In the isomeric title compounds,
viz. 2-, 3- and 4-(chloromethyl)pyridinium chloride, C
6H
7ClN
+·Cl
−, the secondary interactions have been established as follows. Classical N—H
Cl
− hydrogen bonds are observed in the 2- and 3-isomers, whereas the 4-isomer forms inversion-symmetric N—H(
Cl
−)
2H—N dimers involving three-centre hydrogen bonds. Short Cl
Cl contacts are formed in both the 2-isomer (C—Cl
Cl
−, approximately linear at the central Cl) and the 4-isomer (C—Cl
Cl—C, angles at Cl of
ca 75°). Additionally, each compound displays contacts of the form C—H
Cl, mainly to the Cl
− anion. The net effect is to create either a layer structure (3-isomer) or a three-dimensional packing with easily identifiable layer substructures (2- and 4-isomers).
Supporting information
CCDC references: 199433; 199434; 199435
The title compounds were purchased from Avocada Research Chemicals Ltd. and
dried carefully under vacuum. Single crystals were obtained by liquid-liquid
diffusion at 253 K, for (I) from ethanol-diethyl ether (Ratio?), and for (II)
and (III) from dimethylformamide-diethyl ether (Ratio?). Crystals of (I) are
hygroscopic and those of (II) extremely so; they had to be transferred rapidly
from the mother liquor to the mounting oil, thence to the glass fibre and
finally to the cold gas stream. The crystals of (II), being thin needles, of
necessity then lay at the side of the fibre in a moderately large oil drop.
The long exposure times precluded the measurement of sufficient equivalents to
perform an adequate absorption correction.
The acidic H atoms (at N) were refined freely. The remaining H atoms were
refined with a riding model, with C—H distances of 0.95 Å for aromatic
C—H and 0.99 Å for CH2, and with Uiso(H) = 1.2Ueq(C).
The crystal of (I) gave diffraction patterns suggestive of twinning; although
a unit cell was found without difficulty, an appreciable number of significant
reflections remained unindexed. The original data collection involved 12218
reflections, 2138 unique. The refinement gave satisfactory R values
(Rint 0.031 and R1 0.039; however, wR2 was rather
high at 0.118) but unsatisfactory residual electron density (1.05 e Å-3).
Inspection with the program GEMINI (Bruker, 2002) clearly showed two
twin domains related by a rotation of 180° about [001]. The data were
integrated with SAINT32A (Bruker, 2002), which allows the use of two
orientation matrices for the two twin domains. The program TWINABS 1.02
(Bruker, 2002) was used for scaling and merging. Because SAINT treats
equivalent reflections independently, ca 30% of the data were
integrated as non-overlapped, although equivalents of them were overlapped by
a reflection of the second domain. These reflections could not be merged,
which led to an artificially high apparent number of data. Therefore, these
data were omitted. The fractional contribution of the second domain refined to
0.1854 (12).
For all compounds, data collection: SMART (Bruker, 1998); cell refinement: SAINT (Bruker, 1998); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP (Siemens, 1994); software used to prepare material for publication: SHELXL97.
(I) 2-chloromethylpyridinium chloride
top
Crystal data top
C6H7ClN+·Cl− | F(000) = 336 |
Mr = 164.03 | Dx = 1.479 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
a = 7.9273 (14) Å | Cell parameters from 7727 reflections |
b = 12.721 (2) Å | θ = 2.6–30.5° |
c = 7.4773 (14) Å | µ = 0.79 mm−1 |
β = 102.382 (6)° | T = 133 K |
V = 736.5 (2) Å3 | Lath, colourless |
