The crystal structure of metaraminol hydrogen tartrate has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional theory techniques.
Keywords: powder diffraction, aramine, Rietveld refinement, density functional theory, crystal structure
Abstract
The crystal structure of the title salt, C9H14NO2+·HC4H4O6−, has been solved and refined using synchrotron X-ray powder diffraction data and optimized using density functional theory techniques. The crystal structure consists of alternating hydrophobic and hydrophilic layers lying parallel to the ab plane. Hydrogen bonds link the cations and anions in the hydrophilic layers. The anions are linked by very strong charge-assisted O—H⋯O hydrogen bonds into chains propagating along the a-axis direction. Each H atom of the protonated N atom of the cation acts as a donor in at least one N—H⋯O hydrogen bond to an anion.
1. Chemical context
Metaraminol hydrogen tartrate, C9H14NO2+·HC4H4O6− (I), also known as metaraminol bitartrate, and marketed as Aramine (obsolete), Pressonex and others in various countries, is used to treat hypotension (low blood pressure), particularly associated with patients receiving spinal anesthesia (Grauslyte et al., 2022 ▸). The systematic name (CAS Registry Number 33402-03-8) is 3-[(1R,2S)-2-azaniumyl-1-hydroxypropyl]phenol (2S,3S)-hydrogen 2,3-dihydroxybutanedioate.
This work was carried out as part of a project (Kaduk et al., 2014 ▸) to determine the crystal structures of large-volume commercial pharmaceuticals, and includes high-quality powder diffraction data for them in the Powder Diffraction File (Kabekkodu et al., 2024 ▸).
2. Structural commentary
The asymmetric unit of (I) is illustrated in Fig. 1 ▸ and consists of one C9H14NO2+ cation and one HC4H4O6− anion in space group P212121. The root-mean-square difference of the non-H atoms in the Rietveld-refined and VASP-optimized structures of (I), calculated using the Mercury (Macrae et al., 2020 ▸) CSD-Materials/search/crystal packing similarity tool is 0.325 Å. The root-mean-square Cartesian displacements of the non-H atoms in the refined and optimized structures of the cation and anion, calculated using the Mercury calculate/molecule overlay tool, are 0.235 and 0.167 Å, respectively (Figs. 2 ▸ and 3 ▸). The agreements are within the normal range for correct structures (van de Streek & Neumann, 2014 ▸). The remaining discussion will emphasize the VASP-optimized structure.
Figure 1.
The asymmetric unit of (I), with the atom numbering. The atoms are represented by 50% probability spheroids.
Figure 2.
Comparison of the refined structure of the metaraminol cation in (I) (red) to the VASP-optimized structure (blue). The comparison was generated using the Mercury calculate/molecule overlay tool; the r.m.s. difference is 0.235 Å.
Figure 3.
Comparison of the refined structure of the bitartrate anion in (I) (red) to the VASP-optimized structure (blue). The comparison was generated using the Mercury calculate/molecule overlay tool; the r.m.s. difference is 0.167 Å.
Almost all of the bond distances, bond angles, and torsion angles fall within the normal ranges indicated by a Mercury Mogul geometry check (Macrae et al., 2020 ▸). Only the C7—C5—C4 bond angle of 117.1° [average = 114.1 (9)°; Z-score = 3.4] is flagged as unusual. The standard uncertainty on the average is very small, inflating the Z-score, so this angle is not of concern. The conformation about the C6—C4—C5—N3 torsion angle is trans (179.2°), and falls within the normal distribution. The torsion angles involving rotation about the C4—C6 bond (such as 77.9° for C5—C4—C6—C8) fall within the typical broad ranges for similar torsion angles. The tartrate anion is in the trans conformation, as indicated by the C35—C34—C32—C33 torsion angle of −177.2°.
Quantum chemical geometry optimizations of the isolated metaraminol cation and bitartrate anion (DFT/B3LYP/6-31G*/water) using Spartan ’24 (Wavefunction, 2025 ▸) indicated that both the cation and anion were geometrically (r.m.s. difference = 0.277 and 0.173 Å, respectively) similar to local minima, but energetically different (6.1 and 21.2 kcal mol−1, respectively). The global minimum-energy conformations were found to be more compact (featuring intramolecular hydrogen bonds), showing that intermolecular interactions are important in determining the solid-state conformations of these species in (I).
