Polynuclear chloromercurate(II) systems in their chloropyridinium salts

The chloromercurate(II) salts of 2-, 3- and 4-chloropyridine display a variety of anion stoichiometries and structures, including the rare [Hg₃Cl₁₀]⁴⁻ stoichiometry. 2-Chloropyridinium trichloromercurate(II), (I), (C₅H₅ClN)[HgCl₃], monoclinic, P2₁/n, a = 9.094 (8), b = 18.143 (4), c = 12.902 (3) Å, β = 106.13 (4)° with Z = 8, has the [HgCl₃]⁻ stoichiometry, but the anions are infinite chains composed of [HgCl₃]⁻, HgCl₂ and Cl⁻ moieties linked by longer Hg...Cl contacts. Hydrogen bonds link the cations to the formal Cl⁻ ions. Tetrakis(3-chloropyridinium) decachlorotrimercurate(II), (II), (C₅H₅ClN)₄[Hg₃Cl₁₀], monoclinic, P2₁/n, a = 7.522 (2), b = 28.046 (3), c = 9.165 (2) Å, β = 105.78 (2)° with Z = 2, has the rare [Hg₃Cl₁₀]⁴⁻ stoichiometry and contains infinite one-dimensional double-stranded {([HgCl₄]²⁻)₂ [HgCl₂]}_n anionic chains made up of linear HgCl₂ and distorted [HgCl₄]²⁻ entities linked together by longer Hg...Cl contacts. The HgCl₂ moieties are joined by double [HgCl₄]²⁻ bridges. Hydrogen bonds link the cations to the sides of the anionic columns. Tetrakis(4-chloropyridinium) decachlorotrimercurate(II), (III), (C₅H₅ClN)₄[Hg₃Cl₁₀], triclinic, P1, a = 9.907 (3), b = 13.226 (2), c = 7.282 (2) Å, α = 84.41 (2), β = 74.81 (2), γ = 87.34 (2)° with Z = 1, also has the [Hg₃Cl₁₀]⁴⁻ stoichiometry and the same type of {([HgCl₄]²⁻)₂­[HgCl₂]}_n anionic chains that were found in compound (II), but the formal HgCl₂ and [HgCl₄]²⁻ moieties are more discrete with much weaker contacts linking the individual units. Bifurcated hydrogen bonds with the cations cross-link the anionic chains to form an infinite two-dimensional network. Second forms of the 3- and 4-­chloropyridinium salts were also obtained. 3-Chloro­pyridinium trichloromercurate(II), (IV), (C₅H₅ClN)[HgCl₃], monoclinic, P2₁/c, a = 7.243 (5), b = 22.145 (8), c = 12.320 (3) Å, β = 99.52 (3)° with Z = 8, has the [HgCl₃]⁻ stoichiometry, but the anions are infinite chains composed of distorted [Hg₂Cl₆]²⁻ moieties. Bifurcated hydrogen bonds from the cations cross-link the anionic chains to form infinite two-­dimensional layers. Bis(4-chloropyridinium) hexachlorodimer­curate(II), (V), (C₅H₅ClN)₂[Hg₂Cl₆], monoclinic, C2/m, a = 13.447 (3), b = 7.534 (2), c = 9.939 (2) Å, β = 97.48 (2)° with Z = 2, contains highly symmetrical discrete [Hg₂Cl₆]²⁻anions. Bifurcated hydrogen bonds from the cations interconnect the anions to form infinite one-dimensional chains.

Computing details

For all compounds, data collection: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1991); cell refinement: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1991); data reduction: TEXSAN PROCESS (Molecular Structure Corporation, 1989). Program(s) used to solve structure: SHELXS86 Patterson (Sheldrick, 1990) for (I); DIRDIF92 Patterson (Beurskens et al., 1992) for (II), (III), (IV), (V). For all compounds, program(s) used to refine structure: TEXSAN LS (Molecular Structure Corporation, 1989); molecular graphics: ORTEPIII (Burnett & Johnson, 1996); software used to prepare material for publication: TEXSAN FINISH (Molecular Structure Corporation, 1989) and local programs.

(I) 2-chloropyridinium trichloromercurate(II)

Crystal data

C5H5ClN^+·HgCl3^−	F(000) = 1520
Mr = 421.49	Dx = 2.738 Mg m^−3
Monoclinic, P21/n	Melting point = 377–379 K
Hall symbol: -P 2yn	Mo Kα radiation, λ = 0.71069 Å
a = 9.094 (8) Å	Cell parameters from 25 reflections
b = 18.143 (4) Å	θ = 19.5–20.0°
c = 12.902 (3) Å	µ = 16.04 mm^−1
β = 106.13 (4)°	T = 173 K
V = 2045 (2) Å^3	Prism, colourless
Z = 8	0.40 × 0.25 × 0.15 mm

Data collection

Rigaku AFC-5R diffractometer	3153 reflections with I > 2σ(I)
Radiation source: Rigaku rotating anode generator	Rint = 0.273
Graphite monochromator	θmax = 27.5°, θmin = 2.5°
ω–2θ scans	h = 0→11
Absorption correction: empirical (using intensity measurements) via ψ scan (North, Phillips & Mathews, 1968)	k = 0→23
Tmin = 0.026, Tmax = 0.090	l = −16→16
5129 measured reflections	3 standard reflections every 150 reflections
4679 independent reflections	intensity decay: no decay

Refinement

Refinement on F	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.044	H-atom parameters not refined
wR(F^2) = 0.036	Weighting scheme based on measured s.u.'s w = 1/[σ^2(Fo) + (0.005Fo)^2]
S = 1.68	(Δ/σ)max = 0.0002
3153 reflections	Δρmax = 1.66 e Å^−3
200 parameters	Δρmin = −2.33 e Å^−3
0 restraints	Extinction correction: Zachariasen (1963)
0 constraints	Extinction coefficient: 9.3E-8 (8)
Primary atom site location: heavy-atom method

