Crystal structure and Hirshfeld surface analysis of (S)-N-methyl-1-phenyl­ethan-1-aminium chloride

Kirchhoff, J.-L.; Brieger, L.; Strohmann, C.

doi:10.1107/S2056989021013645

research communications

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 78| Part 2| February 2022| Pages 130-134

https://doi.org/10.1107/S2056989021013645

Open

access

Crystal structure and Hirshfeld surface analysis of (S)-N-methyl-1-phenylethan-1-aminium chloride

Jan-Lukas Kirchhoff,^a Lukas Brieger ^a and Carsten Strohmann ^a ^*

^aTechnische Universität Dortmund, Fakultät Chemie und Chemische Biologie, Otto-Hahn-Strasse 6, 44227 Dortmund, Germany
^*Correspondence e-mail: carsten.strohmann@tu-dortmund.de

Edited by D. Chopra, Indian Institute of Science Education and Research Bhopal, India (Received 29 November 2021; accepted 28 December 2021; online 7 January 2022)

The title compound C₉H₁₄N⁺·Cl⁻, (1), can be synthesized starting from (S)-N-methyl-1-phenylethan-1-amine (2). Compound 2 upon addition of HCl·Et₂O leads to crystallization of compound 1 as colorless blocks. The configuration of compound 1 is stable as well as preserved in space group P2₁2₁2₁. Ammonium chlorides, like the title compound, are often observed as undesirable by-products in aminosilylation of chlorosilanes. Additionally, these by-products are usually soluble in selected organic solvents, which require difficult separation steps. Therefore, detailed studies on structural features and intermolecular interactions performed by Hirshfeld atom refinement (HAR) using NoSpherA2 [Kleemiss et al. (2021 ). Chem. Sci. 12, 1675–1692] and Hirshfeld surface analysis were used to address structural issues on that separation problem.

Keywords: crystal structure; chiral amines; Hirshfeld atom refinement (HAR); NoSpherA2; separation strategies; Hirshfeld surface analysis.

CCDC reference: 2132333

1. Chemical context

Chiral amines represent a central role in synthetic chemistry, finding more and more applications in asymmetric syntheses (Liu et al., 2020 ). In addition to asymmetric inductions on double bonds of organic molecules, they also serve as amination reagents of chlorosilanes (Wannagat & Klemke, 1979 ; Veith, 1987 ). Next to methoxysilanes, those chlorosilanes are the most important starting compounds for the synthesis of aminosilanes (Bauer & Strohmann, 2012 ). The title compound (S)-N-methyl-1-phenylethan-1-aminium chloride (1), represents the ammonium chloride salt of (S)-N-methyl-1-phenylethan-1-amine (2), which is often used as a chiral auxiliary in reagent inductions on prochiral silicon centers (Bauer & Strohmann, 2014 ). Compound 2 and its derivatives are characterized by well-known methods of enantiomeric resolution (Ingersoll, 1937 ; Baltzly & Russell, 1953 ). The synthesis of Si–N-functionalized silanes starting from chlorosilanes in combination with amines is also very well known (Sakaba et al., 2015 ; Zibula et al., 2020 ). However, the formation of the undesirable ammonium chloride is often observed as a by-product, which is also soluble in small amounts of selected organic solvents. The corresponding reaction is shown in the scheme below.

Compound 1 was crystallized for the first time and may be used to analyze supramolecular interactions, in particular those which could be directly related to the aforementioned separation problem. To describe the positions of the hydrogen atoms as accurately as possible, all hydrogen atoms were refined anisotropically by NoSpherA2 (Kleemiss et al., 2021).

2. Structural commentary

Compound 1 crystallized from diethyl ether at room temperature in the shape of colorless blocks with orthorhombic (P2₁2₁2₁) symmetry. The absolute configuration of the chiral ammonium chloride 1 in the measured crystal can be assigned with the (S)-configuration using the Cahn–Ingold–Prelog (CIP) prioritization (Cahn et al., 1966 ); the Flack parameter amounts to −0.03 (3) (Flack, 1983 ). The molecular structure of 1 is illustrated in Fig. 1. All hydrogen atoms except H1b were refined using NoSpherA2 (Kleemiss et al., 2021). No particularly large ellipsoids are observed here, whereas hydrogen atom H1b is highly deformed and distorted in anisotropic treatment. The substantial contribution from deformation of the electron density involving the chloride ion, which also includes polarization, may be responsible for the observed ellipsoidal shape of the hydrogen atom H1b. Thus it is difficult to deconvolute the effect of thermal motion in this interaction and to model the same satisfactorily. Therefore, the hydrogen atom H1b was isotropically modeled for following analyses as shown in Fig. 1(a).