3. Supramolecular features
The extended structure of (I) (Fig. 4 ▸) consists of alternating hydrophobic and hydrophilic layers lying parallel to the ab plane. Hydrogen bonds (discussed below) link the cations and anions in the hydrophilic layers. The Mercury aromatics analyser indicated one strong (d = 4.97 Å) interaction between the phenyl rings of the cations, and two moderate (d = 6.15 Å) interactions. The mean plane of the phenyl ring in the asymmetric unit is approximately (
11).
Figure 4.
The crystal structure of (I), viewed down the b-axis direction.
Analysis of the contributions to the total crystal energy of the structure using the Forcite module of Materials Studio (Dassault Systèmes, 2025 ▸) indicated that bond, angle, and torsion distortion terms contribute significantly to the intramolecular energy. The intermolecular energy is small, and is dominated by van der Waals attractions, which in this force field-based analysis includes hydrogen bonds. The hydrogen bonds are better discussed using the results of the DFT calculation.
Hydrogen bonds (Table 1 ▸) are prominent in the structure. The anions are linked by very strong charge-assisted O29—H41⋯O26 hydrogen bonds into chains propagating along the a-axis direction. The O29—H41 single bond has a Mulliken overlap population of 0.175 e, with a bond energy [calculated using the correlation of Rammohan & Kaduk (2018 ▸)] of 23.9 kcal mol−1. The H41⋯O26 hydrogen bond is only slightly weaker, with an overlap population of 0.117 e and a bond energy of 18.7 kcal mol−1. Both alcoholic hydroxyl groups of the hydrogen tartrate anion act as donors in O—H⋯O hydrogen bonds, one to another anion and one to a cation.
Table 1. Hydrogen-bond geometry (Å, °).
| D—H⋯A | D—H | H⋯A | D⋯A | D—H⋯A |
|---|---|---|---|---|
| O29—H41⋯O26i | 1.14 | 1.33 | 2.464 | 173 |
| O30—H37⋯O1 | 0.99 | 1.70 | 2.686 | 169 |
| O31—H36⋯O29ii | 0.99 | 1.95 | 2.885 | 156 |
| O31—H36⋯O28 | 0.99 | 2.36 | 2.644 | 96 |
| N3—H40⋯O31iii | 1.05 | 1.72 | 2.762 | 172 |
| N3—H21⋯O28ii | 1.05 | 1.69 | 2.718 | 166 |
| N3—H20⋯O27 | 1.05 | 1.78 | 2.796 | 161 |
| N3—H20⋯O30 | 1.05 | 2.50 | 3.111 | 116 |
| O2—H25⋯O27iv | 1.00 | 1.76 | 2.709 | 157 |
| O1—H22⋯O2iv | 0.98 | 2.19 | 3.113 | 155 |
| C5—H14⋯O26 | 1.10 | 2.40 | 3.364 | 145 |
| C12—H24⋯O26 | 1.09 | 2.72 | 3.758 | 154 |
| C4—H13⋯O28 | 1.11 | 2.61 | 3.410 | 128 |
| C9—H19⋯O29 | 1.09 | 2.95 | 4.033 | 171 |
Symmetry codes: (i) 
; (ii) 
; (iii) 
; (iv) 
.
Each H atom of the protonated –N3H3+ grouping of the cation acts as a donor in at least one N—H⋯O hydrogen bond to an anion. The energies of these hydrogen bonds were calculated using the correlation of Wheatley & Kaduk (2019 ▸). One hydroxyl group of the cation forms an O—H⋯O hydrogen bond to another cation, while the other bonds to the anion. Several C—H⋯O hydrogen bonds (from both the cation and anion) also contribute to the cohesion of the structure.
The volume enclosed by the Hirshfeld surface of (I) (Fig. 5 ▸; Spackman et al., 2021 ▸) is 366.73 Å3, or 98.13% of 1/4 of the unit-cell volume. The packing density is thus typical. The close contacts (red in Fig. 5 ▸) correspond to the hydrogen bonds noted above. The volume per non-hydrogen atom is slightly smaller than normal, at 17.0 Å3.
Figure 5.
The Hirshfeld surface of (I). Intermolecular contacts longer than the sums of the van der Waals radii are colored blue, and contacts shorter than the sums of the radii are colored red. Contacts equal to the sums of radii are white.
The Bravais–Friedel–Donnay–Harker (Bravais, 1866 ▸; Friedel, 1907 ▸; Donnay & Harker, 1937 ▸) algorithm suggests that we might expect platy morphology for (I), with {001} as the principal faces. A second-order spherical harmonic model for preferred orientation was included. The texture index was 1.001, indicating that the preferred orientation was negligible in this rotated capillary specimen.
