N-Methyl-N-propyl­pyrrolidinium iodide

The asymmetric unit of the title compound, C₈H₁₈N⁺·I^-, contains one crystallographically independent N-methyl-N-propyl­pyrrolidinium cation and one iodide anion, both located in general positions. No significant hydrogen bonding between the carbon-bound H atoms and the halide anion is observed.

Key indicators

• Single-crystal X-ray study
• T = 170 K
• Mean [sigma](C-C) = 0.006 Å
• Disorder in main residue
• R factor = 0.027
• wR factor = 0.073
• Data-to-parameter ratio = 29.5

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low .......       0.96
PLAT301_ALERT_3_C Main Residue  Disorder .........................       9.00 Perc.

Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           29.30
           From the CIF: _reflns_number_total               2891
           Count of symmetry unique reflns         1736
           Completeness (_total/calc)            166.53%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured      1155
           Fraction of Friedel pairs measured     0.665
           Are heavy atom types Z>Si present        yes

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   2 ALERT level C = Check and explain
   1 ALERT level G = General alerts; check

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   2 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: X-AREA (Stoe & Cie, 2002); cell refinement: X-AREA; data reduction: X-AREA; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg, 1996); software used to prepare material for publication: SHELXL97.

N-methyl-N-propyl-pyrrolidinium iodide

Crystal data

C8H18N^+·I^−	Dx = 1.552 Mg m^−3
Mr = 255.13	Melting point: not measured K
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 20726 reflections
a = 7.6816 (8) Å	θ = 2.4–29.3°
b = 11.8247 (15) Å	µ = 2.88 mm^−1
c = 12.0196 (14) Å	T = 170 K
V = 1091.8 (2) Å^3	Prism, white
Z = 4	0.30 × 0.20 × 0.10 mm
F(000) = 504

Data collection

Stoe IPDS-II diffractometer	2891 independent reflections
Radiation source: fine-focus sealed tube	2796 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.075
φ scans	θmax = 29.3°, θmin = 2.4°
Absorption correction: numerical [X-RED (Stoe & Cie, 2002) and X-SHAPE (Stoe & Cie, 2001)]	h = −10→10
Tmin = 0.468, Tmax = 0.697	k = −15→15
14164 measured reflections	l = −16→16

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.027	w = 1/[σ^2(Fo^2) + (0.0366P)^2 + 0.7962P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.073	(Δ/σ)max < 0.001
S = 1.09	Δρmax = 0.77 e Å^−3
2891 reflections	Δρmin = −0.73 e Å^−3
98 parameters	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
0 restraints	Extinction coefficient: 0.0164 (12)
Primary atom site location: structure-invariant direct methods	Absolute structure: Flack (1983), 1228 Friedel pairs
Secondary atom site location: difference Fourier map	Absolute structure parameter: −0.01 (4)

Special details

Experimental. A suitable single-crystal was carefully selected under a polarizing microscope and mounted in a glass capillary. The scattering intensities were collected with an imaging plate diffractometer (Stoe IPDS-II) equipped with a fine focus sealed tube X-ray source (Mo Kα, λ = 0.71073 Å) operating at 50 kV and 30 mA. Intensity data were collected at 173 K by φ scans in 360 frames (0 < φ < 180° exposure time of 6 min) in the 2Θ range 2.29 - °·Structure solution and refinement were carried out using the program SHELXL97 (Sheldrick, 1997). A numerical absorption correction (X-RED (Stoe & Cie, 2001) was applied after optimization of the crystal shape (X-SHAPE (Stoe & Cie, 2001)). The final difference maps were free of any chemically significant features. The refinement was based on F² for ALL reflections.

