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0228 (8) | 0.0430 (9) | 0.0122 (8) | 0.0059 (6) | −0.0052 (6) | −0.0044 (7) |
O2 | 0.0276 (8) | 0.0317 (8) | 0.0143 (8) | −0.0002 (6) | 0.0056 (6) | 0.0056 (6) |
O3 | 0.0217 (7) | 0.0387 (9) | 0.0185 (8) | 0.0006 (6) | −0.0022 (6) | 0.0122 (7) |
O4 | 0.0247 (8) | 0.0400 (9) | 0.0114 (7) | −0.0035 (7) | 0.0055 (6) | −0.0047 (6) |
C1 | 0.0175 (10) | 0.0226 (10) | 0.0085 (9) | 0.0064 (7) | 0.0016 (8) | −0.0021 (8) |
C2 | 0.0128 (9) | 0.0265 (10) | 0.0109 (10) | −0.0050 (7) | −0.0016 (8) | 0.0008 (8) |
N1 | 0.0153 (8) | 0.0194 (8) | 0.0120 (8) | −0.0007 (7) | −0.0004 (7) | −0.0002 (6) |
C3 | 0.0176 (9) | 0.0211 (10) | 0.0187 (10) | −0.0045 (8) | −0.0009 (8) | 0.0010 (8) |
C4 | 0.0275 (12) | 0.0354 (13) | 0.0334 (14) | −0.0027 (10) | 0.0150 (11) | 0.0028 (10) |
C5 | 0.0199 (9) | 0.0203 (9) | 0.0181 (10) | 0.0036 (7) | −0.0028 (8) | 0.0008 (8) |
C6 | 0.0365 (13) | 0.0322 (12) | 0.0306 (13) | 0.0062 (10) | −0.0179 (11) | −0.0034 (10) |
C7 | 0.0188 (10) | 0.0249 (10) | 0.0134 (10) | 0.0039 (8) | 0.0026 (8) | −0.0021 (8) |
C8 | 0.0243 (11) | 0.0342 (11) | 0.0216 (11) | 0.0024 (9) | 0.0090 (9) | 0.0016 (9) |
C9 | 0.0172 (9) | 0.0242 (10) | 0.0125 (10) | −0.0029 (8) | −0.0015 (8) | −0.0014 (8) |
C10 | 0.0226 (11) | 0.0291 (11) | 0.0176 (11) | −0.0012 (8) | −0.0068 (9) | 0.0012 (9) |
N2 | 0.0121 (7) | 0.0252 (9) | 0.0119 (8) | −0.0003 (7) | −0.0011 (7) | 0.0019 (7) |
C11 | 0.0161 (9) | 0.0250 (10) | 0.0156 (9) | 0.0006 (8) | −0.0026 (8) | 0.0053 (9) |
C12 | 0.0217 (10) | 0.0316 (11) | 0.0239 (11) | −0.0041 (9) | −0.0012 (9) | 0.0084 (9) |
C13 | 0.0141 (9) | 0.0296 (10) | 0.0149 (10) | 0.0031 (8) | 0.0032 (8) | 0.0019 (9) |
C14 | 0.0239 (11) | 0.0331 (11) | 0.0159 (10) | 0.0019 (8) | 0.0035 (8) | −0.0017 (9) |
C15 | 0.0171 (9) | 0.0300 (11) | 0.0140 (10) | 0.0002 (8) | −0.0055 (8) | 0.0014 (8) |
C16 | 0.0249 (10) | 0.0346 (11) | 0.0146 (10) | −0.0017 (9) | −0.0041 (8) | −0.0032 (9) |
C17 | 0.0120 (9) | 0.0279 (11) | 0.0132 (10) | −0.0013 (8) | 0.0007 (7) | 0.0008 (8) |
C18 | 0.0216 (10) | 0.0296 (11) | 0.0128 (10) | −0.0006 (8) | 0.0014 (8) | 0.0014 (8) |
O5 | 0.0169 (7) | 0.0371 (8) | 0.0109 (7) | −0.0003 (6) | 0.0004 (7) | 0.0001 (6) |
