2-Methyl-N-[(E)-4-nitro­ben­zyl­i­dene]pro­pan-2-am­ine

Hosten, E.C.; Betz, R.

doi:10.1107/S2414314625011368

organic compounds

IUCrDATA

ISSN: 2414-3146

Volume 10| Part 12| December 2025| x251136

https://doi.org/10.1107/S2414314625011368

Open

access

2-Methyl-N-[(E)-4-nitrobenzylidene]propan-2-amine

Eric Cyriel Hosten ^a and Richard Betz ^a ^*

^aNelson Mandela University, Summerstrand Campus, Department of Chemistry, University Way, Summerstrand, PO Box 77000, Port Elizabeth, 6031, South Africa
^*Correspondence e-mail: [email protected]

Edited by M. Bolte, Goethe-Universität Frankfurt, Germany (Received 1 December 2025; accepted 16 December 2025; online 24 December 2025)

The title compound, C₁₁H₁₄N₂O₂, is a Schiff base derived from tert-butylamine and para-nitrobenzaldehyde. All atoms except the methyl groups are located on a mirror plane. Thus, there is only half a molecule in the asymmetric unit. The tert-butyl group shows rotational disorder over four positions. The molecule is E-configured. In the extended structure, C—H⋯O contacts connect the molecules into chains along [010] in the crystal structure.

Keywords: crystal structure; rotational disorder; mirror symmetry.

CCDC reference: 2516436

Structure description

Imines – also known as Schiff bases – are the condensation products between a primary amine and a carbonyl compound and, thus, have found application as protection group for either one of the two compounds during classical organic multi-step synthesis procedures (Becker et al., 2000 ; Greene & Wuts, 2007 ). They have also found use as ligands in transition-metal chemistry for transition metals such as rhenium (Mukiza et al., 2020 ; Yumata et al., 2011b ; Habarurema et al., 2014a ,b ,c , 2015a ,b ; Potgieter et al., 2013 ; Gerber et al., 2011 , 2012 ) or rare-earth metals (Abrahams et al., 2017 ) and, in a structural variation, also play a role in carbohydrate chemistry in the shape of hydrazones that, in turn, give rise to osazones (Lindhorst, 2007 ). In a continuation of our interest in structural aspects of Schiff bases (Potgieter et al., 2011 ; Booysen et al., 2011a ,b ; Mohamed et al., 2023 ; Schmitt et al., 2011 , 2014 , 2015a ,b ; Yumata et al., 2011a ; Habarurema et al., 2014a,b; Madanhire et al., 2015a ,b ) we initiated a study around the metrical parameters of Schiff bases derived from aromatic aldehydes and the influence of coordination towards transition metals on these values. An intriguing family of compounds are derivatives featuring strongly deactivating nitro groups on the aromatic aldehyde core such as the series of mononitro-substituted benzaldehydes. The literature abounds in structural information around Schiff bases derived from ortho-nitrobenzladehyde (e.g. Cueno-Cabezas et al., 2025 ; Shan et al., 2004 ; Duggin et al., 2024 ) and some derived coordination compounds with mercury (Sheikh et al., 2025 ) and manganese (Mansour et al., 2024 ) as well as meta-nitrobenzaldehyde (e.g. Priyadharshini et al., 2025 ; Glidewell et al., 2005 ; Akkurt et al., 2008 ) and some derived coordination compounds with tin (Cui et al., 2022 ) and antimony (Artemeva et al., 2019 ) and para-nitrobenzaldehyde (e.g. Rogalewicz et al., 2025 ; Chuskit et al., 2025 ; Watson et al., 1984 ) and some derived coordination compounds with nickel, copper, zinc and palladium (Rogalewicz et al., 2025).

The structure solution shows the presence of a Schiff base derived from 4-nitrobenzaldehyde and tert-butylamine. The C=N double bond is (E)-configured (C2—N1—C1— C11 = 180 and N1—C1—C11—C12 = 0°]) (Fig. 1). The tert-butyl group shows rotational disorder. Except for the methyl groups, the molecule is exactly planar. Intracyclic C—C—C angles cover a range of 118.48 (19)–122.28 (18)° with the largest angle located on the carbon atom bearing the nitro group and the smallest angle on one of the CH groups directly adjacent to the latter carbon atom. All other bond lengths and angles are in good agreement with comparable values reported for other Schiff bases whose molecular and crystal structures have been determined on grounds of diffraction studies carried out on single crystals and whose metrical parameters have been deposited with the Cambridge Structural Database (Groom et al., 2016 ).

