1,3-Diethyl­benzimidazolium iodide

The title salt, C₁₁H₁₅N₂⁺·I⁻, crystallizes with two formula units in the asymmetric unit. The two crystallographically unique cations form alternating columns along the a axis, linked by protruding ethyl groups and interspersed with iodide counter-ions. Cations in a given column stack in centrosymmetrically related pairs with interionic C...C and C...N distances consistent with substantial π–π bonding. One of the iodide ions appears to form a weak hydrogen bond with the most acidic proton in one of the cations.

Key indicators

• Single-crystal X-ray study
• T = 277 K
• Mean [sigma](C-C) = 0.008 Å
• R factor = 0.041
• wR factor = 0.114
• Data-to-parameter ratio = 17.0

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low .......       0.99
PLAT094_ALERT_2_C Ratio of Maximum / Minimum Residual Density ....       2.98
PLAT220_ALERT_2_C Large Non-Solvent    C     Ueq(max)/Ueq(min) ...       2.91 Ratio
PLAT220_ALERT_2_C Large Non-Solvent    C     Ueq(max)/Ueq(min) ...       3.09 Ratio
PLAT222_ALERT_3_C Large Non-Solvent    H     Ueq(max)/Ueq(min) ...       3.35 Ratio
PLAT222_ALERT_3_C Large Non-Solvent    H     Ueq(max)/Ueq(min) ...       3.42 Ratio
PLAT242_ALERT_2_C Check Low    U(eq) as Compared to Neighbors ....        C1A
PLAT242_ALERT_2_C Check Low    U(eq) as Compared to Neighbors ....        C2A
PLAT720_ALERT_4_C Number of Unusual/Non-Standard Label(s) ........         10

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

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   5 ALERT type 2 Indicator that the structure model may be wrong or deficient
   3 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: SMART (Bruker, 2000); cell refinement: SMART; data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPIII (Burnett & Johnson, 1996) and ORTEP-32 (Farrugia, 1997); software used to prepare material for publication: SHELXTL (Bruker, 2000).

1,3-diethylbenzimidazolium iodide

Crystal data

C11H15N2^+·I^−	F(000) = 1184
Mr = 302.15	Dx = 1.607 Mg m^−3
Monoclinic, P21/c	Melting point: 510 K
Hall symbol: -P 2ybc	Mo Kα radiation, λ = 0.71073 Å
a = 11.2578 (5) Å	Cell parameters from 900 reflections
b = 14.6014 (7) Å	θ = 2.7–22.5°
c = 15.1903 (5) Å	µ = 2.53 mm^−1
β = 90.212 (3)°	T = 277 K
V = 2496.96 (18) Å^3	Rod, colorless
Z = 8	0.50 × 0.10 × 0.04 mm

Data collection

Bruker SMART CCD area-detector diffractometer	4368 independent reflections
Radiation source: fine-focus sealed tube	3384 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.033
φ and ω scans	θmax = 25.0°, θmin = 1.8°
Absorption correction: multi-scan (SADABS; Blessing, 1995)	h = −12→13
Tmin = 0.690, Tmax = 0.904	k = −16→17
17742 measured reflections	l = −18→18

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)] = 0.041	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.114	H-atom parameters constrained
S = 1.00	w = 1/[σ^2(Fo^2) + (0.0654P)^2 + 2.1072P] where P = (Fo^2 + 2Fc^2)/3
4368 reflections	(Δ/σ)max = 0.001
257 parameters	Δρmax = 1.18 e Å^−3
2 restraints	Δρmin = −0.40 e Å^−3

