(S)-2-(Pyrrolidinium-2-ylmethyl­sulfan­yl)pyridinium dibromide

Abstract

In the title compound, C₁₀H₁₆N₂S²⁺·2Br⁻, the pyrrolidine ring displays an envelope conformation, with the flap C atom lying 0.484 (5) Å out of the plane of the rest of the pyrrolidine ring. The thio­ether group connects the pyridine ring and the 2-methyl­pyrrolidine group. Both pyrrolidine NH bonds form hydrogen bonds to the bromide anions. These hydrogen bonds link the cations and anions in a helical chain along the c axis.

Related literature

For related literature, see: Ishii et al. (2004 ▶); Xu et al. (2007 ▶); Larson (1970 ▶).

Experimental

Crystal data

• C₁₀H₁₆N₂S²⁺·2Br⁻

• M _r = 356.12

• Trigonal,

• a = 8.9892 (9) Å

• c = 15.4567 (14) Å

• V = 1081.66 (18) ų

• Z = 3

• Mo Kα radiation

• μ = 5.76 mm⁻¹

• T = 296 (1) K

• 0.35 × 0.30 × 0.23 mm

Data collection

• Rigaku R-AXIS RAPID diffractometer

• Absorption correction: multi-scan (ABSCOR; Higashi,1995 ▶) T _min = 0.162, T _max = 0.266

• 10585 measured reflections

• 3169 independent reflections

• 1902 reflections with F ² > 2.0σ(F ²)

• R _int = 0.061

Refinement

• R[F ² > 2σ(F ²)] = 0.036

• wR(F ²) = 0.108

• S = 1.01

• 3169 reflections

• 138 parameters

• H-atom parameters constrained

• Δρ_max = 0.67 e Å⁻³

• Δρ_min = −0.53 e Å⁻³

• Absolute structure: Flack (1983 ▶), 1037 Friedel pairs

• Flack parameter: 0.017 (2)

Data collection: PROCESS-AUTO (Rigaku, 1998 ▶); cell refinement: PROCESS-AUTO; data reduction: CrystalStructure (Rigaku/MSC, 2004 ▶); program(s) used to solve structure: SIR97 (Altomare et al., 1999 ▶); program(s) used to refine structure: CRYSTALS (Betteridge et al., 2003 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶); software used to prepare material for publication: CrystalStructure.

Supplementary Material

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H2⋯Br1	0.86	2.45	3.278 (7)	163
N1—H3⋯Br1i	0.86	2.43	3.271 (5)	165

Symmetry code: (i) .

supplementary crystallographic information

Comment

In recent years, proline and its derivatives have been studied extensively because of their ability to catalyze a large number of reactions (Ishii et al., 2004). The title compound is a hydrobromide of an ionic compound that was synthesized from L-proline. It was prepared as a kind of ionic organocatalyst for use in the asymmetric Michael addition of carbonyl compounds to nitroalkenes (Xu et al., 2007). The compound consists of two ionic pairs, protonated ammoniums and Br^- anions. The chiral atom C1 has the expected S conformation, and the C1/C3/C4/N1 atoms of pyrrolidine are almost coplanar. The distance of atom C2 to the C1/C3/C4/N1 mean plane is 0.484 (5) Å, while the distance of atom C5 to the plane is 0.865 (9) Å. In addition, the dihedral angle of the C1/N1/C3/C4 mean plane and the pyridine ring is 67.82 (4) °. The thioether group connects the pyridine ring and the 2-methylpyrrolidine group, the torsion angle of C6—S1—C5—C1 is 97.13 (4) °.

Experimental

The title compound was readily synthesized by treating 2-mercaptopyridine with (S)-(+)-2-bromomethylpyrrolidine hydrobromide in MeCN. The compound (S)-(+)-2-bromomethylpyrrolidine hydrobromide was obtained from commercially available L-proline by reduction with NaBH₄ and subsequent bromination with PBr₃. Suitable crystals were obtained by slow evaporation of methanol at room temperature.

Refinement

All H atoms were placed in calculated positions with C—H=0.98 Å (sp), C—H=0.97 Å (sp2), C—H=0.93 Å (aromatic), N—H=0.86 Å and included in the final cycles of refinement as a riding model, with U_iso(H)=1.2U_eq of the carrier atoms.

Figures

Fig. 1.

The asymmetric unit of the title compound, with the atomic labeling scheme. Displacement ellipsoids are drawn at the 40% probability level.

Fig. 2.

Hydrogen bonding in the title compound. Symmetry codes: (i) 1-y, 1+x-y, -1/3+z; (ii) 1-y, 1+x-y, 2/3+z; (iii) -x+y, 1-x, 1/3+z.