Figure 1
The molecular structure of the title compound, with atom labels and anisotropic displacement ellipsoids (drawn at 50% probability level). Only one of the four positions of the disordered methyl groups is shown.

In the crystal, C—H⋯O contacts (Table 1) whose range falls by more than 0.1 Å below the sum of the van der Waals radii of the atoms participating in them are observed. These are established between one hydrogen atom each of two methyl groups as donors and one of the nitro group's oxygen atoms as acceptor. In terms of graph-set analysis (Etter et al., 1990 ; Bernstein et al., 1995 ), the descriptor for these contacts is C₁¹(11). π-Stacking is not a prominent consolidating feature in the crystal structure of the title compound, with the shortest intercentroid distance in between two centers of gravity measured at 4.0640 (6) Å.

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C5—H5B⋯O1ⁱ	0.98	2.53	3.41 (3)	149
C6—H6C⋯O1ⁱⁱ	0.98	2.58	3.459 (19)	149
C7—H7B⋯O1ⁱ	0.98	2.56	3.35 (2)	138
Symmetry codes: (i) ; (ii) .

Synthesis and crystallization

The compound was obtained following a standard procedure by reacting para-nitrobenzaldehyde with tert-butylamine (Becker et al., 2000). Crystals suitable for the diffraction study were obtained straight from the solidified isolated product.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2.

Table 2
Experimental details

Crystal data
Chemical formula	C₁₁H₁₄N₂O₂
M_r	206.24
Crystal system, space group	Orthorhombic, Pnma
Temperature (K)	200
a, b, c (Å)	9.5110 (4), 7.2400 (3), 16.2386 (7)
V (Å³)	1118.18 (8)
Z	4
Radiation type	Mo Kα
μ (mm⁻¹)	0.09
Crystal size (mm)	0.39 × 0.25 × 0.14

Data collection
Diffractometer	Bruker APEXII CCD
Absorption correction	Numerical (SADABS; Krause et al., 2015 )
T_min, T_max	0.951, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections	38579, 1388, 1087
R_int	0.027
(sin θ/λ)_max (Å⁻¹)	0.649

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.051, 0.168, 1.17
No. of reflections	1388
No. of parameters	127
No. of restraints	30
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.14, −0.28
Computer programs: APEX2 and SAINT (Bruker, 2014 ), SHELXS97 (Sheldrick 2008 ), ORTEP-3 for Windows (Farrugia, 2012 ), Mercury (Macrae et al., 2020 ), SHELXL2019/3 (Sheldrick, 2015 ) and PLATON (Spek, 2020 ).

Structural data

CCDC reference: 2516436

Crystal structure: contains datablock I. DOI: https://doi.org/10.1107/S2414314625011368/bt4193sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314625011368/bt4193Isup2.hkl

Supporting information file. DOI: https://doi.org/10.1107/S2414314625011368/bt4193Isup3.cml

checkCIF report

Computing details top

2-Methyl-N-[(E)-4-nitrobenzylidene]propan-2-amine top

Crystal data top

C₁₁H₁₄N₂O₂	D_x = 1.225 Mg m⁻³
M_r = 206.24	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pnma	Cell parameters from 9822 reflections
a = 9.5110 (4) Å	θ = 2.5–27.5°
b = 7.2400 (3) Å	µ = 0.09 mm⁻¹
c = 16.2386 (7) Å	T = 200 K
V = 1118.18 (8) Å³	Block, colourless
Z = 4	0.39 × 0.25 × 0.14 mm
F(000) = 440

Data collection top

Bruker APEXII CCD diffractometer	1087 reflections with I > 2σ(I)
φ and ω scans	R_int = 0.027
Absorption correction: numerical (SADABS; Krause et al., 2015)	θ_max = 27.5°, θ_min = 2.5°
T_min = 0.951, T_max = 1.000	h = −12→12
38579 measured reflections	k = −9→9
1388 independent reflections	l = −21→21

