Weak hydrogen and halogen bonding in 4-[(2,2-di­fluoro­eth­oxy)meth­yl]pyridinium iodide and 4-[(3-chloro-2,2,3,3-tetra­fluoro­prop­oxy)meth­yl]pyridinium iodide

To enable a comparison between a C—H...X hydrogen bond and a halogen bond, the structures of two fluorous-substituted pyridinium iodide salts have been determined. 4-[(2,2-Di­fluoro­eth­oxy)meth­yl]pyridinium iodide, C₈H₁₀F₂NO⁺·I⁻, (1), has a –CH₂OCH₂CF₂H substituent at the para position of the pyridinium ring and 4-[(3-chloro-2,2,3,3-tetra­fluoro­prop­oxy)meth­yl]pyridinium iodide, C₉H₉ClF₄NO⁺·I⁻, (2), has a –CH₂OCH₂CF₂CF₂Cl substituent at the para position of the pyridinium ring. In salt (1), the iodide anion is involved in one N—H...I and three C—H...I hydrogen bonds, which, together with C—H...F hydrogen bonds, link the cations and anions into a three-dimensional network. For salt (2), the iodide anion is involved in one N—H...I hydrogen bond, two C—H...I hydrogen bonds and one C—Cl...I halogen bond; additional C—H...F and C—F...F inter­actions link the cations and anions into a three-dimensional arrangement.

Computing details

Data collection: APEX2 (Bruker, 2015) for i16183; Bruker Instrument Service v2012.12.0.3 for i16319. For both structures, cell refinement: SAINT (Bruker, 2015); data reduction: SAINT (Bruker, 2015). Program(s) used to solve structure: SHELXS97 (Sheldrick 2008) for i16183; SHELXT (Sheldrick, 2015a) for i16319. For both structures, program(s) used to refine structure: SHELXL2013 (Sheldrick, 2015b). Molecular graphics: SHELXTL (Sheldrick 2008) for i16183; shelXle (Hübschle et al., 2011) for i16319. Software used to prepare material for publication: SHELXTL (Sheldrick 2008) for i16183; WinGX (Farrugia, 2012) for i16319.

4-[(2,2-Difluoroethoxy)methyl]pyridinium iodide (i16183)

Crystal data

C8H10F2NO^+·I^−	F(000) = 576
Mr = 301.07	Dx = 1.982 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 4.9221 (1) Å	Cell parameters from 9922 reflections
b = 8.4974 (2) Å	θ = 2.5–27.2°
c = 24.1323 (7) Å	µ = 3.17 mm^−1
β = 91.610 (1)°	T = 100 K
V = 1008.94 (4) Å^3	Plate, colourless
Z = 4	0.34 × 0.30 × 0.08 mm

Data collection

Bruker APEXII CCD diffractometer	2208 reflections with I > 2σ(I)
φ and ω scans	Rint = 0.024
Absorption correction: multi-scan (SADABS; Bruker, 2015)	θmax = 27.1°, θmin = 1.7°
Tmin = 0.819, Tmax = 0.971	h = −6→6
34955 measured reflections	k = −10→10
2231 independent reflections	l = −30→30

Refinement

Refinement on F^2	Hydrogen site location: mixed
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F^2 > 2σ(F^2)] = 0.014	w = 1/[σ^2(Fo^2) + 1.0459P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.029	(Δ/σ)max = 0.002
S = 1.28	Δρmax = 0.38 e Å^−3
2231 reflections	Δρmin = −0.37 e Å^−3
122 parameters	Extinction correction: SHELXL2013 (Sheldrick, 2015b), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
0 restraints	Extinction coefficient: 0.00303 (13)