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

	x	y	z	Uiso*/Ueq
Hg1	0.13401 (6)	0.04692 (3)	0.13608 (4)	0.03324 (18)
Hg2	0.26398 (6)	0.00416 (3)	0.46822 (3)	0.03023 (17)
Cl1	0.1802 (3)	−0.05881 (15)	0.0335 (2)	0.0248 (10)
Cl2	0.0080 (3)	0.03031 (16)	0.2800 (2)	0.0276 (10)
Cl3	0.2063 (4)	0.17045 (16)	0.1019 (2)	0.0279 (10)
Cl4	0.2795 (4)	0.12691 (17)	0.5241 (2)	0.0347 (11)
Cl5	0.4371 (3)	0.01605 (15)	0.3200 (2)	0.0264 (10)
Cl6	0.2392 (4)	−0.12373 (17)	0.4683 (2)	0.0369 (12)
Cl7	0.6412 (4)	−0.05774 (17)	0.1025 (3)	0.0425 (13)
N1	0.4981 (11)	−0.1340 (5)	0.2147 (7)	0.026 (4)
C2	0.5716 (12)	−0.1372 (6)	0.1377 (8)	0.022 (4)
C3	0.5874 (13)	−0.2044 (7)	0.0922 (8)	0.024 (4)
C4	0.5298 (14)	−0.2665 (6)	0.1280 (8)	0.025 (4)
C5	0.4548 (15)	−0.2609 (7)	0.2069 (9)	0.030 (5)
C6	0.4387 (15)	−0.1935 (7)	0.2499 (8)	0.030 (5)
Cl8	0.6674 (4)	0.1408 (2)	0.1466 (3)	0.0599 (16)
N21	0.5387 (11)	0.1780 (5)	0.2937 (7)	0.025 (4)
C22	0.5934 (13)	0.2036 (7)	0.2158 (8)	0.024 (4)
C23	0.5908 (16)	0.2777 (7)	0.1946 (9)	0.035 (5)
C24	0.5280 (18)	0.3256 (8)	0.2562 (12)	0.057 (7)
C25	0.4776 (16)	0.2969 (10)	0.3378 (11)	0.052 (6)
C26	0.4813 (16)	0.2231 (9)	0.3554 (9)	0.046 (6)
H1	0.488	−0.087	0.246	0.031*
H3	0.638	−0.208	0.037	0.029*
H4	0.542	−0.313	0.098	0.030*
H5	0.414	−0.304	0.231	0.036*
H6	0.386	−0.189	0.304	0.036*
H21	0.540	0.126	0.306	0.031*
H31	0.631	0.296	0.139	0.042*
H41	0.521	0.377	0.241	0.068*
H51	0.440	0.329	0.383	0.063*
H61	0.444	0.203	0.411	0.055*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Hg1	0.0408 (3)	0.0252 (3)	0.0342 (3)	−0.0022 (3)	0.0113 (2)	−0.0032 (2)
Hg2	0.0278 (3)	0.0277 (3)	0.0342 (2)	0.0019 (3)	0.0070 (2)	−0.0017 (2)
Cl1	0.0237 (16)	0.0235 (16)	0.0275 (14)	−0.0015 (13)	0.0077 (12)	−0.0032 (12)
Cl2	0.0245 (17)	0.0304 (18)	0.0249 (13)	0.0048 (14)	0.0019 (12)	0.0017 (12)
Cl3	0.0299 (18)	0.0302 (17)	0.0245 (14)	−0.0038 (15)	0.0093 (13)	−0.0006 (12)
Cl4	0.040 (2)	0.0308 (18)	0.0312 (15)	0.0092 (16)	0.0053 (15)	−0.0083 (13)
Cl5	0.0296 (17)	0.0226 (16)	0.0265 (13)	0.0021 (13)	0.0072 (12)	−0.0020 (11)
Cl6	0.040 (2)	0.0279 (18)	0.0353 (16)	−0.0072 (16)	−0.0016 (15)	0.0056 (14)
Cl7	0.048 (2)	0.0248 (18)	0.059 (2)	−0.0079 (17)	0.0218 (18)	0.0058 (15)
N1	0.022 (6)	0.027 (6)	0.028 (5)	0.000 (5)	0.005 (4)	−0.003 (4)
C2	0.007 (6)	0.029 (7)	0.026 (6)	−0.008 (5)	0.000 (5)	0.000 (5)
C3	0.011 (6)	0.034 (8)	0.026 (6)	−0.004 (6)	0.004 (5)	−0.003 (5)
C4	0.024 (7)	0.026 (7)	0.026 (6)	0.003 (6)	0.009 (5)	−0.002 (5)
C5	0.039 (8)	0.025 (7)	0.031 (6)	−0.008 (6)	0.016 (6)	0.004 (5)
C6	0.038 (8)	0.038 (8)	0.019 (6)	−0.007 (7)	0.014 (6)	0.006 (5)
Cl8	0.043 (3)	0.080 (3)	0.053 (2)	0.024 (2)	0.0065 (19)	−0.026 (2)
N21	0.031 (6)	0.024 (6)	0.020 (5)	−0.003 (5)	0.005 (4)	0.006 (4)
C22	0.011 (6)	0.031 (7)	0.025 (6)	0.002 (6)	−0.002 (5)	−0.001 (5)
C23	0.036 (9)	0.033 (8)	0.033 (7)	0.001 (7)	0.004 (6)	0.016 (6)
C24	0.052 (11)	0.024 (8)	0.069 (11)	−0.002 (8)	−0.025 (9)	0.001 (7)
C25	0.023 (8)	0.077 (13)	0.047 (9)	0.015 (9)	−0.007 (7)	−0.038 (9)
C26	0.032 (9)	0.075 (12)	0.025 (7)	0.007 (9)	0.001 (6)	0.006 (7)

Geometric parameters (Å, º)

