1-Ethyl-2,3-di­methyl­imidazolium bromide monohydrate

The asymmetric unit of the title compound, C₇H₁₁N₂⁺·Br⁻·H₂O, consists of one crystallographically independent 1-ethyl-2,3-di­methyl­imidazolidinium cation, one bromide anion and one water mol­ecule, all of them located in general positions. In the crystal structure, the bromide anions and the water mol­ecules are connected via O—H...Br hydrogen bonding to form dimers which are located on centres of inversion. In addition, the cations are connected to the water mol­ecules via weak C—H...O hydrogen bonding.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.007 Å
• R factor = 0.054
• wR factor = 0.168
• Data-to-parameter ratio = 23.8

checkCIF/PLATON results

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Alert level C
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT341_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ...          7
PLAT380_ALERT_4_C Check Incorrectly? Oriented X(sp2)-Methyl Moiety         C8

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

   1 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
   1 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: IPDS1 Software (Stoe & Cie, 1996); cell refinement: IPDS1 Software; data reduction: IPDS1 Software; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: X-SEED (Barbour, 2001); software used to prepare material for publication: SHELXL97.

1-Ethyl-2,3-dimethylimidazolium bromide monohydrate

Crystal data

C7H13N2^+·Br^−·H2O	F(000) = 456
Mr = 223.12	Dx = 1.456 Mg m^−3
Monoclinic, P21/n	Melting point: not measured K
Hall symbol: -P 2yn	Mo Kα radiation, λ = 0.71073 Å
a = 7.388 (2) Å	Cell parameters from 1493 reflections
b = 9.2652 (15) Å	θ = 0–23.2°
c = 15.117 (4) Å	µ = 3.99 mm^−1
β = 100.37 (3)°	T = 293 K
V = 1017.9 (4) Å^3	Shapeless, colorless
Z = 4	0.5 × 0.3 × 0.2 mm

Data collection

Stoe IPDS-I diffractometer	2454 independent reflections
Radiation source: fine-focus sealed tube	1550 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.078
Detector resolution: not measured pixels mm^-1	θmax = 28.1°, θmin = 2.6°
phi scan	h = −9→9
Absorption correction: numerical [X-RED (Stoe & Cie, 2002) and X-SHAPE (Stoe & Cie, 1999)]	k = −12→12
Tmin = 0.251, Tmax = 0.455	l = −19→19
11811 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.054	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.168	H-atom parameters constrained
S = 1.05	w = 1/[σ^2(Fo^2) + (0.099P)^2] where P = (Fo^2 + 2Fc^2)/3
2454 reflections	(Δ/σ)max < 0.001
103 parameters	Δρmax = 0.48 e Å^−3
0 restraints	Δρmin = −0.32 e Å^−3