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.051	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.168	H-atom parameters constrained
S = 1.17	w = 1/[σ²(F_o²) + (0.0741P)² + 0.2341P] where P = (F_o² + 2F_c²)/3
1388 reflections	(Δ/σ)_max < 0.001
127 parameters	Δρ_max = 0.14 e Å⁻³
30 restraints	Δρ_min = −0.28 e Å⁻³

Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Refinement. H atoms were placed in calculated positions (C–H 0.95 Å for aromatic and vinylic carbon atoms, C–H 0.98 Å for the methyl groups) and were included in the refinement in the riding model approximation, with U(H) set to 1.2U_eq(C) (aromatic and vinylic carbon atoms) and U(H) set to 1.5U_eq(C) (methyl carbon atoms).

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

	x	y	z	U_iso*/U_eq	Occ. (<1)
O1	0.80982 (18)	0.250000	0.41353 (13)	0.0882 (6)
O2	0.7034 (2)	0.250000	0.29689 (12)	0.0958 (7)
N1	0.16773 (16)	0.250000	0.61550 (10)	0.0528 (4)
N2	0.7029 (2)	0.250000	0.37195 (13)	0.0682 (6)
C1	0.1760 (2)	0.250000	0.53874 (12)	0.0519 (5)
H1	0.091886	0.250000	0.507196	0.062*
C2	0.0296 (2)	0.250000	0.65746 (12)	0.0536 (5)
C11	0.31255 (19)	0.250000	0.49559 (12)	0.0484 (5)
C12	0.4375 (2)	0.250000	0.53988 (13)	0.0542 (5)
H12	0.435145	0.250000	0.598363	0.065*
C13	0.5655 (2)	0.250000	0.49924 (14)	0.0574 (5)
H13	0.651108	0.250000	0.529340	0.069*
C14	0.5664 (2)	0.250000	0.41468 (13)	0.0539 (5)
C15	0.4456 (2)	0.250000	0.36931 (13)	0.0611 (6)
H15	0.448969	0.250000	0.310839	0.073*
C16	0.3178 (2)	0.250000	0.41056 (13)	0.0591 (5)
H16	0.232716	0.250000	0.379898	0.071*
C3	−0.0973 (5)	0.265 (4)	0.6039 (3)	0.068 (3)	0.25
H3A	−0.182003	0.263914	0.638266	0.102*	0.25
H3B	−0.093343	0.381236	0.572847	0.102*	0.25
H3C	−0.099806	0.160966	0.565549	0.102*	0.25
C4	0.031 (2)	0.409 (3)	0.7219 (14)	0.065 (5)	0.25
H4A	−0.059907	0.412007	0.750737	0.098*	0.25
H4B	0.106252	0.387595	0.761811	0.098*	0.25
H4C	0.046114	0.526941	0.693901	0.098*	0.25
C5	0.025 (2)	0.067 (3)	0.7079 (13)	0.059 (4)	0.25
H5A	−0.064623	0.058891	0.737398	0.089*	0.25
H5B	0.034319	−0.038276	0.670486	0.089*	0.25
H5C	0.102642	0.065927	0.747639	0.089*	0.25
C6	−0.062 (2)	0.4163 (17)	0.6252 (12)	0.056 (3)	0.25
H6A	−0.082575	0.398370	0.566662	0.084*	0.25
H6B	−0.149716	0.422350	0.656392	0.084*	0.25
H6C	−0.009376	0.531863	0.632479	0.084*	0.25
C7	−0.047 (2)	0.073 (2)	0.6354 (16)	0.100 (8)	0.25
H7A	−0.062591	0.069305	0.575825	0.150*	0.25
H7B	0.010265	−0.032942	0.652070	0.150*	0.25
H7C	−0.137343	0.069667	0.664117	0.150*	0.25
C8	0.0610 (8)	0.276 (4)	0.7447 (4)	0.120 (7)	0.25
H8A	−0.026868	0.277721	0.776207	0.180*	0.25
H8B	0.120741	0.175117	0.764160	0.180*	0.25
H8C	0.110222	0.394110	0.752281	0.180*	0.25