Hg1—Cl1	2.432 (3)	Cl8—C22	1.699 (12)
Hg1—Cl1^i	3.086 (4)	N21—C22	1.323 (13)
Hg1—Cl2	2.456 (3)	N21—C26	1.343 (16)
Hg1—Cl3	2.411 (3)	C22—C23	1.370 (15)
Hg1—Cl5	3.148 (4)	C23—C24	1.402 (19)
Hg2—Cl2	2.898 (3)	C24—C25	1.36 (2)
Hg2—Cl4	2.333 (3)	C25—C26	1.36 (2)
Hg2—Cl5	2.803 (3)	N1—H1	0.95
Hg2—Cl5^ii	3.296 (3)	C3—H3	0.95
Hg2—Cl6	2.331 (3)	C4—H4	0.95
Cl7—C2	1.686 (11)	C5—H5	0.95
N1—C2	1.344 (13)	C6—H6	0.95
N1—C6	1.341 (14)	N21—H21	0.95
C2—C3	1.378 (15)	C23—H31	0.95
C3—C4	1.376 (15)	C24—H41	0.95
C4—C5	1.377 (15)	C25—H51	0.95
C5—C6	1.368 (16)	C26—H61	0.95
Cl1—Hg1—Cl1^i	86.28 (9)	C4—C5—C6	119.8 (11)
Cl1—Hg1—Cl2	120.13 (9)	N1—C6—C5	118.8 (11)
Cl1—Hg1—Cl3	122.45 (10)	C22—N21—C26	121.8 (11)
Cl1—Hg1—Cl5	91.29 (9)	Cl8—C22—N21	116.8 (9)
Cl2—Hg1—Cl1^i	90.57 (10)	Cl8—C22—C23	122.7 (10)
Cl2—Hg1—Cl3	117.42 (10)	N21—C22—C23	120.4 (11)
Cl2—Hg1—Cl5	84.44 (10)	C22—C23—C24	118.8 (12)
Cl3—Hg1—Cl1^i	92.92 (9)	C23—C24—C25	118.6 (13)
Cl3—Hg1—Cl5	94.43 (9)	C24—C25—C26	120.5 (13)
Cl1^i—Hg1—Cl5	172.43 (8)	N21—C26—C25	119.8 (13)
Cl2—Hg2—Cl4	93.91 (9)	C2—N1—H1	118.4
Cl2—Hg2—Cl5	83.59 (10)	C6—N1—H1	118.4
Cl2—Hg2—Cl5^ii	176.65 (8)	C2—C3—H3	120.4
Cl2—Hg2—Cl6	96.21 (9)	C4—C3—H3	120.4
Cl4—Hg2—Cl5	98.04 (10)	C3—C4—H4	120.0
Cl4—Hg2—Cl5^ii	83.39 (9)	C5—C4—H4	120.0
Cl4—Hg2—Cl6	161.35 (11)	C4—C5—H5	120.1
Cl5—Hg2—Cl5^ii	94.81 (8)	C6—C5—H5	120.1
Cl5—Hg2—Cl6	98.62 (10)	N1—C6—H6	120.6
Cl6—Hg2—Cl5^ii	86.93 (9)	C5—C6—H6	120.6
Hg1—Cl1—Hg1^i	93.72 (9)	C22—N21—H21	119.1
Hg1—Cl2—Hg2	102.63 (12)	C26—N21—H21	119.1
Hg2—Cl5—Hg1	89.30 (10)	C22—C23—H31	120.6
Hg1—Cl5—Hg2^ii	173.03 (10)	C24—C23—H31	120.6
Hg2—Cl5—Hg2^ii	85.19 (8)	C23—C24—H41	120.7
C2—N1—C6	123.2 (10)	C25—C24—H41	120.7
Cl7—C2—N1	117.6 (9)	C24—C25—H51	119.8
Cl7—C2—C3	123.4 (9)	C26—C25—H51	119.7
N1—C2—C3	119.0 (10)	N21—C26—H61	120.1
C2—C3—C4	119.1 (10)	C25—C26—H61	120.1
C3—C4—C5	120.1 (11)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···Cl5	0.95	2.22	3.161 (10)	173
N21—H21···Cl5	0.95	2.24	3.127 (10)	155

(II) tetrakis(3-chloropyridinium) decachlorotrimercurate(II)

Crystal data

(C5H5ClN^+)4·Hg3Cl10^4^−	F(000) = 1292
Mr = 1414.52	Dx = 2.524 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71069 Å
Hall symbol: -P 2yn	Cell parameters from 25 reflections
a = 7.522 (2) Å	θ = 19.5–20.0°
b = 28.046 (3) Å	µ = 13.37 mm^−1
c = 9.165 (2) Å	T = 173 K
β = 105.78 (2)°	Prism, colourless
V = 1860.5 (7) Å^3	0.37 × 0.35 × 0.28 mm
Z = 2

Data collection

Rigaku AFC-5R diffractometer	4337 reflections with I > 2σ(I)
Radiation source: Rigaku rotating anode generator	Rint = 0.046
Graphite monochromator	θmax = 30°, θmin = 2.5°
ω scans	h = 0→10
Absorption correction: empirical (using intensity measurements) via ψ scan (North, Phillips & Mathews, 1968)	k = 0→39
Tmin = 0.010, Tmax = 0.024	l = −12→12
5915 measured reflections	3 standard reflections every 150 reflections
5426 independent reflections	intensity decay: no decay

Refinement

Refinement on F	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.036	H-atom parameters not refined
wR(F^2) = 0.038	Weighting scheme based on measured s.u.'s w = 1/[σ^2(Fo) + (0.005Fo)^2]
S = 1.95	(Δ/σ)max = 0.001
4337 reflections	Δρmax = 2.15 e Å^−3
188 parameters	Δρmin = −2.32 e Å^−3
0 restraints	Extinction correction: Zachariasen (1963)
0 constraints	Extinction coefficient: 1.3E-7 (2)
Primary atom site location: heavy-atom method

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

	x	y	z	Uiso*/Ueq
Hg1	0.0	0.0	0.0	0.02077 (13)
Hg2	0.44770 (4)	0.12603 (1)	−0.21367 (3)	0.02059 (9)
Cl1	−0.0673 (3)	−0.04381 (6)	−0.2260 (2)	0.0243 (6)
Cl2	0.2445 (3)	0.06871 (6)	−0.0959 (2)	0.0238 (6)
Cl3	0.3173 (3)	0.12483 (8)	−0.4810 (2)	0.0368 (7)
Cl4	0.4927 (3)	0.18989 (7)	−0.0298 (2)	0.0326 (7)
Cl5	0.7291 (3)	0.07370 (7)	−0.1353 (3)	0.0315 (7)
Cl6	−0.0203 (3)	0.25279 (8)	−0.2269 (3)	0.0408 (8)
N1	0.0286 (10)	0.1501 (2)	0.0704 (8)	0.031 (2)
C2	0.0188 (11)	0.1736 (3)	−0.0608 (9)	0.026 (3)
C3	−0.0109 (10)	0.2217 (3)	−0.0638 (9)	0.023 (2)
C4	−0.0348 (12)	0.2441 (3)	0.0637 (11)	0.033 (3)
C5	−0.0191 (13)	0.2187 (3)	0.1975 (10)	0.036 (3)
C6	0.0113 (11)	0.1704 (3)	0.1980 (9)	0.028 (3)
Cl7	0.8257 (3)	0.15591 (8)	0.5247 (3)	0.0384 (8)
N21	0.5482 (9)	0.0657 (3)	0.2230 (7)	0.031 (2)
C22	0.6193 (12)	0.1067 (3)	0.2914 (9)	0.028 (3)
C23	0.7391 (11)	0.1037 (3)	0.4323 (9)	0.025 (3)
C24	0.7860 (12)	0.0592 (3)	0.5012 (10)	0.033 (3)
C25	0.7089 (12)	0.0196 (3)	0.4243 (10)	0.034 (3)
C26	0.5876 (12)	0.0236 (3)	0.2864 (10)	0.032 (3)
H1	0.049	0.117	0.072	0.037*
H2	0.032	0.157	−0.148	0.031*
H4	−0.062	0.277	0.060	0.040*
H5	−0.029	0.234	0.287	0.043*
H6	0.020	0.152	0.287	0.034*
H21	0.466	0.067	0.124	0.037*
H22	0.587	0.137	0.243	0.034*
H24	0.870	0.057	0.599	0.039*
H25	0.741	−0.011	0.468	0.040*
H26	0.530	−0.004	0.235	0.039*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Hg1	0.0241 (2)	0.02007 (19)	0.0191 (2)	−0.00327 (16)	0.00748 (15)	−0.00288 (16)
Hg2	0.02245 (15)	0.02047 (14)	0.01912 (15)	−0.00038 (12)	0.00612 (11)	0.00143 (11)
Cl1	0.0352 (11)	0.0209 (8)	0.0169 (9)	−0.0024 (8)	0.0073 (8)	−0.0008 (7)
Cl2	0.0244 (9)	0.0218 (9)	0.0289 (10)	−0.0049 (7)	0.0137 (8)	0.0010 (7)
Cl3	0.0376 (12)	0.0498 (13)	0.0191 (10)	−0.0004 (11)	0.0008 (8)	0.0015 (9)
Cl4	0.0497 (13)	0.0231 (9)	0.0255 (10)	−0.0043 (9)	0.0113 (9)	−0.0053 (8)
Cl5	0.0211 (9)	0.0277 (10)	0.0413 (12)	0.0057 (8)	0.0010 (9)	−0.0011 (9)
Cl6	0.0559 (15)	0.0328 (11)	0.0322 (11)	−0.0076 (11)	0.0096 (10)	0.0087 (10)
N1	0.039 (4)	0.018 (3)	0.038 (4)	0.001 (3)	0.013 (3)	0.000 (3)
C2	0.028 (4)	0.022 (4)	0.027 (4)	0.003 (3)	0.006 (3)	−0.005 (3)
C3	0.025 (4)	0.021 (4)	0.022 (4)	−0.006 (3)	0.005 (3)	0.004 (3)
C4	0.043 (5)	0.019 (4)	0.041 (5)	−0.001 (4)	0.017 (4)	−0.003 (4)
C5	0.047 (6)	0.034 (5)	0.029 (5)	−0.001 (4)	0.015 (4)	−0.009 (4)
C6	0.033 (5)	0.028 (4)	0.022 (4)	0.000 (3)	0.003 (3)	0.003 (3)
Cl7	0.0456 (13)	0.0344 (11)	0.0344 (12)	−0.0078 (10)	0.0093 (10)	−0.0105 (10)
N21	0.034 (4)	0.035 (4)	0.019 (3)	0.002 (3)	−0.001 (3)	−0.002 (3)
C22	0.036 (5)	0.023 (4)	0.023 (4)	0.001 (3)	0.005 (4)	0.003 (3)
C23	0.026 (4)	0.030 (4)	0.022 (4)	0.000 (3)	0.010 (3)	−0.005 (3)
C24	0.030 (5)	0.038 (5)	0.030 (5)	0.005 (4)	0.008 (4)	0.004 (4)
C25	0.046 (5)	0.021 (4)	0.037 (5)	0.006 (4)	0.017 (4)	0.003 (4)
C26	0.039 (5)	0.025 (4)	0.035 (5)	−0.002 (4)	0.015 (4)	−0.003 (4)