Special details

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
I1	0.22285 (4)	0.77617 (3)	0.22484 (2)	0.07140 (16)
N21	0.5984 (4)	0.4339 (3)	0.8401 (2)	0.0575 (10)
N23	0.5236 (4)	0.3344 (3)	0.9316 (3)	0.0572 (10)
C2A	0.6360 (6)	0.4777 (5)	0.7569 (4)	0.0856 (18)
C2B	0.5408 (8)	0.4852 (8)	0.6926 (5)	0.164 (5)
C21	0.6374 (4)	0.4591 (3)	0.9234 (3)	0.0532 (11)
C22	0.5334 (5)	0.3590 (4)	0.8478 (3)	0.0601 (12)
C23	0.5897 (4)	0.3951 (3)	0.9814 (3)	0.0533 (11)
C24	0.6102 (5)	0.4016 (4)	1.0713 (3)	0.0664 (14)
C25	0.6799 (5)	0.4736 (5)	1.0992 (4)	0.0792 (17)
C26	0.7256 (5)	0.5376 (5)	1.0417 (4)	0.0737 (16)
C27	0.7066 (5)	0.5324 (4)	0.9526 (4)	0.0645 (13)
C28	0.4537 (6)	0.2560 (4)	0.9634 (4)	0.0726 (15)
C29	0.5307 (6)	0.1757 (5)	0.9863 (5)	0.099 (2)
H2A1	0.6662	0.5384	0.7698	0.103*
H2A2	0.7003	0.4423	0.7316	0.103*
H2B1	0.5120	0.4252	0.6781	0.246*
H2B2	0.5702	0.5144	0.6404	0.246*
H2B3	0.4773	0.5210	0.7168	0.246*
H22	0.4990	0.3277	0.8008	0.072*
H24	0.5786	0.3595	1.1107	0.080*
H25	0.6967	0.4793	1.1589	0.095*
H26	0.7707	0.5857	1.0640	0.088*
H27	0.7381	0.5753	0.9138	0.077*
H28A	0.3972	0.2379	0.9182	0.087*
H28B	0.4092	0.2743	1.0150	0.087*
H29A	0.5790	0.1599	0.9365	0.149*
H29B	0.4816	0.1244	1.0016	0.149*
H29C	0.5809	0.1912	1.0353	0.149*
I2	0.28172 (4)	0.24859 (3)	0.21393 (3)	0.07422 (16)
N11	0.0127 (3)	0.5644 (3)	0.3303 (2)	0.0544 (10)
N13	0.0819 (4)	0.6593 (3)	0.4283 (2)	0.0539 (10)
C1A	0.1147 (6)	0.7462 (4)	0.4718 (4)	0.0809 (18)
C1B	0.0183 (9)	0.8142 (6)	0.4711 (8)	0.152 (4)
C11	0.0826 (4)	0.5133 (3)	0.3881 (3)	0.0539 (12)
C12	0.0168 (4)	0.6509 (4)	0.3562 (3)	0.0569 (12)
C13	0.1249 (4)	0.5730 (3)	0.4507 (3)	0.0523 (11)
C14	0.1947 (4)	0.5441 (4)	0.5211 (3)	0.0653 (14)
C15	0.2197 (5)	0.4507 (5)	0.5241 (5)	0.0816 (18)
C16	0.1782 (6)	0.3919 (5)	0.4597 (5)	0.086 (2)
C17	0.1086 (5)	0.4207 (4)	0.3915 (4)	0.0729 (15)
C18	−0.0536 (5)	0.5316 (4)	0.2527 (3)	0.0682 (14)
C19	0.0257 (7)	0.5164 (6)	0.1759 (4)	0.108 (3)
H1A1	0.1370	0.7336	0.5324	0.097*
H1A2	0.1834	0.7720	0.4425	0.097*
H1B1	0.0007	0.8313	0.4114	0.228*
H1B2	0.0426	0.8674	0.5037	0.228*
H1B3	−0.0513	0.7883	0.4976	0.228*
H12	−0.0209	0.6992	0.3275	0.068*
H14	0.2229	0.5846	0.5635	0.078*