Z = 4 | 0.45 × 0.15 × 0.09 mm |
Data collection top
Bruker SMART 1000 CCD area-detector diffractometer | 2150 independent reflections |
Radiation source: normal-focus sealed tube | 1864 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.030 |
Detector resolution: 8.192 pixels mm-1 | θmax = 30.0°, θmin = 2.6° |
ω and ϕ scans | h = −11→10 |
Absorption correction: multi-scan (TWINABS; Bruker, 2002) | k = −0→17 |
Tmin = 0.795, Tmax = 0.928 | l = −0→10 |
15781 measured reflections | |
Refinement top
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.027 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.071 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.04 | w = 1/[σ2(Fo2) + (0.0474P)2 + 0.0509P] where P = (Fo2 + 2Fc2)/3 |
2150 reflections | (Δ/σ)max = 0.001 |
87 parameters | Δρmax = 0.51 e Å−3 |
0 restraints | Δρmin = −0.22 e Å−3 |
Crystal data top
C6H7ClN+·Cl− | V = 736.5 (2) Å3 |
Mr = 164.03 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 7.9273 (14) Å | µ = 0.79 mm−1 |
b = 12.721 (2) Å | T = 133 K |
c = 7.4773 (14) Å | 0.45 × 0.15 × 0.09 mm |
β = 102.382 (6)° | |
Data collection top
Bruker SMART 1000 CCD area-detector diffractometer | 2150 independent reflections |
Absorption correction: multi-scan (TWINABS; Bruker, 2002) | 1864 reflections with I > 2σ(I) |
Tmin = 0.795, Tmax = 0.928 | Rint = 0.030 |
15781 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.027 | 0 restraints |
wR(F2) = 0.071 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.04 | Δρmax = 0.51 e Å−3 |
2150 reflections | Δρmin = −0.22 e Å−3 |
87 parameters | |
Special details top
Experimental. 2-chloromethylpyridinium chloride |
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 (Å2) top | x | y | z | Uiso*/Ueq | |
Cl1 | 1.13705 (4) | 0.38768 (2) | 0.65418 (4) | 0.02290 (9) | |
Cl2 | 0.74048 (4) | 0.56737 (2) | 0.76914 (4) | 0.02132 (9) | |
N1 | 0.73592 (14) | 0.34524 (9) | 0.65134 (14) | 0.0203 (2) | |
H0 | 0.751 (2) | 0.4136 (16) | 0.676 (3) | 0.032 (4)* | |
C2 | 0.86485 (15) | 0.27775 (10) | 0.71730 (15) | 0.0182 (2) | |
C3 | 0.83591 (15) | 0.17123 (10) | 0.69203 (16) | 0.0208 (2) | |
H3 | 0.9250 | 0.1223 | 0.7386 | 0.025* | |
C4 | 0.67506 (17) | 0.13633 (10) | 0.59774 (18) | 0.0246 (3) | |
H4 | 0.6530 | 0.0632 | 0.5812 | 0.029* | |
C5 | 0.54737 (16) | 0.20847 (11) | 0.52814 (19) | 0.0255 (3) | |
H5 | 0.4380 | 0.1855 | 0.4610 | 0.031* | |
C6 | 0.58063 (15) | 0.31375 (11) | 0.55736 (17) | 0.0241 (3) | |
H6 | 0.4938 | 0.3642 | 0.5111 | 0.029* | |
C7 | 1.03361 (17) | 0.32280 (11) | 0.81455 (17) | 0.0260 (3) | |
H7A | 1.1090 | 0.2659 | 0.8771 | 0.031* | |
H7B | 1.0142 | 0.3736 | 0.9084 | 0.031* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Cl1 | 0.02133 (14) | 0.02466 (16) | 0.02290 (15) | −0.00464 (10) | 0.00515 (11) | 0.00051 (11) |
Cl2 | 0.02065 (14) | 0.02001 (15) | 0.02203 (15) | 0.00069 (10) | 0.00176 (11) | −0.00155 (10) |
N1 | 0.0234 (5) | 0.0195 (5) | 0.0178 (5) | 0.0014 (4) | 0.0041 (4) | 0.0002 (4) |
C2 | 0.0177 (5) | 0.0243 (6) | 0.0127 (5) | −0.0009 (5) | 0.0033 (4) | 0.0009 (4) |
C3 | 0.0202 (5) | 0.0227 (6) | 0.0198 (6) | 0.0035 (5) | 0.0050 (4) | 0.0018 (4) |
C4 | 0.0281 (6) | 0.0224 (6) | 0.0238 (6) | −0.0055 (5) | 0.0070 (5) | −0.0037 (5) |
C5 | 0.0187 (5) | 0.0354 (7) | 0.0212 (6) | −0.0059 (5) | 0.0017 (5) | −0.0010 (5) |
C6 | 0.0186 (5) | 0.0321 (7) | 0.0211 (6) | 0.0046 (5) | 0.0028 (4) | 0.0047 (5) |
C7 | 0.0239 (6) | 0.0363 (7) | 0.0160 (6) | −0.0108 (5) | 0.0000 (4) | 0.0037 (5) |