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0537 (10)	0.1050 (15)	0.1060 (15)	0.000	0.0215 (9)	0.000
O2	0.0840 (13)	0.1273 (18)	0.0762 (12)	0.000	0.0377 (10)	0.000
N1	0.0448 (8)	0.0618 (10)	0.0518 (9)	0.000	0.0050 (7)	0.000
N2	0.0630 (11)	0.0611 (11)	0.0805 (14)	0.000	0.0266 (10)	0.000
C1	0.0457 (9)	0.0615 (11)	0.0486 (10)	0.000	0.0014 (7)	0.000
C2	0.0440 (9)	0.0643 (12)	0.0525 (10)	0.000	0.0078 (8)	0.000
C11	0.0477 (10)	0.0472 (10)	0.0502 (10)	0.000	0.0060 (7)	0.000
C12	0.0513 (11)	0.0587 (12)	0.0526 (10)	0.000	0.0061 (8)	0.000
C13	0.0489 (10)	0.0589 (12)	0.0644 (12)	0.000	0.0055 (8)	0.000
C14	0.0523 (10)	0.0449 (10)	0.0645 (12)	0.000	0.0183 (9)	0.000
C15	0.0657 (12)	0.0674 (13)	0.0502 (11)	0.000	0.0120 (9)	0.000
C16	0.0531 (11)	0.0740 (14)	0.0502 (10)	0.000	0.0036 (8)	0.000
C3	0.049 (2)	0.095 (9)	0.060 (3)	0.013 (7)	0.0064 (19)	−0.024 (7)
C4	0.079 (8)	0.060 (6)	0.057 (7)	−0.014 (5)	0.011 (5)	0.006 (5)
C5	0.057 (5)	0.064 (7)	0.057 (7)	−0.004 (5)	0.020 (5)	0.008 (7)
C6	0.045 (4)	0.045 (5)	0.079 (6)	0.010 (4)	0.012 (4)	0.001 (4)
C7	0.067 (9)	0.109 (13)	0.124 (16)	0.003 (7)	0.040 (9)	0.017 (9)
C8	0.084 (5)	0.23 (2)	0.049 (3)	0.065 (12)	0.017 (3)	0.017 (10)

Geometric parameters (Å, º) top

O1—N2	1.221 (3)	C15—H15	0.9500
O2—N2	1.219 (3)	C16—H16	0.9500
N1—C1	1.249 (2)	C3—H3A	0.9800
N1—C2	1.480 (2)	C3—H3B	0.9800
N2—C14	1.472 (2)	C3—H3C	0.9800
C1—C11	1.476 (2)	C4—H4A	0.9800
C1—H1	0.9500	C4—H4B	0.9800
C2—C8	1.460 (7)	C4—H4C	0.9800
C2—C3	1.491 (5)	C5—H5A	0.9800
C2—C7	1.513 (11)	C5—H5B	0.9800
C2—C4	1.555 (11)	C5—H5C	0.9800
C2—C5	1.557 (10)	C6—H6A	0.9800
C2—C6	1.574 (8)	C6—H6B	0.9800
C11—C16	1.382 (3)	C6—H6C	0.9800
C11—C12	1.389 (3)	C7—H7A	0.9800
C12—C13	1.384 (3)	C7—H7B	0.9800
C12—H12	0.9500	C7—H7C	0.9800
C13—C14	1.373 (3)	C8—H8A	0.9800
C13—H13	0.9500	C8—H8B	0.9800
C14—C15	1.365 (3)	C8—H8C	0.9800
C15—C16	1.388 (3)