H15	0.2651	0.4276	0.5702	0.098*
H16	0.1986	0.3302	0.4631	0.104*
H17	0.0799	0.3801	0.3493	0.087*
H18A	−0.1139	0.5763	0.2371	0.082*
H18B	−0.0934	0.4747	0.2672	0.082*
H19A	0.0612	0.5735	0.1589	0.163*
H19B	−0.0198	0.4924	0.1276	0.163*
H19C	0.0869	0.4736	0.1918	0.163*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
I1	0.0868 (3)	0.0720 (3)	0.0555 (2)	0.00469 (19)	0.00713 (18)	0.00111 (16)
N21	0.065 (3)	0.058 (3)	0.049 (2)	−0.001 (2)	0.0037 (19)	0.0050 (18)
N23	0.057 (2)	0.054 (2)	0.060 (2)	−0.0018 (19)	0.0070 (19)	0.0034 (19)
C2A	0.111 (5)	0.080 (4)	0.065 (4)	−0.008 (4)	0.016 (3)	0.013 (3)
C2B	0.165 (8)	0.258 (14)	0.070 (5)	−0.063 (9)	−0.023 (5)	0.073 (6)
C21	0.049 (3)	0.055 (3)	0.056 (3)	0.010 (2)	0.003 (2)	0.000 (2)
C22	0.065 (3)	0.064 (3)	0.051 (3)	0.000 (3)	0.006 (2)	−0.008 (2)
C23	0.047 (3)	0.060 (3)	0.052 (3)	0.009 (2)	0.005 (2)	0.002 (2)
C24	0.064 (3)	0.083 (4)	0.053 (3)	0.014 (3)	0.002 (2)	0.006 (3)
C25	0.071 (4)	0.101 (5)	0.066 (3)	0.018 (3)	−0.017 (3)	−0.011 (3)
C26	0.063 (4)	0.075 (4)	0.084 (4)	0.003 (3)	−0.013 (3)	−0.013 (3)
C27	0.055 (3)	0.061 (3)	0.077 (3)	0.003 (2)	0.002 (3)	0.001 (3)
C28	0.068 (4)	0.070 (4)	0.079 (4)	−0.007 (3)	0.012 (3)	0.009 (3)
C29	0.091 (5)	0.070 (4)	0.137 (6)	−0.005 (3)	0.024 (4)	0.026 (4)
I2	0.0756 (3)	0.0661 (3)	0.0809 (3)	−0.00430 (18)	−0.0178 (2)	−0.00358 (17)
N11	0.058 (2)	0.054 (3)	0.052 (2)	−0.0058 (18)	−0.0009 (18)	−0.0009 (18)
N13	0.065 (3)	0.053 (2)	0.044 (2)	−0.0064 (19)	0.0003 (18)	0.0007 (17)
C1A	0.105 (5)	0.076 (4)	0.062 (3)	−0.012 (3)	−0.017 (3)	−0.008 (3)
C1B	0.171 (9)	0.064 (5)	0.221 (11)	0.035 (5)	−0.060 (8)	−0.054 (6)
C11	0.047 (3)	0.055 (3)	0.060 (3)	0.000 (2)	0.013 (2)	0.007 (2)
C12	0.062 (3)	0.055 (3)	0.053 (3)	0.000 (2)	0.000 (2)	0.001 (2)
C13	0.046 (3)	0.063 (3)	0.048 (2)	0.000 (2)	0.010 (2)	0.005 (2)
C14	0.053 (3)	0.089 (4)	0.054 (3)	−0.001 (3)	0.005 (2)	0.010 (3)
C15	0.063 (4)	0.092 (5)	0.090 (4)	0.017 (3)	0.006 (3)	0.031 (4)
C16	0.075 (4)	0.065 (4)	0.120 (5)	0.022 (3)	0.023 (4)	0.026 (4)
C17	0.069 (4)	0.058 (3)	0.092 (4)	0.003 (3)	0.020 (3)	−0.004 (3)
C18	0.066 (3)	0.065 (3)	0.073 (4)	−0.009 (3)	−0.010 (3)	−0.012 (3)
C19	0.102 (5)	0.156 (8)	0.068 (4)	−0.017 (5)	−0.007 (4)	−0.034 (4)