O6 | 0.0195 (8) | 0.0351 (8) | 0.0159 (8) | 0.0004 (6) | −0.0043 (7) | 0.0009 (7) |
O1—C1 | 1.252 (3) | N2—C11 | 1.510 (3) |
O2—C1 | 1.258 (3) | N2—C13 | 1.518 (3) |
O3—C2 | 1.256 (3) | N2—C15 | 1.522 (3) |
O4—C2 | 1.252 (3) | N2—C17 | 1.524 (2) |
C1—C2 | 1.533 (3) | C11—C12 | 1.520 (3) |
N1—C9 | 1.511 (2) | C11—H11A | 0.9900 |
N1—C7 | 1.513 (2) | C11—H11B | 0.9900 |
N1—C5 | 1.520 (3) | C12—H12A | 0.9800 |
N1—C3 | 1.522 (3) | C12—H12B | 0.9800 |
C3—C4 | 1.508 (3) | C12—H12C | 0.9800 |
C3—H3A | 0.9900 | C13—C14 | 1.514 (3) |
C3—H3B | 0.9900 | C13—H13A | 0.9900 |
C4—H4A | 0.9800 | C13—H13B | 0.9900 |
C4—H4B | 0.9800 | C14—H14A | 0.9800 |
C4—H4C | 0.9800 | C14—H14B | 0.9800 |
C5—C6 | 1.514 (3) | C14—H14C | 0.9800 |
C5—H5A | 0.9900 | C15—C16 | 1.514 (3) |
C5—H5B | 0.9900 | C15—H15A | 0.9900 |
C6—H6A | 0.9800 | C15—H15B | 0.9900 |
C6—H6B | 0.9800 | C16—H16A | 0.9800 |
C6—H6C | 0.9800 | C16—H16B | 0.9800 |
C7—C8 | 1.521 (3) | C16—H16C | 0.9800 |
C7—H7A | 0.9900 | C17—C18 | 1.509 (3) |
C7—H7B | 0.9900 | C17—H17A | 0.9900 |
C8—H8A | 0.9800 | C17—H17B | 0.9900 |
C8—H8B | 0.9800 | C18—H18A | 0.9800 |
C8—H8C | 0.9800 | C18—H18B | 0.9800 |
C9—C10 | 1.517 (3) | C18—H18C | 0.9800 |
C9—H9A | 0.9900 | O5—H3W | 0.87 (4) |
C9—H9B | 0.9900 | O5—H4W | 0.86 (4) |
C10—H10A | 0.9800 | O6—H1W | 0.82 (4) |
C10—H10B | 0.9800 | O6—H2W | 0.87 (4) |
C10—H10C | 0.9800 | ||
O1—C1—O2 | 126.7 (2) | H10A—C10—H10C | 109.5 |
O1—C1—C2 | 116.77 (19) | H10B—C10—H10C | 109.5 |
O2—C1—C2 | 116.50 (18) | C11—N2—C13 | 110.73 (16) |
O4—C2—O3 | 126.7 (2) | C11—N2—C15 | 111.11 (16) |
O4—C2—C1 | 116.34 (18) | C13—N2—C15 | 106.39 (15) |
O3—C2—C1 | 116.95 (18) | C11—N2—C17 | 106.56 (15) |
C9—N1—C7 | 111.62 (15) | C13—N2—C17 | 111.08 (16) |
C9—N1—C5 | 106.21 (16) | C15—N2—C17 | 111.05 (16) |
C7—N1—C5 | 111.38 (16) | N2—C11—C12 | 114.34 (16) |
C9—N1—C3 | 111.07 (16) | N2—C11—H11A | 108.7 |
C7—N1—C3 | 105.78 (16) | C12—C11—H11A | 108.7 |
C5—N1—C3 | 110.86 (15) | N2—C11—H11B | 108.7 |
C4—C3—N1 | 114.95 (18) | C12—C11—H11B | 108.7 |
C4—C3—H3A | 108.5 | H11A—C11—H11B | 107.6 |
N1—C3—H3A | 108.5 | C11—C12—H12A | 109.5 |
C4—C3—H3B | 108.5 | C11—C12—H12B | 109.5 |
N1—C3—H3B | 108.5 | H12A—C12—H12B | 109.5 |
H3A—C3—H3B | 107.5 | C11—C12—H12C | 109.5 |
C3—C4—H4A | 109.5 | H12A—C12—H12C | 109.5 |
C3—C4—H4B | 109.5 | H12B—C12—H12C | 109.5 |
