Di­ammonium potassium citrate, (NH4)2KC6H5O7

Patel, N.V.; Golab, J.T.; Kaduk, J.A.

doi:10.1107/S2414314620006124

metal-organic compounds

IUCrDATA

ISSN: 2414-3146

Volume 5| Part 5| May 2020| x200612

https://doi.org/10.1107/S2414314620006124

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Diammonium potassium citrate, (NH₄)₂KC₆H₅O₇

Nilan V. Patel,^a Joseph T. Golab ^a and James A. Kaduk ^b ^*

^aIllinois Mathematics and Science Academy, 1500 Sullivan Road, Aurora IL 60506 , USA, and ^bDepartment of Chemistry, North Central College, 131 S. Loomis, St., Naperville IL, 60540 , USA
^*Correspondence e-mail: kaduk@polycrystallography.com

Edited by W. T. A. Harrison, University of Aberdeen, Scotland (Received 11 February 2020; accepted 5 May 2020; online 12 May 2020)

The crystal structure of diammonium potassium citrate, 2NH₄⁺·K⁺·C₆H₅O₇³⁻, has been solved and refined using laboratory X-ray powder diffraction data and optimized using density functional theory. The KO₇ coordination polyhedra are isolated. The ammonium cations and the hydrophobic methylene sides of the citrate anions occupy the spaces between the coordination polyhedra. Each hydrogen atom of the ammonium ions acts as a donor in a charge-assisted N—H⋯O, N—H⋯(O,O) or N—H⋯(O,O,O) hydrogen bond. There is an intramolecular O—H⋯O hydrogen bond in the citrate anion between the hydroxide group and one of the terminal carboxylate groups.

Keywords: powder diffraction; density functional theory; citrate anion; ammonium; potasssium.

CCDC references: 2001358; 2001359

Structure description

A systematic study of the crystal structures of Group 1 (alkali metal) citrate salts has been reported by Rammohan & Kaduk (2018 ). The study was extended to ammonium citrates by Wheatley & Kaduk (2019 ). The title compound represents a further extension to mixed ammonium Group 1 citrates, specifically diammonium potassium citrate, (NH₄)₂KC₆H₅O₇.

The structure of (NH₄)₂KC₆H₅O₇ was solved and refined from powder X-ray data and optimized by density functional theory (DFT) calculations (see Experimental section) and is illustrated in Fig. 1. The root-mean-square Cartesian displacement of the non-hydrogen citrate atoms in the Rietveld-refined and DFT-optimized structures is 0.108 Å (Fig. 2). The maximum deviation is 0.211 Å, at O14. The r.m.s. displacement of the potassium ions is 0.054 Å. The r.m.s. displacements of the ammonium ions N19 and N20 are 0.111 and 0.151 Å respectively. The good agreement between the two structures is strong evidence that the experimental structure is correct (van de Streek & Neumann, 2014 ). All of the citrate bond distances, bond angles, and torsion angles fall within the normal ranges indicated by a Mercury Mogul Geometry Check (Macrae et al., 2020 ). The citrate anion occurs in the trans,trans-conformation (about C2—C3 and C3—C4), which is one of the two low-energy conformations of an isolated citrate anion (Rammohan & Kaduk, 2018). The central carboxylate group and the hydroxyl group exhibit a small twist [O16—C6—C3—O17 torsion angle = 7.0°] from the normal planar arrangement. The Mulliken overlap populations indicate that the K—O bonds are ionic.

Figure 1
The asymmetric unit of (NH₄)₂KC₆H₅O₇ with the atom numbering and 50% probability spheroids.

Figure 2
Comparison of the refined and optimized structures of (NH₄)₂KC₆H₅O₇. The refined structure is in red, and the DFT-optimized structure is in blue.

The citrate anion doubly chelates to K21 through the hydroxyl group O17 and the terminal carboxylate group (atom O11). The anion doubly chelates to another potassium cation through the hydroxyl group and the other terminal carboxylate group (atom O14). Each oxygen atom bonds to a single potassium cation. As a result, K21 is seven-coordinate (capped trigonal prismatic), with a bond-valence sum of 0.98.