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

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

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

	x	y	z	Uiso*/Ueq	Occ. (<1)
I	0.18890 (2)	0.189837 (14)	0.243215 (17)	0.03647 (9)
N	0.3788 (4)	0.5098 (2)	0.0347 (3)	0.0368 (6)
C1	0.2319 (5)	0.5916 (4)	0.0680 (4)	0.0538 (11)
H1A	0.1891	0.5743	0.1438	0.065*
H1B	0.2735	0.6709	0.0663	0.065*
C2	0.0908 (5)	0.5736 (4)	−0.0164 (3)	0.0480 (8)
H2A	0.1182	0.6110	−0.0880	0.058*	0.75
H2B	−0.0235	0.6004	0.0110	0.058*	0.75
H2C	0.0756	0.6425	−0.0622	0.058*	0.25
H2D	−0.0208	0.5569	0.0213	0.058*	0.25
C3	0.0965 (7)	0.4432 (5)	−0.0266 (5)	0.0523 (12)	0.75
H3A	0.0408	0.4071	0.0386	0.063*	0.75
H3B	0.0360	0.4178	−0.0949	0.063*	0.75
C3'	0.1453 (17)	0.4722 (10)	−0.0913 (12)	0.043 (3)*	0.25
H3C	0.0460	0.4200	−0.1023	0.052*	0.25
H3D	0.1848	0.4993	−0.1650	0.052*	0.25
C4	0.2903 (5)	0.4139 (3)	−0.0318 (4)	0.0469 (9)
H4A	0.3321	0.4125	−0.1097	0.056*	0.75
H4B	0.3132	0.3394	0.0028	0.056*	0.75
H4C	0.3726	0.3790	−0.0851	0.056*	0.25
H4D	0.2450	0.3545	0.0186	0.056*	0.25
C5	0.5075 (5)	0.5732 (3)	−0.0380 (4)	0.0505 (10)
H5A	0.4440	0.6183	−0.0931	0.076*
H5B	0.5831	0.5190	−0.0764	0.076*
H5C	0.5786	0.6233	0.0084	0.076*
C6	0.4676 (4)	0.4625 (3)	0.1376 (3)	0.0370 (7)
H6A	0.3816	0.4174	0.1800	0.044*
H6B	0.5038	0.5266	0.1854	0.044*
C7	0.6269 (5)	0.3885 (3)	0.1150 (4)	0.0436 (8)
H7A	0.7214	0.4349	0.0826	0.052*
H7B	0.5965	0.3284	0.0610	0.052*
C8	0.6889 (5)	0.3348 (3)	0.2248 (4)	0.0494 (8)
H8A	0.7088	0.3943	0.2800	0.074*
H8B	0.7976	0.2934	0.2118	0.074*
H8C	0.5998	0.2825	0.2523	0.074*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
I	0.03338 (11)	0.03446 (12)	0.04157 (14)	0.00112 (6)	0.00041 (8)	−0.00156 (8)
N	0.0326 (13)	0.0326 (13)	0.0453 (18)	0.0024 (10)	−0.0051 (11)	−0.0076 (11)
C1	0.0428 (19)	0.061 (2)	0.058 (3)	0.0232 (17)	−0.0136 (17)	−0.0228 (19)
C2	0.0377 (17)	0.061 (2)	0.045 (2)	0.0080 (16)	−0.0030 (14)	0.0014 (17)
C3	0.042 (2)	0.056 (3)	0.059 (4)	−0.005 (2)	−0.011 (2)	0.000 (3)
C4	0.0437 (19)	0.047 (2)	0.050 (2)	−0.0005 (16)	−0.0050 (16)	−0.0177 (15)
C5	0.053 (2)	0.0413 (18)	0.057 (3)	−0.0031 (16)	−0.0072 (16)	0.0150 (17)
C6	0.0316 (13)	0.0339 (14)	0.045 (2)	−0.0003 (11)	−0.0017 (13)	−0.0020 (12)
C7	0.0350 (14)	0.0449 (17)	0.051 (2)	0.0078 (13)	−0.0038 (15)	0.0025 (15)
C8	0.0419 (16)	0.0491 (16)	0.057 (2)	0.0065 (13)	−0.0090 (17)	0.0048 (15)