H4A—C4—H4B | 109.5 | C14—C13—N2 | 114.72 (16) |
C3—C4—H4C | 109.5 | C14—C13—H13A | 108.6 |
H4A—C4—H4C | 109.5 | N2—C13—H13A | 108.6 |
H4B—C4—H4C | 109.5 | C14—C13—H13B | 108.6 |
C6—C5—N1 | 115.14 (17) | N2—C13—H13B | 108.6 |
C6—C5—H5A | 108.5 | H13A—C13—H13B | 107.6 |
N1—C5—H5A | 108.5 | C13—C14—H14A | 109.5 |
C6—C5—H5B | 108.5 | C13—C14—H14B | 109.5 |
N1—C5—H5B | 108.5 | H14A—C14—H14B | 109.5 |
H5A—C5—H5B | 107.5 | C13—C14—H14C | 109.5 |
C5—C6—H6A | 109.5 | H14A—C14—H14C | 109.5 |
C5—C6—H6B | 109.5 | H14B—C14—H14C | 109.5 |
H6A—C6—H6B | 109.5 | C16—C15—N2 | 114.97 (16) |
C5—C6—H6C | 109.5 | C16—C15—H15A | 108.5 |
H6A—C6—H6C | 109.5 | N2—C15—H15A | 108.5 |
H6B—C6—H6C | 109.5 | C16—C15—H15B | 108.5 |
N1—C7—C8 | 114.48 (17) | N2—C15—H15B | 108.5 |
N1—C7—H7A | 108.6 | H15A—C15—H15B | 107.5 |
C8—C7—H7A | 108.6 | C15—C16—H16A | 109.5 |
N1—C7—H7B | 108.6 | C15—C16—H16B | 109.5 |
C8—C7—H7B | 108.6 | H16A—C16—H16B | 109.5 |
H7A—C7—H7B | 107.6 | C15—C16—H16C | 109.5 |
C7—C8—H8A | 109.5 | H16A—C16—H16C | 109.5 |
C7—C8—H8B | 109.5 | H16B—C16—H16C | 109.5 |
H8A—C8—H8B | 109.5 | C18—C17—N2 | 114.90 (16) |
C7—C8—H8C | 109.5 | C18—C17—H17A | 108.5 |
H8A—C8—H8C | 109.5 | N2—C17—H17A | 108.5 |
H8B—C8—H8C | 109.5 | C18—C17—H17B | 108.5 |
N1—C9—C10 | 113.75 (17) | N2—C17—H17B | 108.5 |
N1—C9—H9A | 108.8 | H17A—C17—H17B | 107.5 |
C10—C9—H9A | 108.8 | C17—C18—H18A | 109.5 |
N1—C9—H9B | 108.8 | C17—C18—H18B | 109.5 |
C10—C9—H9B | 108.8 | H18A—C18—H18B | 109.5 |
H9A—C9—H9B | 107.7 | C17—C18—H18C | 109.5 |
C9—C10—H10A | 109.5 | H18A—C18—H18C | 109.5 |
C9—C10—H10B | 109.5 | H18B—C18—H18C | 109.5 |
H10A—C10—H10B | 109.5 | H3W—O5—H4W | 100 (3) |
C9—C10—H10C | 109.5 | H1W—O6—H2W | 100 (3) |
O1—C1—C2—O4 | −67.8 (3) | C5—N1—C9—C10 | 179.55 (17) |
O2—C1—C2—O4 | 111.9 (2) | C3—N1—C9—C10 | 58.9 (2) |
O1—C1—C2—O3 | 112.5 (2) | C13—N2—C11—C12 | −60.6 (2) |
O2—C1—C2—O3 | −67.8 (3) | C15—N2—C11—C12 | 57.4 (2) |
C9—N1—C3—C4 | 54.2 (2) | C17—N2—C11—C12 | 178.52 (18) |
C7—N1—C3—C4 | 175.46 (18) | C11—N2—C13—C14 | −62.2 (2) |
C5—N1—C3—C4 | −63.7 (2) | C15—N2—C13—C14 | 176.99 (17) |
C9—N1—C5—C6 | −179.36 (19) | C17—N2—C13—C14 | 56.0 (2) |
C7—N1—C5—C6 | 58.9 (2) | C11—N2—C15—C16 | 56.9 (2) |
C3—N1—C5—C6 | −58.6 (2) | C13—N2—C15—C16 | 177.47 (17) |
