catena-Poly[[bis­(pyrazine-2-carbox­amide)mercury(II)]-di-μ-chlorido]

Abstract

In the polymeric title compound, [HgCl₂(C₅H₅N₃O)₂]_n, the Hg^II atom (site symmetry ) adopts a distorted trans-HgN₂Cl₄ octa­hedral coordination geometry. In the crystal, adjacent mercury ions are bridged by pairs of chloride ions, generating infinite [100] chains, and N—H⋯O and N—H⋯(N,N) hydrogen bonds help to consolidate the packing.

Related literature

For related structures, see: Cati & Stoeckli-Evans (2004 ▶); Hausmann & Brooker (2004 ▶); Mir Mohammad Sadegh et al. (2010 ▶); Miyazaki et al. (2007 ▶).

Experimental

Crystal data

• [HgCl₂(C₅H₅N₃O)₂]

• M _r = 517.73

• Triclinic,

• a = 3.8451 (8) Å

• b = 6.4170 (13) Å

• c = 14.854 (3) Å

• α = 101.14 (3)°

• β = 92.53 (3)°

• γ = 94.69 (3)°

• V = 357.73 (13) ų

• Z = 1

• Mo Kα radiation

• μ = 11.14 mm⁻¹

• T = 298 K

• 0.48 × 0.15 × 0.06 mm

Data collection

• Stoe IPDS II diffractometer

• Absorption correction: numerical [optically, by X-RED and XSHAPE (Stoe & Cie, 2005 ▶)] T _min = 0.150, T _max = 0.515

• 4201 measured reflections

• 1887 independent reflections

• 1880 reflections with I > 2σ(I)

• R _int = 0.096

Refinement

• R[F ² > 2σ(F ²)] = 0.054

• wR(F ²) = 0.144

• S = 1.08

• 1887 reflections

• 97 parameters

• H-atom parameters constrained

• Δρ_max = 3.25 e Å⁻³

• Δρ_min = −3.75 e Å⁻³

Data collection: X-AREA (Stoe & Cie, 2005 ▶); cell refinement: X-AREA; data reduction: X-AREA; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: ORTEP-3 (Farrugia, 1997 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

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

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

Hg1—N2	2.661 (7)
Hg1—Cl1i	2.970 (2)
Hg1—Cl1	2.375 (2)

Hg1—Cl1—Hg1ii

91.31 (7)

Symmetry codes: (i) ; (ii) .

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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N3—H3A⋯O1iii	0.86	2.01	2.864 (12)	176
N3—H3B⋯N1	0.86	2.40	2.758 (12)	105
N3—H3B⋯N1iv	0.86	2.54	3.198 (12)	134

Symmetry codes: (iii) ; (iv) .

supplementary crystallographic information

Comment

The coordination chemistry of parazineamides is rich. Examples of coordination via the pyrazine N atoms, the carbonyl O atoms and the amide N atoms of the ligand in a non-, mono-, or bis-deprotonated form are known (Hausmann and Brooker, 2004; Cati & Stoeckli-Evans, 2004; Miyazaki et al. 2007) and metal complexes of the ligands have been used extensively to mimic the properties of biologically active systems. Here we synthesized the title compound, (I), and report here its crystal structure.

The asymmetric unit of the title compound, (I), contains one half-molecule (Fig. 1). The Hg^II atom is six-coordinated in a distorted octahedral configuration by two N atoms from pyrazine amides and four bridging Cl atoms. The bridging function of chloro atoms leads to a one-dimensional chain structure. The Hg—Cl and Hg—N bond lengths and angles (Table 1) are within normal ranges. In the crystal structure (Fig. 2), intermolecular N—H···O and N—H···N hydrogen bonds (Table 2) result in the formation of a supramolecular structure, in which they may be effective in the stabilization of the structure.

Experimental

A solution of pyrazineamide (0.246 g, 2.0 mmol) in methanol (10 ml) was added to a solution of HgCl₂ (0.272 g, 1.0 mmol) in methanol (5 ml) at room temperature. Colourless plates of (I) were obtained by slow evaporation from methanolic solution after one week (yield; 0.359 g, 69.3%).

Refinement

All of the H atoms were positioned geometrically with C—H = 0.93 and 0.86Å for aromatic ring and NH₂ hydrogen atoms respectively, and constrained to ride on their parent atoms, with U_iso(H) = 1.2U_eq(C). The largest peak and deppest hole are near to Hg (0.87 and 0.75Å respectively).

Figures

Fig. 1.