Geometric parameters (Å, º)

N11—C12	1.323 (6)	C2A—H2A1	0.9700
N13—C12	1.321 (6)	C2A—H2A2	0.9700
N11—C11	1.394 (6)	C14—H14	0.9300
N13—C13	1.392 (6)	C26—H26	0.9300
C11—C13	1.375 (7)	C17—H17	0.9300
C11—C17	1.385 (7)	C16—H16	0.9300
C13—C14	1.389 (7)	C28—C29	1.499 (9)
C14—C15	1.393 (10)	C28—H28A	0.9700
C15—C16	1.381 (10)	C28—H28B	0.9700
C16—C17	1.364 (9)	C25—H25	0.9300
N21—C22	1.322 (6)	C15—H15	0.9300
N23—C22	1.328 (6)	C29—H29A	0.9600
N21—C21	1.387 (6)	C29—H29B	0.9600
N23—C23	1.382 (6)	C29—H29C	0.9600
C21—C23	1.393 (7)	C1A—C1B	1.470 (7)
C21—C27	1.395 (7)	C1A—H1A1	0.9700
C23—C24	1.387 (7)	C1A—H1A2	0.9700
C24—C25	1.378 (9)	C18—C19	1.488 (8)
C25—C26	1.380 (9)	C18—H18A	0.9700
C26—C27	1.372 (8)	C18—H18B	0.9700
N13—C1A	1.477 (7)	C1B—H1B1	0.9600
N23—C28	1.472 (7)	C1B—H1B2	0.9600
N11—C18	1.473 (6)	C1B—H1B3	0.9600
N21—C2A	1.479 (6)	C19—H19A	0.9600
C22—H22	0.9300	C19—H19B	0.9600
C12—H12	0.9300	C19—H19C	0.9600
C24—H24	0.9300	C2B—H2B1	0.9600
C27—H27	0.9300	C2B—H2B2	0.9600
C2A—C2B	1.451 (7)	C2B—H2B3	0.9600
C12—N13—C13	108.1 (4)	C17—C16—C15	122.5 (6)
C12—N13—C1A	126.0 (4)	C17—C16—H16	118.7
C13—N13—C1A	125.5 (4)	C15—C16—H16	118.7
C22—N23—C23	107.7 (4)	N23—C28—C29	112.0 (5)
C22—N23—C28	124.8 (5)	N23—C28—H28A	109.2
C23—N23—C28	127.4 (4)	C29—C28—H28A	109.2
C12—N11—C11	107.7 (4)	N23—C28—H28B	109.2
C12—N11—C18	124.4 (4)	C29—C28—H28B	109.2
C11—N11—C18	127.8 (4)	H28A—C28—H28B	107.9
C11—C13—C14	122.2 (5)	C24—C25—C26	122.3 (5)
C11—C13—N13	106.6 (4)	C24—C25—H25	118.8
C14—C13—N13	131.2 (5)	C26—C25—H25	118.8
C22—N21—C21	108.2 (4)	C16—C15—C14	121.2 (6)
C22—N21—C2A	126.4 (4)	C16—C15—H15	119.4
C21—N21—C2A	125.0 (4)	C14—C15—H15	119.4
N21—C22—N23	110.9 (4)	C28—C29—H29A	109.5
N21—C22—H22	124.6	C28—C29—H29B	109.5
N23—C22—H22	124.6	H29A—C29—H29B	109.5
N23—C23—C24	132.1 (5)	C28—C29—H29C	109.5
N23—C23—C21	107.0 (4)	H29A—C29—H29C	109.5
C24—C23—C21	120.9 (5)	H29B—C29—H29C	109.5
N21—C21—C23	106.1 (4)	C1B—C1A—N13	113.1 (6)
N21—C21—C27	131.9 (5)	C1B—C1A—H1A1	109.0
C23—C21—C27	122.0 (5)	N13—C1A—H1A1	109.0
C13—C11—C17	121.5 (5)	C1B—C1A—H1A2	109.0
C13—C11—N11	106.8 (4)	N13—C1A—H1A2	109.0
C17—C11—N11	131.7 (5)	H1A1—C1A—H1A2	107.8
N13—C12—N11	110.7 (4)	N11—C18—C19	111.8 (5)
N13—C12—H12	124.6	N11—C18—H18A	109.3
N11—C12—H12	124.6	C19—C18—H18A	109.3
C25—C24—C23	116.6 (5)	N11—C18—H18B	109.3