Geometric parameters (Å, º)

N—C5	1.518 (5)	C3'—H3D	0.9900
N—C6	1.520 (5)	C4—H4A	0.9900
N—C1	1.539 (4)	C4—H4B	0.9900
N—C4	1.545 (4)	C4—H4C	0.9900
C1—C2	1.500 (5)	C4—H4D	0.9900
C1—H1A	0.9900	C5—H5A	0.9800
C1—H1B	0.9900	C5—H5B	0.9800
C2—C3	1.547 (6)	C5—H5C	0.9800
C2—C3'	1.557 (11)	C6—C7	1.529 (4)
C2—H2A	0.9900	C6—H6A	0.9900
C2—H2B	0.9900	C6—H6B	0.9900
C2—H2C	0.9900	C7—C8	1.540 (5)
C2—H2D	0.9900	C7—H7A	0.9900
C3—C4	1.530 (6)	C7—H7B	0.9900
C3—H3A	0.9900	C8—H8A	0.9800
C3—H3B	0.9900	C8—H8B	0.9800
C3'—C4	1.493 (11)	C8—H8C	0.9800
C3'—H3C	0.9900
C5—N—C6	111.0 (3)	C3—C4—N	103.9 (3)
C5—N—C1	108.5 (3)	C3—C4—H4A	111.0
C6—N—C1	110.4 (3)	N—C4—H4A	111.0
C5—N—C4	110.6 (3)	C3'—C4—H4B	138.2
C6—N—C4	110.4 (3)	C3—C4—H4B	111.0
C1—N—C4	105.9 (3)	N—C4—H4B	111.0
C2—C1—N	105.3 (3)	H4A—C4—H4B	109.0
C2—C1—H1A	110.7	C3'—C4—H4C	111.0
N—C1—H1A	110.7	N—C4—H4C	111.0
C2—C1—H1B	110.7	C3'—C4—H4D	111.0
N—C1—H1B	110.7	N—C4—H4D	111.0
H1A—C1—H1B	108.8	H4C—C4—H4D	109.0
C1—C2—C3	100.1 (3)	N—C5—H5A	109.5
C1—C2—C3'	107.9 (5)	N—C5—H5B	109.5
C1—C2—H2A	111.8	H5A—C5—H5B	109.5
C3—C2—H2A	111.8	N—C5—H5C	109.5
C1—C2—H2B	111.8	H5A—C5—H5C	109.5
C3—C2—H2B	111.8	H5B—C5—H5C	109.5
H2A—C2—H2B	109.5	N—C6—C7	115.1 (3)
C1—C2—H2C	110.1	N—C6—H6A	108.5
C3'—C2—H2C	110.1	C7—C6—H6A	108.5
C1—C2—H2D	110.1	N—C6—H6B	108.5
C3'—C2—H2D	110.1	C7—C6—H6B	108.5
H2C—C2—H2D	108.4	H6A—C6—H6B	107.5
C4—C3—C2	104.9 (4)	C6—C7—C8	109.3 (3)
C4—C3—H3A	110.8	C6—C7—H7A	109.8
C2—C3—H3A	110.8	C8—C7—H7A	109.8
C4—C3—H3B	110.8	C6—C7—H7B	109.8
C2—C3—H3B	110.8	C8—C7—H7B	109.8
H3A—C3—H3B	108.8	H7A—C7—H7B	108.3
C4—C3'—C2	106.2 (8)	C7—C8—H8A	109.5
C4—C3'—H3C	110.5	C7—C8—H8B	109.5
C2—C3'—H3C	110.5	H8A—C8—H8B	109.5
C4—C3'—H3D	110.5	C7—C8—H8C	109.5
C2—C3'—H3D	110.5	H8A—C8—H8C	109.5
H3C—C3'—H3D	108.7	H8B—C8—H8C	109.5
C3'—C4—N	103.7 (5)