Special details

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

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

	x	y	z	Uiso*/Ueq
I1	1.07331 (2)	0.78331 (2)	0.55794 (2)	0.01406 (5)
F1	0.0012 (3)	0.79498 (15)	0.20001 (5)	0.0375 (3)
F2	0.0776 (3)	0.54453 (16)	0.20994 (5)	0.0412 (4)
O1	−0.1092 (3)	0.70739 (15)	0.30691 (5)	0.0188 (3)
N1	0.6050 (3)	0.78417 (19)	0.44880 (6)	0.0164 (3)
H1A	0.721 (4)	0.821 (3)	0.4720 (9)	0.020*
C1	0.5972 (4)	0.6274 (2)	0.44283 (7)	0.0157 (3)
H1	0.7182	0.5626	0.4640	0.019*
C2	0.4137 (3)	0.5610 (2)	0.40595 (7)	0.0147 (3)
H2	0.4073	0.4501	0.4012	0.018*
C3	0.2361 (3)	0.6582 (2)	0.37544 (7)	0.0119 (3)
C4	0.2454 (3)	0.8192 (2)	0.38426 (7)	0.0145 (3)
H4	0.1227	0.8868	0.3646	0.017*
C5	0.4336 (4)	0.8807 (2)	0.42166 (8)	0.0170 (4)
H5	0.4414	0.9910	0.4281	0.020*
C6	0.0439 (3)	0.5855 (2)	0.33335 (7)	0.0146 (3)
H6A	0.1471	0.5263	0.3056	0.018*
H6B	−0.0797	0.5113	0.3518	0.018*
C7	−0.2744 (4)	0.6572 (2)	0.26140 (8)	0.0230 (4)
H7A	−0.4325	0.7287	0.2573	0.028*
H7B	−0.3441	0.5503	0.2691	0.028*
C8	−0.1251 (5)	0.6544 (2)	0.20825 (8)	0.0287 (5)
H8	−0.2545	0.6318	0.1766	0.034*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
I1	0.01415 (6)	0.01339 (6)	0.01443 (6)	−0.00003 (4)	−0.00318 (4)	0.00007 (4)
F1	0.0574 (9)	0.0256 (7)	0.0298 (7)	−0.0105 (6)	0.0058 (6)	0.0051 (5)
F2	0.0712 (10)	0.0341 (7)	0.0186 (6)	0.0168 (7)	0.0054 (6)	−0.0041 (5)
O1	0.0202 (6)	0.0183 (6)	0.0175 (6)	0.0033 (5)	−0.0076 (5)	−0.0012 (5)
N1	0.0131 (7)	0.0215 (8)	0.0145 (7)	−0.0018 (6)	−0.0010 (6)	−0.0035 (6)
C1	0.0148 (8)	0.0192 (9)	0.0131 (8)	0.0021 (7)	0.0009 (6)	0.0021 (7)
C2	0.0159 (8)	0.0146 (8)	0.0136 (8)	0.0006 (7)	0.0016 (7)	0.0011 (7)
C3	0.0118 (7)	0.0149 (8)	0.0092 (7)	−0.0004 (6)	0.0040 (6)	0.0008 (6)
C4	0.0145 (8)	0.0133 (8)	0.0158 (8)	0.0008 (6)	0.0010 (6)	0.0023 (6)
C5	0.0167 (8)	0.0146 (9)	0.0199 (9)	−0.0004 (7)	0.0023 (7)	−0.0022 (7)
C6	0.0150 (8)	0.0148 (8)	0.0139 (8)	0.0019 (7)	−0.0010 (6)	0.0002 (7)
C7	0.0215 (9)	0.0226 (9)	0.0241 (10)	−0.0044 (8)	−0.0121 (8)	0.0029 (8)
C8	0.0467 (13)	0.0182 (10)	0.0206 (10)	−0.0012 (9)	−0.0107 (9)	0.0003 (8)

Geometric parameters (Å, º)