C9—N1—C7—C8 | −59.2 (2) | C17—N2—C15—C16 | −61.6 (2) |
C5—N1—C7—C8 | 59.3 (2) | C11—N2—C17—C18 | 177.74 (17) |
C3—N1—C7—C8 | 179.88 (18) | C13—N2—C17—C18 | 57.1 (2) |
C7—N1—C9—C10 | −58.9 (2) | C15—N2—C17—C18 | −61.1 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
O6—H1W···O1i | 0.82 (4) | 1.96 (4) | 2.749 (2) | 161 (3) |
O6—H2W···O3ii | 0.87 (4) | 2.00 (4) | 2.842 (2) | 162 (3) |
O5—H3W···O2iii | 0.86 (4) | 1.88 (4) | 2.720 (2) | 166 (4) |
O5—H4W···O4iv | 0.85 (4) | 1.89 (4) | 2.732 (2) | 167 (3) |
C3—H3B···O2i | 0.99 | 2.40 | 3.300 (3) | 151 |
C5—H5A···O1 | 0.99 | 2.43 | 3.324 (3) | 149 |
C5—H5B···O4iii | 0.99 | 2.34 | 3.270 (3) | 157 |
C7—H7A···O3ii | 0.99 | 2.44 | 3.332 (3) | 150 |
C8—H8B···O4iii | 0.98 | 2.57 | 3.497 (3) | 158 |
C10—H10A···O2i | 0.98 | 2.50 | 3.450 (3) | 162 |
C11—H11B···O5v | 0.99 | 2.41 | 3.384 (3) | 167 |
C13—H13A···O1vi | 0.99 | 2.37 | 3.334 (3) | 165 |
C15—H15B···O4vi | 0.99 | 2.51 | 3.166 (3) | 124 |
C16—H16C···O6vii | 0.98 | 2.59 | 3.559 (3) | 170 |
C18—H18A···O3i | 0.98 | 2.59 | 3.296 (2) | 129 |
Symmetry codes: (i) x, y−1, z; (ii) −x+1, −y+1, z−1/2; (iii) −x+1, −y+2, z−1/2; (iv) x, y, z−1; (v) −x+1, −y+1, z+1/2; (vi) x+1/2, −y+1, z; (vii) −x+1, −y, z+1/2. |
Experimental details
Crystal data | |
Chemical formula | 2C8H20N+·C2O42−·2H2O |
Mr | 384.55 |
Crystal system, space group | Orthorhombic, Pca21 |
Temperature (K) | 100 |
a, b, c (Å) | 19.9302 (4), 7.6627 (1), 14.3253 (3) |
V (Å3) | 2187.75 (7) |
Z | 4 |
Radiation type | Cu Kα |
µ (mm−1) | 0.70 |
Crystal size (mm) | 0.32 × 0.25 × 0.05 |
Data collection | |
Diffractometer | Bruker SMART APEXII CCD |
Absorption correction | Multi-scan (SADABS; Sheldrick, 2004) |
Tmin, Tmax | 0.808, 0.966 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 17374, 2026, 1953 |
Rint | 0.067 |
(sin θ/λ)max (Å−1) | 0.597 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.031, 0.081, 1.07 |
No. of reflections | 2026 |
No. of parameters | 256 |
No. of restraints | 1 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.20, −0.16 |
Computer programs: APEX2 (Bruker, 2004), SAINT-Plus (Bruker, 2004), SHELXS97 (Sheldrick, 2008), SHELXLE (Hübschle et al., 2011), ORTEP-3 (Farrugia, 1997) and Mercury (Macrae et al., 2006), SHELXL97 (Sheldrick, 2008).