The Bravais–Friedel–Donnay–Harker (Bravais, 1866 ; Friedel, 1907 ; Donnay & Harker, 1937 ) method suggests that we might expect block morphology for diammonium potassium citrate. A 2nd order spherical harmonic preferred orientation model was included in the Rietveld refinement; the texture index was 1.179, indicating that preferred orientation was significant for this rotated flat sheet specimen.

The KO₇ coordination polyhedra are isolated (Fig. 3). The ammonium cations and the hydrophobic methylene sides of the citrate anions occupy the spaces between the coordination polyhedra. Each hydrogen atom of the ammonium ions acts as a donor in a charge-assisted N—H⋯O hydrogen bond; there is one bifurcated M—H⋯(O,O) bond and one trifurcated N—H⋯(O,O,O) bond (Table 1). There is an intramolecular hydrogen bond between the hydroxide group and one of the terminal carboxylate groups. The N—H⋯O hydrogen-bond energies were calculated by the correlation of Wheatley & Kaduk (2019), and the O—H⋯O hydrogen bond energy was calculated by the correlation of Rammohan & Kaduk (2018).

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O17—H18⋯O11	0.90	1.79	2.613 (19)	150
N19—H22⋯O14ⁱ	0.77	2.18	2.88 (3)	150
N19—H22⋯O16ⁱ	0.77	2.46	2.80 (3)	109
N19—H22⋯O17ⁱ	0.77	2.33	2.74 (2)	114
N19—H23⋯O16ⁱ	0.97	2.13	2.80 (3)	125
N19—H24⋯O15ⁱⁱ	0.85	2.13	2.90 (3)	151
N19—H25⋯O14ⁱⁱⁱ	1.07	1.77	2.80 (2)	162
N20—H26⋯O15^iv	0.94	2.58	3.26 (3)	130
N20—H26⋯O16^iv	0.94	1.91	2.84 (3)	173
N20—H27⋯O11^v	0.92	1.78	2.69 (3)	177
N20—H28⋯O13^vi	0.98	1.99	2.89 (3)	154
N20—H29⋯O12^vii	0.86	1.92	2.77 (3)	170
Symmetry codes: (i) -x+2, -y+1, -z+1; (ii) -x+1, -y+1, -z+1; (iii) x, y, z-1; (iv) $[-x+1, y+{\script{1\over 2}}, -z+{\script{3\over 2}}]$ ; (v) x-1, y+1, z; (vi) $[x, -y+{\script{3\over 2}}, z-{\script{1\over 2}}]$ ; (vii) x, y+1, z.

Figure 3
The crystal structure of (NH₄)₂KC₆H₅O₇, viewed along the a axis.

Diammonium potassium citrate is isostructural to trimmonium citrate (Wheatley & Kaduk, 2019; Fig. 4). Comparison of the powder patterns (Fig. 5) confirms the similarity.

Figure 4
Overlay of the crystal structures of diammonium potassium citrate and triammonium citrate, showing that they are isostructural.

Figure 5
Comparison of the X-ray powder diffraction patterns of diammonium potassium citrate (black) and triammonium citrate (green).

Details of the comprehensive literature search for citrate structures are presented in Rammohan & Kaduk (2018). The powder pattern of (NH₄)₂KC₆H₅O₇ was indexed using N-TREOR (Altomare et al., 2013 ). A reduced-cell search of the cell of diammonium potassium citrate in the Cambridge Structural Database (Groom et al., 2016 ) resulted in no hits.

Synthesis and crystallization

Diammonium potassium citrate was synthesized by dissolving 1.1217 g diammonium hydrogen citrate (Fisher Lot #995047) and 0.3279 g potassium carbonate (Sigma–Aldrich Lot #098 K0064) in ∼5 ml of deionized water. The clear solution was dried at 363 K for two days to yield a white solid.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2. A Rietveld plot is presented in Fig. 6.