F1—C8	1.363 (2)	C3—C4	1.385 (2)
F2—C8	1.366 (3)	C3—C6	1.502 (2)
O1—C7	1.414 (2)	C4—C5	1.378 (2)
O1—C6	1.421 (2)	C4—H4	0.9500
N1—C5	1.335 (2)	C5—H5	0.9500
N1—C1	1.340 (2)	C6—H6A	0.9900
N1—H1A	0.85 (2)	C6—H6B	0.9900
C1—C2	1.371 (2)	C7—C8	1.496 (3)
C1—H1	0.9500	C7—H7A	0.9900
C2—C3	1.397 (2)	C7—H7B	0.9900
C2—H2	0.9500	C8—H8	1.0000
C7—O1—C6	114.51 (14)	O1—C6—C3	108.64 (14)
C5—N1—C1	122.83 (16)	O1—C6—H6A	110.0
C5—N1—H1A	120.2 (15)	C3—C6—H6A	110.0
C1—N1—H1A	117.0 (15)	O1—C6—H6B	110.0
N1—C1—C2	119.66 (17)	C3—C6—H6B	110.0
N1—C1—H1	120.2	H6A—C6—H6B	108.3
C2—C1—H1	120.2	O1—C7—C8	112.64 (16)
C1—C2—C3	119.33 (17)	O1—C7—H7A	109.1
C1—C2—H2	120.3	C8—C7—H7A	109.1
C3—C2—H2	120.3	O1—C7—H7B	109.1
C4—C3—C2	119.04 (16)	C8—C7—H7B	109.1
C4—C3—C6	121.87 (15)	H7A—C7—H7B	107.8
C2—C3—C6	119.09 (16)	F1—C8—F2	105.53 (18)
C5—C4—C3	119.62 (16)	F1—C8—C7	110.37 (17)
C5—C4—H4	120.2	F2—C8—C7	111.16 (16)
C3—C4—H4	120.2	F1—C8—H8	109.9
N1—C5—C4	119.46 (17)	F2—C8—H8	109.9
N1—C5—H5	120.3	C7—C8—H8	109.9
C4—C5—H5	120.3

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···I1	0.85 (2)	2.69 (2)	3.4501 (15)	151 (2)
C1—H1···I1^i	0.95	3.16	3.8487 (18)	131
C5—H5···I1^i	0.95	3.07	3.7705 (18)	131
C8—H8···I1^ii	1.00	3.05	3.917 (2)	146
C6—H6A···F1^iii	0.98	2.63	3.443 (2)	140
C7—H7B···F1^iv	0.99	2.43	3.413 (2)	173
C6—H6A···F2	0.99	2.33	3.008 (2)	125

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

4-[(3-Chloro-2,2,3,3-tetrafluoropropoxy)methyl]pyridinium iodide (i16319)

Crystal data

C9H9ClF4NO^+·I^−	F(000) = 736
Mr = 385.52	Dx = 2.100 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 5.3299 (2) Å	Cell parameters from 9996 reflections
b = 27.5016 (7) Å	θ = 2.6–27.2°
c = 8.3227 (2) Å	µ = 2.88 mm^−1
β = 91.813 (2)°	T = 100 K
V = 1219.34 (6) Å^3	Plate, colourless
Z = 4	0.44 × 0.36 × 0.04 mm

Data collection

Bruker APEXII CCD diffractometer	2631 reflections with I > 2σ(I)
φ and ω scans	Rint = 0.032
Absorption correction: multi-scan (SADABS; Bruker, 2015)	θmax = 27.1°, θmin = 2.6°
Tmin = 0.742, Tmax = 0.971	h = −6→6
23618 measured reflections	k = −35→35
2687 independent reflections	l = −10→10

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	Hydrogen site location: mixed
R[F^2 > 2σ(F^2)] = 0.018	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.037	w = 1/[σ^2(Fo^2) + (0.0042P)^2 + 1.4046P] where P = (Fo^2 + 2Fc^2)/3
S = 1.20	(Δ/σ)max = 0.003
2687 reflections	Δρmax = 0.50 e Å^−3
158 parameters	Δρmin = −0.43 e Å^−3