D—H···A | D—H | H···A | D···A | D—H···A |
O6—H1W···O1i | 0.82 (4) | 1.96 (4) | 2.749 (2) | 161 (3) |
O6—H2W···O3ii | 0.87 (4) | 2.00 (4) | 2.842 (2) | 162 (3) |
O5—H3W···O2iii | 0.86 (4) | 1.88 (4) | 2.720 (2) | 166 (4) |
O5—H4W···O4iv | 0.85 (4) | 1.89 (4) | 2.732 (2) | 167 (3) |
C3—H3B···O2i | 0.99 | 2.40 | 3.300 (3) | 151 |
C5—H5A···O1 | 0.99 | 2.43 | 3.324 (3) | 149 |
C5—H5B···O4iii | 0.99 | 2.34 | 3.270 (3) | 157 |
C7—H7A···O3ii | 0.99 | 2.44 | 3.332 (3) | 150 |
C8—H8B···O4iii | 0.98 | 2.57 | 3.497 (3) | 158 |
C10—H10A···O2i | 0.98 | 2.50 | 3.450 (3) | 162 |
C11—H11B···O5v | 0.99 | 2.41 | 3.384 (3) | 167 |
C13—H13A···O1vi | 0.99 | 2.37 | 3.334 (3) | 165 |
C15—H15B···O4vi | 0.99 | 2.51 | 3.166 (3) | 124 |
C16—H16C···O6vii | 0.98 | 2.59 | 3.559 (3) | 170 |
C18—H18A···O3i | 0.98 | 2.59 | 3.296 (2) | 129 |
Symmetry codes: (i) x, y−1, z; (ii) −x+1, −y+1, z−1/2; (iii) −x+1, −y+2, z−1/2; (iv) x, y, z−1; (v) −x+1, −y+1, z+1/2; (vi) x+1/2, −y+1, z; (vii) −x+1, −y, z+1/2. |
Acknowledgements
TJM acknowledges Daniel M. Perrine and Daniel R. Gorbaty for technical assistance and Loyola University Maryland for financial support. RDP thanks the NSF (grant No. CHE-0443345) and the College of William and Mary for the purchase of the X-ray equipment.