Geometric parameters (Å, º) top
Cl1—C7 | 1.7925 (13) | N1—H0 | 0.89 (2) |
N1—C6 | 1.3411 (16) | C3—H3 | 0.9500 |
N1—C2 | 1.3449 (16) | C4—H4 | 0.9500 |
C2—C3 | 1.3805 (17) | C5—H5 | 0.9500 |
C2—C7 | 1.4932 (16) | C6—H6 | 0.9500 |
C3—C4 | 1.3909 (18) | C7—H7A | 0.9900 |
C4—C5 | 1.3826 (19) | C7—H7B | 0.9900 |
C5—C6 | 1.373 (2) | | |
| | | |
C6—N1—C2 | 122.78 (11) | C4—C3—H3 | 120.3 |
N1—C2—C3 | 119.04 (11) | C5—C4—H4 | 120.1 |
N1—C2—C7 | 117.69 (11) | C3—C4—H4 | 120.1 |
C3—C2—C7 | 123.27 (11) | C6—C5—H5 | 120.4 |
C2—C3—C4 | 119.34 (11) | C4—C5—H5 | 120.4 |
C5—C4—C3 | 119.77 (12) | N1—C6—H6 | 120.1 |
C6—C5—C4 | 119.16 (11) | C5—C6—H6 | 120.1 |
N1—C6—C5 | 119.87 (11) | C2—C7—H7A | 109.7 |
C2—C7—Cl1 | 109.97 (8) | Cl1—C7—H7A | 109.7 |
C6—N1—H0 | 117.9 (12) | C2—C7—H7B | 109.7 |
C2—N1—H0 | 119.2 (12) | Cl1—C7—H7B | 109.7 |
C2—C3—H3 | 120.3 | H7A—C7—H7B | 108.2 |
| | | |
C6—N1—C2—C3 | −1.75 (17) | C3—C4—C5—C6 | −1.54 (19) |
C6—N1—C2—C7 | 178.08 (11) | C2—N1—C6—C5 | 1.23 (18) |
N1—C2—C3—C4 | 0.59 (17) | C4—C5—C6—N1 | 0.45 (19) |
C7—C2—C3—C4 | −179.22 (11) | N1—C2—C7—Cl1 | −70.54 (13) |
C2—C3—C4—C5 | 1.02 (18) | C3—C2—C7—Cl1 | 109.28 (12) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H0···Cl2 | 0.89 (2) | 2.08 (2) | 2.9578 (12) | 166 (2) |
C3—H3···Cl2i | 0.95 | 2.75 | 3.5621 (13) | 143 |
C6—H6···Cl2ii | 0.95 | 2.63 | 3.4730 (13) | 148 |
C7—H7B···Cl2iii | 0.99 | 2.85 | 3.5296 (14) | 126 |
C7—H7A···Cl1iv | 0.99 | 2.82 | 3.6603 (15) | 143 |
Symmetry codes: (i) −x+2, y−1/2, −z+3/2; (ii) −x+1, −y+1, −z+1; (iii) −x+2, −y+1, −z+2; (iv) x, −y+1/2, z+1/2. |
(II) 3-chloromethylpyridinium chloride
top
Crystal data top
C6H7ClN+·Cl− | F(000) = 672 |
Mr = 164.03 | Dx = 1.518 Mg m−3 |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71073 Å |
a = 23.037 (4) Å | Cell parameters from 3132 reflections |
b = 4.3310 (8) Å | θ = 2.8–30.4° |
c = 14.855 (3) Å | µ = 0.81 mm−1 |
β = 104.441 (12)° | T = 133 K |
V = 1435.3 (5) Å3 | Needle, colourless |
Z = 8 | 0.50 × 0.06 × 0.03 mm |
Data collection top
Bruker SMART 1000 CCD area-detector diffractometer | 1582 reflections with I > 2σ(I) |
Radiation source: normal-focus sealed tube | Rint = 0.179 |
Graphite monochromator | θmax = 30.0°, θmin = 1.8° |
Detector resolution: 8.192 pixels mm-1 | h = −32→31 |
ω and ϕ scans | k = −6→6 |
8435 measured reflections | l = −20→20 |
2098 independent reflections | |
Refinement top
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.047 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.123 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.01 | w = 1/[σ2(Fo2) + (0.0468P)2] where P = (Fo2 + 2Fc2)/3 |
2098 reflections | (Δ/σ)max = 0.002 |
86 parameters | Δρmax = 0.54 e Å−3 |
0 restraints | Δρmin = −0.57 e Å−3 |
Crystal data top
C6H7ClN+·Cl− | V = 1435.3 (5) Å3 |
Mr = 164.03 | Z = 8 |
Monoclinic, C2/c | Mo Kα radiation |
a = 23.037 (4) Å | µ = 0.81 mm−1 |
b = 4.3310 (8) Å | T = 133 K |
c = 14.855 (3) Å | 0.50 × 0.06 × 0.03 mm |
β = 104.441 (12)° | |
Data collection top
Bruker SMART 1000 CCD area-detector diffractometer | 1582 reflections with I > 2σ(I) |
8435 measured reflections | Rint = 0.179 |
2098 independent reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.047 | 0 restraints |
wR(F2) = 0.123 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.01 | Δρmax = 0.54 e Å−3 |
2098 reflections | Δρmin = −0.57 e Å−3 |
86 parameters | |
Special details top
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 (Å2) top | x | y | z | Uiso*/Ueq | |