Crystal data

C10H16N2S2+·2Br–	Z = 3
Mr = 356.12	F000 = 528.00
Trigonal, P32	Dx = 1.640 Mg m−3
Hall symbol: P 32	Mo Kα radiation λ = 0.71073 Å
a = 8.9892 (9) Å	Cell parameters from 5169 reflections
b = 8.9892 (9) Å	θ = 3.7–27.4º
c = 15.4567 (14) Å	µ = 5.76 mm−1
α = 90º	T = 296 (1) K
β = 90º	Chunk, colorless
γ = 120º	0.35 × 0.30 × 0.23 mm
V = 1081.66 (18) Å3

Data collection

Rigaku R-AXIS RAPID diffractometer	1902 reflections with F2 > 2.0σ(F2)
Detector resolution: 10.00 pixels mm-1	Rint = 0.061
ω scans	θmax = 27.4º
Absorption correction: multi-scan(ABSCOR; Higashi,1995)	h = −11→11
Tmin = 0.162, Tmax = 0.266	k = −11→10
10585 measured reflections	l = −18→20
3169 independent reflections

Refinement

Refinement on F2	(Δ/σ)max = 0.013
R[F2 > 2σ(F2)] = 0.036	Δρmax = 0.67 e Å−3
wR(F2) = 0.108	Δρmin = −0.53 e Å−3
S = 1.01	Extinction correction: Larson (1970) Crystallographic Computing eq. 22
3169 reflections	Extinction coefficient: 385 (18)
138 parameters	Absolute structure: Flack (1983), 1037 Friedel Pairs
H-atom parameters constrained	Flack parameter: 0.017 (2)
w = 1/[0.7600σ(Fo2)]/(4Fo2)

Special details

Refinement. Refinement using all reflections. The weighted R-factor (wR) and goodness of fit (S) are based on F2. R-factor (gt) are based on F. The threshold expression of F2 > 2.0 σ(F2) is used only for calculating R-factor (gt).

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Br1	0.51453 (17)	0.87503 (13)	0.16904 (9)	0.1032 (4)
Br2	0.10004 (11)	0.14553 (10)	0.04190 (9)	0.0605 (2)
S1	0.0678 (3)	0.4733 (3)	0.31433 (12)	0.0671 (7)
N1	0.4515 (9)	0.5570 (8)	0.2963 (3)	0.067 (2)
N2	0.0359 (7)	0.6865 (8)	0.2110 (3)	0.053 (2)
C1	0.3184 (9)	0.4069 (9)	0.2462 (4)	0.053 (2)
C2	0.3905 (11)	0.2858 (11)	0.2388 (5)	0.071 (3)
C3	0.5771 (13)	0.4004 (16)	0.2379 (8)	0.086 (5)
C4	0.6121 (14)	0.5513 (18)	0.2933 (7)	0.077 (5)
C5	0.1434 (10)	0.3261 (10)	0.2879 (4)	0.059 (2)
C6	0.0388 (9)	0.5412 (9)	0.2143 (4)	0.050 (2)
C7	0.0160 (10)	0.4576 (10)	0.1352 (4)	0.059 (2)
C8	−0.0040 (10)	0.5283 (11)	0.0612 (4)	0.066 (2)
C9	−0.0037 (10)	0.6817 (12)	0.0635 (4)	0.067 (2)
C10	0.0138 (10)	0.7576 (11)	0.1396 (4)	0.062 (2)
H1	0.3105	0.4460	0.1880	0.064*
H2	0.4673	0.6511	0.2735	0.080*
H3	0.4187	0.5509	0.3491	0.080*
H7	0.0144	0.3534	0.1330	0.071*
H8	−0.0180	0.4724	0.0087	0.079*
H9	−0.0154	0.7310	0.0130	0.080*
H10	0.0108	0.8593	0.1432	0.074*
H21	0.3560	0.2085	0.2879	0.085*
H22	0.3522	0.2195	0.1857	0.085*
H31	0.6169	0.4377	0.1793	0.103*
H32	0.6343	0.3421	0.2614	0.103*
H41	0.6450	0.5369	0.3511	0.092*
H42	0.7033	0.6564	0.2682	0.092*
H51	0.1477	0.2708	0.3409	0.071*
H52	0.0614	0.2403	0.2484	0.071*
H201	0.0494	0.7403	0.2590	0.064*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
Br1	0.1369 (10)	0.0925 (8)	0.0513 (4)	0.0357 (7)	0.0061 (5)	0.0034 (4)
Br2	0.0670 (6)	0.0510 (5)	0.0630 (4)	0.0292 (4)	0.0073 (4)	0.0054 (3)
S1	0.0848 (16)	0.0802 (16)	0.0554 (11)	0.0555 (14)	0.0125 (10)	0.0098 (10)
N1	0.072 (4)	0.063 (4)	0.053 (3)	0.026 (4)	−0.001 (3)	−0.006 (3)
N2	0.055 (4)	0.055 (4)	0.053 (3)	0.029 (3)	0.011 (2)	0.003 (2)
C1	0.052 (4)	0.046 (4)	0.058 (4)	0.022 (4)	−0.001 (3)	−0.001 (3)
C2	0.055 (5)	0.082 (6)	0.084 (5)	0.040 (5)	0.000 (4)	−0.005 (4)
C3	0.070 (8)	0.088 (10)	0.090 (14)	0.032 (7)	0.004 (7)	0.000 (10)
C4	0.061 (7)	0.083 (14)	0.093 (10)	0.041 (9)	−0.004 (6)	−0.003 (10)
C5	0.051 (5)	0.063 (5)	0.065 (5)	0.030 (4)	0.011 (3)	0.009 (3)
C6	0.056 (5)	0.041 (4)	0.060 (4)	0.030 (4)	0.008 (3)	−0.003 (3)
C7	0.075 (5)	0.056 (5)	0.055 (4)	0.040 (4)	0.002 (3)	0.002 (3)
C8	0.071 (6)	0.078 (6)	0.053 (4)	0.041 (5)	0.001 (3)	0.001 (4)
C9	0.077 (6)	0.082 (6)	0.053 (4)	0.049 (5)	−0.002 (3)	0.002 (4)
C10	0.088 (6)	0.061 (5)	0.050 (4)	0.048 (5)	0.002 (3)	0.009 (3)