Figure 1
(a) The molecular structure of 1 illustrated showing 50% displacement ellipsoids including. All hydrogen atoms except H1b were refined by Hirshfeld atom refinement (HAR) performed by NoSpherA2 implementation in OLEX2. (b) Visualization of the calculated structure of compound 1 with Molekel 4.3 performed at the M062X/6–31+G(d) levels.

In the literature, known Csp³—N bond lengths are in a range of 1.4816 (4) Å (N1—C3) and 1.5034 (4) Å (N1—C3), which are typical for most structurally analyzed ammonium salts (Allen et al., 1987 ). To discuss the bond distances in the solid-state structure, quantum chemical calculations were performed at the level M062X/6-31+G(d), which gave comparable results. The molecular structure of compound 1 in the gas phase is shown in Fig. 1(b). All conformations were taken from the solid-state structure at the start of the optimization. The result of the calculation provides smaller Csp³—N bond lengths than from the solid-state structure in principle. The calculated bond lengths are 1.4762 Å (N1—C3) and 1.4946 Å (N1—C2).

Hydrogen-bond lengths as well as associated angles are shown in Table 1. The calculated hydrogen bond of 1.7051 Å (N1—H1b⋯Cl1) was not described sufficiently with the addition of the used potential and basis set. Therefore, a large deviation can be observed from the analyzed distance compared to the crystal structure. Further analyses concerning supramolecular interactions are discussed in detail in the next section.

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1a⋯Cl1ⁱ	1.029 (6)	2.088 (6)	3.1075 (3)	170.4 (5)
N1—H1b⋯Cl1	1.031 (6)	2.062 (6)	3.0925 (4)	177.8 (5)
Symmetry code: (i) $[-x+1, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]$ .

The stereogenic carbon center features a tetrahedral geometry, which is slightly distorted as shown by the angle of 107.44 (2)° (C1—C2—N1). However, the geometric distortion of a tetrahedral carbon center has been observed in many compounds with different substituents (Xu et al., 2000 ).

3. Supramolecular features

The crystal packing along the a-axis of compound 1 is shown in Fig. 2. To analyze supramolecular packing interactions in more detail, Hirshfeld surface analyses were performed. The Hirshfeld surface mapped over d_norm in the range from −0.5483 to 1.5337 arbitrary units generated by CrystalExplorer2021 (Spackman et al., 2021 ; Turner et al., 2017 ) is shown in Fig. 3. Fingerprint plots, which are illustrated in Fig. 4, were also generated by CrystalExplorer2021. First, the crystal structure was analyzed to clarify for the influence of hydrogen bonds. Particularly noticeable on the Hirshfeld surface are C—H⋯Cl contacts, which are shown in red on the potential surface in Fig. 3.

Figure 2
A view along the a-axis direction of the crystal packing of compound 1. Selected hydrogen-bond lengths (in Å) are indicated.

Figure 3
Hirshfeld surface of compound 1 generated by CrystalExplorer21.

Figure 4
Two-dimensional fingerprint plots of compound 1 showing close contacts of (a) all contributions in the crystal and those delineated into (b) H⋯H, (c) C⋯H/H⋯C and (d) Cl⋯H/H⋯Cl-interactions. Symmetry codes: (i) $[{1\over 2}]$ − x, −y, $[{1\over 2}]$ + z; (ii) −x, $[{1\over 2}]$ + y, $[{1\over 2}]$ − z; (iii) $[{1\over 2}]$ + x, $[{1\over 2}]$ − y, −z.

The primary share of 66.9% can be assigned to weak van der Waals H⋯H contacts, which should play a minor role in terms of crystal packing. In contrast, Cl⋯H/H⋯Cl contacts in particular, which represent the smallest fraction of interactions (15.1%), however represent the most intense contacts on the surface (Fig. 4). Hydrogen bonds with a length up to 2.200 Å are shown in Table 1. The analysis of the hydrogen-bonding network leads to the result that all hydrogen bridges can be assigned to one graph-set motif. Both hydrogen bonds in Table 1 can be assigned D₁¹ (2) (Etter et al., 1990 ).