Table 2
Experimental details

Crystal data
Chemical formula	2NH₄⁺·K⁺·C₆H₅O₇³⁻
M_r	264.27
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	300
a, b, c (Å)	6.0238 (5), 13.2925 (6), 13.4155 (8)
β (°)	93.131 (4)
V (Å³)	1072.60 (12)
Z	4
Radiation type	Kα_1,2, λ = 1.54059, 1.54445 Å
Specimen shape, size (mm)	Flat sheet, 25 × 25

Data collection
Diffractometer	Bruker D2 Phaser
Specimen mounting	Standard sample holder with Kapton window
Data collection mode	Reflection
Scan method	Step
2θ values (°)	2θ_min = 5.051, 2θ_max = 100.038, 2θ_step = 0.020

Refinement
R factors and goodness of fit	R_p = 0.056, R_wp = 0.072, R_exp = 0.038, R(F²) = 0.16190, χ² = 3.656
No. of parameters	78
H-atom treatment	Only H-atom displacement parameters refined
The same symmetry and lattice parameters were used for the DFT calculations as for the powder diffraction study. Computer programs: Data Collector (Bruker, 2015 ), FOX (Favre-Nicolin & Černý, 2002), GSAS-II (Toby & Von Dreele, 2013), DIAMOND (Crystal Impact, 2015 ) and Mercury (Macrae et al., 2020).

Figure 6
Rietveld plot for (NH₄)₂KC₆H₅O₇. The blue crosses represent the observed data points, and the green line is the calculated pattern. The cyan curve is the normalized error plot. The vertical scale has been multiplied by a factor of 10× for 2θ > 50.0°. The row of blue tick marks indicates the calculated reflection positions. The red line is the background curve.

The structure was solved using Monte Carlo simulated annealing techniques with FOX (Favre-Nicolin & Černý 2002 ) using a citrate anion, one K⁺ cation and two ammonium cations as fragments. The structure was refined by the Rietveld method using GSAS-II (Toby & Von Dreele, 2013 ). The hydrogen atoms were included in fixed positions, which were recalculated during the course of the refinement using Materials Studio (Dassault Systems, 2019 ). All C—C and C—O bond distances and all bond angles were restrained based on a Mercury/Mogul Geometry Check (Sykes et al., 2011 ; Bruno et al., 2004 ) of the molecule. The U_iso values of the atoms in the central and outer portions of the citrate were constrained to be equal, and the U_iso values of the hydrogen atoms were constrained to be 1.3× those of the atoms to which they are attached. A Chebyschev background function with three coefficients was used to model the background. A ten-term diffuse scattering function was used to describe the scattering from the capillary and any amorphous component. A density functional geometry optimization was carried out using CRYSTAL14 (Dovesi et al., 2014 ). The basis sets for the H, C, N, and O atoms were those of Gatti et al. (1994 ), and the basis set for K was that of Peintinger et al. (2013 ). The calculation was run on eight 2.1 GHz Xeon cores (each with 6 Gb RAM) of a 304-core Dell Linux cluster at IIT, using 8 k-points and the B3LYP functional, and took ∼5 days.

Structural data

CCDC references: 2001358; 2001359

Crystal structure: contains datablocks global, I, I_DFT. DOI: https://doi.org/10.1107/S2414314620006124/hb4336sup1.cif

Supporting information file. DOI: https://doi.org/10.1107/S2414314620006124/hb4336Isup2.cml

checkCIF report

Computing details top

Data collection: Data Collector (Bruker, 2015) for (I). Program(s) used to solve structure: FOX (Favre-Nicolin & Černý, 2002) for (I). Program(s) used to refine structure: GSAS-II (Toby & Von Dreele, 2013) for (I). Molecular graphics: DIAMOND (Crystal Impact, 2015) and Mercury (Macrae et al., 2020) for (I). Software used to prepare material for publication: DIAMOND (Crystal Impact, 2015) and Mercury (Macrae et al., 2020) for (I).

Diammonium potassium citrate (I) top

Crystal data top

2NH₄⁺·K⁺·C₆H₅O₇³⁻	Z = 4
M_r = 264.27	D_x = 1.637 Mg m⁻³
Monoclinic, P2₁/c	Kα_1,2 radiation, λ = 1.54059, 1.54445 Å
Hall symbol: -P 2ybc	T = 300 K
a = 6.0238 (5) Å	Particle morphology: powder
b = 13.2925 (6) Å	white
c = 13.4155 (8) Å	flat_sheet, 25 × 25 mm
β = 93.131 (4)°	Specimen preparation: Prepared at 363 K and 101 kPa
V = 1072.60 (12) Å³