Geometric parameters (Å, °)

S1—C5	1.811 (11)	N1—H3	0.860
S1—C6	1.729 (7)	N2—H201	0.860
N1—C1	1.496 (8)	C1—H1	0.980
N1—C4	1.471 (18)	C2—H21	0.970
N2—C6	1.321 (12)	C2—H22	0.970
N2—C10	1.339 (10)	C3—H31	0.970
C1—C2	1.524 (16)	C3—H32	0.970
C1—C5	1.508 (10)	C4—H41	0.970
C2—C3	1.465 (12)	C4—H42	0.970
C3—C4	1.499 (9)	C5—H51	0.970
C6—C7	1.396 (9)	C5—H52	0.970
C7—C8	1.363 (12)	C7—H7	0.930
C8—C9	1.379 (16)	C8—H8	0.930
C9—C10	1.329 (10)	C9—H9	0.930
N1—H2	0.860	C10—H10	0.930
C5—S1—C6	103.5 (4)	C1—C2—H22	110.8
C1—N1—C4	108.0 (8)	C3—C2—H21	110.8
C6—N2—C10	125.8 (6)	C3—C2—H22	110.8
N1—C1—C2	104.4 (7)	H21—C2—H22	109.5
N1—C1—C5	112.6 (6)	C2—C3—H31	110.3
C2—C1—C5	113.7 (6)	C2—C3—H32	110.3
C1—C2—C3	104.2 (8)	C4—C3—H31	110.3
C2—C3—C4	106.2 (11)	C4—C3—H32	110.3
N1—C4—C3	106.5 (8)	H31—C3—H32	109.5
S1—C5—C1	115.3 (6)	N1—C4—H41	110.2
S1—C6—N2	117.7 (5)	N1—C4—H42	110.2
S1—C6—C7	126.9 (7)	C3—C4—H41	110.2
N2—C6—C7	115.4 (7)	C3—C4—H42	110.2
C6—C7—C8	120.2 (9)	H41—C4—H42	109.5
C7—C8—C9	120.7 (7)	S1—C5—H51	108.0
C8—C9—C10	118.4 (8)	S1—C5—H52	108.0
N2—C10—C9	119.5 (10)	C1—C5—H51	108.0
C1—N1—H2	109.8	C1—C5—H52	108.0
C1—N1—H3	109.8	H51—C5—H52	109.5
C4—N1—H2	109.8	C6—C7—H7	119.9
C4—N1—H3	109.8	C8—C7—H7	119.9
H2—N1—H3	109.5	C7—C8—H8	119.7
C6—N2—H201	117.1	C9—C8—H8	119.7
C10—N2—H201	117.1	C8—C9—H9	120.8
N1—C1—H1	108.7	C10—C9—H9	120.8
C2—C1—H1	108.7	N2—C10—H10	120.2
C5—C1—H1	108.7	C9—C10—H10	120.2
C1—C2—H21	110.8
C5—S1—C6—N2	−159.4 (5)	N1—C1—C5—S1	51.7 (8)
C5—S1—C6—C7	21.3 (8)	C2—C1—C5—S1	170.2 (5)
C6—S1—C5—C1	66.8 (5)	C5—C1—C2—C3	−153.7 (7)
C1—N1—C4—C3	2.2 (10)	C1—C2—C3—C4	32.4 (11)
C4—N1—C1—C2	17.3 (7)	C2—C3—C4—N1	−22.0 (12)
C4—N1—C1—C5	141.1 (8)	S1—C6—C7—C8	−179.4 (6)
C6—N2—C10—C9	−1.5 (12)	N2—C6—C7—C8	1.2 (11)
C10—N2—C6—S1	−179.6 (5)	C6—C7—C8—C9	−0.6 (10)
C10—N2—C6—C7	−0.1 (9)	C7—C8—C9—C10	−1.0 (12)
N1—C1—C2—C3	−30.6 (8)	C8—C9—C10—N2	2.1 (12)

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H2···Br1	0.86	2.45	3.278 (7)	163
N1—H3···Br1i	0.86	2.43	3.271 (5)	165

Symmetry codes: (i) −x+y, −x+1, z+1/3.