1,1′-Dimethyl-4,4′-bipyridinium bis­(triiodide)

Abstract

In the title compound, C₁₂H₁₄N₂ ²⁺·2I₃ ⁻, the 1,1′-dimethyl-4,4′-bipyridinium (DMBP) dication is charge balanced by two triiodide ions. The DMBP dication is planar within 0.010 (5) Å. The asymmetric unit contains only half of the dication, the other half being generated by an inversion center. Weak C—H⋯I inter­actions link the ions into sheets parallel to (121).

Related literature

For a dication with similar geometry, see: Russell & Wallwork (1972 ▶). For anions with comparable geometry, see: Marsh (2004 ▶); Madsen et al. (1999 ▶).

Experimental

Crystal data

• C₁₂H₁₄N₂ ²⁺·2I₃ ⁻

• M _r = 947.65

• Triclinic,

• a = 7.5457 (4) Å

• b = 7.9541 (6) Å

• c = 9.3029 (6) Å

• α = 90.306 (5)°

• β = 94.192 (4)°

• γ = 102.332 (5)°

• V = 543.88 (6) ų

• Z = 1

• Mo Kα radiation

• μ = 8.56 mm⁻¹

• T = 296 K

• 0.22 × 0.16 × 0.08 mm

Data collection

• Bruker SMART CCD area-detector diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.211, T _max = 0.504

• 12956 measured reflections

• 2683 independent reflections

• 1468 reflections with I > 2σ(I)

• R _int = 0.052

Refinement

• R[F ² > 2σ(F ²)] = 0.040

• wR(F ²) = 0.073

• S = 1.02

• 2683 reflections

• 93 parameters

• H-atom parameters constrained

• Δρ_max = 0.97 e Å⁻³

• Δρ_min = −0.86 e Å⁻³

Data collection: SMART (Bruker, 2007 ▶); cell refinement: SAINT-Plus (Bruker, 2007 ▶); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

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

Table 1. Selected geometric parameters (Å, °).

I1—I2	2.9341 (8)
I2—I3	2.9061 (8)

I3—I2—I1

177.49 (2)

Table 2. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C3—H3⋯I3i	0.93	3.05	3.951 (8)	163
C2—H2⋯I1ii	0.93	3.16	4.066 (8)	164
C5—H5⋯I2i	0.93	3.13	3.839 (7)	135

Symmetry codes: (i) ; (ii) .

supplementary crystallographic information

Comment

The title compound, (I), was obtained by chance when we tried to prepare the salt of the Pb(II) cation and DMBP in MeOH. This paper provides the first crystal structure of the DMBP dication with two triiodide anions.

Only half of the dication of DMBP is contained in the asymmetric unit, while the other half is generated by the inversion center at (1/2,1/2,1/2) (Fig 1.). The N,N'-dimethyl-4,4'bipyridylium(II) dication has an essentially planar conformation, the maximum deviation of the C1 atom (the methyl group) from its mean plane being 0.010 (5) Å. The geometry of the dication is similar to the one observed in Russell & Wallwork (1972). Meanwhile, the geometry of the anion is comparable to that described in Marsh (2004) and Madsen et al. (1999).

Weak C3—H3···I3 interactions link two I₃ anions to each dication. A weaker C2—I2···H1 interaction links each anion to a further DMBP cation, to form sheets parallel to (121). Adjacent sheets are packed into a three-dimensional motif (Fig. 2).

Experimental

C₁₂H₁₄N₂.4Cl (0.5 mmol, 128 mg) and KI (10 mmol, 1660 mg) were added to 50 ml of CH₃CN. After stirring and refluxing for 12 h, the mixture was filtered, and the clear solution was allowed to evaporate slowly under inert atmosphere. Prismatic crystals of the title compound were obtained after 5 days. The crystals were filtered, washed by cool EtOH and dried in air.

Refinement

All of the H atoms were positioned geometrically and refined using a riding model with C—H = 0.930 Å and 0.96 Å, with U_iso(H) = 1.2 and 1.5 times U_eq(C), for aromatic and methyl hydrogens, respectively.

Figures

Fig. 1.

Molecular structure showing 50% probability displacement ellipsoids. The atoms marked with A are derived from the reference atoms by means of the (1 - x, 1 - y, 1 - z) symmetry transformation..

Fig. 2.

Packing diagram viewed down the a axis. Weak C—H···I interactions are shown as dotted lines.

Crystal data

C12H14N22+·2I3−	Z = 1
Mr = 947.65	F(000) = 418
Triclinic, P1	Dx = 2.893 Mg m−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.5457 (4) Å	Cell parameters from 4412 reflections
b = 7.9541 (6) Å	θ = 2.6–27.6°
c = 9.3029 (6) Å	µ = 8.56 mm−1
α = 90.306 (5)°	T = 296 K
β = 94.192 (4)°	Prism, black
γ = 102.332 (5)°	0.22 × 0.16 × 0.08 mm
V = 543.88 (6) Å3

Data collection

Bruker SMART CCD area-detector diffractometer	2683 independent reflections
Radiation source: fine-focus sealed tube	1468 reflections with I > 2σ(I)
graphite	Rint = 0.052
φ and ω scans	θmax = 28.3°, θmin = 3.9°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −10→10
Tmin = 0.211, Tmax = 0.504	k = −10→10
12956 measured reflections	l = −11→12

