1,1′-(Butane-1,4-di­yl)bis­(1H-benzimidazol-3-ium) diiodo­(pyridine-2,6-dicarboxyl­ato-κ³O,N,O′)mercurate(II)

In the title complex, (C₁₈H₂₀N₄)[HgI₂(C₇H₃NO₄)], the Hg atom exists in a distorted trigonal–bipyramidal geometry formed by two I atoms, one pyridine N and two carboxyl­ate O atoms from a chelating 2,6-pyridine­dicarboxyl­ate ligand. Extensive hydrogen bonding between the carboxyl­ate groups and the 1,1′-(butane-1,4-di­yl)bis­(1H-benzimidazol-3-ium) ion is present in the structure, as well as π–π stacking inter­actions. The cation has a crystallographic centre of symmetry. In the anion, a crystallographic twofold rotation axis coincides with the Hg–N bond.

Key indicators

• Single-crystal X-ray study
• T = 291 K
• Mean [sigma](C-C) = 0.014 Å
• R factor = 0.053
• wR factor = 0.129
• Data-to-parameter ratio = 16.4

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT342_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ...         13
PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd.  #          1
              C18 H20 N4
PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd.  #          2
              C7 H3 Hg I2 N O4

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

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   2 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: SHELXTL (Bruker, 2000); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

1,1'-(Butane-1,4-diyl)bis(1H-benzimidazol-3-ium) diiodo(pyridine-2,6-dicarboxylato-κ³O,N,O')mercury(II)

Crystal data

(C18H20N4)[HgI2(C7H3NO4)]	F(000) = 1704
Mr = 911.87	Dx = 2.143 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 1415 reflections
a = 21.696 (4) Å	θ = 2.1–25.7°
b = 15.158 (3) Å	µ = 7.67 mm^−1
c = 8.9959 (18) Å	T = 291 K
β = 107.16 (3)°	Block, pink
V = 2826.8 (11) Å^3	0.20 × 0.17 × 0.17 mm
Z = 4

Data collection

Bruker SMART APEX CCD area-detector diffractometer	2786 independent reflections
Radiation source: sealed tube	2157 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.045
φ and ω scans	θmax = 26.0°, θmin = 1.7°
Absorption correction: multi-scan (SADABS; Bruker, 2000)	h = −26→26
Tmin = 0.24, Tmax = 0.27	k = −18→18
7241 measured reflections	l = −11→11

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)] = 0.053	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.129	H-atom parameters constrained
S = 1.03	w = 1/[σ^2(Fo^2) + (0.07P)^2 + 1.94P] where P = (Fo^2 + 2Fc^2)/3
2786 reflections	(Δ/σ)max < 0.001
170 parameters	Δρmax = 0.66 e Å^−3
0 restraints	Δρmin = −1.56 e Å^−3

Special details

Experimental. IR (KBr)/cm^-1: 1738 (s), 1436 (w), 1342 (s), 1214 (w), 754 (s), 695 (m).