4. Database survey
A process for preparing metaraminol bitartrate is claimed in US Patent 10,087,136 B2 (Brenna et al., 2018 ▸; Laboratori Alchemia S.r.l.), which includes NMR data, but no X-ray diffraction data, is provided. A synthesis method for metaraminol bitartrate is also claimed in Chinese Patent CN 103739504A (Pu et al., 2013 ▸; Guangzhou Person Pharmaceutical Co., Ltd.). We are unaware of any published diffraction data for metaraminol bitartrate.
A reduced cell search in the Cambridge Structural Database (CSD version 2026.1.0; Groom et al., 2016 ▸), combined with the chemistry C, H, N, and O only, yielded 31 hits, but no structures of metaraminol or its derivatives.
5. Synthesis and crystallization
Metaraminolhydrogen tartrate is a commercial reagent, purchased from TargetMol (Batch #118859), and was used as received.
6. Refinement
Crystal data, data collection and structure refinement details are summarized in Table 2 ▸. The white powder was packed into a 1.5 mm diameter Kapton capillary, and rotated during the measurement at ∼50 Hz. The powder pattern was measured at 295 K at beam line 11-BM (Lee et al., 2008 ▸; Wang et al., 2008 ▸; Antao et al., 2008 ▸) of the Advanced Photon Source at Argonne National Laboratory using a wavelength of 0.4687342 Å from 0.5–50° 2θ with a step size of 0.001° and a counting time of 0.1 sec step−1. The high-resolution powder diffraction data were collected using twelve silicon crystal analyzers that allow for high angular resolution, high precision, and accurate peak positions. A mixture of silicon (NIST SRM 640c) and alumina (NIST SRM 676a) standards (ratio Al2O3:Si = 2:1 by weight) was used to calibrate the instrument and refine the monochromatic wavelength used in the experiment.
Table 2. Experimental details.
| (I) | |
|---|---|
| Crystal data | |
| Chemical formula | C9H14NO2+·C4H5O6− |
| M r | 317.29 |
| Crystal system, space group | Orthorhombic, P212121 |
| Temperature (K) | 295 |
| a, b, c (Å) | 7.190512 (12), 8.421634 (17), 24.69323 (5) |
| V (Å3) | 1495.32 (1) |
| Z | 4 |
| Radiation type | Synchrotron, λ = 0.46873 Å |
| μ (mm−1) | 0.001 |
| Specimen shape, size (mm) | Cylinder, 2.0 × 1.5 |
| Data collection | |
| Diffractometer | 11-BM, APS |
| Specimen mounting | Kapton capillary |
| Data collection mode | Transmission |
| Scan method | Step |
| 2θ values (°) | 2θmin = 0.510, 2θmax = 49.995, 2θstep = 0.001 |
| Refinement | |
| R factors and goodness of fit | Rp = 0.090, Rwp = 0.105, Rexp = 0.039, R(F2) = 0.09024, χ2 = 7.530 |
| No. of parameters | 85 |
| No. of restraints | 50 |
| (Δ/σ)max | 2.873 |
The pattern was indexed on a primitive orthorhombic unit cell with a = 7.19584, b = 8.42890, c = 24.73316 Å, V = 1500.14 Å3, and Z = 4 using JADE Pro (MDI, 2025 ▸). The suggested space group was P212121, which was confirmed by the successful solution and refinement of the structure.
The molecular structure of metaraminol was downloaded from PubChem (Kim et al., 2023 ▸) as Conformer3D_COMPOUND_CID_5906.sdf. It was converted to a *.mol2 file using Mercury (Macrae et al., 2020 ▸), and to a Fenske–Hall Z-matrix using Open Babel (O’Boyle et al., 2011 ▸). The tartrate anion model was taken from our structure of eliglustat hemitartrate (Kaduk et al., 2026 ▸). The structure was solved using Monte Carlo simulated annealing techniques as implemented in DASH (David et al., 2006 ▸), EXPO2014 (Altomare et al., 2013 ▸), and FOX (Favre-Nicolin & Černý, 2002 ▸). All three programs yielded essentially the same structure. The EXPO2014 model was chosen for refinement.
Atom H40 was added to protonate N3 using Materials Studio (Dassault Systèmes, 2025 ▸). Analysis of O⋯O distances for potential hydrogen bonds suggested that O29 was protonated (O29⋯O26 = 2.39 Å), so H41 was added 0.90 Å from O29 on the O29⋯O26 vector using Materials Studio.