In addition to the influence of C—H⋯Cl contacts, the influence of possible π-interactions was analyzed by CrystalExplorer2021. As can be seen in Fig. 2, compound 1 forms one-dimensional chains along the a-axis direction in the crystal structure. These can be attributed to the strong C—H⋯Cl interactions already mentioned, as well as additional C—H⋯π interactions, which are illustrated in Fig. 2. Consequently, these π-interactions could contribute a significant part to the crystal packing structure. However, C—H⋯π contacts are only weakly visible on the Hirshfeld surface.

4. Database survey

There are some crystallographically characterized examples based on the structure of compound 1. Depicted examples found in Cambridge Structural Database (WebCSD, November 2021; Groom et al., 2016 ) include N,N′-bis(1-phenylethyl)cyclohex-4-ene-1,2-diaminium dichloride monohydrate, C₂₂H₃₂N₂O₂Cl (CSD refcode KIZHIM; Savoia et al., 2014 ), 2-(ethoxycarbonyl)-N-(1-phenylethyl)cyclopentan-1-aminium chloride, C₁₆H₂₄ClNO₂ (BAJSIS; Lee et al., 2021 ), N-[(R)-(cyclohexan-(R)-2-ol)]-(R)-a-methylbenzyl ammonium chloride, C₁₄H₂₂NOCl (TAYWOF; Barbaro et al., 1996 ), [2-(1H-inden-3-yl)ethyl][(1R)-1-phenylethyl]ammonium chloride, C₁₉H₂₂NCl (GOGCUC; Ross et al., 2015 ), cis-(aR,1R,2S)-2-methoxy-1-(1-phenylethylamino)cyclopentanecarboxamide hydrochloride, C₁₅H₂₃N₂O₂Cl (NAFZIE; Meyer et al., 2004 ). A comparison with the last two structures mentioned shows that compound 1 is characterized by particularly short C—H⋯Cl (2.0-2.1 Å) hydrogen bonds. The smallest observed hydrogen bond of the two literature known compounds amounts to 2.2 Å. These longer distances could be due to the more sterically demanding substituents, which are less pronounced in compound 1. Moreover, in terms of the crystal packing, the compounds do not exhibit one-dimensional chains, as C—H⋯π contacts were not observed. This unique feature of (S)-N-methyl-1-phenylethan-1-aminium chloride (1), which does not appear in the literature compounds, could again be attributed to the steric crowding of the other compounds.

5. Synthesis and crystallization

The reaction scheme for the synthesis of compound 1 is illustrated in the scheme below. (S)-N-methyl-1-phenylethan-1-amine (2) (1.48 mmol) was dissolved in diethyl ether (5 mL). A 2 M solution of HCl in diethyl ether (1.78 mmol) was added dropwise. The solution was stored at 298 K for three days. Afterwards all volatile compounds were removed and the raw product was washed with cold n-pentane (1 ml). (S)-N-methyl-1-phenylethan-1-aminium chloride (1) was isolated as colorless crystalline plates.

¹H NMR (300.13 MHz, CDCl₃): δ = 1.88 (s, 3H, CHCH₃), 2.46 (s, 3H, NCH₃), 1.65–1.90 (br. s, 1H, CHCH₃), 7.38–7.45 (m, 3H, CH_{ar, meta}, CH_{ar, para}), 7.60 (d, 2H, ³J_H–H = 3.9 Hz, CH_{ar, ortho}), 9.78 (br. s, 1H, NH⋯Cl), 10.17 (br. s, 1H, NH⋯Cl) ppm.

{1H}¹³C NMR (100.64 MHz, CDCl₃): δ = 20.5 (1C, CHCH₃), 31.0 (1C, CHCH₃), 60.2 (2C, NCH₃), 127.9 (2C, C_orthoH_ar), 129.5 (2C, C_metaH_ar), 135.6 (1C, C_paraH_ar) ppm.

CHN analysis: calculated: C = 62.97%, H = 8.22% N = 8.16%; Found: C = 62.6%, H = 7.9%, N = 7.8%.

R_f: (CH₂Cl₂ / MeOH; 10:1) = 0.20.

6. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2. All H atoms except H1b were refined freely using independent values of each U_iso(H). Hirshfeld atom refinements (HAR; Fugel et al., 2018 ) was performed with the NoSpherA2 (Kleemiss et al., 2021) implementation in OLEX2 (Dolomanov et al., 2009 ), using the restricted Khom–Sham method with the PBE-functional (Perdew et al., 1996 ) and basis set def2-SVP (Weigend & Ahlrichs, 2005 ). For the HAR approach, all H atoms except H1b were refined anisotropically and independently. Atom H1b was refined freely without using HAR by NoSpherA2.