C1—N1—C2	121.03 (17)	C2—C3—H3A	109.5
O2—N2—O1	123.4 (2)	C2—C3—H3B	109.5
O2—N2—C14	118.4 (2)	H3A—C3—H3B	109.5
O1—N2—C14	118.3 (2)	C2—C3—H3C	109.5
N1—C1—C11	121.96 (18)	H3A—C3—H3C	109.5
N1—C1—H1	119.0	H3B—C3—H3C	109.5
C11—C1—H1	119.0	C2—C4—H4A	109.5
C8—C2—N1	105.4 (3)	C2—C4—H4B	109.5
N1—C2—C3	116.7 (3)	H4A—C4—H4B	109.5
C8—C2—C7	116.0 (9)	C2—C4—H4C	109.5
N1—C2—C7	108.5 (10)	H4A—C4—H4C	109.5
N1—C2—C4	107.7 (9)	H4B—C4—H4C	109.5
C3—C2—C4	110.0 (8)	C2—C5—H5A	109.5
N1—C2—C5	105.5 (7)	C2—C5—H5B	109.5
C3—C2—C5	110.3 (8)	H5A—C5—H5B	109.5
C4—C2—C5	105.9 (5)	C2—C5—H5C	109.5
C8—C2—C6	109.6 (8)	H5A—C5—H5C	109.5
N1—C2—C6	109.6 (8)	H5B—C5—H5C	109.5
C7—C2—C6	107.6 (5)	C2—C6—H6A	109.5
C16—C11—C12	119.11 (17)	C2—C6—H6B	109.5
C16—C11—C1	120.41 (18)	H6A—C6—H6B	109.5
C12—C11—C1	120.48 (17)	C2—C6—H6C	109.5
C13—C12—C11	120.36 (19)	H6A—C6—H6C	109.5
C13—C12—H12	119.8	H6B—C6—H6C	109.5
C11—C12—H12	119.8	C2—C7—H7A	109.5
C14—C13—C12	118.9 (2)	C2—C7—H7B	109.5
C14—C13—H13	120.6	H7A—C7—H7B	109.5
C12—C13—H13	120.6	C2—C7—H7C	109.5
C15—C14—C13	122.28 (18)	H7A—C7—H7C	109.5
C15—C14—N2	119.19 (19)	H7B—C7—H7C	109.5
C13—C14—N2	118.5 (2)	C2—C8—H8A	109.5
C14—C15—C16	118.48 (19)	C2—C8—H8B	109.5
C14—C15—H15	120.8	H8A—C8—H8B	109.5
C16—C15—H15	120.8	C2—C8—H8C	109.5
C11—C16—C15	120.91 (19)	H8A—C8—H8C	109.5
C11—C16—H16	119.5	H8B—C8—H8C	109.5
C15—C16—H16	119.5

C2—N1—C1—C11	180.000 (1)	C12—C13—C14—C15	0.000 (1)
C1—N1—C2—C8	−172.2 (12)	C12—C13—C14—N2	180.000 (1)
C1—N1—C2—C3	−4.8 (12)	O2—N2—C14—C15	0.000 (1)
C1—N1—C2—C7	63.0 (10)	O1—N2—C14—C15	180.000 (1)
C1—N1—C2—C4	−129.1 (11)	O2—N2—C14—C13	180.000 (1)
C1—N1—C2—C5	118.1 (10)	O1—N2—C14—C13	0.000 (1)
C1—N1—C2—C6	−54.3 (8)	C13—C14—C15—C16	0.000 (1)
N1—C1—C11—C16	180.000 (1)	N2—C14—C15—C16	180.000 (1)
N1—C1—C11—C12	0.000 (1)	C12—C11—C16—C15	0.000 (1)
C16—C11—C12—C13	0.000 (1)	C1—C11—C16—C15	180.000 (1)
C1—C11—C12—C13	180.000 (1)	C14—C15—C16—C11	0.000 (1)
C11—C12—C13—C14	0.000 (1)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C5—H5B···O1ⁱ	0.98	2.53	3.41 (3)	149
C6—H6C···O1ⁱⁱ	0.98	2.58	3.459 (19)	149
C7—H7B···O1ⁱ	0.98	2.56	3.35 (2)	138