Data collection top

Bruker D2 Phaser diffractometer	Data collection mode: reflection
Radiation source: sealed X-ray tube	Scan method: step
Ni filter monochromator	2θ_min = 5.051°, 2θ_max = 100.038°, 2θ_step = 0.020°
Specimen mounting: standard sample holder with Kapton window

Refinement top

Least-squares matrix: full	78 parameters
R_p = 0.056	3 constraints
R_wp = 0.072	Only H-atom displacement parameters refined
R_exp = 0.038	Weighting scheme based on measured s.u.'s
R(F²) = 0.16190	(Δ/σ)_max < 0.001
4700 data points	Background function: Background function: "chebyschev" function with 3 terms: 434.7(23), -456(8), 208(14), Background Debye function parameters: A, R, U: 11.0(8), 1.430, 0.100, 30(5), 2.270, 0.100, 95(21), 2.940, 0.100, -4.4(4), 8.740, 0.100, -28(3), 1.970, 0.100, -104(22), 2.880, 0.100, -8.4(18), 3.580, 0.100, 8.2(6), 14.000, 0.100, 2.5(7), 17.810, 0.100, -0.4(8), 4.000, 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 3.537, -1.411, 1.973, 2.482, 0.000, 0.048, Crystallite size in microns with "isotropic" model: parameters: Size, G/L mix 1.000, 1.000, Microstrain, "generalized" model (10⁶ * delta Q/Q) parameters: S400, S040, S004, S220, S202, S022, S301, S103, S121, G/L mix 14695.026, 1.365, 571.072, 1337.970, 183.112, -17.422, 2458.309, -70.133, 156.113, 1.000,	Preferred orientation correction: Simple spherical harmonic correction Order = 0 Coefficients:

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
C1	0.886 (3)	0.0374 (11)	0.8584 (14)	0.012 (2)*
C2	0.757 (2)	0.0812 (8)	0.9422 (10)	0.036 (7)*
C3	0.7931 (14)	0.1942 (7)	0.9608 (7)	0.036*
C4	0.669 (2)	0.2264 (7)	1.0527 (10)	0.036*
C5	0.656 (2)	0.3389 (7)	1.0721 (15)	0.0123*
C6	0.7043 (15)	0.2540 (13)	0.8679 (10)	0.0123*
H7	0.77670	0.04320	0.99960	0.046*
H8	0.57450	0.06940	0.92620	0.046*
H9	0.50370	0.20020	1.04630	0.046*
H10	0.71580	0.19530	1.10950	0.046*
O12	0.807 (2)	−0.0389 (9)	0.8144 (10)	0.0123*
O13	0.473 (2)	0.3730 (9)	1.0971 (13)	0.0123*
O14	0.827 (2)	0.3899 (9)	1.0640 (13)	0.0123*
O15	0.4977 (17)	0.2596 (12)	0.8525 (10)	0.0123*
O16	0.845 (2)	0.2922 (10)	0.8155 (9)	0.0123*
O17	1.0258 (16)	0.2132 (9)	0.9785 (9)	0.0123*
O11	1.061 (2)	0.0808 (9)	0.8363 (12)	0.0123*
H18	1.08650	0.16790	0.93840	0.016*
N19	0.825 (4)	0.6005 (14)	0.0743 (17)	0.040000*
N20	0.369 (4)	0.9754 (16)	0.7422 (14)	0.040*
K21	0.8415 (12)	0.7585 (6)	0.3071 (5)	0.040*
H22	0.93790	0.61560	0.05380	0.052000*
H23	0.90790	0.60060	0.13800	0.052000*
H24	0.69960	0.62600	0.08460	0.052000*
H25	0.79170	0.52180	0.07060	0.052000*
H26	0.30840	0.91370	0.72030	0.052000*
H27	0.26010	1.01030	0.77260	0.052000*
H28	0.38690	1.01050	0.67920	0.052000*
H29	0.50180	0.97670	0.76900	0.052000*