The molecular staucture with displacement ellipsoids drawn at 30% probability level.

Fig. 2.

A packing diagram of (I) in b-directrion. Hydrogen bonds are shown as dashed lines.

Crystal data

[HgCl2(C5H5N3O)2]	Z = 1
Mr = 517.73	F(000) = 242
Triclinic, P1	Dx = 2.403 Mg m−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 3.8451 (8) Å	Cell parameters from 976 reflections
b = 6.4170 (13) Å	θ = 3.3–29.1°
c = 14.854 (3) Å	µ = 11.14 mm−1
α = 101.14 (3)°	T = 298 K
β = 92.53 (3)°	Plate, colourless
γ = 94.69 (3)°	0.48 × 0.15 × 0.06 mm
V = 357.73 (13) Å3

Data collection

Stoe IPDS II diffractometer	1880 reflections with I > 2σ(I)
ω scans	Rint = 0.096
Absorption correction: numerical [optically, by X-RED and X-SHAPE (Stoe & Cie, 2005)]	θmax = 29.1°, θmin = 3.3°
Tmin = 0.150, Tmax = 0.515	h = −5→4
4201 measured reflections	k = −8→8
1887 independent reflections	l = −20→20

Refinement

Refinement on F2	0 restraints
Least-squares matrix: full	H-atom parameters constrained
R[F2 > 2σ(F2)] = 0.054	w = 1/[σ2(Fo2) + (0.110P)2 + 0.204P] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.144	(Δ/σ)max < 0.001
S = 1.08	Δρmax = 3.25 e Å−3
1887 reflections	Δρmin = −3.75 e Å−3
97 parameters

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.

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

	x	y	z	Uiso*/Ueq
C1	0.397 (3)	0.5265 (12)	0.2863 (6)	0.0431 (16)
H1	0.3077	0.6583	0.3014	0.052*
C2	0.400 (3)	0.4268 (13)	0.1935 (6)	0.0431 (16)
H2	0.3177	0.4953	0.1482	0.052*
C3	0.632 (2)	0.1435 (13)	0.2363 (6)	0.0391 (14)
H3	0.7083	0.008	0.2215	0.047*
C4	0.639 (2)	0.2438 (11)	0.3279 (5)	0.0341 (12)
C5	0.793 (2)	0.1365 (12)	0.3999 (6)	0.0385 (14)
N1	0.520 (2)	0.4354 (11)	0.3536 (5)	0.0429 (14)
N2	0.519 (2)	0.2350 (11)	0.1690 (5)	0.0412 (13)
N3	0.784 (3)	0.2340 (13)	0.4863 (6)	0.0516 (19)
H3A	0.8724	0.1795	0.5296	0.062*
H3B	0.6888	0.352	0.4994	0.062*
O1	0.924 (3)	−0.0327 (12)	0.3755 (5)	0.0539 (18)
Cl1	0.8689 (6)	−0.2371 (3)	0.05218 (16)	0.0444 (4)
Hg1	0.5	0	0	0.03963 (18)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
C1	0.054 (4)	0.036 (3)	0.041 (4)	0.016 (3)	−0.005 (3)	0.007 (3)
C2	0.056 (4)	0.042 (3)	0.034 (4)	0.011 (3)	0.000 (3)	0.012 (3)
C3	0.046 (4)	0.042 (3)	0.029 (3)	0.016 (3)	0.001 (3)	0.004 (2)
C4	0.038 (3)	0.036 (3)	0.029 (3)	0.009 (2)	−0.001 (3)	0.006 (2)
C5	0.045 (4)	0.040 (3)	0.030 (3)	0.006 (3)	−0.004 (3)	0.008 (2)
N1	0.052 (4)	0.038 (3)	0.038 (3)	0.012 (2)	−0.001 (3)	0.003 (2)
N2	0.049 (4)	0.045 (3)	0.031 (3)	0.014 (2)	−0.001 (3)	0.007 (2)
N3	0.077 (6)	0.045 (3)	0.035 (3)	0.032 (3)	−0.003 (3)	0.003 (3)
O1	0.084 (5)	0.047 (3)	0.033 (3)	0.033 (3)	0.001 (3)	0.004 (2)
Cl1	0.0448 (9)	0.0477 (9)	0.0434 (10)	0.0146 (7)	0.0022 (8)	0.0114 (7)
Hg1	0.0397 (2)	0.0505 (3)	0.0305 (2)	0.01765 (14)	−0.00015 (15)	0.00733 (15)