Cl1 | 0.23991 (3) | 0.21847 (14) | 0.63712 (3) | 0.02789 (17) | |
Cl2 | −0.05793 (3) | 0.40869 (12) | 0.33846 (3) | 0.02246 (16) | |
N1 | 0.05678 (9) | 0.0692 (4) | 0.40334 (12) | 0.0211 (4) | |
H1 | 0.0261 (14) | 0.166 (7) | 0.3818 (19) | 0.031 (8)* | |
C2 | 0.08531 (11) | 0.1126 (5) | 0.49168 (14) | 0.0215 (4) | |
H2 | 0.0682 | 0.2411 | 0.5301 | 0.026* | |
C3 | 0.13930 (10) | −0.0273 (5) | 0.52752 (12) | 0.0189 (4) | |
C4 | 0.16232 (10) | −0.2140 (5) | 0.46944 (13) | 0.0215 (4) | |
H4 | 0.1997 | −0.3148 | 0.4925 | 0.026* | |
C5 | 0.13112 (11) | −0.2546 (5) | 0.37808 (14) | 0.0231 (5) | |
H5 | 0.1468 | −0.3834 | 0.3381 | 0.028* | |
C6 | 0.07780 (11) | −0.1089 (5) | 0.34585 (13) | 0.0221 (4) | |
H6 | 0.0558 | −0.1339 | 0.2831 | 0.027* | |
C7 | 0.17049 (11) | 0.0168 (6) | 0.62706 (13) | 0.0239 (5) | |
H7A | 0.1785 | −0.1866 | 0.6580 | 0.029* | |
H7B | 0.1446 | 0.1364 | 0.6584 | 0.029* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Cl1 | 0.0258 (3) | 0.0329 (3) | 0.0224 (2) | −0.0011 (2) | 0.0011 (2) | −0.0024 (2) |
Cl2 | 0.0253 (3) | 0.0253 (3) | 0.0176 (2) | 0.0062 (2) | 0.00681 (18) | 0.00161 (18) |
N1 | 0.0201 (10) | 0.0224 (9) | 0.0200 (7) | 0.0036 (8) | 0.0034 (7) | 0.0013 (7) |
C2 | 0.0246 (12) | 0.0205 (10) | 0.0214 (9) | 0.0009 (9) | 0.0096 (8) | −0.0008 (8) |
C3 | 0.0210 (11) | 0.0217 (10) | 0.0144 (7) | −0.0009 (8) | 0.0052 (7) | 0.0017 (7) |
C4 | 0.0214 (11) | 0.0249 (11) | 0.0186 (8) | 0.0028 (9) | 0.0054 (8) | 0.0017 (8) |
C5 | 0.0248 (12) | 0.0275 (12) | 0.0181 (8) | 0.0019 (9) | 0.0072 (8) | −0.0037 (8) |
C6 | 0.0248 (12) | 0.0252 (11) | 0.0155 (8) | −0.0007 (9) | 0.0037 (8) | −0.0009 (8) |
C7 | 0.0249 (12) | 0.0306 (11) | 0.0161 (8) | −0.0006 (10) | 0.0048 (8) | −0.0007 (8) |
Geometric parameters (Å, º) top
Cl1—C7 | 1.795 (2) | N1—H1 | 0.81 (3) |
N1—C2 | 1.326 (3) | C2—H2 | 0.9500 |
N1—C6 | 1.328 (3) | C4—H4 | 0.9500 |
C2—C3 | 1.366 (3) | C5—H5 | 0.9500 |
C3—C4 | 1.381 (3) | C6—H6 | 0.9500 |
C3—C7 | 1.486 (3) | C7—H7A | 0.9900 |
C4—C5 | 1.379 (3) | C7—H7B | 0.9900 |
C5—C6 | 1.358 (3) | | |
| | | |
C2—N1—C6 | 123.2 (2) | C3—C2—H2 | 120.0 |
N1—C2—C3 | 120.06 (19) | C5—C4—H4 | 119.9 |
C2—C3—C4 | 118.05 (19) | C3—C4—H4 | 119.9 |
C2—C3—C7 | 119.86 (19) | C6—C5—H5 | 120.3 |
C4—C3—C7 | 122.1 (2) | C4—C5—H5 | 120.3 |
C5—C4—C3 | 120.1 (2) | N1—C6—H6 | 120.5 |
C6—C5—C4 | 119.43 (19) | C5—C6—H6 | 120.5 |
N1—C6—C5 | 119.1 (2) | C3—C7—H7A | 109.6 |
C3—C7—Cl1 | 110.18 (14) | Cl1—C7—H7A | 109.6 |
C2—N1—H1 | 119 (2) | C3—C7—H7B | 109.6 |
C6—N1—H1 | 117.7 (19) | Cl1—C7—H7B | 109.6 |
N1—C2—H2 | 120.0 | H7A—C7—H7B | 108.1 |
| | | |
C6—N1—C2—C3 | 0.5 (3) | C3—C4—C5—C6 | 0.2 (3) |
N1—C2—C3—C4 | −0.5 (3) | C2—N1—C6—C5 | −0.1 (3) |
N1—C2—C3—C7 | −178.7 (2) | C4—C5—C6—N1 | −0.2 (3) |
C2—C3—C4—C5 | 0.2 (3) | C2—C3—C7—Cl1 | −115.5 (2) |
C7—C3—C4—C5 | 178.4 (2) | C4—C3—C7—Cl1 | 66.3 (3) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···Cl2 | 0.81 (3) | 2.16 (3) | 2.967 (2) | 174 (3) |
C2—H2···Cl2i | 0.95 | 2.53 | 3.443 (2) | 161 |
C7—H7B···Cl2i | 0.99 | 2.81 | 3.720 (3) | 153 |
C6—H6···Cl2ii | 0.95 | 2.69 | 3.383 (2) | 130 |
C4—H4···Cl1iii | 0.95 | 2.93 | 3.636 (2) | 132 |
C5—H5···Cl1iv | 0.95 | 2.93 | 3.640 (2) | 133 |
C7—H7A···Cl1iii | 0.99 | 2.99 | 3.797 (3) | 139 |
C7—H7A···Cl2v | 0.99 | 2.95 | 3.323 (2) | 103 |
Symmetry codes: (i) −x, −y+1, −z+1; (ii) −x, y−1, −z+1/2; (iii) x, y−1, z; (iv) −x+1/2, −y−1/2, −z+1; (v) −x, −y, −z+1. |
(III) 4-chloromethylpyridinium chloride
top
Crystal data top
C6H7ClN+·Cl− | Z = 2 |
Mr = 164.03 | F(000) = 168 |