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-I) 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 for [C₇H₁₃N₂]⁺ [Br]^- * H₂O were collected at 293 K by φ scans in 125 frames (0 < φ < 250° exposure time of 6 min) in the 2Θ range 3.8–56.30°·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, 1999)). 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
N1	−0.1176 (5)	0.6340 (4)	0.0891 (2)	0.0395 (7)
N3	−0.1079 (5)	0.4236 (4)	0.1491 (3)	0.0423 (8)
C2	−0.0063 (6)	0.5296 (4)	0.1246 (3)	0.0375 (8)
C4	−0.2917 (6)	0.4638 (5)	0.1298 (3)	0.0497 (11)
H4	−0.3933	0.4083	0.1411	0.060*
C5	−0.2997 (6)	0.5935 (5)	0.0926 (4)	0.0500 (11)
H5	−0.4075	0.6486	0.0722	0.060*
C6	−0.0690 (7)	0.7749 (5)	0.0555 (3)	0.0469 (10)
H6A	−0.1637	0.8031	0.0034	0.056*
H6B	0.0500	0.7666	0.0346	0.056*
C7	−0.0544 (10)	0.8899 (5)	0.1260 (5)	0.0692 (16)
H7A	−0.0214	0.9817	0.1009	0.104*
H7B	0.0406	0.8632	0.1774	0.104*
H7C	−0.1729	0.9001	0.1459	0.104*
C8	−0.0401 (7)	0.2914 (5)	0.1977 (4)	0.0559 (12)
H8A	−0.1449	0.2319	0.2069	0.084*
H8B	0.0336	0.3169	0.2561	0.084*
H8C	0.0360	0.2371	0.1625	0.084*
C9	0.1973 (6)	0.5293 (5)	0.1358 (3)	0.0496 (11)
H9A	0.2365	0.6033	0.0969	0.074*
H9B	0.2393	0.4344	0.1192	0.074*
H9C	0.2507	0.5501	0.1986	0.074*
Br1	0.06073 (8)	0.63194 (6)	0.34915 (4)	0.0590 (2)
O1	0.3656 (6)	0.8309 (4)	0.0284 (3)	0.0654 (10)
H1	0.3837	0.9011	0.0619	0.098*
H2	0.3920	0.8502	−0.0206	0.098*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0445 (18)	0.0335 (16)	0.0399 (17)	−0.0042 (15)	0.0058 (14)	0.0011 (14)
N3	0.048 (2)	0.0314 (16)	0.048 (2)	−0.0034 (15)	0.0111 (16)	−0.0040 (15)
C2	0.039 (2)	0.037 (2)	0.036 (2)	0.0001 (17)	0.0064 (16)	−0.0056 (16)
C4	0.033 (2)	0.050 (3)	0.066 (3)	−0.0093 (19)	0.0092 (19)	−0.004 (2)
C5	0.033 (2)	0.050 (3)	0.066 (3)	−0.0012 (19)	0.0046 (19)	−0.004 (2)
C6	0.050 (2)	0.043 (2)	0.046 (2)	−0.004 (2)	0.0054 (19)	0.0109 (19)
C7	0.098 (5)	0.035 (2)	0.076 (4)	−0.010 (3)	0.018 (3)	0.000 (2)
C8	0.066 (3)	0.036 (2)	0.067 (3)	0.004 (2)	0.014 (3)	0.010 (2)
C9	0.035 (2)	0.055 (3)	0.061 (3)	0.001 (2)	0.0123 (19)	−0.005 (2)
Br1	0.0657 (4)	0.0578 (3)	0.0544 (3)	0.0051 (2)	0.0130 (2)	−0.0019 (2)
O1	0.075 (2)	0.0496 (19)	0.080 (3)	−0.0085 (18)	0.036 (2)	0.0044 (18)

Geometric parameters (Å, º)

N1—C2	1.319 (5)	C6—H6B	0.9900
N1—C5	1.406 (6)	C7—H7A	0.9800
N1—C6	1.468 (5)	C7—H7B	0.9800
N3—C2	1.329 (6)	C7—H7C	0.9800
N3—C4	1.387 (6)	C8—H8A	0.9800
N3—C8	1.470 (6)	C8—H8B	0.9800
C2—C9	1.484 (6)	C8—H8C	0.9800
C4—C5	1.324 (7)	C9—H9A	0.9800
C4—H4	0.9500	C9—H9B	0.9800
C5—H5	0.9500	C9—H9C	0.9800
C6—C7	1.498 (7)	O1—H1	0.8201
C6—H6A	0.9900	O1—H2	0.8200
C2—N1—C5	108.6 (4)	H6A—C6—H6B	107.9
C2—N1—C6	128.2 (4)	C6—C7—H7A	109.5
C5—N1—C6	123.0 (4)	C6—C7—H7B	109.5
C2—N3—C4	108.9 (4)	H7A—C7—H7B	109.5
C2—N3—C8	126.7 (4)	C6—C7—H7C	109.5
C4—N3—C8	124.2 (4)	H7A—C7—H7C	109.5
N1—C2—N3	108.2 (4)	H7B—C7—H7C	109.5
N1—C2—C9	126.3 (4)	N3—C8—H8A	109.5
N3—C2—C9	125.4 (4)	N3—C8—H8B	109.5
C5—C4—N3	107.5 (4)	H8A—C8—H8B	109.5
C5—C4—H4	126.3	N3—C8—H8C	109.5
N3—C4—H4	126.3	H8A—C8—H8C	109.5
C4—C5—N1	106.8 (4)	H8B—C8—H8C	109.5
C4—C5—H5	126.6	C2—C9—H9A	109.5
N1—C5—H5	126.6	C2—C9—H9B	109.5
N1—C6—C7	112.2 (4)	H9A—C9—H9B	109.5
N1—C6—H6A	109.2	C2—C9—H9C	109.5
C7—C6—H6A	109.2	H9A—C9—H9C	109.5
N1—C6—H6B	109.2	H9B—C9—H9C	109.5
C7—C6—H6B	109.2	H1—O1—H2	110.3

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C5—H5···O1^i	0.95	2.39	3.321 (6)	168
O1—H1···Br1^ii	0.82	2.52	3.337 (4)	174
O1—H2···Br1^iii	0.82	2.52	3.309 (4)	163

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