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
Hg1	0.5000	−0.21816 (3)	0.7500	0.05324 (19)
I1	0.43216 (4)	−0.30359 (5)	0.49367 (10)	0.0683 (2)
N1	0.5000	−0.0622 (5)	0.7500	0.0318 (17)
N2	0.2494 (3)	−0.1942 (5)	0.1645 (7)	0.0388 (14)
N3	0.2933 (4)	−0.1086 (5)	0.0300 (9)	0.0509 (18)
H3B	0.3213	−0.0843	−0.0073	0.061*
O1	0.5899 (3)	−0.1526 (4)	0.6481 (9)	0.0562 (16)
O2	0.6270 (3)	−0.0256 (4)	0.5811 (8)	0.0559 (16)
C1	0.5896 (4)	−0.0710 (5)	0.6401 (10)	0.0435 (18)
C2	0.5418 (3)	−0.0193 (5)	0.6964 (9)	0.0331 (15)
C3	0.5419 (4)	0.0731 (5)	0.6874 (10)	0.0411 (17)
H3A	0.5690	0.1027	0.6412	0.049*
C4	0.5000	0.1189 (6)	0.7500	0.043 (3)
H4A	0.5000	0.1802	0.7500	0.051*
C5	0.2002 (4)	−0.1446 (5)	0.0691 (9)	0.0388 (16)
C6	0.1331 (4)	−0.1433 (6)	0.0484 (11)	0.050 (2)
H6A	0.1145	−0.1798	0.1064	0.060*
C7	0.0961 (6)	−0.0859 (7)	−0.0611 (14)	0.065 (3)
H7A	0.0519	−0.0817	−0.0764	0.078*
C8	0.1263 (6)	−0.0333 (7)	−0.1499 (15)	0.071 (3)
H8A	0.1008	0.0022	−0.2283	0.086*
C9	0.1913 (6)	−0.0330 (7)	−0.1247 (13)	0.066 (3)
H9A	0.2103	0.0047	−0.1798	0.080*
C10	0.2284 (4)	−0.0906 (5)	−0.0144 (9)	0.0410 (17)
C11	0.3055 (5)	−0.1705 (7)	0.1414 (10)	0.051 (2)
H11A	0.3459	−0.1932	0.1937	0.062*
C12	0.2449 (4)	−0.2588 (5)	0.2822 (10)	0.0432 (18)
H12A	0.2789	−0.3022	0.2949	0.052*
H12B	0.2039	−0.2893	0.2462	0.052*
C13	0.2507 (4)	−0.2157 (6)	0.4400 (10)	0.0460 (19)
H13B	0.2908	−0.1829	0.4742	0.055*
H13A	0.2154	−0.1746	0.4291	0.06 (3)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Hg1	0.0542 (3)	0.0415 (3)	0.0681 (4)	0.000	0.0243 (2)	0.000
I1	0.0682 (5)	0.0594 (4)	0.0754 (5)	−0.0085 (3)	0.0182 (4)	−0.0039 (3)
N1	0.028 (4)	0.029 (4)	0.038 (5)	0.000	0.009 (4)	0.000
N2	0.037 (3)	0.054 (4)	0.030 (3)	−0.013 (3)	0.017 (3)	−0.002 (3)
N3	0.052 (4)	0.056 (4)	0.051 (4)	−0.007 (3)	0.026 (4)	0.005 (3)
O1	0.053 (3)	0.044 (3)	0.083 (5)	0.006 (3)	0.037 (3)	−0.009 (3)
O2	0.056 (4)	0.054 (3)	0.077 (5)	−0.008 (3)	0.049 (4)	−0.001 (3)
C1	0.040 (4)	0.040 (4)	0.051 (5)	0.004 (3)	0.015 (4)	−0.009 (3)
C2	0.032 (3)	0.036 (3)	0.035 (4)	−0.001 (3)	0.015 (3)	0.002 (3)
C3	0.040 (4)	0.048 (4)	0.043 (4)	0.005 (3)	0.023 (4)	0.004 (3)
C4	0.055 (7)	0.022 (5)	0.060 (7)	0.000	0.030 (6)	0.000
C5	0.057 (4)	0.030 (3)	0.036 (4)	−0.009 (3)	0.023 (3)	−0.008 (3)
C6	0.051 (5)	0.056 (5)	0.052 (5)	−0.003 (4)	0.030 (4)	0.001 (4)
C7	0.070 (6)	0.065 (6)	0.071 (7)	−0.004 (5)	0.038 (6)	−0.005 (5)
C8	0.083 (8)	0.057 (6)	0.079 (8)	0.026 (5)	0.032 (6)	0.017 (5)
C9	0.099 (8)	0.052 (5)	0.063 (6)	0.009 (5)	0.048 (6)	0.011 (5)
C10	0.050 (4)	0.042 (4)	0.034 (4)	−0.006 (3)	0.018 (3)	−0.012 (3)
C11	0.067 (5)	0.063 (5)	0.029 (4)	−0.007 (4)	0.023 (4)	−0.001 (4)
C12	0.053 (4)	0.038 (4)	0.043 (4)	−0.011 (3)	0.020 (4)	−0.002 (3)
C13	0.052 (5)	0.052 (5)	0.039 (4)	−0.002 (4)	0.022 (4)	0.001 (4)

Geometric parameters (Å, º)