References
Barthel, J. & Kunz, W. (1988). J. Solution Chem. 17, 399–415. CrossRef CAS Web of Science Google Scholar
Beagley, B. & Small, R. W. H. (1964). Acta Cryst. 17, 783–788. CSD CrossRef CAS IUCr Journals Web of Science Google Scholar
Bruker (2004). APEX2 and SAINT-Plus. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Chernoff, L. H. (1920). J. Am. Chem. Soc. 42, 1784–1785. CrossRef CAS Google Scholar
Darensbourg, D. J., Chojnacki, J. A. & Reibenspies, J. H. (1992). Inorg. Chem. 31, 3428–3433. CSD CrossRef CAS Web of Science Google Scholar
Demadis, K. D. & Coucouvanis, D. (1995). Inorg. Chem. 34, 436–448. CSD CrossRef CAS Web of Science Google Scholar
Diop, L., Mahon, M. F., Molloy, K. C. & Sidibe, M. (1997). Main Group Met. Chem. 20, 649–654. CrossRef CAS Google Scholar
Engels, R., Smit, C. J. & van Tilborg, W. J. M. (1983). Angew. Chem. Int. Ed. Engl. 22, 492–493. CrossRef Web of Science Google Scholar
Etter, M. C., MacDonald, J. C. & Bernstein, J. (1990). Acta Cryst. B46, 256–262. CSD CrossRef CAS Web of Science IUCr Journals Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Gilli, G. & Gilli, P. (2009). The Nature of the Hydrogen Bond. Outline of a Comprehensive Hydrogen Bond Theory, p. 61. Oxford, New York: International Union of Crystallography, Oxford University Press. Google Scholar
Heck, R. F. (1982). Org. React. 27, 345–390. CAS Google Scholar
Hübschle, C. B., Sheldrick, G. M. & Dittrich, B. (2011). J. Appl. Cryst. 44, 1281–1284. Web of Science CrossRef IUCr Journals Google Scholar
Jeffrey, G. A. & Parry, G. S. (1954). J. Am. Chem. Soc. 76, 5283–5286. CSD CrossRef CAS Web of Science Google Scholar
Macrae, C. F., Edgington, P. R., McCabe, P., Pidcock, E., Shields, G. P., Taylor, R., Towler, M. & van de Streek, J. (2006). J. Appl. Cryst. 39, 453–457. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Markowitz, M. M. (1957). J. Org. Chem. 22, 983–984. CrossRef CAS Web of Science Google Scholar
McNeese, T. J., Cohen, M. B. & Foxman, B. M. (1984). Organometallics, 3, 552–556. CSD CrossRef CAS Web of Science Google Scholar
Robertson, J. H. (1965). Acta Cryst. 18, 410–417. CSD CrossRef CAS IUCr Journals Web of Science Google Scholar
Sheldrick, G. M. (2004). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Starks, C. M. (1971). J. Am. Chem. Soc. 93, 195–199. CrossRef CAS Web of Science 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.
Tetraalkylammonium salts are important compounds as phase-transfer catalysts (Starks, 1971), as electrolytes in electrochemical studies (Barthel & Kunz, 1988), in organic Heck-type synthetic reactions (Heck, 1982), and in preparing and isolating polynuclear organometallic complexes (McNeese et al., 1984). A procedure for synthesizing quaternary ammonium salts involves neutralization of a tetraalkylammonium hydroxide with the acid of the desired anion (Markowitz, 1957).
The title compound, (Et4N)2C2O4.2H2O, synthesized by reaction of Et4NOH and H2C2O4.2H2O in a 2:1 mole ratio, is deliquescent and rapidly absorbs moisture from air. Previously prepared and used in situ or as a noncrystalline solid, it has been employed as a reductant in aprotic electrochemical cells (Engels et al., 1983) and in the synthesis of oxalate-containing organometallic complexes (Diop et al., 1997; Demadis & Coucouvanis, 1995; Darensbourg et al., 1992).
Oxalate bond distances (C—C and C—O) and angles (O—C—O and O—C—C) are comparable to other reported oxalate salts containing NH4+ and alkali metal ions. The oxalate ion is planar in Li2C2O4 (Beagley & Small, 1964) and Na2C2O4 (Jeffrey & Parry, 1954), but the dihedral angle between planes of symmetrical carboxylate groups of the oxalate fragment is 26.6° in (NH4)2C2O4.H2O (Robertson, 1965). The directional character of the hydrogen bonding pattern in the monohydrate is believed responsible for the observed non-planar stereochemistry of the oxalate ion. A dihedral angle of 64.37 (2)° is present in the title compound (Fig. 1). The non-planarity of the oxalate ion is maintained by moderate hydrogen bonds (Table 1) that link the oxygen atoms of the oxalate ion and the water molecules into a ring motif R44(12) (Etter et al., 1990). (For the classification of the hydrogen bonds, see Gilli & Gilli, 2009). In addition, there are also present weak C-H···O interactions in the structure (Tab. 1). Fig. 2 illustrates the packing diagram for the structure of the title compound.