Geometric parameters (Å, º)

Hg1—Cl1	2.3420 (18)	N21—C26	1.313 (10)
Hg1—Cl2	2.9575 (18)	C22—C23	1.362 (10)
Hg1—Cl5^i	2.9303 (19)	C23—C24	1.398 (11)
Hg2—Cl2	2.6427 (18)	C24—C25	1.359 (11)
Hg2—Cl3	2.379 (2)	C25—C26	1.347 (12)
Hg2—Cl4	2.4193 (19)	N1—H1	0.95
Hg2—Cl5	2.5148 (19)	C2—H2	0.95
Cl6—C3	1.716 (8)	C4—H4	0.95
N1—C2	1.354 (10)	C5—H5	0.95
N1—C6	1.338 (10)	C6—H6	0.95
C2—C3	1.367 (10)	N21—H21	0.95
C3—C4	1.382 (11)	C22—H22	0.95
C4—C5	1.396 (12)	C24—H24	0.95
C5—C6	1.373 (11)	C25—H25	0.95
Cl7—C23	1.729 (8)	C26—H26	0.95
N21—C22	1.349 (10)
Cl1—Hg1—Cl1^ii	180.0	Cl7—C23—C22	118.4 (6)
Cl1—Hg1—Cl2	94.66 (6)	Cl7—C23—C24	121.3 (6)
Cl1—Hg1—Cl2^ii	85.34 (6)	C22—C23—C24	120.3 (7)
Cl1—Hg1—Cl5^i	92.17 (6)	C23—C24—C25	118.3 (8)
Cl1—Hg1—Cl5^iii	87.83 (6)	C24—C25—C26	120.2 (8)
Cl2—Hg1—Cl2^ii	180.0	N21—C26—C25	120.2 (8)
Cl2—Hg1—Cl5^i	80.31 (6)	C2—N1—H1	117.5
Cl2—Hg1—Cl5^iii	99.69 (6)	C6—N1—H1	117.4
Cl5^i—Hg1—Cl5^iii	180.0	N1—C2—H2	121.2
Cl2—Hg2—Cl3	106.84 (7)	C3—C2—H2	121.1
Cl2—Hg2—Cl4	98.77 (7)	C3—C4—H4	119.7
Cl2—Hg2—Cl5	93.66 (7)	C5—C4—H4	119.7
Cl3—Hg2—Cl4	131.94 (8)	C4—C5—H5	120.5
Cl3—Hg2—Cl5	111.43 (8)	C6—C5—H5	120.6
Cl4—Hg2—Cl5	106.60 (7)	N1—C6—H6	121.0
Hg1—Cl2—Hg2	173.34 (8)	C5—C6—H6	120.9
Hg1^iii—Cl5—Hg2	165.22 (9)	C22—N21—H21	118.4
C2—N1—C6	125.2 (7)	C26—N21—H21	118.4
N1—C2—C3	117.7 (7)	N21—C22—H22	121.2
Cl6—C3—C2	119.2 (7)	C23—C22—H22	121.2
Cl6—C3—C4	121.4 (6)	C23—C24—H24	120.8
C2—C3—C4	119.4 (7)	C25—C24—H24	120.8
C3—C4—C5	120.6 (7)	C24—C25—H25	119.9
C4—C5—C6	118.9 (8)	C26—C25—H25	119.9
N1—C6—C5	118.1 (8)	N21—C26—H26	119.9
C22—N21—C26	123.2 (7)	C25—C26—H26	119.9
N21—C22—C23	117.6 (7)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···Cl1^ii	0.95	2.47	3.284 (7)	144
N1—H1···Cl2	0.95	2.75	3.395 (7)	126
N21—H21···Cl2	0.95	2.24	3.184 (7)	173

Symmetry code: (ii) −x, −y, −z.