Table 2
Experimental details

Crystal data
Chemical formula	C₉H₁₄N⁺·Cl⁻
M_r	171.67
Crystal system, space group	Orthorhombic, P2₁2₁2₁
Temperature (K)	100
a, b, c (Å)	6.7723 (6), 7.1806 (5), 20.542 (2)
V (Å³)	998.96 (16)
Z	4
Radiation type	Mo Kα
μ (mm⁻¹)	0.32
Crystal size (mm)	0.48 × 0.39 × 0.37

Data collection
Diffractometer	Bruker D8 Venture
Absorption correction	Multi-scan (SADABS; Bruker, 2021 )
T_min, T_max	0.602, 0.650
No. of measured, independent and observed [I ≥ 2σ(I)] reflections	45327, 4856, 4785
R_int	0.026
(sin θ/λ)_max (Å⁻¹)	0.834

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.011, 0.024, 1.14
No. of reflections	4856
No. of parameters	221
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.14, −0.22
Absolute structure	Hooft et al., 2010
Absolute structure parameter	−0.011 (7)
Computer programs: APEX4 and SAINT (Bruker, 2021), SHELXS (Sheldrick, 2008 ), SHELXL (Sheldrick, 2015 ), OLEX2 (Dolomanov et al., 2009), CrystalExplorer21 (Spackman et al., 2021; Turner et al., 2017), publCIF (Westrip, 2010 ), Mercury (Macrae et al., 2020 ), NoSpherA2 (Kleemiss et al., 2021), GaussView 6.016 (Frisch et al., 2016 ), Gaussian 09 (Frisch et al., 2016), Molekel 4.3 (Flükiger et al., 2000 ) and PLATON (Spek, 2020 ).

Supporting information

CCDC reference: 2132333

Crystal structure: contains datablocks global, I. DOI: https://doi.org/10.1107/S2056989021013645/dx2041sup1.cif

Supporting information file. DOI: https://doi.org/10.1107/S2056989021013645/dx2041Isup2.cml

checkCIF report

Computing details top

Cell refinement: SAINT (Bruker, 2021); data reduction: APEX4 (Bruker, 2021); program(s) used to solve structure: SHELXS (Sheldrick, 2008); program(s) used to refine structure: SHELXL (Sheldrick, 2015); molecular graphics: OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: APEX4 (Bruker, 2021), CrystalExplorer21 (Spackman et al., 2021; Turner et al., 2017), publCIF (Westrip, 2010), Mercury (Macrae et al., 2020), NoSpherA2 (Kleemiss et al., 2021), GaussView 6.016 (Frisch et al., 2016), Gaussian 09 Revision A.02 (Frisch et al., 2016), Molekel 4.3 (Flükiger et al., 2000), PLATON (Spek, 2020).

(S)-N-Methyl-1-phenylethan-1-aminium chloride top

Crystal data top

C₉H₁₄N⁺·Cl⁻	D_x = 1.141 Mg m⁻³
M_r = 171.67	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, P2₁2₁2₁	Cell parameters from 1282 reflections
a = 6.7723 (6) Å	θ = 3.2–30.5°
b = 7.1806 (5) Å	µ = 0.32 mm⁻¹
c = 20.542 (2) Å	T = 100 K
V = 998.96 (16) Å³	Block, colourless
Z = 4	0.48 × 0.39 × 0.37 mm
F(000) = 368.574

Data collection top

Bruker D8 Venture diffractometer	4785 reflections with I ≥ 2σ(I)
Detector resolution: 10.4167 pixels mm^-1	R_int = 0.026
ω and φ scans	θ_max = 36.4°, θ_min = 3.0°
Absorption correction: multi-scan (SADABS; Bruker, 2021)	h = −11→11
T_min = 0.602, T_max = 0.650	k = −11→11
45327 measured reflections	l = −34→34
4856 independent reflections

Refinement top

Refinement on F²	Primary atom site location: iterative
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F² > 2σ(F²)] = 0.011	w = 1/[σ²(F_o²) + (0.0056P)² + 0.0168P] where P = (F_o² + 2F_c²)/3
wR(F²) = 0.024	(Δ/σ)_max = −0.001
S = 1.14	Δρ_max = 0.14 e Å⁻³
4856 reflections	Δρ_min = −0.22 e Å⁻³
221 parameters	Absolute structure: Hooft et al., 2010
0 restraints	Absolute structure parameter: −0.011 (7)
0 constraints