Geometric parameters (Å, º) top

C1—C2	1.520 (3)	O15—K21^iv	2.887 (13)
C1—O12	1.254 (5)	O16—C6	1.238 (6)
C1—O11	1.249 (4)	O16—K21^v	2.659 (15)
C2—C1	1.520 (3)	O17—C3	1.431 (4)
C2—C3	1.536 (3)	O17—H18	0.899
C2—H7	0.923	O17—K21ⁱⁱⁱ	3.004 (14)
C2—H8	1.119	O11—C1	1.249 (4)
C3—C2	1.536 (3)	O11—K21^v	2.956 (15)
C3—C4	1.537 (3)	H18—O17	0.899
C3—C6	1.549 (3)	N19—H22	0.774
C3—O17	1.431 (4)	N19—H23	0.966
C4—C3	1.537 (3)	N19—H24	0.847
C4—C5	1.520 (3)	N19—H25	1.065
C4—H9	1.055	N20—H26	0.937
C4—H10	0.899	N20—H27	0.916
C5—C4	1.520 (3)	N20—H28	0.977
C5—O13	1.251 (5)	N20—H29	0.861
C5—O14	1.244 (4)	K21—O12^vi	2.928 (14)
C6—C3	1.549 (3)	K21—O13^vii	2.799 (16)
C6—O15	1.253 (6)	K21—O14^viii	3.108 (16)
C6—O16	1.238 (6)	K21—O15^iv	2.887 (13)
H7—C2	0.923	K21—O16^v	2.659 (15)
H8—C2	1.119	K21—O17^viii	3.004 (14)
H9—C4	1.055	K21—O11^v	2.956 (15)
H9—H10	1.4957	H22—N19	0.774
H10—C4	0.899	H23—N19	0.966
O12—C1	1.254 (5)	H24—N19	0.847
O12—K21ⁱ	2.928 (14)	H25—N19	1.065
O13—C5	1.251 (5)	H26—N20	0.937
O13—K21ⁱⁱ	2.799 (16)	H27—N20	0.916
O14—C5	1.244 (4)	H28—N20	0.977
O14—K21ⁱⁱⁱ	3.108 (16)	H29—N20	0.861
O15—C6	1.253 (6)

C2—C1—O12	117.5 (5)	C4—C5—O13	117.3 (5)
C2—C1—O11	118.1 (4)	C4—C5—O14	118.0 (4)
O12—C1—O11	124.4 (4)	O13—C5—O14	124.7 (4)
C1—C2—C3	114.9 (4)	C3—C6—O15	117.4 (3)
C1—C2—H7	111.1	C3—C6—O16	116.8 (3)
C3—C2—H7	112.9	O15—C6—O16	125.9 (4)
C1—C2—H8	110.0	C6—O16—K21^v	141.1 (13)
C3—C2—H8	107.3	C3—O17—H18	102.1
H7—C2—H8	99.4	H22—N19—H23	83.8
C2—C3—C4	109.4 (4)	H22—N19—H24	139.7
C2—C3—C6	109.4 (4)	H23—N19—H24	106.1
C4—C3—C6	109.9 (4)	H22—N19—H25	113.9
C2—C3—O17	109.2 (4)	H23—N19—H25	97.5
C4—C3—O17	109.4 (4)	H24—N19—H25	103.5
C6—C3—O17	109.6 (4)	H26—N20—H27	108.0
C3—C4—C5	116.4 (5)	H26—N20—H28	102.0
C3—C4—H9	110.0	H27—N20—H28	105.1
C5—C4—H9	106.2	H26—N20—H29	119.0
C3—C4—H10	114.1	H27—N20—H29	118.4
C5—C4—H10	108.9	H28—N20—H29	101.9
H9—C4—H10	99.6

Symmetry codes: (i) x, −y+1/2, z+1/2; (ii) −x+1, y−1/2, −z+3/2; (iii) −x+2, y−1/2, −z+3/2; (iv) −x+1, −y+1, −z+1; (v) −x+2, −y+1, −z+1; (vi) x, −y+1/2, z−1/2; (vii) −x+1, y+1/2, −z+3/2; (viii) −x+2, y+1/2, −z+3/2.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O17—H18···O11	0.90	1.79	2.613 (19)	150
N19—H22···O14^v	0.77	2.18	2.88 (3)	150
N19—H22···O16^v	0.77	2.46	2.80 (3)	109
N19—H22···O17^v	0.77	2.33	2.74 (2)	114
N19—H23···O16^v	0.97	2.13	2.80 (3)	125
N19—H24···O15^iv	0.85	2.13	2.90 (3)	151
N19—H25···O14^ix	1.07	1.77	2.80 (2)	162
N20—H26···O15^vii	0.94	2.58	3.26 (3)	130
N20—H26···O16^vii	0.94	1.91	2.84 (3)	173
N20—H27···O11^x	0.92	1.78	2.69 (3)	177
N20—H28···O13^xi	0.98	1.99	2.89 (3)	154
N20—H29···O12^xii	0.86	1.92	2.77 (3)	170