(III) tetrakis(4-chloropyridinium) decachlorotrimercurate(II)

Crystal data

(C5H5ClN^+)4·Hg3Cl10^4^−	Z = 1
Mr = 1414.52	F(000) = 646
Triclinic, P1	Dx = 2.564 Mg m^−3
Hall symbol: -P 1	Melting point = 373–375 K
a = 9.907 (3) Å	Mo Kα radiation, λ = 0.71069 Å
b = 13.226 (2) Å	Cell parameters from 25 reflections
c = 7.282 (2) Å	θ = 19.5–20.0°
α = 84.41 (2)°	µ = 13.58 mm^−1
β = 74.81 (2)°	T = 173 K
γ = 87.34 (2)°	Prism, colourless
V = 916.2 (4) Å^3	0.43 × 0.27 × 0.11 mm

Data collection

Rigaku AFC-5R diffractometer	4398 reflections with I > 2σ(I)
Radiation source: Rigaku rotating anode generator	Rint = 0.019
Graphite monochromator	θmax = 30°, θmin = 2.5°
ω–2θ scans	h = −13→0
Absorption correction: analytical (De Meulenaer & Tompa, 1965)	k = −18→18
Tmin = 0.055, Tmax = 0.270	l = −10→9
5621 measured reflections	3 standard reflections every 150 reflections
5337 independent reflections	intensity decay: no decay

Refinement

Refinement on F	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.038	Only H-atom displacement parameters refined
wR(F^2) = 0.039	Weighting scheme based on measured s.u.'s w = 1/[σ^2(Fo) + (0.005Fo)^2]
S = 2.20	(Δ/σ)max = 0.003
4398 reflections	Δρmax = 2.31 e Å^−3
198 parameters	Δρmin = −2.12 e Å^−3
0 restraints	Extinction correction: Zachariasen (1963)
0 constraints	Extinction coefficient: 1.8E-6 (1)
Primary atom site location: heavy-atom method

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

	x	y	z	Uiso*/Ueq
Hg1	0.00000	0.00000	0.00000	0.03401 (15)
Hg2	0.21586 (3)	−0.21696 (2)	0.36228 (4)	0.02723 (10)
Cl1	−0.22481 (19)	−0.05156 (16)	0.0342 (3)	0.0339 (6)
Cl2	0.0786 (2)	−0.23234 (16)	0.1300 (3)	0.0418 (8)
Cl3	0.45688 (19)	−0.15944 (14)	0.2166 (3)	0.0308 (6)
Cl4	0.2307 (2)	−0.39314 (15)	0.5343 (3)	0.0330 (6)
Cl5	0.0895 (2)	−0.11267 (15)	0.6232 (3)	0.0354 (6)
Cl6	0.2874 (2)	0.36338 (16)	0.4862 (3)	0.0389 (7)
N1	0.4770 (8)	0.0724 (5)	0.2840 (9)	0.039 (3)
C2	0.3415 (10)	0.0747 (6)	0.3784 (12)	0.042 (3)
C3	0.2802 (9)	0.1644 (7)	0.4447 (11)	0.036 (3)
C4	0.3625 (8)	0.2487 (6)	0.4119 (9)	0.025 (2)
C5	0.5014 (9)	0.2444 (6)	0.3187 (10)	0.031 (3)
C6	0.5590 (10)	0.1536 (7)	0.2530 (11)	0.041 (3)
Cl7	−0.4724 (2)	−0.45326 (18)	1.2083 (3)	0.0378 (7)
N21	−0.0582 (6)	−0.3942 (6)	0.8109 (8)	0.031 (2)
C22	−0.1042 (8)	−0.4889 (7)	0.8448 (10)	0.033 (3)
C23	−0.2321 (8)	−0.5115 (6)	0.9670 (10)	0.030 (3)
C24	−0.3116 (7)	−0.4303 (6)	1.0525 (9)	0.026 (2)
C25	−0.2618 (8)	−0.3331 (6)	1.0169 (10)	0.028 (2)
C26	−0.1333 (8)	−0.3164 (7)	0.8931 (10)	0.032 (3)
H1	0.517	0.010	0.237	0.07 (2)*
H2	0.288	0.015	0.399	0.04 (2)*
H3	0.184	0.168	0.511	0.06 (2)*
H5	0.557	0.303	0.300	0.04 (2)*
H6	0.655	0.149	0.187	0.10 (2)*
H21	0.031	−0.382	0.725	0.06 (2)*
H22	−0.047	−0.542	0.783	0.06 (2)*
H23	−0.265	−0.579	0.992	0.024 (18)*
H25	−0.316	−0.279	1.077	0.05 (2)*
H26	−0.097	−0.250	0.866	0.05 (2)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Hg1	0.0243 (2)	0.0378 (3)	0.0390 (2)	−0.00639 (2)	−0.00424 (2)	−0.0071 (2)
Hg2	0.02805 (2)	0.02555 (2)	0.02693 (1)	−0.00194 (1)	−0.00431 (1)	−0.00374 (1)
Cl1	0.0208 (9)	0.0337 (11)	0.0465 (11)	−0.0025 (8)	−0.0028 (8)	−0.0160 (9)
Cl2	0.0611 (14)	0.0276 (11)	0.0506 (12)	−0.0019 (10)	−0.0393 (11)	−0.0024 (9)
Cl3	0.0254 (9)	0.0247 (9)	0.0375 (9)	−0.0013 (8)	0.0000 (7)	−0.0019 (8)
Cl4	0.0300 (10)	0.0238 (9)	0.0366 (9)	0.0038 (8)	0.0039 (8)	0.0022 (8)
Cl5	0.0394 (11)	0.0316 (11)	0.0291 (9)	−0.0038 (9)	0.0057 (8)	−0.0123 (8)
Cl6	0.0526 (13)	0.0301 (11)	0.0356 (10)	0.0060 (10)	−0.0128 (9)	−0.0110 (8)
N1	0.057 (5)	0.026 (4)	0.034 (4)	0.009 (4)	−0.012 (3)	−0.005 (3)
C2	0.061 (6)	0.022 (4)	0.048 (5)	−0.010 (4)	−0.022 (5)	0.001 (4)
C3	0.035 (5)	0.031 (5)	0.042 (4)	−0.004 (4)	−0.011 (4)	0.000 (4)
C4	0.037 (4)	0.021 (4)	0.019 (3)	0.002 (3)	−0.010 (3)	−0.001 (3)
C5	0.039 (5)	0.025 (4)	0.031 (4)	−0.005 (4)	−0.010 (3)	−0.001 (3)
C6	0.052 (6)	0.042 (5)	0.028 (4)	0.006 (5)	−0.012 (4)	−0.002 (4)
Cl7	0.0257 (10)	0.0492 (13)	0.0342 (10)	−0.0084 (9)	0.0023 (8)	−0.0062 (9)
N21	0.020 (3)	0.044 (4)	0.026 (3)	−0.002 (3)	−0.002 (2)	−0.001 (3)
C22	0.027 (4)	0.037 (5)	0.033 (4)	0.004 (4)	−0.004 (3)	−0.008 (4)
C23	0.033 (4)	0.029 (4)	0.028 (4)	0.000 (4)	−0.006 (3)	−0.005 (3)
C24	0.026 (4)	0.034 (4)	0.020 (3)	−0.006 (3)	−0.006 (3)	−0.004 (3)
C25	0.030 (4)	0.026 (4)	0.027 (3)	−0.001 (3)	−0.007 (3)	−0.006 (3)
C26	0.033 (4)	0.037 (5)	0.030 (4)	−0.003 (4)	−0.013 (3)	−0.002 (3)