Triclinic, P1 | Dx = 1.569 Mg m−3 |
a = 6.9531 (4) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 7.4755 (6) Å | Cell parameters from 4785 reflections |
c = 7.4978 (4) Å | θ = 2.9–30.5° |
α = 71.119 (3)° | µ = 0.84 mm−1 |
β = 75.731 (3)° | T = 133 K |
γ = 72.694 (3)° | Tablet, colourless |
V = 347.16 (4) Å3 | 0.3 × 0.2 × 0.1 mm |
Data collection top
Bruker SMART 1000 CCD area-detector diffractometer | 2024 independent reflections |
Radiation source: normal-focus sealed tube | 1856 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.015 |
Detector resolution: 8.192 pixels mm-1 | θmax = 30.0°, θmin = 2.9° |
ω and ϕ scans | h = −9→9 |
Absorption correction: multi-scan (SADABS; Bruker, 1998) | k = −10→10 |
Tmin = 0.797, Tmax = 0.928 | l = −10→10 |
6548 measured reflections | |
Refinement top
Refinement on F2 | Primary atom site location: Patterson |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.024 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.070 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.12 | w = 1/[σ2(Fo2) + (0.0407P)2 + 0.0639P] where P = (Fo2 + 2Fc2)/3 |
2024 reflections | (Δ/σ)max = 0.001 |
86 parameters | Δρmax = 0.48 e Å−3 |
0 restraints | Δρmin = −0.25 e Å−3 |
Crystal data top
C6H7ClN+·Cl− | γ = 72.694 (3)° |
Mr = 164.03 | V = 347.16 (4) Å3 |
Triclinic, P1 | Z = 2 |
a = 6.9531 (4) Å | Mo Kα radiation |
b = 7.4755 (6) Å | µ = 0.84 mm−1 |
c = 7.4978 (4) Å | T = 133 K |
α = 71.119 (3)° | 0.3 × 0.2 × 0.1 mm |
β = 75.731 (3)° | |
Data collection top
Bruker SMART 1000 CCD area-detector diffractometer | 2024 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 1998) | 1856 reflections with I > 2σ(I) |
Tmin = 0.797, Tmax = 0.928 | Rint = 0.015 |
6548 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.024 | 0 restraints |
wR(F2) = 0.070 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.12 | Δρmax = 0.48 e Å−3 |
2024 reflections | Δρmin = −0.25 e Å−3 |
86 parameters | |
Special details top
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. Non-bonded distances etc.: 3.6051 (0.0006) Cl1 - Cl1_$7 74.54 (0.03) C7 - Cl1 - Cl1_$7 Operator $7: 1 - x,-y,-z |
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 (Å2) top | x | y | z | Uiso*/Ueq | |
Cl1 | 0.33807 (4) | −0.06919 (4) | 0.22620 (4) | 0.02315 (9) | |
Cl2 | 0.16744 (4) | 0.67292 (4) | 0.90416 (3) | 0.01863 (8) | |
N1 | 0.16318 (14) | 0.36330 (15) | 0.70640 (13) | 0.01928 (19) | |
H1 | 0.108 (3) | 0.413 (3) | 0.811 (3) | 0.048 (5)* | |
C2 | 0.14217 (17) | 0.18762 (17) | 0.71882 (15) | 0.0203 (2) | |
H2 | 0.0837 | 0.1120 | 0.8367 | 0.024* | |
C3 | 0.20571 (16) | 0.11577 (16) | 0.55986 (14) | 0.0182 (2) | |
H3 | 0.1919 | −0.0095 | 0.5683 | 0.022* | |
C4 | 0.29005 (15) | 0.22861 (15) | 0.38753 (14) | 0.01510 (19) | |
C5 | 0.31261 (16) | 0.41082 (16) | 0.38110 (15) | 0.0177 (2) | |
H5 | 0.3720 | 0.4893 | 0.2657 | 0.021* | |
C6 | 0.24790 (17) | 0.47519 (17) | 0.54370 (15) | 0.0194 (2) | |
H6 | 0.2630 | 0.5983 | 0.5410 | 0.023* | |
C7 | 0.35539 (17) | 0.17116 (16) | 0.20384 (14) | 0.0181 (2) | |
H7A | 0.4985 | 0.1808 | 0.1523 | 0.022* | |
H7B | 0.2696 | 0.2649 | 0.1101 | 0.022* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Cl1 | 0.02739 (15) | 0.02024 (15) | 0.02529 (14) | −0.00887 (11) | 0.00080 (10) | −0.01170 (11) |
Cl2 | 0.02168 (14) | 0.01816 (14) | 0.01735 (13) | −0.00826 (10) | 0.00121 (9) | −0.00660 (9) |
N1 | 0.0192 (4) | 0.0218 (5) | 0.0167 (4) | −0.0002 (4) | −0.0035 (3) | −0.0089 (3) |
C2 | 0.0204 (5) | 0.0216 (5) | 0.0159 (4) | −0.0038 (4) | −0.0002 (4) | −0.0044 (4) |