Symmetry codes: (iv) −x+1, −y+1, −z+1; (v) −x+2, −y+1, −z+1; (vii) −x+1, y+1/2, −z+3/2; (ix) x, y, z−1; (x) x−1, y+1, z; (xi) x, −y+3/2, z−1/2; (xii) x, y+1, z.

(I_DFT) top

Crystal data top

C6H13KN2O₇	c = 13.4156 Å
M_r = 264.27	β = 93.1310°
Monoclinic, P2₁/c	V = 1072.60 Å³
Hall symbol: -P 2ybc	Z = 4
a = 6.0238 Å	D_x = 1.637 Mg m⁻³
b = 13.2926 Å

Data collection top

h = →	l = →
k = →

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
C1	0.87318	0.03565	0.86687	0.01230*
C2	0.72599	0.08314	0.94344	0.03600*
C3	0.76903	0.19496	0.96828	0.03600*
C4	0.63480	0.22315	1.05833	0.03600*
C5	0.63310	0.33416	1.08863	0.01230*
C6	0.68765	0.25946	0.87689	0.01230*
H7	0.75607	0.03931	1.01180	0.04600*
H8	0.55188	0.07301	0.91973	0.04600*
H9	0.46410	0.19855	1.04385	0.04600*
H10	0.70341	0.18054	1.12249	0.04600*
O12	0.80347	−0.04262	0.82266	0.01230*
O13	0.44391	0.37143	1.10579	0.01230*
O14	0.81343	0.38194	1.09793	0.01230*
O15	0.48252	0.26029	0.85377	0.01230*
O16	0.83050	0.30870	0.83032	0.01230*
O17	0.99968	0.21047	0.99448	0.01230*
O11	1.06265	0.07558	0.85523	0.01230*
H18	1.07924	0.17143	0.94538	0.01600*
N20	0.37168	0.98204	0.74458	0.04000*
K21	0.86217	0.75540	0.30100	0.04000*
H22	0.78800	0.60364	0.00308	0.05200*
H23	0.95796	0.62600	0.10404	0.05200*
N19	0.81121	0.59136	1.07827	0.04000*
H24	0.68536	0.63002	0.11046	0.05200*
H25	0.80797	0.51452	0.09426	0.05200*
H26	0.30306	0.91502	0.71752	0.05200*
H27	0.25619	1.01594	0.78942	0.05200*
H28	0.40466	1.03125	0.68656	0.05200*
H29	0.52233	0.96762	0.78341	0.05200*

Bond lengths (Å) top

C1—C2	1.530	C6—O16	1.272
C1—O12	1.258	O17—H18	0.984
C1—O11	1.276	N20—H26	1.039
C2—C3	1.542	N20—H27	1.046
C2—H7	1.093	N20—H28	1.044
C2—H8	1.088	N20—H29	1.039
C3—C4	1.536	H22—N19ⁱ	1.024
C3—C6	1.553	H23—N19ⁱ	1.039
C3—O17	1.429	N19—H23ⁱⁱ	1.039
C4—C5	1.531	N19—H22ⁱⁱ	1.024
C4—H9	1.086	N19—H24ⁱⁱ	1.030
C4—H10	1.093	N19—H25ⁱⁱ	1.044
C5—O13	1.275	H24—N19ⁱ	1.030
C5—O14	1.259	H25—N19ⁱ	1.044
C6—O15	1.257

Symmetry codes: (i) x, y, z−1; (ii) x, y, z+1.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N20—H29···O12	1.039	1.751	2.770	165.64
N20—H28···O13	1.044	1.712	2.746	169.62
N20—H27···O11	1.046	1.697	2.742	176.08
N20—H26···O16	1.039	1.732	2.769	175.39
N19—H25···O14	1.044	1.763	2.796	159.41
N19—H24···O15	1.030	1.853	2.833	157.81
N19—H23···O16	1.039	1.741	2.764	167.24
N19—H22···O13	1.024	1.993	2.879	143.23
O17—H18···O11	0.984	1.756	2.632	146.38

Acknowledgements

We thank North Central College for allowing us the space and resources to pursue this research project. We also thank the Illinois Mathematics and Science Academy for offering us the opportunity to work on this project. We thank Andrey Rogachev for the use of computing resources at the Illinois Institute of Technology.