Geometric parameters (Å, º)

Hg1—Cl1	2.3032 (19)	N21—C26	1.337 (10)
Hg1—Cl2	3.247 (2)	C22—C23	1.371 (10)
Hg1—Cl5^i	3.1518 (19)	C23—C24	1.398 (10)
Hg2—Cl2	2.4598 (18)	C24—C25	1.375 (10)
Hg2—Cl3	2.4677 (19)	C25—C26	1.367 (10)
Hg2—Cl4	2.553 (2)	N1—H1	0.95
Hg2—Cl5	2.4869 (19)	C2—H2	0.95
Cl6—C4	1.729 (7)	C3—H3	0.95
N1—C2	1.339 (12)	C5—H5	0.95
N1—C6	1.343 (11)	C6—H6	0.95
C2—C3	1.378 (12)	N21—H21	0.95
C3—C4	1.376 (10)	C22—H22	0.95
C4—C5	1.367 (10)	C23—H23	0.95
C5—C6	1.379 (11)	C25—H25	0.95
Cl7—C24	1.717 (7)	C26—H26	0.95
N21—C22	1.330 (10)
Cl1—Hg1—Cl1^ii	180.0	C22—C23—C24	116.8 (7)
Cl1—Hg1—Cl2	88.07 (7)	Cl7—C24—C23	119.3 (6)
Cl1—Hg1—Cl2^ii	91.93 (7)	Cl7—C24—C25	119.7 (6)
Cl1—Hg1—Cl5^i	87.71 (6)	C23—C24—C25	121.1 (7)
Cl1—Hg1—Cl5^iii	92.29 (6)	C24—C25—C26	118.8 (7)
Cl2—Hg1—Cl2^ii	180.0	N21—C26—C25	119.8 (8)
Cl2—Hg1—Cl5^i	73.91 (6)	C2—N1—H1	118.4
Cl2—Hg1—Cl5^iii	106.09 (6)	C6—N1—H1	118.4
Cl5^i—Hg1—Cl5^iii	180.0	N1—C2—H2	120.2
Cl2—Hg2—Cl3	113.94 (7)	C3—C2—H2	120.2
Cl2—Hg2—Cl4	107.15 (7)	C2—C3—H3	121.0
Cl2—Hg2—Cl5	111.63 (8)	C4—C3—H3	121.0
Cl3—Hg2—Cl4	107.82 (7)	C4—C5—H5	120.6
Cl3—Hg2—Cl5	112.14 (7)	C6—C5—H5	120.6
Cl4—Hg2—Cl5	103.41 (7)	N1—C6—H6	120.6
Hg1—Cl2—Hg2	104.82 (7)	C5—C6—H6	120.6
Hg1^iii—Cl5—Hg2	164.11 (9)	C22—N21—H21	118.9
C2—N1—C6	123.1 (8)	C26—N21—H21	118.9
N1—C2—C3	119.5 (8)	N21—C22—H22	119.3
C2—C3—C4	118.1 (8)	C23—C22—H22	119.3
Cl6—C4—C3	119.1 (6)	C22—C23—H23	121.6
Cl6—C4—C5	119.2 (6)	C24—C23—H23	121.6
C3—C4—C5	121.6 (7)	C24—C25—H25	120.6
C4—C5—C6	118.8 (8)	C26—C25—H25	120.6
N1—C6—C5	118.9 (8)	N21—C26—H26	120.1
C22—N21—C26	122.2 (7)	C25—C26—H26	120.1
N21—C22—C23	121.3 (7)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···Cl3	0.95	2.38	3.175 (7)	141
N1—H1···Cl1^iv	0.95	2.73	3.469 (8)	135
N21—H21···Cl4	0.95	2.11	3.037 (6)	166

Symmetry code: (iv) x+1, y, z.

(IV) 3-chloropyridinium trichloromercurate(II)

Crystal data

C5H5ClN^+·HgCl3^−	F(000) = 1520
Mr = 421.49	Dx = 2.873 Mg m^−3
Monoclinic, P21/c	Melting point = 367–370 K
Hall symbol: -P 2ybc	Mo Kα radiation, λ = 0.71069 Å
a = 7.243 (5) Å	Cell parameters from 25 reflections
b = 22.145 (8) Å	θ = 19.0–20.0°
c = 12.320 (3) Å	µ = 16.83 mm^−1
β = 99.52 (3)°	T = 173 K
V = 1948.8 (13) Å^3	Prism, colourless
Z = 8	0.38 × 0.30 × 0.28 mm

Data collection

Rigaku AFC-5R diffractometer	4100 reflections with I > 2σ(I)
Radiation source: Rigaku rotating anode generator	Rint = 0.073
Graphite monochromator	θmax = 30°, θmin = 2.5°
ω–2θ scans	h = 0→10
Absorption correction: empirical (using intensity measurements) via ψ scan (North, Phillips & Mathews, 1968)	k = 0→31
Tmin = 0.004, Tmax = 0.009	l = −17→17
6239 measured reflections	3 standard reflections every 150 reflections
5681 independent reflections	intensity decay: no decay

Refinement

Refinement on F	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.049	H-atom parameters not refined
wR(F^2) = 0.049	Weighting scheme based on measured s.u.'s w = 1/[σ^2(Fo) + (0.005Fo)^2]
S = 2.01	(Δ/σ)max = 0.001
4100 reflections	Δρmax = 4.06 e Å^−3
200 parameters	Δρmin = −2.79 e Å^−3
0 restraints	Extinction correction: Zachariasen (1963)
0 constraints	Extinction coefficient: 1.9E-7 (1)
Primary atom site location: heavy-atom method

