1,4-Dimethyl­pyridinium triiodide

In an attempt to synthesize 1,4-dimethyl­pyridinium dodeca­tungsto­phosphate and 1,4-dimethyl­pyridinium dodeca­molybdo­phosphate, the title compound, C₇H₁₀N⁺·I₃^-, was obtained as a by-product. The crystal structure contains a disordered 1,4-dimethyl­pyridinium cation and a triiodide anion.

Key indicators

• Single-crystal X-ray study
• T = 288 K
• Mean [sigma](C-C) = 0.013 Å
Some non-H atoms missing
• Disorder in main residue
• R factor = 0.044
• wR factor = 0.105
• Data-to-parameter ratio = 25.4

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT041_ALERT_1_C Calc. and Rep. SumFormula Strings    Differ ....          ?
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT077_ALERT_4_C Unitcell contains non-integer number of atoms ..          ?
PLAT241_ALERT_2_C Check High      Ueq as Compared to Neighbors for         C4
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         N1
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         C1
PLAT301_ALERT_3_C Main Residue  Disorder .........................      14.00 Perc.
PLAT342_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ...         13

Alert level G
FORMU01_ALERT_2_G  There is a discrepancy between the atom counts in the
            _chemical_formula_sum and the formula from the _atom_site* data.
            Atom count from _chemical_formula_sum:C7 H10 I3 N1
            Atom count from the _atom_site data:  C6.64 H10 I3 N1.36
CELLZ01_ALERT_1_G Difference between formula and atom_site contents detected.
CELLZ01_ALERT_1_G ALERT: Large difference may be due to a
            symmetry error - see SYMMG tests
           From the CIF: _cell_formula_units_Z    1
           From the CIF: _chemical_formula_sum  C7 H10 I3 N1
           TEST: Compare cell contents of formula and atom_site data

           atom    Z*formula  cif sites diff
           C          7.00      6.64    0.36
           H         10.00     10.00    0.00
           I          3.00      3.00    0.00
           N          1.00      1.36   -0.36

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

   4 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   4 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: SMART (Bruker, 2000); cell refinement: SMART; data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 2000); software used to prepare material for publication: SHELXL97.

1,4-Dimethylpyridinium triiodide

Crystal data

C7H10N^+·I3^−	Z = 1
Mr = 488.86	F(000) = 218.3
Triclinic, P1	Dx = 2.525 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 5.469 (2) Å	Cell parameters from 380 reflections
b = 7.786 (3) Å	θ = 7.5–27.0°
c = 8.463 (3) Å	µ = 7.24 mm^−1
α = 108.604 (5)°	T = 288 K
β = 92.357 (6)°	Needle, brown
γ = 107.546 (5)°	0.36 × 0.18 × 0.08 mm
V = 321.9 (2) Å^3

Data collection

Bruker SMART CCD area-detector diffractometer	1346 independent reflections
Radiation source: fine-focus sealed tube	925 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.027
φ and ω scans	θmax = 27.0°, θmin = 2.6°
Absorption correction: multi-scan (SADABS; Bruker, 2000)	h = −4→6
Tmin = 0.225, Tmax = 0.557	k = −9→9
1956 measured reflections	l = −10→9

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)] = 0.044	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.105	H-atom parameters constrained
S = 0.93	w = 1/[σ^2(Fo^2) + (0.0542P)^2] where P = (Fo^2 + 2Fc^2)/3
1346 reflections	(Δ/σ)max < 0.001
53 parameters	Δρmax = 0.75 e Å^−3
0 restraints	Δρmin = −0.84 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	Occ. (<1)
N1	0.4626 (13)	0.6366 (9)	0.1389 (9)	0.070 (3)	0.68 (10)
C1	0.4626 (13)	0.6366 (9)	0.1389 (9)	0.070 (3)	0.32 (10)
C2	0.3525 (17)	0.6049 (12)	−0.0182 (11)	0.080 (2)
H2	0.2498	0.6761	−0.0331	0.096*
C3	0.6100 (17)	0.5304 (13)	0.1554 (10)	0.079 (2)
H3	0.6878	0.5497	0.2622	0.094*
C4	0.4213 (19)	0.7812 (15)	0.2901 (12)	0.098 (3)
H4A	0.5213	0.7873	0.3888	0.148*
H4B	0.2406	0.7447	0.3013	0.148*
H4C	0.4752	0.9048	0.2776	0.148*
I1	0.05217 (13)	0.26565 (8)	0.34224 (7)	0.0949 (3)
I2	0.0000	0.0000	0.0000	0.0669 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.070 (5)	0.073 (5)	0.068 (5)	0.025 (4)	0.017 (3)	0.023 (4)
C1	0.070 (5)	0.073 (5)	0.068 (5)	0.025 (4)	0.017 (3)	0.023 (4)
C2	0.091 (6)	0.090 (6)	0.073 (6)	0.050 (5)	0.010 (5)	0.027 (5)
C3	0.079 (6)	0.097 (6)	0.060 (5)	0.036 (5)	0.001 (4)	0.022 (4)
C4	0.117 (8)	0.092 (6)	0.081 (6)	0.045 (5)	0.030 (5)	0.012 (5)
I1	0.1301 (6)	0.0918 (5)	0.0515 (4)	0.0402 (4)	0.0162 (3)	0.0066 (3)
I2	0.0878 (6)	0.0609 (4)	0.0579 (4)	0.0338 (4)	0.0159 (3)	0.0192 (3)

Geometric parameters (Å, º)

N1—C3	1.349 (10)	C3—H3	0.9300
N1—C2	1.351 (10)	C4—H4A	0.9600
N1—C4	1.488 (11)	C4—H4B	0.9600
C2—C3^i	1.368 (12)	C4—H4C	0.9600
C2—H2	0.9300	I1—I2	2.916 (1)
C3—C2^i	1.368 (12)	I2—I1^ii	2.9159 (11)
C3—N1—C2	117.8 (7)	C2^i—C3—H3	119.3
C3—N1—C4	120.5 (8)	N1—C4—H4A	109.5
C2—N1—C4	121.7 (7)	N1—C4—H4B	109.5
N1—C2—C3^i	120.9 (7)	H4A—C4—H4B	109.5
N1—C2—H2	119.6	N1—C4—H4C	109.5
C3^i—C2—H2	119.6	H4A—C4—H4C	109.5
N1—C3—C2^i	121.4 (8)	H4B—C4—H4C	109.5
N1—C3—H3	119.3	I1^ii—I2—I1	180.00 (4)

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