Special details top

Refinement. Refinement using NoSpherA2, an implementation of NOn-SPHERical Atom-form-factors in Olex2. 2021 NoSpherA2 implementation of HAR makes use of tailor-made aspherical atomic form factors calculated on-the-fly from a Hirshfeld-partitioned electron density (ED) - not from spherical-atom form factors. Hydrogen atom H1b was refined isotropically and freely without using calculated ED. Distances and Angles concerning H1b were evaluated by PLATON.

The ED is calculated from a gaussian basis set single determinant SCF wavefunction - either Hartree-Fock or DFT using selected funtionals - for a fragment of the crystal. This fragment can be embedded in an electrostatic crystal field by employing cluster charges or modelled using implicit solvation models, depending on the software used. The following options were used: SOFTWARE: Olex2 1.5 alpha, B1387_0m.wfn as wfn-file, PARTITIONING: NoSpherA2, INT ACCURACY: Normal, METHOD: PBE, BASIS SET: def2-SVP, CHARGE: 0, MULTIPLICITY: 1, DATE: 2021.12.08_16:09:30.

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

	x	y	z	U_iso*/U_eq
Cl1	0.592521 (11)	0.543691 (10)	0.179385 (3)	0.016339 (15)
N1	0.41684 (4)	0.47620 (3)	0.316327 (11)	0.01307 (4)
H1a	0.4079 (9)	0.3344 (8)	0.3230 (3)	0.0295 (14)
H1b	0.4763 (8)	0.4952 (8)	0.2706 (3)	0.0192 (14)*
C1	0.09588 (5)	0.45714 (5)	0.262760 (15)	0.01939 (5)
H1c	0.1708 (9)	0.4643 (10)	0.2151 (3)	0.0406 (16)
H1d	0.0800 (10)	0.3125 (8)	0.2759 (3)	0.0423 (17)
H1e	−0.0497 (8)	0.5137 (10)	0.2588 (3)	0.0407 (17)
C2	0.21347 (4)	0.56000 (4)	0.314781 (13)	0.01314 (4)
H2	0.2339 (7)	0.7048 (6)	0.3009 (2)	0.0231 (12)
C3	0.55360 (4)	0.55695 (5)	0.365038 (15)	0.01794 (5)
H3a	0.5664 (10)	0.7052 (8)	0.3574 (3)	0.0433 (17)
H3b	0.4987 (8)	0.5322 (10)	0.4134 (3)	0.0409 (16)
H3c	0.6979 (9)	0.4918 (9)	0.3592 (3)	0.0420 (18)
C4	0.11585 (4)	0.55281 (5)	0.380803 (13)	0.01459 (4)
C5	0.10068 (6)	0.38632 (5)	0.415554 (17)	0.02390 (6)
H5	0.1630 (10)	0.2592 (8)	0.3963 (3)	0.0438 (17)
C6	0.00496 (6)	0.38292 (6)	0.47550 (2)	0.02996 (8)
H6	−0.0039 (10)	0.2515 (11)	0.5014 (4)	0.062 (2)
C7	−0.07980 (5)	0.54394 (7)	0.500661 (15)	0.02628 (6)
H7	−0.1515 (9)	0.5389 (10)	0.5478 (3)	0.0464 (17)
C8	−0.06743 (5)	0.70924 (5)	0.465812 (16)	0.02150 (6)
H8	−0.1335 (10)	0.8354 (8)	0.4853 (3)	0.0462 (18)
C9	0.03231 (5)	0.71413 (5)	0.406506 (15)	0.01653 (5)
H9	0.0436 (8)	0.8430 (8)	0.3791 (3)	0.0330 (15)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Cl1	0.02160 (3)	0.01263 (2)	0.01478 (2)	−0.00082 (3)	0.00376 (2)	−0.00023 (2)
N1	0.01278 (8)	0.01374 (9)	0.01268 (8)	−0.00043 (8)	0.00098 (8)	−0.00014 (8)
H1a	0.028 (3)	0.022 (3)	0.038 (4)	−0.001 (3)	−0.002 (3)	0.005 (3)
C1	0.01783 (11)	0.02068 (12)	0.01965 (11)	−0.00110 (14)	−0.00559 (11)	−0.00209 (11)
H1c	0.034 (3)	0.067 (5)	0.021 (3)	−0.008 (4)	−0.006 (3)	−0.008 (3)
H1d	0.051 (4)	0.033 (4)	0.043 (4)	−0.011 (3)	−0.024 (4)	0.002 (3)
H1e	0.020 (3)	0.055 (5)	0.047 (4)	0.007 (3)	−0.014 (3)	−0.004 (3)
C2	0.01310 (9)	0.01303 (10)	0.01329 (10)	−0.00042 (8)	−0.00041 (8)	0.00049 (9)
H2	0.023 (3)	0.016 (3)	0.031 (3)	−0.003 (2)	−0.003 (2)	0.003 (2)
C3	0.01450 (11)	0.01998 (13)	0.01934 (12)	−0.00051 (10)	−0.00309 (9)	−0.00190 (11)
H3a	0.049 (4)	0.016 (3)	0.065 (4)	−0.005 (3)	−0.015 (4)	−0.003 (3)
H3b	0.030 (3)	0.065 (5)	0.028 (3)	−0.009 (4)	−0.001 (3)	0.001 (3)
H3c	0.026 (3)	0.059 (5)	0.041 (4)	0.015 (3)	−0.003 (3)	−0.015 (3)
C4	0.01291 (10)	0.01579 (11)	0.01505 (10)	0.00125 (10)	0.00171 (8)	0.00135 (10)
C5	0.02478 (14)	0.02138 (14)	0.02555 (14)	0.00664 (13)	0.01142 (13)	0.00891 (12)
H5	0.059 (4)	0.028 (3)	0.045 (4)	0.009 (3)	0.020 (3)	0.014 (3)
C6	0.02922 (17)	0.03372 (19)	0.02696 (17)	0.00858 (15)	0.01400 (14)	0.01358 (15)
H6	0.071 (5)	0.050 (4)	0.066 (4)	0.026 (4)	0.034 (4)	0.036 (4)
C7	0.02098 (13)	0.03984 (18)	0.01803 (12)	0.00485 (17)	0.00607 (11)	0.00307 (14)
H7	0.049 (4)	0.062 (4)	0.028 (3)	0.005 (4)	0.020 (3)	0.005 (3)
C8	0.01775 (13)	0.02930 (15)	0.01743 (12)	0.00201 (12)	0.00142 (10)	−0.00627 (12)
H8	0.058 (5)	0.036 (4)	0.045 (4)	0.009 (3)	0.016 (4)	−0.011 (3)
C9	0.01530 (11)	0.01815 (13)	0.01614 (11)	0.00065 (10)	−0.00044 (9)	−0.00345 (10)
H9	0.026 (3)	0.034 (3)	0.039 (3)	0.001 (3)	0.006 (3)	0.003 (3)