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

	x	y	z	Uiso*/Ueq
Hg1	−0.05411 (7)	0.57150 (3)	0.36436 (4)	0.02636 (17)
Hg2	0.38188 (7)	0.60230 (2)	0.21518 (3)	0.01930 (14)
Cl1	−0.1703 (4)	0.51782 (13)	0.2032 (2)	0.0214 (9)
Cl2	−0.0229 (5)	0.58621 (14)	0.5531 (2)	0.0247 (10)
Cl3	0.1175 (4)	0.66586 (12)	0.2803 (2)	0.0180 (8)
Cl4	0.6411 (4)	0.66852 (13)	0.2927 (2)	0.0178 (8)
Cl5	0.3091 (5)	0.56245 (14)	0.0324 (2)	0.0268 (10)
Cl6	0.3566 (4)	0.52641 (13)	0.3688 (2)	0.0207 (9)
Cl7	0.1227 (5)	0.23839 (14)	−0.0429 (3)	0.0291 (10)
N1	0.1987 (14)	0.4106 (5)	0.0256 (8)	0.022 (3)
C2	0.1859 (18)	0.3567 (6)	−0.0270 (9)	0.022 (4)
C3	0.1413 (15)	0.3066 (5)	0.0255 (8)	0.016 (3)
C4	0.1031 (16)	0.3099 (6)	0.1328 (9)	0.021 (4)
C5	0.1121 (19)	0.3651 (7)	0.1814 (10)	0.029 (4)
C6	0.1569 (18)	0.4175 (6)	0.1280 (10)	0.026 (4)
Cl8	0.6317 (5)	0.22561 (14)	0.4759 (3)	0.0258 (10)
N21	0.5419 (15)	0.3964 (4)	0.4002 (8)	0.024 (3)
C22	0.5583 (18)	0.3430 (6)	0.4581 (9)	0.022 (4)
C23	0.6106 (15)	0.2930 (5)	0.4051 (9)	0.015 (3)
C24	0.6498 (15)	0.2970 (5)	0.3008 (9)	0.017 (4)
C25	0.6319 (18)	0.3536 (6)	0.2450 (10)	0.024 (4)
C26	0.5820 (16)	0.4024 (6)	0.2989 (10)	0.022 (4)
H1	0.238	0.445	−0.011	0.027*
H2	0.208	0.354	−0.101	0.026*
H4	0.072	0.275	0.170	0.026*
H5	0.087	0.368	0.254	0.035*
H6	0.158	0.456	0.162	0.031*
H21	0.499	0.431	0.434	0.028*
H22	0.534	0.341	0.532	0.027*
H24	0.689	0.262	0.265	0.021*
H25	0.655	0.357	0.171	0.028*
H26	0.575	0.441	0.265	0.027*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Hg1	0.0309 (3)	0.0359 (3)	0.0121 (2)	−0.0066 (2)	0.00277 (18)	−0.00733 (19)
Hg2	0.0236 (3)	0.0194 (2)	0.0139 (2)	−0.0034 (2)	0.00022 (17)	−0.00361 (18)
Cl1	0.0343 (18)	0.0170 (14)	0.0117 (12)	−0.0061 (12)	0.0000 (12)	−0.0016 (10)
Cl2	0.0387 (19)	0.0254 (17)	0.0106 (12)	−0.0016 (14)	0.0060 (12)	−0.0024 (11)
Cl3	0.0137 (13)	0.0147 (13)	0.0267 (14)	0.0011 (12)	0.0068 (11)	0.0023 (11)
Cl4	0.0097 (13)	0.0204 (14)	0.0230 (14)	−0.0017 (11)	0.0022 (11)	−0.0037 (11)
Cl5	0.0393 (19)	0.0243 (17)	0.0151 (13)	−0.0049 (14)	−0.0005 (12)	−0.0080 (11)
Cl6	0.0311 (17)	0.0142 (14)	0.0171 (13)	0.0065 (12)	0.0045 (12)	0.0028 (10)
Cl7	0.0308 (18)	0.0218 (17)	0.0314 (17)	0.0047 (14)	−0.0045 (14)	−0.0081 (13)
N1	0.021 (6)	0.022 (6)	0.024 (5)	−0.001 (5)	0.003 (4)	0.004 (4)
C2	0.033 (7)	0.022 (7)	0.010 (5)	0.006 (6)	0.004 (5)	0.001 (4)
C3	0.013 (6)	0.018 (6)	0.014 (5)	−0.005 (5)	−0.002 (4)	0.001 (4)
C4	0.018 (6)	0.030 (7)	0.017 (6)	0.002 (5)	0.003 (5)	0.000 (5)
C5	0.032 (8)	0.043 (9)	0.013 (6)	0.007 (7)	0.005 (5)	0.000 (5)
C6	0.024 (7)	0.024 (7)	0.028 (7)	0.003 (6)	−0.004 (5)	−0.004 (5)
Cl8	0.0290 (17)	0.0191 (15)	0.0275 (15)	0.0006 (13)	−0.0006 (13)	0.0075 (12)
N21	0.038 (7)	0.009 (5)	0.024 (5)	0.006 (5)	0.007 (5)	−0.004 (4)
C22	0.028 (7)	0.022 (7)	0.020 (6)	−0.004 (6)	0.009 (5)	−0.006 (5)
C23	0.008 (5)	0.014 (6)	0.022 (6)	−0.002 (4)	0.002 (4)	−0.003 (4)
C24	0.009 (6)	0.014 (6)	0.030 (6)	0.002 (5)	0.006 (5)	−0.003 (5)
C25	0.026 (7)	0.024 (7)	0.021 (6)	−0.001 (6)	0.005 (5)	0.000 (5)
C26	0.016 (6)	0.018 (6)	0.033 (7)	−0.003 (5)	0.005 (5)	0.000 (5)

Geometric parameters (Å, º)

Hg1—Cl1	2.348 (3)	N21—C22	1.376 (15)
Hg1—Cl2	2.322 (3)	N21—C26	1.333 (15)
Hg1—Cl3	2.723 (3)	C22—C23	1.371 (15)
Hg1—Cl4^i	3.103 (3)	C23—C24	1.365 (15)
Hg1—Cl6	3.130 (4)	C24—C25	1.426 (16)
Hg2—Cl3	2.607 (3)	C25—C26	1.349 (16)
Hg2—Cl4	2.448 (3)	N1—H1	0.95
Hg2—Cl5	2.395 (3)	C2—H2	0.95
Hg2—Cl6	2.560 (3)	C4—H4	0.95
Cl7—C3	1.724 (12)	C5—H5	0.95
N1—C2	1.353 (15)	C6—H6	0.95
N1—C6	1.354 (15)	N21—H21	0.95
C2—C3	1.351 (16)	C22—H22	0.95
C3—C4	1.397 (15)	C24—H24	0.95
C4—C5	1.358 (18)	C25—H25	0.95
C5—C6	1.399 (18)	C26—H26	0.95
Cl8—C23	1.722 (12)
Cl1—Hg1—Cl2	151.65 (11)	N21—C22—C23	117.0 (10)
Cl1—Hg1—Cl3	100.90 (10)	Cl8—C23—C22	117.9 (9)
Cl1—Hg1—Cl4^i	88.36 (10)	Cl8—C23—C24	121.2 (9)
Cl1—Hg1—Cl6	93.42 (10)	C22—C23—C24	120.9 (11)
Cl2—Hg1—Cl3	107.37 (10)	C23—C24—C25	119.6 (10)
Cl2—Hg1—Cl4^i	97.75 (10)	C24—C25—C26	118.5 (11)
Cl2—Hg1—Cl6	95.31 (10)	N21—C26—C25	119.9 (11)
Cl3—Hg1—Cl4^i	73.05 (9)	C2—N1—H1	118.8
Cl3—Hg1—Cl6	76.05 (8)	C6—N1—H1	118.7
Cl4^i—Hg1—Cl6	148.81 (8)	N1—C2—H2	120.0
Cl3—Hg2—Cl4	96.40 (10)	C3—C2—H2	120.0
Cl3—Hg2—Cl5	115.44 (11)	C3—C4—H4	121.2
Cl3—Hg2—Cl6	88.92 (9)	C5—C4—H4	121.2
Cl4—Hg2—Cl5	128.51 (11)	C4—C5—H5	118.8
Cl4—Hg2—Cl6	104.42 (10)	C6—C5—H5	118.8
Cl5—Hg2—Cl6	114.94 (10)	N1—C6—H6	121.6
Hg1—Cl3—Hg2	96.17 (9)	C5—C6—H6	121.6
Hg1^ii—Cl4—Hg2	99.20 (10)	C22—N21—H21	118.0
Hg1—Cl6—Hg2	87.81 (8)	C26—N21—H21	118.0
C2—N1—C6	122.5 (10)	N21—C22—H22	121.5
N1—C2—C3	119.9 (10)	C23—C22—H22	121.5
Cl7—C3—C2	119.4 (9)	C23—C24—H24	120.2
Cl7—C3—C4	119.8 (9)	C25—C24—H24	120.2
C2—C3—C4	120.7 (11)	C24—C25—H25	120.7
C3—C4—C5	117.5 (12)	C26—C25—H25	120.7
C4—C5—C6	122.5 (11)	N21—C26—H26	120.1
N1—C6—C5	116.7 (11)	C25—C26—H26	120.1
C22—N21—C26	123.9 (10)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···Cl1^iii	0.95	2.48	3.210 (10)	134
N1—H1···Cl5	0.95	2.69	3.455 (10)	138
N21—H21···Cl6	0.95	2.43	3.173 (10)	135
N21—H21···Cl6^iv	0.95	2.65	3.298 (10)	126