Special details

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

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

	x	y	z	Uiso*/Ueq
I1	−0.07294 (2)	0.54576 (2)	0.78282 (2)	0.01335 (4)
Cl1	0.93422 (10)	0.15860 (2)	0.70756 (6)	0.01902 (11)
F1	0.7905 (2)	0.26201 (4)	0.67304 (14)	0.0149 (2)
F2	1.0714 (2)	0.25388 (4)	0.86687 (14)	0.0180 (3)
F3	1.0913 (2)	0.20815 (4)	0.47562 (14)	0.0210 (3)
F4	1.3589 (2)	0.19877 (4)	0.67401 (17)	0.0236 (3)
O1	1.0798 (3)	0.34294 (5)	0.69182 (17)	0.0150 (3)
N1	0.3803 (3)	0.45367 (6)	0.8043 (2)	0.0152 (3)
C1	0.3836 (4)	0.45246 (7)	0.6427 (3)	0.0165 (4)
H1	0.2658	0.4710	0.5805	0.020*
C2	0.5576 (4)	0.42433 (7)	0.5680 (2)	0.0143 (4)
H2	0.5615	0.4234	0.4540	0.017*
C4	0.7296 (4)	0.39695 (7)	0.6611 (2)	0.0116 (4)
C5	0.7249 (4)	0.40050 (7)	0.8278 (2)	0.0134 (4)
H5	0.8435	0.3831	0.8932	0.016*
C6	0.5467 (4)	0.42942 (7)	0.8975 (3)	0.0159 (4)
H6	0.5423	0.4321	1.0112	0.019*
C7	0.9082 (4)	0.36433 (7)	0.5774 (2)	0.0146 (4)
H7A	0.8134	0.3385	0.5191	0.017*
H7B	1.0019	0.3833	0.4980	0.017*
C8	1.1868 (4)	0.29899 (7)	0.6391 (3)	0.0143 (4)
H8A	1.3642	0.2970	0.6775	0.017*
H8B	1.1825	0.2980	0.5202	0.017*
C9	1.0403 (4)	0.25630 (7)	0.7042 (2)	0.0118 (4)
C10	1.1159 (4)	0.20667 (7)	0.6368 (2)	0.0141 (4)
H1A	0.267 (5)	0.4713 (9)	0.841 (3)	0.019 (6)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
I1	0.01386 (7)	0.01387 (7)	0.01234 (7)	0.00388 (5)	0.00054 (5)	0.00106 (5)
Cl1	0.0182 (3)	0.0135 (2)	0.0256 (3)	−0.00237 (18)	0.0049 (2)	0.00308 (19)
F1	0.0076 (5)	0.0182 (6)	0.0190 (6)	0.0026 (4)	0.0006 (4)	0.0000 (5)
F2	0.0209 (6)	0.0229 (6)	0.0102 (6)	−0.0009 (5)	−0.0006 (5)	0.0007 (5)
F3	0.0305 (7)	0.0185 (6)	0.0144 (6)	−0.0010 (5)	0.0076 (5)	−0.0028 (5)
F4	0.0100 (6)	0.0178 (6)	0.0430 (8)	0.0040 (5)	0.0022 (5)	0.0030 (6)
O1	0.0158 (7)	0.0126 (7)	0.0164 (7)	0.0048 (6)	−0.0013 (6)	−0.0016 (5)
N1	0.0134 (9)	0.0135 (8)	0.0189 (9)	0.0025 (7)	0.0025 (7)	−0.0023 (7)
C1	0.0163 (10)	0.0129 (9)	0.0201 (11)	0.0008 (8)	−0.0033 (8)	0.0011 (8)
C2	0.0162 (10)	0.0134 (9)	0.0132 (10)	−0.0004 (8)	−0.0023 (8)	0.0006 (7)
C4	0.0116 (9)	0.0077 (8)	0.0154 (10)	−0.0018 (7)	0.0008 (7)	0.0011 (7)
C5	0.0136 (10)	0.0121 (9)	0.0146 (10)	0.0006 (7)	0.0001 (8)	0.0027 (7)
C6	0.0176 (10)	0.0143 (10)	0.0159 (10)	−0.0011 (8)	0.0016 (8)	−0.0006 (8)
C7	0.0167 (10)	0.0130 (9)	0.0140 (10)	0.0035 (8)	0.0007 (8)	0.0013 (8)
C8	0.0121 (10)	0.0120 (9)	0.0189 (10)	0.0033 (7)	0.0038 (8)	0.0000 (8)
C9	0.0096 (9)	0.0156 (9)	0.0102 (9)	0.0016 (7)	−0.0009 (7)	0.0005 (7)
C10	0.0121 (10)	0.0135 (9)	0.0169 (10)	0.0007 (7)	0.0025 (8)	0.0020 (8)