Rietveld refinement was carried out using GSAS-II (Toby & Von Dreele, 2013 ▸). Only the 1.5–28.0° portion of the pattern was included in the refinement (dmin = 0.969 Å). All non-H bond distances and angles were subjected to restraints, based on a Mercury/Mogul Geometry Check (Sykes et al., 2011 ▸; Bruno et al., 2004 ▸). The Mogul average and standard deviation for each quantity were used as the restraint parameters. The phenyl ring was restrained to be planar. The restraints contributed 1.5% to the overall χ2. The hydrogen atoms were included in calculated positions, which were recalculated during the refinement using Materials Studio (Dassault Systèmes, 2025 ▸). The Uiso of the non-H atoms were grouped by chemical similarity. The Uiso of the H atoms were fixed at 1.2× the Uiso of the heavy atom to which they are attached. The peak profiles were described using a uniaxial microstrain model, with [001] as the unique axis. The background was modeled using a six-term shifted Chebyshev polynomial, with a peak at 6.00° to model the scattering from the Kapton capillary and any amorphous component of the sample.
The final refinement of 85 variables using 26,501 observations and 50 restraints yielded the residuals Rwp = 0.1055 and GOF = 2.74. The largest peak (0.24 Å from N3) and hole (0.82 Å from C6) in the difference Fourier map were calculated to be 0.56 (11) and −0.45 (11) e Å−3, respectively. The final Rietveld plot is shown in Fig. 6 ▸. The largest features in the normalized error plot are in the shapes of some of the strong low-angle peaks.
Figure 6.
The Rietveld plot for (I). The blue crosses represent the observed data points, and the green line is the calculated pattern. The cyan curve is the normalized error plot, and the red line is the background curve. The blue tick marks indicate the peak positions. The vertical scale has been multiplied by a factor of 10× for 2θ > 12.0°, and by a factor of 40× for 2θ > 21.8°.
The crystal structure of (I) was optimized (fixed experimental unit cell) with density functional theory techniques using VASP (Kresse & Furthmüller, 1996 ▸) through the MedeA graphical interface (Materials Design, 2024 ▸). The calculation was carried out on 32 cores of a 144-core (768 GB memory) HPE Superdome Flex 280 Linux server at North Central College. The calculation used the GGA-PBE functional, a plane wave cutoff energy of 400.0 eV, and a k-point spacing of 0.5 Å−1 leading to a 2 × 2 × 1 mesh, and took ∼8.5 h. Single-point density functional theory calculations (fixed experimental cell) and population analysis were carried out using CRYSTAL23 (Erba et al., 2023 ▸). The basis sets for the H, C, N and O atoms in the calculation were those of Gatti et al. (1994 ▸). The calculations were run on a 3.5 GHz PC using 8 k-points and the B3LYP functional, and took ∼1.9 h. The powder pattern of (I) has been submitted to ICDD for inclusion in the Powder Diffraction File.>
Supplementary Material
Crystal structure: contains datablock(s) I, I_VASP. DOI: 10.1107/S2056989026009497/hb8243sup1.cif
Additional supporting information: crystallographic information; 3D view; checkCIF report
Acknowledgments
Use of the Advanced Photon Source at Argonne National Laboratory was supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02–06CH11357. We thank Saul Lapidus for his assistance in the data collection. We also thank the ICDD team – Megan Rost, Steve Trimble, and Dave Bohnenberger – for their contribution to research, sample preparation, and in-house XRD data collection and verification.