Geometric parameters (Å, º) top

N1—H1a	1.029 (6)	C3—H3c	1.090 (6)
N1—H1b	1.031 (6)	C4—C5	1.3962 (4)
N1—C2	1.5034 (4)	C4—C9	1.3931 (4)
N1—C3	1.4816 (4)	C5—H5	1.080 (6)
C1—H1c	1.104 (6)	C5—C6	1.3919 (5)
C1—H1d	1.079 (6)	C6—H6	1.085 (7)
C1—H1e	1.070 (5)	C6—C7	1.3905 (6)
C1—C2	1.5237 (4)	C7—H7	1.084 (5)
C2—H2	1.087 (4)	C7—C8	1.3886 (6)
C2—C4	1.5097 (4)	C8—H8	1.087 (6)
C3—H3a	1.080 (6)	C8—C9	1.3935 (5)
C3—H3b	1.075 (5)	C9—H9	1.086 (6)

H1b—N1—H1a	106.0 (5)	H3c—C3—N1	108.5 (3)
C2—N1—H1a	110.2 (3)	H3c—C3—H3a	109.6 (5)
C2—N1—H1b	106.6 (3)	H3c—C3—H3b	109.9 (4)
C3—N1—H1a	109.5 (3)	C5—C4—C2	121.39 (3)
C3—N1—H1b	108.6 (3)	C9—C4—C2	119.33 (3)
C3—N1—C2	115.49 (2)	C9—C4—C5	119.23 (3)
H1d—C1—H1c	108.3 (5)	H5—C5—C4	120.5 (3)
H1e—C1—H1c	109.8 (4)	C6—C5—C4	120.11 (3)
H1e—C1—H1d	107.0 (5)	C6—C5—H5	119.4 (3)
C2—C1—H1c	111.1 (3)	H6—C6—C5	118.4 (4)
C2—C1—H1d	110.0 (3)	C7—C6—C5	120.44 (4)
C2—C1—H1e	110.6 (3)	C7—C6—H6	121.2 (4)
C1—C2—N1	107.44 (2)	H7—C7—C6	119.3 (4)
H2—C2—N1	105.8 (3)	C8—C7—C6	119.62 (3)
H2—C2—C1	110.3 (3)	C8—C7—H7	121.1 (4)
C4—C2—N1	111.62 (2)	H8—C8—C7	119.9 (3)
C4—C2—C1	112.62 (2)	C9—C8—C7	120.10 (3)
C4—C2—H2	108.9 (2)	C9—C8—H8	120.0 (3)
H3a—C3—N1	109.7 (3)	C8—C9—C4	120.48 (3)
H3b—C3—N1	110.1 (3)	H9—C9—C4	118.9 (3)
H3b—C3—H3a	109.0 (5)	H9—C9—C8	120.6 (3)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1a···Cl1ⁱ	1.029 (6)	2.088 (6)	3.1075 (3)	170.4 (5)
N1—H1b···Cl1	1.031 (6)	2.062 (6)	3.0925 (4)	177.8 (5)

Symmetry code: (i) −x+1, y−1/2, −z+1/2.

Acknowledgements

J-LK, LB and CS thank the Fonds der Chemischen Industrie for two doctoral fellowships.