Geometric parameters (Å, º)

Cl1—C10	1.751 (2)	C2—H2	0.9500
F1—C9	1.357 (2)	C4—C5	1.392 (3)
F2—C9	1.360 (2)	C4—C7	1.496 (3)
F3—C10	1.345 (2)	C5—C6	1.380 (3)
F4—C10	1.340 (2)	C5—H5	0.9500
O1—C8	1.412 (2)	C6—H6	0.9500
O1—C7	1.426 (2)	C7—H7A	0.9900
N1—C6	1.338 (3)	C7—H7B	0.9900
N1—C1	1.346 (3)	C8—C9	1.519 (3)
N1—H1A	0.84 (3)	C8—H8A	0.9900
C1—C2	1.372 (3)	C8—H8B	0.9900
C1—H1	0.9500	C9—C10	1.534 (3)
C2—C4	1.401 (3)
C8—O1—C7	113.73 (15)	O1—C7—H7B	109.7
C6—N1—C1	122.52 (19)	C4—C7—H7B	109.7
C6—N1—H1A	123.1 (17)	H7A—C7—H7B	108.2
C1—N1—H1A	114.4 (17)	O1—C8—C9	109.48 (16)
N1—C1—C2	119.81 (19)	O1—C8—H8A	109.8
N1—C1—H1	120.1	C9—C8—H8A	109.8
C2—C1—H1	120.1	O1—C8—H8B	109.8
C1—C2—C4	119.51 (19)	C9—C8—H8B	109.8
C1—C2—H2	120.2	H8A—C8—H8B	108.2
C4—C2—H2	120.2	F1—C9—F2	106.50 (15)
C5—C4—C2	118.76 (18)	F1—C9—C8	110.76 (16)
C5—C4—C7	122.59 (18)	F2—C9—C8	110.16 (16)
C2—C4—C7	118.64 (18)	F1—C9—C10	107.49 (16)
C6—C5—C4	119.59 (19)	F2—C9—C10	107.16 (15)
C6—C5—H5	120.2	C8—C9—C10	114.41 (16)
C4—C5—H5	120.2	F4—C10—F3	107.35 (16)
N1—C6—C5	119.73 (19)	F4—C10—C9	108.85 (16)
N1—C6—H6	120.1	F3—C10—C9	108.63 (16)
C5—C6—H6	120.1	F4—C10—Cl1	109.92 (14)
O1—C7—C4	109.88 (16)	F3—C10—Cl1	108.70 (14)
O1—C7—H7A	109.7	C9—C10—Cl1	113.22 (14)
C4—C7—H7A	109.7

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···I1	0.84 (3)	2.77 (3)	3.501 (2)	147 (2)
C6—H6···I1^i	0.95	3.14	3.788 (2)	127
C7—H7B···I1^ii	0.99	3.08	4.005 (2)	157
C10—Cl1···I1^iii	1.75 (1)	3.65 (1)	5.341 (2)	161 (1)
C8—H8A···F1^iv	0.99	2.47	3.378 (2)	152
C9—F1···F4^v	1.36 (1)	2.88 (1)	3.962 (2)	135 (1)
C9—F1···F2^vi	1.36 (1)	2.80 (1)	3.710 (2)	122 (1)
C9—F1···F3^vii	1.36 (1)	2.88 (1)	3.483 (2)	105 (1)
C9—F2···F1^vii	1.36 (1)	2.80 (1)	4.114 (2)	161 (1)
C9—F2···F3^vii	1.36 (1)	2.93 (1)	3.483 (2)	102 (1)
C10—F3···F1^viii	1.34 (1)	2.88 (1)	4.091 (2)	149 (1)
C10—F3···F2^viii	1.34 (1)	2.93 (1)	3.530 (2)	105 (1)
C10—F4···F1^iv	1.34 (1)	2.88 (1)	3.907 (2)	132 (1)

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