Hg1—N1	2.364 (8)	C4—C3^i	1.387 (9)
Hg1—O1	2.585 (6)	C4—H4A	0.9300
Hg1—O1^i	2.585 (6)	C5—C10	1.371 (11)
Hg1—I1	2.6755 (11)	C5—C6	1.412 (12)
Hg1—I1^i	2.6755 (11)	C6—C7	1.381 (15)
N1—C2	1.318 (8)	C6—H6A	0.9300
N1—C2^i	1.318 (8)	C7—C8	1.419 (16)
N2—C11	1.341 (11)	C7—H7A	0.9300
N2—C5	1.379 (11)	C8—C9	1.360 (16)
N2—C12	1.466 (10)	C8—H8A	0.9300
N3—C11	1.341 (12)	C9—C10	1.385 (14)
N3—C10	1.373 (11)	C9—H9A	0.9300
N3—H3B	0.8600	C11—H11A	0.9300
O1—C1	1.239 (10)	C12—C13	1.533 (12)
O2—C1	1.291 (10)	C12—H12A	0.9700
C1—C2	1.502 (10)	C12—H12B	0.9700
C2—C3	1.403 (11)	C13—C13^ii	1.505 (16)
C3—C4	1.387 (9)	C13—H13B	0.9700
C3—H3A	0.9300	C13—H13A	0.9700
N1—Hg1—O1	67.39 (13)	C10—C5—C6	121.9 (8)
N1—Hg1—O1^i	67.39 (13)	N2—C5—C6	132.0 (7)
O1—Hg1—O1^i	134.8 (3)	C7—C6—C5	117.5 (8)
N1—Hg1—I1	118.95 (2)	C7—C6—H6A	121.2
O1—Hg1—I1	99.28 (16)	C5—C6—H6A	121.2
O1^i—Hg1—I1	102.18 (16)	C6—C7—C8	119.2 (10)
N1—Hg1—I1^i	118.95 (2)	C6—C7—H7A	120.4
O1—Hg1—I1^i	102.18 (16)	C8—C7—H7A	120.4
O1^i—Hg1—I1^i	99.28 (16)	C9—C8—C7	122.5 (11)
I1—Hg1—I1^i	122.10 (4)	C9—C8—H8A	118.8
C2—N1—C2^i	120.8 (9)	C7—C8—H8A	118.8
C2—N1—Hg1	119.6 (4)	C8—C9—C10	118.1 (9)
C2^i—N1—Hg1	119.6 (4)	C8—C9—H9A	120.9
C11—N2—C5	109.2 (7)	C10—C9—H9A	120.9
C11—N2—C12	123.1 (7)	C5—C10—N3	107.9 (8)
C5—N2—C12	127.5 (6)	C5—C10—C9	120.6 (8)
C11—N3—C10	108.4 (7)	N3—C10—C9	131.5 (8)
C11—N3—H3B	125.8	N3—C11—N2	108.4 (9)
C10—N3—H3B	125.8	N3—C11—H11A	125.8
C1—O1—Hg1	114.4 (5)	N2—C11—H11A	125.8
O1—C1—O2	124.3 (7)	N2—C12—C13	112.3 (7)
O1—C1—C2	119.5 (7)	N2—C12—H12A	109.1
O2—C1—C2	116.2 (7)	C13—C12—H12A	109.1
N1—C2—C3	121.8 (7)	N2—C12—H12B	109.1
N1—C2—C1	118.9 (7)	C13—C12—H12B	109.1
C3—C2—C1	119.2 (6)	H12A—C12—H12B	107.9
C4—C3—C2	117.6 (7)	C13^ii—C13—C12	110.9 (9)
C4—C3—H3A	121.2	C13^ii—C13—H13B	109.5
C2—C3—H3A	121.2	C12—C13—H13B	109.5
C3^i—C4—C3	120.1 (10)	C13^ii—C13—H13A	109.5
C3^i—C4—H4A	120.0	C12—C13—H13A	109.5
C3—C4—H4A	120.0	H13B—C13—H13A	108.0
C10—C5—N2	106.1 (7)
O1—Hg1—N1—C2	2.2 (4)	C2—C3—C4—C3^i	−2.7 (5)
O1^i—Hg1—N1—C2	−177.8 (4)	C11—N2—C5—C10	0.7 (9)
I1—Hg1—N1—C2	−86.1 (4)	C12—N2—C5—C10	176.7 (7)
I1^i—Hg1—N1—C2	93.9 (4)	C11—N2—C5—C6	−179.9 (9)
O1—Hg1—N1—C2^i	−177.8 (4)	C12—N2—C5—C6	−3.9 (14)
O1^i—Hg1—N1—C2^i	2.2 (4)	C10—C5—C6—C7	0.6 (13)
I1—Hg1—N1—C2^i	93.9 (4)	N2—C5—C6—C7	−178.6 (9)
I1^i—Hg1—N1—C2^i	−86.1 (4)	C5—C6—C7—C8	1.8 (15)
N1—Hg1—O1—C1	−3.0 (6)	C6—C7—C8—C9	−4.4 (18)
O1^i—Hg1—O1—C1	−3.0 (6)	C7—C8—C9—C10	4.1 (18)
I1—Hg1—O1—C1	114.6 (6)	N2—C5—C10—N3	0.6 (8)
I1^i—Hg1—O1—C1	−119.5 (6)	C6—C5—C10—N3	−178.9 (8)
Hg1—O1—C1—O2	−174.4 (7)	N2—C5—C10—C9	178.6 (8)
Hg1—O1—C1—C2	3.5 (10)	C6—C5—C10—C9	−0.8 (12)
C2^i—N1—C2—C3	−2.9 (6)	C11—N3—C10—C5	−1.7 (10)
Hg1—N1—C2—C3	177.1 (6)	C11—N3—C10—C9	−179.4 (9)
C2^i—N1—C2—C1	178.5 (8)	C8—C9—C10—C5	−1.5 (15)
Hg1—N1—C2—C1	−1.5 (8)	C8—C9—C10—N3	176.0 (10)
O1—C1—C2—N1	−1.6 (12)	C10—N3—C11—N2	2.1 (10)
O2—C1—C2—N1	176.4 (7)	C5—N2—C11—N3	−1.8 (10)
O1—C1—C2—C3	179.8 (8)	C12—N2—C11—N3	−178.0 (7)
O2—C1—C2—C3	−2.2 (12)	C11—N2—C12—C13	89.4 (10)
N1—C2—C3—C4	5.6 (11)	C5—N2—C12—C13	−86.1 (10)
C1—C2—C3—C4	−175.8 (6)	N2—C12—C13—C13^ii	−177.1 (8)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N3—H3B···O2^iii	0.86	1.71	2.568 (9)	174

Symmetry code: (iii) −x+1, y, −z+1/2.