C3 | 0.0206 (5) | 0.0163 (5) | 0.0178 (4) | −0.0056 (4) | −0.0011 (4) | −0.0051 (4) |
C4 | 0.0141 (4) | 0.0155 (5) | 0.0159 (4) | −0.0023 (4) | −0.0028 (3) | −0.0054 (3) |
C5 | 0.0199 (5) | 0.0158 (5) | 0.0177 (4) | −0.0058 (4) | −0.0023 (4) | −0.0044 (4) |
C6 | 0.0211 (5) | 0.0173 (5) | 0.0213 (5) | −0.0031 (4) | −0.0052 (4) | −0.0073 (4) |
C7 | 0.0243 (5) | 0.0159 (5) | 0.0156 (4) | −0.0063 (4) | −0.0014 (4) | −0.0062 (4) |
Geometric parameters (Å, º) top
N1—C2 | 1.3353 (15) | N1—H1 | 0.921 (19) |
N1—C6 | 1.3466 (14) | C2—H2 | 0.9500 |
C2—C3 | 1.3849 (15) | C3—H3 | 0.9500 |
C3—C4 | 1.3929 (14) | C5—H5 | 0.9500 |
C4—C5 | 1.4011 (14) | C6—H6 | 0.9500 |
C4—C7 | 1.4987 (14) | C7—H7A | 0.9900 |
C5—C6 | 1.3787 (15) | C7—H7B | 0.9900 |
C7—Cl1 | 1.7874 (11) | | |
| | | |
C2—N1—C6 | 122.40 (9) | C3—C2—H2 | 120.0 |
N1—C2—C3 | 119.98 (10) | C2—C3—H3 | 120.3 |
C2—C3—C4 | 119.48 (10) | C4—C3—H3 | 120.3 |
C3—C4—C5 | 118.81 (9) | C6—C5—H5 | 120.3 |
C3—C4—C7 | 124.51 (9) | C4—C5—H5 | 120.3 |
C5—C4—C7 | 116.66 (9) | N1—C6—H6 | 120.1 |
C6—C5—C4 | 119.41 (9) | C5—C6—H6 | 120.1 |
N1—C6—C5 | 119.89 (10) | C4—C7—H7A | 108.7 |
C4—C7—Cl1 | 114.14 (7) | Cl1—C7—H7A | 108.7 |
C2—N1—H1 | 118.1 (12) | C4—C7—H7B | 108.7 |
C6—N1—H1 | 119.3 (12) | Cl1—C7—H7B | 108.7 |
N1—C2—H2 | 120.0 | H7A—C7—H7B | 107.6 |
| | | |
C6—N1—C2—C3 | −1.03 (16) | C7—C4—C5—C6 | 177.50 (10) |
N1—C2—C3—C4 | −0.42 (17) | C2—N1—C6—C5 | 1.37 (16) |
C2—C3—C4—C5 | 1.46 (16) | C4—C5—C6—N1 | −0.27 (16) |
C2—C3—C4—C7 | −177.04 (10) | C3—C4—C7—Cl1 | −5.40 (14) |
C3—C4—C5—C6 | −1.12 (15) | C5—C4—C7—Cl1 | 176.07 (8) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···Cl2i | 0.921 (19) | 2.545 (19) | 3.2301 (10) | 131.6 (15) |
N1—H1···Cl2 | 0.921 (19) | 2.440 (19) | 3.1369 (10) | 132.5 (15) |
C2—H2···Cl2i | 0.95 | 2.84 | 3.3592 (11) | 115 |
C6—H6···Cl2 | 0.95 | 2.84 | 3.3393 (11) | 114 |
C7—H7B···Cl2ii | 0.99 | 2.90 | 3.7286 (11) | 142 |
C7—H7B···Cl2iii | 0.99 | 2.96 | 3.6809 (12) | 131 |
C7—H7A···Cl2iv | 0.99 | 2.74 | 3.6589 (11) | 155 |
C6—H6···Cl1v | 0.95 | 2.90 | 3.5983 (12) | 132 |
C3—H3···Cl2vi | 0.95 | 2.86 | 3.5141 (11) | 127 |
Symmetry codes: (i) −x, −y+1, −z+2; (ii) x, y, z−1; (iii) −x, −y+1, −z+1; (iv) −x+1, −y+1, −z+1; (v) x, y+1, z; (vi) x, y−1, z. |
Experimental details
| (I) | (II) | (III) |
Crystal data |
Chemical formula | C6H7ClN+·Cl− | C6H7ClN+·Cl− | C6H7ClN+·Cl− |
Mr | 164.03 | 164.03 | 164.03 |
Crystal system, space group | Monoclinic, P21/c | Monoclinic, C2/c | Triclinic, P1 |
Temperature (K) | 133 | 133 | 133 |
a, b, c (Å) | 7.9273 (14), 12.721 (2), 7.4773 (14) | 23.037 (4), 4.3310 (8), 14.855 (3) | 6.9531 (4), 7.4755 (6), 7.4978 (4) |
α, β, γ (°) | 90, 102.382 (6), 90 | 90, 104.441 (12), 90 | 71.119 (3), 75.731 (3), 72.694 (3) |
V (Å3) | 736.5 (2) | 1435.3 (5) | 347.16 (4) |
Z | 4 | 8 | 2 |
Radiation type | Mo Kα | Mo Kα | Mo Kα |
µ (mm−1) | 0.79 | 0.81 | 0.84 |
Crystal size (mm) | 0.45 × 0.15 × 0.09 | 0.50 × 0.06 × 0.03 | 0.3 × 0.2 × 0.1 |
|
Data collection |
Diffractometer | Bruker SMART 1000 CCD area-detector diffractometer | Bruker SMART 1000 CCD area-detector diffractometer | Bruker SMART 1000 CCD area-detector diffractometer |
Absorption correction | Multi-scan (TWINABS; Bruker, 2002) | – | Multi-scan (SADABS; Bruker, 1998) |
Tmin, Tmax | 0.795, 0.928 | – | 0.797, 0.928 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 15781, 2150, 1864 | 8435, 2098, 1582 | 6548, 2024, 1856 |
Rint | 0.030 | 0.179 | 0.015 |