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

References

Abrahams, A., Madanhire, T., Hosten, E. & Betz, R. (2017). J. Coord. Chem. 70, 1994–2014. CrossRef CAS Google Scholar
Akkurt, M., Jarrahpour, A. A., Aye, M., Gençaslan, M. & Büyükgüngör, O. (2008). Acta Cryst. E64, o2175–o2176. Web of Science CSD CrossRef IUCr Journals Google Scholar
Artem'eva, E. V., Sharutin, V. V. & Sharutina, O. K. (2019). Russ. J. Inorg. Chem. 64, 1410–1417. CAS Google Scholar
Becker, H. G. O., Berger, W., Domschke, G., Fanghänel, E., Faust, J., Fischer, M., Gentz, F., Gewald, K., Gluch, R., Mayer, R., Müller, K., Pavel, D., Schmidt, H., Schollberg, K., Schwetlick, K., Seiler, E. & Zeppenfeld, G. (2000). Organikum – Organisch-Chemisches Grundpraktikum 21st ed. Weinheim: Wiley-VCH. Google Scholar
Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555–1573. CrossRef CAS Web of Science Google Scholar
Booysen, I., Muhammed, I., Soares, A., Gerber, T., Hosten, E. & Betz, R. (2011a). Acta Cryst. E67, o1592. Web of Science CSD CrossRef IUCr Journals Google Scholar
Booysen, I., Muhammed, I., Soares, A., Gerber, T., Hosten, E. & Betz, R. (2011b). Acta Cryst. E67, o2025–o2026. Web of Science CSD CrossRef IUCr Journals Google Scholar
Bruker (2014). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Chuskit, S., Kumar, S. & Das, D. (2025). CrystEngComm 27, 3247–3256. CrossRef CAS Google Scholar
Cuenú-Cabezas, F., Bernal, M. C. D. & Castaño, J. A. G. (2025). Acta Cryst. C81, 365–373. CrossRef IUCr Journals Google Scholar
Cui, Y., Wang, H., Wang, J., Li, C. & Liu, C. (2022). J. Mol. Struct. 1267, 133664. CrossRef Google Scholar
Duggin, M., Olivier, W. J., Canty, A. J., Lim, L. F., Cox, N., Turner, G. F., Moggach, S. A., Thickett, S. C., Bissember, A. C. & Fuller, R. O. (2024). J. Org. Chem. 89, 9405–9419. CrossRef CAS PubMed Google Scholar
Etter, M. C., MacDonald, J. C. & Bernstein, J. (1990). Acta Cryst. B46, 256–262. CrossRef ICSD CAS Web of Science IUCr Journals Google Scholar
Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849–854. Web of Science CrossRef CAS IUCr Journals Google Scholar
Gerber, T. I. A., Betz, R., Booysen, I. N., Potgieter, K. C. & Mayer, P. (2011). Polyhedron 30, 1739–1745. CrossRef CAS Google Scholar
Gerber, T. I. A., Yumata, N. C. & Betz, R. (2012). Inorg. Chem. Commun. 15, 69–72. CrossRef CAS Google Scholar
Glidewell, C., Low, J. N., Skakle, J. M. S. & Wardell, J. L. (2005). Acta Cryst. C61, o312–o316. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Greene, T. W. & Wuts, P. G. M. (2007). Organic Synthesis 4th ed. Hoboken: Wiley-Interscience. 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
Habarurema, G., Gerber, T. I. A., Hosten, E. C. & Betz, R. (2014b). Z. Kristallogr. New Cryst. Struct. 229, 383–384. CrossRef CAS Google Scholar
Habarurema, G., Gerber, T. I. A., Hosten, E. C. & Betz, R. (2014c). Z. Kristallogr. New Cryst. Struct. 229, 365–366. CrossRef CAS Google Scholar
Habarurema, G., Gerber, T. I. A., Hosten, E. C. & Betz, R. (2015a). Z. Kristallogr. New Cryst. Struct. 230, 38–40. CrossRef CAS Google Scholar
Habarurema, G., Gerber, T. I. A., Hosten, E. C. & Betz, R. (2015b). Z. Kristallogr. New Cryst. Struct. 230, 153–155. CrossRef CAS Google Scholar
Habarurema, G., Hosten, E. C., Betz, R. & Gerber, T. I. A. (2014a). Inorg. Chem. Commun. 47, 159–161. CrossRef CAS Google Scholar