C25—C24—H24	121.7	C19—C18—H18B	109.3
C23—C24—H24	121.7	H18A—C18—H18B	107.9
C26—C27—C21	116.1 (5)	C1A—C1B—H1B1	109.5
C26—C27—H27	121.9	C1A—C1B—H1B2	109.5
C21—C27—H27	121.9	H1B1—C1B—H1B2	109.5
C2B—C2A—N21	113.3 (5)	C1A—C1B—H1B3	109.5
C2B—C2A—H2A1	108.9	H1B1—C1B—H1B3	109.5
N21—C2A—H2A1	108.9	H1B2—C1B—H1B3	109.5
C2B—C2A—H2A2	108.9	C18—C19—H19A	109.5
N21—C2A—H2A2	108.9	C18—C19—H19B	109.5
H2A1—C2A—H2A2	107.7	H19A—C19—H19B	109.5
C13—C14—C15	115.9 (6)	C18—C19—H19C	109.5
C13—C14—H14	122.1	H19A—C19—H19C	109.5
C15—C14—H14	122.1	H19B—C19—H19C	109.5
C27—C26—C25	122.0 (6)	C2A—C2B—H2B1	109.5
C27—C26—H26	119.0	C2A—C2B—H2B2	109.5
C25—C26—H26	119.0	H2B1—C2B—H2B2	109.5
C16—C17—C11	116.7 (6)	C2A—C2B—H2B3	109.5
C16—C17—H17	121.6	H2B1—C2B—H2B3	109.5
C11—C17—H17	121.6	H2B2—C2B—H2B3	109.5
C12—N13—C13—C11	0.3 (5)	C18—N11—C11—C17	−1.2 (8)
C1A—N13—C13—C11	−173.4 (5)	C13—N13—C12—N11	0.9 (5)
C12—N13—C13—C14	−178.4 (5)	C1A—N13—C12—N11	174.6 (5)
C1A—N13—C13—C14	7.9 (8)	C11—N11—C12—N13	−1.7 (5)
C21—N21—C22—N23	1.9 (6)	C18—N11—C12—N13	179.2 (4)
C2A—N21—C22—N23	175.2 (5)	N23—C23—C24—C25	−178.4 (5)
C23—N23—C22—N21	−2.2 (6)	C21—C23—C24—C25	−0.4 (7)
C28—N23—C22—N21	177.7 (5)	N21—C21—C27—C26	178.3 (5)
C22—N23—C23—C24	179.8 (5)	C23—C21—C27—C26	0.3 (7)
C28—N23—C23—C24	0.0 (9)	C22—N21—C2A—C2B	45.3 (10)
C22—N23—C23—C21	1.5 (5)	C21—N21—C2A—C2B	−142.5 (8)
C28—N23—C23—C21	−178.3 (5)	C11—C13—C14—C15	0.3 (7)
C22—N21—C21—C23	−0.9 (5)	N13—C13—C14—C15	178.8 (5)
C2A—N21—C21—C23	−174.2 (5)	C21—C27—C26—C25	0.6 (8)
C22—N21—C21—C27	−179.2 (5)	C13—C11—C17—C16	−0.1 (7)
C2A—N21—C21—C27	7.5 (8)	N11—C11—C17—C16	−177.9 (5)
N23—C23—C21—N21	−0.4 (5)	C11—C17—C16—C15	1.4 (9)
C24—C23—C21—N21	−178.9 (4)	C22—N23—C28—C29	102.9 (7)
N23—C23—C21—C27	178.1 (4)	C23—N23—C28—C29	−77.3 (7)
C24—C23—C21—C27	−0.4 (7)	C23—C24—C25—C26	1.3 (8)
C14—C13—C11—C17	−0.7 (7)	C27—C26—C25—C24	−1.4 (9)
N13—C13—C11—C17	−179.5 (4)	C17—C16—C15—C14	−1.8 (9)
C14—C13—C11—N11	177.5 (4)	C13—C14—C15—C16	0.9 (8)
N13—C13—C11—N11	−1.3 (5)	C12—N13—C1A—C1B	38.5 (9)
C12—N11—C11—C13	1.9 (5)	C13—N13—C1A—C1B	−148.9 (7)
C18—N11—C11—C13	−179.1 (4)	C12—N11—C18—C19	100.9 (7)
C12—N11—C11—C17	179.8 (5)	C11—N11—C18—C19	−78.0 (7)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C22—H22···I2^i	0.93	2.99	3.820 (5)	149

Symmetry code: (i) x, −y+1/2, z+1/2.