References

Altomare, A., Cuocci, C., Giacovazzo, C., Moliterni, A., Rizzi, R., Corriero, N. & Falcicchio, A. (2013). J. Appl. Cryst. 46, 1231–1235. Web of Science CrossRef CAS IUCr Journals Google Scholar
Bravais, A. (1866). Etudes Cristallographiques. Paris: Gauthier Villars. Google Scholar
Bruker (2015). Data Collector. Bruker AXS Inc., Maddison, Wisconsin, USA. Google Scholar
Bruno, I. J., Cole, J. C., Kessler, M., Luo, J., Motherwell, W. D. S., Purkis, L. H., Smith, B. R., Taylor, R., Cooper, R. I., Harris, S. E. & Orpen, A. G. (2004). J. Chem. Inf. Comput. Sci. 44, 2133–2144. Web of Science CrossRef PubMed CAS Google Scholar
Crystal Impact (2015). DIAMOND. Crystal Impact GbR, Bonn, Germany. Google Scholar
Dassault Systems. (2019). Materials Studio, BIOVIA, San Diego, USA. Google Scholar
Donnay, J. D. H. & Harker, D. (1937). Am. Mineral. 22, 446–467. CAS Google Scholar
Dovesi, R., Orlando, R., Erba, A., Zicovich-Wilson, C. M., Civalleri, B., Casassa, S., Maschio, L., Ferrabone, M., De La Pierre, M., D'Arco, P., Noël, Y., Causà, M., Rérat, M. & Kirtman, B. (2014). Int. J. Quantum Chem. 114, 1287–1317. Web of Science CrossRef CAS Google Scholar
Favre-Nicolin, V. & Černý, R. (2002). J. Appl. Cryst. 35, 734–743. Web of Science CrossRef CAS IUCr Journals Google Scholar
Friedel, G. (1907). Bull. Soc. Fr. Mineral. 30, 326–455. Google Scholar
Gatti, C., Saunders, V. R. & Roetti, C. (1994). J. Chem. Phys. 101, 10686–10696. CrossRef CAS Web of Science Google Scholar
Groom, C. R., Bruno, I. J., Lightfoot, M. P. & Ward, S. C. (2016). Acta Cryst. B72, 171–179. Web of Science CrossRef IUCr Journals Google Scholar
Macrae, C. F., Sovago, I., Cottrell, S. J., Galek, P. T. A., McCabe, P., Pidcock, E., Platings, M., Shields, G. P., Stevens, J. S., Towler, M. & Wood, P. A. (2020). J. Appl. Cryst. 53, 226–235. Web of Science CrossRef CAS IUCr Journals Google Scholar
Peintinger, M. F., Oliveira, D. V. & Bredow, T. (2013). J. Comput. Chem. 34, 451–459. Web of Science CrossRef CAS PubMed Google Scholar
Rammohan, A. & Kaduk, J. A. (2018). Acta Cryst. B74, 239–252. Web of Science CSD CrossRef IUCr Journals Google Scholar
Streek, J. van de & Neumann, M. A. (2014). Acta Cryst. B70, 1020–1032. Web of Science CrossRef IUCr Journals Google Scholar
Sykes, R. A., McCabe, P., Allen, F. H., Battle, G. M., Bruno, I. J. & Wood, P. A. (2011). J. Appl. Cryst. 44, 882–886. Web of Science CrossRef CAS IUCr Journals Google Scholar
Toby, B. H. & Von Dreele, R. B. (2013). J. Appl. Cryst. 46, 544–549. Web of Science CrossRef CAS IUCr Journals Google Scholar
Wheatley, A. M. & Kaduk, J. A. (2019). Powder Diffr. 34, 35–43. Web of Science CrossRef CAS Google Scholar

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