(sin θ/λ)max (Å−1) | 0.704 | 0.704 | 0.704 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.027, 0.071, 1.04 | 0.047, 0.123, 1.01 | 0.024, 0.070, 1.12 |
No. of reflections | 2150 | 2098 | 2024 |
No. of parameters | 87 | 86 | 86 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement | H atoms treated by a mixture of independent and constrained refinement | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.51, −0.22 | 0.54, −0.57 | 0.48, −0.25 |
Selected geometric parameters (Å, º) for (I) topN1—C6 | 1.3411 (16) | N1—C2 | 1.3449 (16) |
| | | |
C6—N1—C2 | 122.78 (11) | N1—C2—C3 | 119.04 (11) |
| | | |
C3—C2—C7—Cl1 | 109.28 (12) | | |
Hydrogen-bond geometry (Å, º) for (I) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H0···Cl2 | 0.89 (2) | 2.08 (2) | 2.9578 (12) | 166 (2) |
C3—H3···Cl2i | 0.95 | 2.75 | 3.5621 (13) | 143 |
C6—H6···Cl2ii | 0.95 | 2.63 | 3.4730 (13) | 148 |
C7—H7B···Cl2iii | 0.99 | 2.85 | 3.5296 (14) | 126 |
C7—H7A···Cl1iv | 0.99 | 2.82 | 3.6603 (15) | 143 |
Symmetry codes: (i) −x+2, y−1/2, −z+3/2; (ii) −x+1, −y+1, −z+1; (iii) −x+2, −y+1, −z+2; (iv) x, −y+1/2, z+1/2. |
Selected geometric parameters (Å, º) for (II) topN1—C2 | 1.326 (3) | N1—C6 | 1.328 (3) |
| | | |
C2—N1—C6 | 123.2 (2) | C2—C3—C4 | 118.05 (19) |
| | | |
C4—C3—C7—Cl1 | 66.3 (3) | | |
Hydrogen-bond geometry (Å, º) for (II) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···Cl2 | 0.81 (3) | 2.16 (3) | 2.967 (2) | 174 (3) |
C2—H2···Cl2i | 0.95 | 2.53 | 3.443 (2) | 161 |
C7—H7B···Cl2i | 0.99 | 2.81 | 3.720 (3) | 153 |
C6—H6···Cl2ii | 0.95 | 2.69 | 3.383 (2) | 130 |
C4—H4···Cl1iii | 0.95 | 2.93 | 3.636 (2) | 132 |
C5—H5···Cl1iv | 0.95 | 2.93 | 3.640 (2) | 133 |
C7—H7A···Cl1iii | 0.99 | 2.99 | 3.797 (3) | 139 |
C7—H7A···Cl2v | 0.99 | 2.95 | 3.323 (2) | 103 |
Symmetry codes: (i) −x, −y+1, −z+1; (ii) −x, y−1, −z+1/2; (iii) x, y−1, z; (iv) −x+1/2, −y−1/2, −z+1; (v) −x, −y, −z+1. |
Selected geometric parameters (Å, º) for (III) topN1—C2 | 1.3353 (15) | N1—C6 | 1.3466 (14) |
| | | |
C2—N1—C6 | 122.40 (9) | C3—C4—C7 | 124.51 (9) |
C3—C4—C5 | 118.81 (9) | | |
| | | |
C3—C4—C7—Cl1 | −5.40 (14) | | |
Hydrogen-bond geometry (Å, º) for (III) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···Cl2i | 0.921 (19) | 2.545 (19) | 3.2301 (10) | 131.6 (15) |
N1—H1···Cl2 | 0.921 (19) | 2.440 (19) | 3.1369 (10) | 132.5 (15) |
C2—H2···Cl2i | 0.95 | 2.84 | 3.3592 (11) | 115 |
C6—H6···Cl2 | 0.95 | 2.84 | 3.3393 (11) | 114 |
C7—H7B···Cl2ii | 0.99 | 2.90 | 3.7286 (11) | 142 |
C7—H7B···Cl2iii | 0.99 | 2.96 | 3.6809 (12) | 131 |
C7—H7A···Cl2iv | 0.99 | 2.74 | 3.6589 (11) | 155 |
C6—H6···Cl1v | 0.95 | 2.90 | 3.5983 (12) | 132 |
C3—H3···Cl2vi | 0.95 | 2.86 | 3.5141 (11) | 127 |
Symmetry codes: (i) −x, −y+1, −z+2; (ii) x, y, z−1; (iii) −x, −y+1, −z+1; (iv) −x+1, −y+1, −z+1; (v) x, y+1, z; (vi) x, y−1, z. |
We are interested in secondary bonding interactions (generally hydrogen bonds and halogen-halogen contacts) in halides of simple halogenated nitrogen bases, such as anilines (Gray & Jones, 2002, and references therein) and pyridines (Freytag & Jones, 2001, and references therein). Here, we present the structures of the series of isomers 2-, 3- and 4-chloromethylpyridinium chloride (chloro-2-, -3- and -4-picolinium chloride), (I), (II) and (III), respectively. \sch
All three structures crystallize without imposed symmetry. For reasons discussed below, each is shown as a hydrogen-bonded dimer in Figs. 1–3. The numbering is standard; C7 is the methylene C atom and Cl2 the anionic Cl-.