Krause, L., Herbst-Irmer, R., Sheldrick, G. M. & Stalke, D. (2015). J. Appl. Cryst. 48, 3–10. Web of Science CSD CrossRef ICSD CAS IUCr Journals Google Scholar
Lindhorst, T. K. (2007). Essentials of Carbohydrate Chemistry and Biochemistry 3rd ed. Weinheim: Wiley-VCH. 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
Madanhire, T., Abrahams, A., Hosten, E. C. & Betz, R. (2015a). Z. Kristallogr. New Cryst. Struct. 230, 13–14. CrossRef CAS Google Scholar
Madanhire, T., Abrahams, A., Hosten, E. C. & Betz, R. (2015b). Z. Kristallogr. New Cryst. Struct. 230, 89–90. CrossRef CAS Google Scholar
Mansour, A. M., Khaled, R. M. & Shehab, O. R. (2024). Dalton Trans. 53, 19022–19057. CrossRef CAS PubMed Google Scholar
Mohamed, H. A., Bekheit, M. S., Ewies, E. F., Awad, H. M., Betz, R., Hosten, E. C. & Abdel-Wahab, B. F. (2023). J. Mol. Struct. 1274, 134415. Web of Science CSD CrossRef Google Scholar
Mukiza, J., Habarurema, G., Gerber, T. I. A., Hosten, E. C., Betz, R. & Umumararungu, T. (2020). Polyhedron 175, 114192. CrossRef Google Scholar
Potgieter, K., Hosten, E., Gerber, T. & Betz, R. (2011). Acta Cryst. E67, o2785–o2786. Web of Science CSD CrossRef IUCr Journals Google Scholar
Potgieter, K., Mayer, P., Gerber, T., Yumata, N., Hosten, E., Booysen, I., Betz, R., Ismail, M. & van Brecht, B. (2013). Polyhedron 49, 67–73. CrossRef CAS Google Scholar
Priyadharshini, S., Veilumuthu, P. G., Godwin Christopher, J. & Anitha, K. (2025). J. Mol. Liq. 431, 127773. CrossRef Google Scholar
Rogalewicz, B., Świątkowski, M., Iwan, M., Michalczuk, M., Kubik, J., Korga-Plewko, A., Pitucha, M., Gajda, A., Ścieszka, S., Kordialik-Bogacka, E., Stępniak, A., Kubicki, J. & Czylkowska, A. (2025). J. Inorg. Biochem. 271, 112962. CrossRef PubMed Google Scholar
Schmitt, B., Gerber, T., Hosten, E. & Betz, R. (2011). Acta Cryst. E67, o2206–o2207. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Schmitt, B., Gerber, T. I. A., Hosten, E. C. & Betz, R. (2014). Z. Kristallogr. New Cryst. Struct. 229, 470–472. CrossRef CAS Google Scholar
Schmitt, B., Gerber, T. I. A., Hosten, E. C. & Betz, R. (2015a). Z. Kristallogr. New Cryst. Struct. 230, 47–49. CrossRef CAS Google Scholar
Schmitt, B., Gerber, T. I. A., Hosten, E. C. & Betz, R. (2015b). Z. Kristallogr. New Cryst. Struct. 230, 69–70. CrossRef CAS Google Scholar
Shan, S., Wang, X.-J., Hu, W.-X. & Xu, D.-J. (2004). Acta Cryst. E60, o1954–o1956. Web of Science CSD CrossRef IUCr Journals Google Scholar
Sheikh, A. H., Choudhury, R. B., Deb, V. K., Shahnowaz, T., Mukherjee, S., Pramanick, K., Kaminsky, W., Choudhury, N. A., Roy, S., Shukla, R., Gurbanov, A. V., Mahmoudi, G. & Adhikari, S. (2025). New J. Chem. 49, 7900–7909. CrossRef CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Sheldrick, G. M. (2015). Acta Cryst. C71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Spek, A. L. (2020). Acta Cryst. E76, 1–11. Web of Science CrossRef IUCr Journals Google Scholar
Watson, W. H., Galloy, J., Grossie, D. A., Voegtle, F. & Mueller, W. M. (1984). J. Org. Chem. 49, 347–353. CrossRef CAS Google Scholar
Yumata, N., Gerber, T. & Betz, R. (2011b). Acta Cryst. E67, m1337. CrossRef IUCr Journals Google Scholar
Yumata, N., Gerber, T., Hosten, E. & Betz, R. (2011a). Acta Cryst. E67, o2175. CrossRef IUCr Journals 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.