References

Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19. CrossRef Web of Science Google Scholar
Baltzly, R. & Russell, P. B. (1953). J. Am. Chem. Soc. 75, 5598–5602. CrossRef CAS Web of Science Google Scholar
Barbaro, P., Bianchini, C. & Sernau, V. (1996). Tetrahedron Asymmetry, 7, 843–850. CSD CrossRef CAS Web of Science Google Scholar
Bauer, J. O. & Strohmann, C. (2012). Chem. Commun. 48, 7212–7214. Web of Science CSD CrossRef CAS Google Scholar
Bauer, J. O. & Strohmann, C. (2014). Angew. Chem. Int. Ed. 53, 8167–8171. Web of Science CSD CrossRef CAS Google Scholar
Bruker (2021). APEX4, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Cahn, R. S., Ingold, C. & Prelog, V. (1966). Angew. Chem. Int. Ed. Engl. 5, 385–415. CrossRef CAS Web of Science Google Scholar
Dolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339–341. Web of Science CrossRef CAS IUCr Journals 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
Flack, H. D. (1983). Acta Cryst. A39, 876–881. CrossRef CAS Web of Science IUCr Journals Google Scholar
Flükiger, P., Lüthi, H. P., Portmann, S. & Weber, J. (2000). MOLEKEL 4.3. Swiss Center for Scientific Computing, Manno, Switzerland. Google Scholar
Frisch, M. J., Trucks, G. W., Schlegel, H. B., Scuseria, G. E., Robb, M. A., Cheeseman, J. R., Scalmani, G., Barone, V., Petersson, G. A., Nakatsuji, H., Li, X., Caricato, M., Marenich, A., Bloino, J., Janesko, B. G., Gomperts, R., Mennucci, B., Hratchian, H. P., Ortiz, J. V., Izmaylov, A. F., Sonnenberg, J. L., Williams-Young, D., Ding, F., Lipparini, F., Egidi, F., Goings, J., Peng, B., Petrone, A., Henderson, T., Ranasinghe, D., Zakrzewski, V. G., Gao, J., Rega, N., Zheng, G., Liang, W., Hada, M., Ehara, M., Toyota, K., Fukuda, R., Hasegawa, J., Ishida, M., Nakajima, T., Honda, Y., Kitao, O., Nakai, H., Vreven, T., Throssell, K., Montgomery, J. A. Jr, Peralta, J. E., Ogliaro, F., Bearpark, M., Heyd, J. J., Brothers, E., Kudin, K. N., Staroverov, V. N., Keith, T., Kobayashi, R., Normand, J., Raghavachari, K., Rendell, A., Burant, J. C., Iyengar, S. S., Tomasi, J., Cossi, M., Millam, J. M., Klene, M., Adamo, C., Cammi, R., Ochterski, J. W., Martin, R. L., Morokuma, K., Far kas, O., Foresman, J. B. & Fox, D. J. (2016). Gaussian 09. Revision A.02. Gaussian, Inc., Wallingford, CT, USA. Google Scholar
Fugel, M., Jayatilaka, D., Hupf, E., Overgaard, J., Hathwar, V. R., Macchi, P., Turner, M. J., Howard, J. A. K., Dolomanov, O. V., Puschmann, H., Iversen, B. B., Bürgi, H.-B. & Grabowsky, S. (2018). IUCrJ, 5, 32–44. Web of Science CSD CrossRef CAS PubMed IUCr Journals 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
Hooft, R. W. W., Straver, L. H. & Spek, A. L. (2010). J. Appl. Cryst. 43, 665–668. Web of Science CrossRef CAS IUCr Journals Google Scholar