The structures of the cations of (I), (II) and (III) are unexceptional. Common features, consistent with previous observations (Freytag & Jones, 2001), include the wider ring angles at the N atom (ca 122–123°), slightly narrow ring angles at the CH2Cl substituent (ca 119°) and C—N bond lengths of ca 1.32–1.35 Å. For the 2- and 3-isomers, the substituent is rotated by ca 70° out of the ring plane, but for the 4-isomer, it is approximately coplanar with the ring. This may explain the wide C3—C4—C7 angle (for detailed values see Tables 1, 3 and 5).
As in the other series of compounds, the main interest centres on the packing features. In the 2-isomer, (I), the classical N—H···Cl- hydrogen bond combines with the shortest H···Cl interaction, C6—H6···Cl2, to form a centrosymmetric dimer (Fig. 1). The central R44(10) ring is easily recognisable in the extended packing diagram (Fig. 4), which involves three additional H···Cl interactions (Table 2) and a Cl1···Cl2i contact of 3.5505 (7) Å [symmetry code: (i) 2 - x, 1 - y, 1 - z; C—Cl···Cl 157.26 (4)°]. Although the packing is three-dimensional, vertical layers perpendicular to the b axis at y ≈ 1/4, 3/4, etc., are easily recognisable and can be seen edge-on in Fig. 4a. Perhaps ironically, these layers involve all the secondary contacts except the classical hydrogen bond. The perpendicular view onto such a layer is given in Fig. 4 b.
In the 3-isomer, (II), a centrosymmetric dimeric unit can be constructed that involves the classical N—H···Cl- hydrogen bond, the very short H2···Cl2 interaction and the H7B···Cl2 interaction (Fig. 2). The dimers are linked by H6···Cl2 interactions to form layers perpendicular to the bc plane at x ≈ 0, 1/2, 1, etc. (Fig. 5). The other H···Cl contacts (Table 4) are all much longer (>= 2.93 Å). There are no significant Cl···Cl contacts; the shortest is Cl1···Cl1ii 3.9210 (10) Å [symmetry code: (ii) 1/2 - x, 1/2 + y, 3/2 - z].
In the 4-isomer, (III), centrosymmetric dimers (Fig. 3) are built up via a three-centre N—H(···Cl)2 hydrogen bond. Within this dimer, the short and highly angled H2···Cl2 and H6···Cl2 contacts are probably imposed by the three-centre hydrogen bond, rather than being of intrinsic significance. Further secondary interactions build up a three-dimensional packing, but the layer shown in Fig. 6 shows most of the salient features. The four-membered rings of Fig. 3 are capped above and below by another three-centre interaction, H7B···Cl2, to form distorted octahedra. The H7A···Cl2 hydrogen bond and, finally, the Cl1···Cl1iii contact [3.6051 (6) Å, C—Cl···Cl 74.54 (3)°; symmetry code: (iii) 1 - x,-y,-z], link the octahedra to form a thick layer with the hydrophilic region at x ≈ 0. The next such layer at x ≈ 1 provides the three-dimensional extension. The other two H···Cl contacts, involving atoms H3 and H6 (Table 6), are long and have narrow angles, but both lie within the layer of Fig. 6 (from which, however, they have been omitted for clarity) and may make a small contribution to the stability of the packing.
It is notable that the crystallographically determined density increases significantly in the order 2-isomer < 3-isomer < 4-isomer, as was also observed for the series of chloropyridines (Freytag & Jones, 2001; Freytag et al., 1999). One might then postulate an increased efficiency of packing in the same sequence, but it is not easy to identify the factors concerned at the molecular level, beyond commenting that the isomer with the highest density also has the largest number of hydrogen bonds.