Refinement

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.040	H-atom parameters constrained
wR(F2) = 0.073	w = 1/[σ2(Fo2) + (0.005P)2 + 2.2853P] where P = (Fo2 + 2Fc2)/3
S = 1.02	(Δ/σ)max < 0.001
2683 reflections	Δρmax = 0.97 e Å−3
93 parameters	Δρmin = −0.86 e Å−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0028 (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	0.11371 (7)	0.64766 (7)	0.84204 (6)	0.0705 (2)
I2	0.19121 (6)	0.80427 (6)	0.56237 (6)	0.05927 (17)
I3	0.25337 (8)	0.96496 (8)	0.28546 (6)	0.0816 (2)
N1	0.3773 (9)	0.2800 (7)	0.8128 (7)	0.0588 (16)
C1	0.3276 (13)	0.1852 (11)	0.9438 (9)	0.085 (3)
H1A	0.4248	0.2166	1.0179	0.128*
H1B	0.3064	0.0638	0.9235	0.128*
H1C	0.2190	0.2131	0.9758	0.128*
C2	0.5358 (12)	0.3875 (11)	0.8116 (9)	0.074 (2)
H2	0.6149	0.4034	0.8944	0.088*
C3	0.2652 (11)	0.2566 (10)	0.6956 (10)	0.072 (2)
H3	0.1526	0.1813	0.6969	0.086*
C4	0.5864 (9)	0.4764 (10)	0.6903 (8)	0.061 (2)
H4	0.6984	0.5532	0.6924	0.074*
C5	0.3120 (10)	0.3414 (10)	0.5722 (8)	0.066 (2)
H5	0.2309	0.3216	0.4906	0.079*
C6	0.4743 (8)	0.4540 (7)	0.5658 (7)	0.0396 (14)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
I1	0.0689 (4)	0.0899 (4)	0.0576 (3)	0.0291 (3)	0.0010 (3)	0.0076 (3)
I2	0.0503 (3)	0.0648 (3)	0.0672 (3)	0.0224 (2)	0.0040 (2)	0.0045 (2)
I3	0.0838 (4)	0.0895 (4)	0.0816 (4)	0.0335 (3)	0.0267 (3)	0.0292 (3)
N1	0.066 (4)	0.051 (4)	0.063 (4)	0.016 (3)	0.016 (4)	0.010 (3)
C1	0.106 (7)	0.076 (6)	0.075 (6)	0.017 (5)	0.017 (5)	0.015 (5)
C2	0.071 (6)	0.088 (6)	0.061 (5)	0.020 (5)	−0.011 (4)	0.015 (5)
C3	0.062 (5)	0.066 (5)	0.078 (6)	−0.010 (4)	0.011 (5)	−0.003 (5)
C4	0.039 (4)	0.077 (5)	0.058 (5)	−0.004 (4)	−0.016 (3)	0.006 (4)
C5	0.052 (5)	0.080 (6)	0.054 (5)	−0.007 (4)	−0.003 (4)	−0.001 (4)
C6	0.031 (3)	0.032 (3)	0.054 (4)	0.005 (3)	−0.002 (3)	−0.003 (3)

Geometric parameters (Å, °)

I1—I2	2.9341 (8)	C2—H2	0.9300
I2—I3	2.9061 (8)	C3—C5	1.364 (10)
N1—C2	1.314 (9)	C3—H3	0.9300
N1—C3	1.317 (9)	C4—C6	1.371 (8)
N1—C1	1.467 (9)	C4—H4	0.9300
C1—H1A	0.9600	C5—C6	1.359 (9)
C1—H1B	0.9600	C5—H5	0.9300
C1—H1C	0.9600	C6—C6i	1.464 (12)
C2—C4	1.370 (10)
I3—I2—I1	177.49 (2)	N1—C3—C5	120.9 (7)
C2—N1—C3	119.7 (7)	N1—C3—H3	119.5
C2—N1—C1	119.8 (7)	C5—C3—H3	119.5
C3—N1—C1	120.5 (7)	C2—C4—C6	121.0 (6)
N1—C1—H1A	109.5	C2—C4—H4	119.5
N1—C1—H1B	109.5	C6—C4—H4	119.5
H1A—C1—H1B	109.5	C6—C5—C3	121.6 (7)
N1—C1—H1C	109.5	C6—C5—H5	119.2
H1A—C1—H1C	109.5	C3—C5—H5	119.2
H1B—C1—H1C	109.5	C5—C6—C4	115.9 (6)
N1—C2—C4	121.0 (7)	C5—C6—C6i	122.1 (7)
N1—C2—H2	119.5	C4—C6—C6i	122.1 (7)
C4—C2—H2	119.5
C3—N1—C2—C4	0.3 (12)	N1—C3—C5—C6	−0.7 (13)
C1—N1—C2—C4	179.4 (7)	C3—C5—C6—C4	0.0 (11)
C2—N1—C3—C5	0.6 (12)	C3—C5—C6—C6i	−179.8 (8)
C1—N1—C3—C5	−178.5 (7)	C2—C4—C6—C5	0.9 (11)
N1—C2—C4—C6	−1.0 (12)	C2—C4—C6—C6i	−179.3 (8)

Symmetry codes: (i) −x+1, −y+1, −z+1.

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3···I3ii	0.93	3.05	3.951 (8)	163
C2—H2···I1iii	0.93	3.16	4.066 (8)	164
C5—H5···I2ii	0.93	3.13	3.839 (7)	135

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