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

(V) bis(4-chloropyridinium) hexachlorodimercurate(II)

Crystal data

(C5H5ClN^+)2·Hg2Cl6^2^−	F(000) = 760
Mr = 842.98	Dx = 2.804 Mg m^−3
Monoclinic, C2/m	Melting point: 385 K
Hall symbol: -C 2y	Mo Kα radiation, λ = 0.71069 Å
a = 13.447 (3) Å	Cell parameters from 25 reflections
b = 7.534 (2) Å	θ = 19.0–20.0°
c = 9.939 (2) Å	µ = 16.46 mm^−1
β = 97.48 (2)°	T = 173 K
V = 998.3 (3) Å^3	Prism, colourless
Z = 2	0.35 × 0.25 × 0.15 mm

Data collection

Rigaku AFC-5R diffractometer	1329 reflections with I > 2σ(I)
Radiation source: Rigaku rotating anode generator	Rint = 0.088
Graphite monochromator	θmax = 30°, θmin = 2.5°
ω–2θ scans	h = 0→18
Absorption correction: analytical (De Meulenaer & Tompa, 1965)	k = 0→10
Tmin = 0.034, Tmax = 0.200	l = −13→13
1618 measured reflections	3 standard reflections every 150 reflections
1557 independent reflections	intensity decay: no decay

Refinement

Refinement on F	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.053	H-atom parameters not refined
wR(F^2) = 0.064	Weighting scheme based on measured s.u.'s w = 1/[σ^2(Fo) + (0.015Fo)^2]
S = 0.07	(Δ/σ)max = 0.001
1328 reflections	Δρmax = 2.81 e Å^−3
61 parameters	Δρmin = −3.16 e Å^−3
0 restraints	Extinction correction: Zachariasen (1963)
0 constraints	Extinction coefficient: 1.6E-6 (3)
Primary atom site location: heavy-atom method

Special details

Refinement. Reflection 4 0 0 omitted because of suspected severe extinction effects.

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

	x	y	z	Uiso*/Ueq
Hg1	0.13306 (5)	0.0	0.10021 (6)	0.0285 (2)
Cl1	0.0973 (4)	0.0	0.3259 (4)	0.0346 (12)
Cl2	0.2412 (3)	0.0	−0.0668 (4)	0.0337 (12)
Cl3	0.0	0.2556 (4)	0.0	0.0233 (9)
Cl4	−0.1695 (4)	0.5	0.6409 (4)	0.0365 (13)
N1	−0.0926 (11)	0.5	0.2258 (14)	0.034 (4)
C2	−0.1031 (9)	0.3417 (14)	0.2835 (11)	0.031 (3)
C3	−0.1292 (9)	0.3398 (14)	0.4131 (12)	0.033 (3)
C4	−0.1415 (11)	0.5	0.4790 (14)	0.023 (4)
H1	−0.076	0.5	0.136	0.041*
H2	−0.093	0.234	0.237	0.037*
H3	−0.139	0.230	0.457	0.040*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Hg1	0.0281 (3)	0.0363 (4)	0.0220 (3)	0.0	0.0065 (2)	0.0
Cl1	0.050 (3)	0.037 (2)	0.0170 (16)	0.0	0.0049 (15)	0.0
Cl2	0.031 (2)	0.043 (2)	0.0292 (19)	0.0	0.0116 (15)	0.0
Cl3	0.0304 (17)	0.0172 (13)	0.0236 (15)	0.0	0.0084 (13)	0.0
Cl4	0.051 (3)	0.039 (2)	0.0224 (18)	0.0	0.0156 (17)	0.0
N1	0.038 (8)	0.043 (8)	0.024 (7)	0.0	0.013 (6)	0.0
C2	0.036 (6)	0.026 (5)	0.031 (5)	0.001 (5)	0.008 (4)	−0.002 (4)
C3	0.041 (6)	0.022 (5)	0.037 (6)	0.000 (5)	0.013 (5)	0.002 (5)
C4	0.028 (8)	0.028 (7)	0.015 (6)	0.0	0.004 (5)	0.0

Geometric parameters (Å, º)

Hg1—Cl1	2.354 (4)	C3—C4	1.393 (13)
Hg1—Cl2	2.346 (4)	N1—H1	0.95
Hg1—Cl3	2.727 (2)	C2—H2	0.95
Cl4—C4	1.700 (14)	C3—H3	0.95
N1—C2	1.339 (12)	Hg1—Hg1^i	3.8623 (16)
C2—C3	1.378 (15)
Cl1—Hg1—Cl2	153.72 (16)	Cl4—C4—C3	120.0 (7)
Cl1—Hg1—Cl3	98.19 (8)	C3—C4—C3^ii	120.1 (13)
Cl2—Hg1—Cl3	100.33 (8)	C2—N1—H1	117.0
Cl3—Hg1—Cl3^i	89.84 (10)	N1—C2—H2	121.2
Hg1—Cl3—Hg1^i	90.16 (10)	C3—C2—H2	121.2
C2—N1—C2^ii	126.0 (13)	C2—C3—H3	120.3
N1—C2—C3	117.6 (10)	C4—C3—H3	120.3
C2—C3—C4	119.4 (10)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···Cl3	0.95	2.57	3.272 (11)	131