supplementary crystallographic information
3-[(1R,2S)-2-Azaniumyl-1-hydroxypropyl]phenol (2S,3S)-hydrogen 2,3-dihydroxybutanedioate (I) . Crystal data
| C9H14NO2+·C4H5O6− | Z = 4 |
| Mr = 317.29 | Dx = 1.409 Mg m−3 |
| Orthorhombic, P212121 | Synchrotron radiation, λ = 0.46873 Å |
| a = 7.190512 (12) Å | µ = 0.001 mm−1 |
| b = 8.421634 (17) Å | T = 295 K |
| c = 24.69323 (5) Å | cylinder, 2.0 × 1.5 mm |
| V = 1495.32 (1) Å3 |
3-[(1R,2S)-2-Azaniumyl-1-hydroxypropyl]phenol (2S,3S)-hydrogen 2,3-dihydroxybutanedioate (I) . Data collection
| 11-BM, APS diffractometer | Scan method: step |
| Specimen mounting: Kapton capillary | 2θmin = 0.510°, 2θmax = 49.995°, 2θstep = 0.001° |
| Data collection mode: transmission |
3-[(1R,2S)-2-Azaniumyl-1-hydroxypropyl]phenol (2S,3S)-hydrogen 2,3-dihydroxybutanedioate (I) . Refinement
| Least-squares matrix: full | 85 parameters |
| Rp = 0.090 | 50 restraints |
| Rwp = 0.105 | 19 constraints |
| Rexp = 0.039 | Weighting scheme based on measured s.u.'s |
| R(F2) = 0.09024 | (Δ/σ)max = 2.873 |
| 49486 data points | Background function: Background function: "chebyschev-1" function with 6 terms: 44.39(10), -9.67(15), -6.44(12), -0.91(18), 1.31(17), -5.45(13), Background peak parameters: pos, int, sig, gam: 5.974(12), 1.053(24)e4, 1.09(3)e4, 0.100, |
| Profile function: Finger-Cox-Jephcoat function parameters U, V, W, X, Y, SH/L: peak variance(Gauss) = Utan(Th)2+Vtan(Th)+W: peak HW(Lorentz) = X/cos(Th)+Ytan(Th); SH/L = S/L+H/L U, V, W in (centideg)2, X & Y in centideg 1.163, -0.126, 0.063, 0.000, 0.000, 0.002, | Preferred orientation correction: Simple spherical harmonic correction Order = 2 Coefficients: 0:0:C(2,0) = -0.0120; 0:0:C(2,2) = 0.0660 |
3-[(1R,2S)-2-Azaniumyl-1-hydroxypropyl]phenol (2S,3S)-hydrogen 2,3-dihydroxybutanedioate (I) . Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2)
| x | y | z | Uiso*/Ueq | ||
| O1 | 0.3342 (4) | 0.8022 (3) | 0.93215 (10) | 0.0479 (6)* | |
| O2 | 0.3359 (4) | 0.5307 (3) | 1.10736 (10) | 0.0445 (5)* | |
| N3 | 0.4468 (4) | 0.6614 (4) | 0.82720 (13) | 0.0479 (6)* | |
| C4 | 0.2734 (5) | 0.6488 (4) | 0.91486 (13) | 0.0479 (6)* | |
| C5 | 0.4270 (5) | 0.5755 (4) | 0.87984 (13) | 0.0479 (6)* | |
| C6 | 0.2282 (5) | 0.5511 (4) | 0.96343 (12) | 0.0445 (5)* | |
| C7 | 0.6176 (5) | 0.5688 (5) | 0.90906 (15) | 0.0479 (6)* | |
| C8 | 0.3051 (6) | 0.5873 (4) | 1.01338 (14) | 0.0445 (5)* | |
| C9 | 0.1121 (5) | 0.4235 (4) | 0.95835 (13) | 0.0445 (5)* | |
| C10 | 0.2652 (5) | 0.4938 (4) | 1.05747 (11) | 0.0445 (5)* | |
| C11 | 0.0749 (5) | 0.3274 (4) | 1.00251 (17) | 0.0445 (5)* | |
| C12 | 0.1529 (6) | 0.3636 (4) | 1.05258 (13) | 0.0445 (5)* | |
| H13 | 0.14930 | 0.66750 | 0.89080 | 0.0665* | |
| H14 | 0.38411 | 0.45668 | 0.86620 | 0.0665* | |