Ingersoll, W. A. (1937). Org. Synth. 17, 80. Google Scholar
Kleemiss, F., Dolomanov, O. V., Bodensteiner, M., Peyerimhoff, N., Midgley, L., Bourhis, L. J., Genoni, A., Malaspina, L. A., Jayatilaka, D., Spencer, J. L., White, F., Grundkötter-Stock, B., Steinhauer, S., Lentz, D., Puschmann, H. & Grabowsky, S. (2021). Chem. Sci. 12, 1675–1692. Web of Science CSD CrossRef CAS Google Scholar
Lee, H.-S., Kim, J. & Lim, D. (2021). CSD Communication (refcode: BAJSIS). CCDC, Cambridge, England. Google Scholar
Liu, Y., Yue, X., Li, L., Li, Z., Zhang, L., Pu, M., Yang, Z., Wang, C., Xiao, J. & Lei, M. (2020). Inorg. Chem. 59, 8404–8411. Web of Science CrossRef CAS PubMed 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
Meyer, U., Breitling, E., Bisel, P. & Frahm, A. W. (2004). Tetrahedron Asymmetry, 15, 2029–2037. Web of Science CSD CrossRef CAS Google Scholar
Perdew, J. P., Burke, K. & Ernzerhof, M. (1996). Phys. Rev. Lett. 77, 3865–3868. CrossRef PubMed CAS Web of Science Google Scholar
Ross, J. H., Rohjans, S. H., Schmidtmann, M. & Doye, S. (2015). Arkivoc, 2015, 76–92. Web of Science CSD CrossRef Google Scholar
Sakaba, H., Tonosaki, H., Isozaki, K. & Kwon, E. (2015). Organometallics, 34, 1029–1037. Web of Science CSD CrossRef CAS Google Scholar
Savoia, D., Balestri, D., Grilli, S. & Monari, M. (2014). Eur. J. Org. Chem. 2014, 1907–1914. Web of Science CSD 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
Spackman, P. R., Turner, M. J., McKinnon, J. J., Wolff, S. K., Grimwood, D. J., Jayatilaka, D. & Spackman, M. A. (2021). J. Appl. Cryst. 54, 1006–1011. Web of Science CrossRef CAS IUCr Journals Google Scholar
Spek, A. L. (2020). Acta Cryst. E76, 1–11. Web of Science CrossRef IUCr Journals Google Scholar
Turner, M. J., McKinnon, J. J., Wolff, S. K., Grimwood, D. J., Spackmann, P. R., Jayatilaka, D. & Spackman, M. A. (2017). CrystalExplorer17, University of Western Australia. Google Scholar
Veith, M. (1987). Angew. Chem. Int. Ed. Engl. 26, 1–14. CrossRef Web of Science Google Scholar
Wannagat, U. & Klemke, S. (1979). Monatsh. Chem. 110, 2868–2881. Google Scholar
Weigend, F. & Ahlrichs, R. (2005). Phys. Chem. Chem. Phys. 7, 3297–3305. Web of Science CrossRef PubMed CAS Google Scholar
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. Web of Science CrossRef CAS IUCr Journals Google Scholar
Xu, Z., Zhao, C. & Lin, Z. (2000). J. Chem. Soc. Perkin Trans. 2, pp. 2319–2323. Web of Science CrossRef Google Scholar
Zibula, L., Achternbosch, M., Wattenberg, J., Otte, F. & Strohmann, C. (2020). Z. Anorg. Allg. Chem. 646, 978–984. Web of Science CSD CrossRef CAS 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.