Geometric parameters (Å, °)

C1—N1	1.340 (12)	C5—N3	1.318 (11)
C1—C2	1.404 (12)	N3—H3A	0.86
C1—H1	0.93	N3—H3B	0.86
C2—N2	1.338 (11)	Cl1—Hg1i	2.970 (2)
C2—H2	0.93	Hg1—Cl1ii	2.375 (2)
C3—N2	1.327 (11)	Hg1—N2ii	2.661 (7)
C3—C4	1.387 (10)	Hg1—Cl1iii	2.970 (2)
C3—H3	0.93	Hg1—N2	2.661 (7)
C4—N1	1.338 (10)	Hg1—Cl1iv	2.970 (2)
C4—C5	1.506 (11)	Hg1—Cl1	2.375 (2)
C5—O1	1.232 (11)
N1—C1—C2	121.3 (7)	C5—N3—H3A	120
N1—C1—H1	119.4	C5—N3—H3B	120
C2—C1—H1	119.4	H3A—N3—H3B	120
N2—C2—C1	121.3 (8)	Hg1—Cl1—Hg1i	91.31 (7)
N2—C2—H2	119.4	Cl1ii—Hg1—Cl1	180.0
C1—C2—H2	119.4	Cl1ii—Hg1—N2	89.49 (17)
N2—C3—C4	122.0 (7)	Cl1—Hg1—N2	90.51 (17)
N2—C3—H3	119	Cl1ii—Hg1—N2ii	90.51 (17)
C4—C3—H3	119	Cl1—Hg1—N2ii	89.49 (17)
N1—C4—C3	121.7 (8)	N2—Hg1—N2ii	180.0
N1—C4—C5	119.3 (7)	Cl1ii—Hg1—Cl1iii	91.31 (7)
C3—C4—C5	118.9 (7)	Cl1—Hg1—Cl1iii	88.69 (7)
O1—C5—N3	124.0 (8)	N2—Hg1—Cl1iii	94.05 (18)
O1—C5—C4	119.1 (7)	N2ii—Hg1—Cl1iii	85.95 (18)
N3—C5—C4	116.9 (7)	Cl1ii—Hg1—Cl1iv	88.69 (7)
C4—N1—C1	116.7 (7)	Cl1—Hg1—Cl1iv	91.31 (7)
C3—N2—C2	117.0 (7)	N2—Hg1—Cl1iv	85.95 (18)
C3—N2—Hg1	116.0 (5)	N2ii—Hg1—Cl1iv	94.05 (18)
C2—N2—Hg1	126.8 (6)	Cl1iii—Hg1—Cl1iv	180.0
N1—C1—C2—N2	1.5 (15)	C1—C2—N2—Hg1	174.2 (7)
N2—C3—C4—N1	2.4 (13)	Hg1i—Cl1—Hg1—N2	−94.04 (18)
N2—C3—C4—C5	−175.8 (8)	Hg1i—Cl1—Hg1—N2ii	85.96 (18)
N1—C4—C5—O1	−174.9 (9)	Hg1i—Cl1—Hg1—Cl1iii	0
C3—C4—C5—O1	3.3 (12)	Hg1i—Cl1—Hg1—Cl1iv	180
N1—C4—C5—N3	4.0 (12)	C3—N2—Hg1—Cl1ii	163.8 (6)
C3—C4—C5—N3	−177.8 (9)	C2—N2—Hg1—Cl1ii	−10.0 (8)
C3—C4—N1—C1	−0.5 (12)	C3—N2—Hg1—Cl1	−16.2 (6)
C5—C4—N1—C1	177.7 (8)	C2—N2—Hg1—Cl1	170.0 (8)
C2—C1—N1—C4	−1.4 (13)	C3—N2—Hg1—Cl1iii	−104.9 (6)
C4—C3—N2—C2	−2.3 (13)	C2—N2—Hg1—Cl1iii	81.3 (8)
C4—C3—N2—Hg1	−176.7 (6)	C3—N2—Hg1—Cl1iv	75.1 (6)
C1—C2—N2—C3	0.4 (13)	C2—N2—Hg1—Cl1iv	−98.7 (8)

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

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
N3—H3A···O1v	0.86	2.01	2.864 (12)	176
N3—H3B···N1	0.86	2.40	2.758 (12)	105
N3—H3B···N1vi	0.86	2.54	3.198 (12)	134

Symmetry codes: (v) −x+2, −y, −z+1; (vi) −x+1, −y+1, −z+1.