| H15 | 0.60500 | 0.49580 | 0.94340 | 0.0665* | |
| H16 | 0.70849 | 0.49856 | 0.88244 | 0.0665* | |
| H17 | 0.67350 | 0.67480 | 0.91330 | 0.0665* | |
| H18 | 0.40460 | 0.68710 | 1.01580 | 0.0655* | |
| H19 | 0.04630 | 0.38770 | 0.92000 | 0.0655* | |
| H20 | 0.34520 | 0.74740 | 0.82580 | 0.0665* | |
| H21 | 0.43010 | 0.59330 | 0.79430 | 0.0665* | |
| H22 | 0.24880 | 0.87450 | 0.92230 | 0.0665* | |
| H23 | −0.02730 | 0.22950 | 1.00070 | 0.0655* | |
| H24 | 0.11220 | 0.29700 | 1.08940 | 0.0655* | |
| H25 | 0.25770 | 0.60010 | 1.12710 | 0.0655* | |
| O26 | 0.5203 (4) | 1.2468 (3) | 0.80511 (12) | 0.0480 (4)* | |
| O27 | 0.5292 (3) | 0.9921 (3) | 0.83009 (11) | 0.0480 (4)* | |
| O28 | −0.1329 (3) | 1.0797 (3) | 0.73408 (11) | 0.0480 (4)* | |
| O30 | 0.1607 (4) | 0.9700 (3) | 0.83668 (10) | 0.0480 (4)* | |
| O31 | 0.2265 (3) | 1.0825 (3) | 0.72509 (10) | 0.0480 (4)* | |
| C32 | 0.2339 (5) | 1.1202 (4) | 0.82380 (14) | 0.0480 (4)* | |
| C33 | 0.4494 (4) | 1.1141 (4) | 0.82050 (19) | 0.0480 (4)* | |
| C34 | 0.1555 (5) | 1.1747 (4) | 0.76783 (14) | 0.0480 (4)* | |
| C35 | −0.0592 (4) | 1.1695 (5) | 0.76762 (16) | 0.0480 (4)* | |
| H36 | 0.18320 | 0.97650 | 0.72600 | 0.0675* | |
| H37 | 0.22630 | 0.92780 | 0.86820 | 0.0675* | |
| H38 | 0.19420 | 1.30100 | 0.76540 | 0.0675* | |
| H39 | 0.19860 | 1.21030 | 0.85250 | 0.0675* | |
| O29 | −0.1365 (4) | 1.2557 (3) | 0.80333 (12) | 0.0480 (4)* | |
| H40 | 0.57713 | 0.71760 | 0.82517 | 0.0665* | |
| H41 | −0.26740 | 1.25380 | 0.80370 | 0.0675* |
3-[(1R,2S)-2-Azaniumyl-1-hydroxypropyl]phenol (2S,3S)-hydrogen 2,3-dihydroxybutanedioate (I) . Geometric parameters (Å, º)
| O1—C4 | 1.429 (3) | H15—C7 | 1.052 (4) |
| O1—H22 | 0.898 (3) | H16—C7 | 1.100 (4) |
| O2—C10 | 1.369 (3) | H17—C7 | 0.984 (4) |
| O2—H25 | 0.946 (3) | H18—C8 | 1.106 (3) |
| N3—C5 | 1.494 (3) | H19—C9 | 1.101 (3) |
| N3—H20 | 1.029 (3) | H20—N3 | 1.029 (3) |
| N3—H21 | 1.002 (3) | H21—N3 | 1.002 (3) |
| N3—H40 | 1.051 (3) | H22—O1 | 0.898 (3) |
| C4—O1 | 1.429 (3) | H23—C11 | 1.106 (3) |
| C4—C5 | 1.533 (3) | H24—C12 | 1.108 (3) |
| C4—C6 | 1.491 (3) | H25—O2 | 0.946 (3) |
| C4—H13 | 1.083 (3) | O26—C33 | 1.286 (3) |
| C5—N3 | 1.494 (3) | O27—C33 | 1.200 (3) |
| C5—C4 | 1.533 (3) | O28—C35 | 1.241 (3) |
| C5—C7 | 1.550 (4) | O30—C32 | 1.407 (3) |
| C5—H14 | 1.100 (3) | O30—H37 | 0.977 (3) |
| C6—C4 | 1.491 (3) | O31—C34 | 1.406 (3) |
| C6—C8 | 1.386 (3) | O31—H36 | 0.946 (3) |
| C6—C9 | 1.366 (3) | C32—O30 | 1.407 (3) |
| C7—C5 | 1.550 (4) | C32—C33 | 1.553 (3) |
| C7—H15 | 1.052 (4) | C32—C34 | 1.562 (4) |
| C7—H16 | 1.100 (4) | C32—H39 | 1.069 (3) |
| C7—H17 | 0.984 (4) | C33—O26 | 1.286 (3) |
| C8—C6 | 1.386 (3) | C33—O27 | 1.200 (3) |
| C8—C10 | 1.374 (3) | C33—C32 | 1.553 (3) |
| C8—H18 | 1.106 (3) | C34—O31 | 1.406 (3) |
| C9—C6 | 1.366 (3) | C34—C32 | 1.562 (4) |
| C9—C11 | 1.384 (3) | C34—C35 | 1.544 (3) |
| C9—H19 | 1.101 (3) | C34—H38 | 1.101 (4) |
| C10—O2 | 1.369 (3) | C35—O28 | 1.241 (3) |
| C10—C8 | 1.374 (3) | C35—C34 | 1.544 (3) |
| C10—C12 | 1.367 (3) | C35—O29 | 1.270 (3) |
| C11—C9 | 1.384 (3) | H36—O31 | 0.946 (3) |
| C11—C12 | 1.391 (3) | H37—O30 | 0.977 (3) |
| C11—H23 | 1.106 (3) | H38—C34 | 1.101 (4) |
| C12—C10 | 1.367 (3) | H39—C32 | 1.069 (3) |
| C12—C11 | 1.391 (3) | O29—C35 | 1.270 (3) |
| C12—H24 | 1.108 (3) | O29—H41 | 0.942 (3) |
| H13—C4 | 1.083 (3) | H40—N3 | 1.051 (3) |
| H14—C5 | 1.100 (3) | H41—O29 | 0.942 (3) |
| C4—O1—H22 | 108.8 (3) | C6—C9—H19 | 123.8 (3) |
| C10—O2—H25 | 112.5 (3) | C11—C9—H19 | 115.8 (3) |
| C5—N3—H20 | 107.6 (3) | O2—C10—C8 | 120.4 (3) |
| C5—N3—H21 | 114.6 (3) | O2—C10—C12 | 118.8 (3) |
| H20—N3—H21 | 106.9 (3) | C8—C10—C12 | 120.85 (19) |
| C5—N3—H40 | 110.1 (3) | C9—C11—C12 | 119.6 (2) |
| H20—N3—H40 | 108.3 (3) | C9—C11—H23 | 122.2 (4) |
| H21—N3—H40 | 109.0 (3) | C12—C11—H23 | 117.8 (4) |
| O1—C4—C5 | 108.2 (3) | C10—C12—C11 | 119.5 (2) |
| O1—C4—C6 | 109.0 (3) | C10—C12—H24 | 119.3 (3) |
| C5—C4—C6 | 112.9 (3) | C11—C12—H24 | 120.8 (4) |
| O1—C4—H13 | 106.5 (3) | C32—O30—H37 | 109.1 (3) |
| C5—C4—H13 | 110.1 (3) | C34—O31—H36 | 112.6 (3) |
| C6—C4—H13 | 110.0 (3) | O30—C32—C33 | 110.8 (3) |
| N3—C5—C4 | 111.4 (3) | O30—C32—C34 | 109.3 (3) |
| N3—C5—C7 | 109.8 (3) | C33—C32—C34 | 108.9 (3) |
| C4—C5—C7 | 112.9 (3) | O30—C32—H39 | 113.6 (3) |
| N3—C5—H14 | 101.6 (3) | C33—C32—H39 | 107.2 (3) |
| C4—C5—H14 | 109.7 (3) | C34—C32—H39 | 107.0 (3) |
| C7—C5—H14 | 111.0 (3) | O26—C33—O27 | 127.8 (3) |
| C4—C6—C8 | 120.5 (3) | O26—C33—C32 | 112.5 (3) |
| C4—C6—C9 | 119.6 (3) | O27—C33—C32 | 119.7 (3) |
| C8—C6—C9 | 119.89 (19) | O31—C34—C32 | 111.8 (3) |
| C5—C7—H15 | 108.7 (3) | O31—C34—C35 | 110.2 (3) |
| C5—C7—H16 | 105.5 (3) | C32—C34—C35 | 110.8 (3) |
| H15—C7—H16 | 102.6 (3) | O31—C34—H38 | 113.6 (3) |
| C5—C7—H17 | 112.2 (4) | C32—C34—H38 | 103.9 (3) |
| H15—C7—H17 | 118.7 (4) | C35—C34—H38 | 106.3 (3) |
| H16—C7—H17 | 108.0 (3) | O28—C35—C34 | 116.5 (3) |
| C6—C8—C10 | 119.74 (17) | O28—C35—O29 | 128.7 (3) |
| C6—C8—H18 | 118.3 (3) | C34—C35—O29 | 114.8 (3) |
| C10—C8—H18 | 121.9 (3) | C35—O29—H41 | 115.8 (3) |
| C6—C9—C11 | 120.4 (2) |
(I_VASP). Crystal data
| C9H14NO2+·C4H5O6− | b = 8.42062 Å |
| Mr = 317.29 | c = 24.69000 Å |
| Orthorhombic, P212121 | V = 1494.81 Å3 |
| a = 7.18988 Å | Z = 4 |
(I_VASP). Data collection
| h = → | l = → |
| k = → |
(I_VASP). Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2)
| x | y | z | Biso*/Beq | ||
| O1 | 0.19904 | 0.79641 | 0.90895 | ||
| O2 | 0.30367 | 0.55312 | 1.09380 | ||
| N3 | 0.43993 | 0.67441 | 0.82696 | ||
| C4 | 0.20728 | 0.62634 | 0.89994 | ||
| C5 | 0.40094 | 0.58234 | 0.87743 | ||
| C6 | 0.16477 | 0.53659 | 0.95149 | ||
| C7 | 0.56541 | 0.59839 | 0.91583 | ||
| C8 | 0.24506 | 0.58658 | 1.00022 | ||
| C9 | 0.04789 | 0.40382 | 0.95093 | ||
| C10 | 0.21364 | 0.50247 | 1.04809 | ||
| C11 | 0.01340 | 0.32210 | 0.99913 | ||
| C12 | 0.09585 | 0.36959 | 1.04753 | ||
| H13 | 0.10443 | 0.59411 | 0.86857 | ||
| H14 | 0.39033 | 0.45783 | 0.86419 | ||
| H15 | 0.55482 | 0.51329 | 0.94926 | ||
| H16 | 0.69532 | 0.57332 | 0.89398 | ||
| H17 | 0.57543 | 0.71824 | 0.93284 | ||
| H18 | 0.33191 | 0.69278 | 1.00118 | ||
| H19 | −0.01707 | 0.36538 | 0.91312 | ||
| H20 | 0.45057 | 0.79766 | 0.83301 | ||
| H21 | 0.33607 | 0.65249 | 0.79796 | ||
| H22 | 0.06961 | 0.82381 | 0.91785 | ||
| H23 | −0.07979 | 0.22003 | 0.99895 | ||
| H24 | 0.07184 | 0.30291 | 1.08469 | ||
| H25 | 0.23133 | 0.51970 | 1.12653 | ||
| H40 | 0.56803 | 0.63905 | 0.81033 | ||
| O26 | 0.52321 | 1.25511 | 0.80787 | ||
| O27 | 0.53712 | 0.99571 | 0.83047 | ||
| O28 | −0.14693 | 1.09119 | 0.73653 | ||
| O30 | 0.16346 | 0.95661 | 0.81546 | ||
| O31 | 0.21301 | 1.10837 | 0.71535 | ||
| C32 | 0.23428 | 1.11268 | 0.81422 | ||
| C33 | 0.44886 | 1.11891 | 0.81698 | ||
| C34 | 0.15305 | 1.18926 | 0.76289 | ||
| C35 | −0.05925 | 1.18289 | 0.76641 | ||
| H36 | 0.15446 | 1.00232 | 0.71438 | ||
| H37 | 0.18695 | 0.90728 | 0.85137 | ||
| H38 | 0.19793 | 1.31362 | 0.75953 | ||
| H39 | 0.18481 | 1.18368 | 0.84927 | ||
| O29 | −0.13548 | 1.27646 | 0.80279 | ||
| H41 | −0.29187 | 0125805 | 0.80531 |
(I_VASP). Hydrogen-bond geometry (Å, º)
| D—H···A | D—H | H···A | D···A | D—H···A |
| O29—H41···O26i | 1.14 | 1.33 | 2.464 | 173 |
| O30—H37···O1 | 0.99 | 1.70 | 2.686 | 169 |
| O31—H36···O29ii | 0.99 | 1.95 | 2.885 | 156 |
| O31—H36···O28 | 0.99 | 2.36 | 2.644 | 96 |
| N3—H40···O31iii | 1.05 | 1.72 | 2.762 | 172 |
| N3—H21···O28ii | 1.05 | 1.69 | 2.718 | 166 |
| N3—H20···O27 | 1.05 | 1.78 | 2.796 | 161 |
| N3—H20···O30 | 1.05 | 2.50 | 3.111 | 116 |
| O2—H25···O27iv | 1.00 | 1.76 | 2.709 | 157 |
| O1—H22···O2iv | 0.98 | 2.19 | 3.113 | 155 |
| C5—H14···O26 | 1.10 | 2.40 | 3.364 | 145 |
| C12—H24···O26 | 1.09 | 2.72 | 3.758 | 154 |
| C4—H13···O28 | 1.11 | 2.61 | 3.410 | 128 |
| C9—H19···O29 | 1.09 | 2.95 | 4.033 | 171 |
Symmetry codes: (i) x−1, y, z; (ii) −x, y−1/2, −z+3/2; (iii) −x+1, y+1/2, −z+3/2; (iv) x−1/2, −y+3/2, −z+2.
Funding Statement
Funding for this research was provided by: International Centre for Diffraction Data (grant No. 09-03).
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Crystal structure: contains datablock(s) I, I_VASP. DOI: 10.1107/S2056989026009497/hb8243sup1.cif
Additional supporting information: crystallographic information; 3D view; checkCIF report