catena-Poly[[bis-(pyrazine-2-carbox-amide-κN)mercury(II)]-di-μ-bromido].

In the crystal structure of the title compound, [HgBr(2)(C(5)H(5)N(3)O)(2)](n), the Hg(II) cation is located on an inversion center and is coordinated by two N atoms from the pyrazine rings and four bridging Br(-) anions in a distorted octa-hedral geometry. The Br(-) anions bridge the Hg(II) cations with significantly different Hg-Br bond distances of 2.4775 (8) and 3.1122 (8) Å, forming polymeric chains running along the a axis. Inter-molecular N-H⋯O and N-H⋯N hydrogen bonds are effective in the stabilization of the crystal structure.

Related literature

For metal-binding properties of pyridine and pyrazine ligands, see: Sasan et al. (2008 ▶); Khavasi et al. (2009 ▶); Petro & Mukherjee (1999 ▶); Sigh & Mukherjee (2005 ▶). For the coordination modes of pyrazine­amide, see: Hausmann & Brooker (2004 ▶); Cati & Stoeckli-Evans (2004 ▶); Miyazaki et al. (2007 ▶).

Experimental

Crystal data

[HgBr2(C5H5N3O)2]

M = 606.63

Triclinic,

a = 3.9628 (5) Å

b = 6.5162 (9) Å

c = 15.0388 (19) Å

α = 101.783 (10)°

β = 93.418 (11)°

γ = 95.214 (11)°

V = 377.36 (9) Å3

Z = 1

Mo Kα radiation

μ = 15.50 mm−1

T = 298 K

0.50 × 0.06 × 0.03 mm

Data collection

Stoe IPDS II diffractometer

Absorption correction: multi-scan (X-RED and X-SHAPE; Stoe & Cie, 2005 ▶) T min = 0.345, T max = 0.630

4311 measured reflections

2002 independent reflections

1933 reflections with I > 2σ(I)

R int = 0.144

Refinement

R[F 2 > 2σ(F 2)] = 0.065

wR(F 2) = 0.173

S = 1.11

2002 reflections

97 parameters

H-atom parameters constrained

Δρmax = 3.93 e Å−3

Δρmin = −5.48 e Å−3

Data collection: X-AREA (Stoe & Cie, 2005 ▶); cell refinement: X-AREA; data reduction: X-AREA; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810001182/xu2716sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810001182/xu2716Isup2.hkl

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

[HgBr2(C5H5N3O)2]	Z = 1
Mr = 606.63	F(000) = 278
Triclinic, P1	Dx = 2.669 Mg m−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 3.9628 (5) Å	Cell parameters from 765 reflections
b = 6.5162 (9) Å	θ = 3.2–29.1°
c = 15.0388 (19) Å	µ = 15.50 mm−1
α = 101.783 (10)°	T = 298 K
β = 93.418 (11)°	Needle, colorless
γ = 95.214 (11)°	0.5 × 0.06 × 0.03 mm
V = 377.36 (9) Å3

Stoe IPDS II diffractometer	1933 reflections with I > 2σ(I)
rotation method scans	Rint = 0.144
Absorption correction: multi-scan (X-RED and X-SHAPE; Stoe & Cie, 2005)	θmax = 29.1°, θmin = 3.2°
Tmin = 0.345, Tmax = 0.630	h = −5→5
4311 measured reflections	k = −8→8
2002 independent reflections	l = −20→20

Refinement on F2	0 restraints
Least-squares matrix: full	H-atom parameters constrained
R[F2 > 2σ(F2)] = 0.065	w = 1/[σ2(Fo2) + (0.1262P)2] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.173	(Δ/σ)max < 0.001
S = 1.11	Δρmax = 3.93 e Å−3
2002 reflections	Δρmin = −5.48 e Å−3
97 parameters

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.

	x	y	z	Uiso*/Ueq
C1	0.402 (2)	0.5193 (13)	0.7914 (6)	0.0456 (17)
H1	0.3215	0.6506	0.8064	0.055*
C2	0.400 (2)	0.4210 (13)	0.7010 (6)	0.0444 (16)
H2	0.3156	0.4876	0.6566	0.053*
C3	0.629 (2)	0.1448 (13)	0.7407 (5)	0.0414 (15)
H3	0.7049	0.0123	0.7252	0.05*
C4	0.638 (2)	0.2438 (14)	0.8329 (6)	0.0381 (15)
C5	0.790 (2)	0.1363 (13)	0.9029 (5)	0.0413 (15)
N1	0.519 (2)	0.4278 (10)	0.8588 (5)	0.0420 (14)
N2	0.5148 (18)	0.2350 (10)	0.6752 (4)	0.0422 (13)
N3	0.779 (2)	0.2309 (12)	0.9885 (5)	0.0525 (17)
H3A	0.8633	0.1766	1.0313	0.063*
H3B	0.6883	0.3471	1.0017	0.063*
O1	0.914 (2)	−0.0290 (12)	0.8783 (5)	0.0577 (19)
Hg1	0.5	0	0.5	0.0390 (2)
Br1	0.86218 (19)	−0.24778 (12)	0.55380 (6)	0.0394 (2)

	U11	U22	U33	U12	U13	U23
C1	0.065 (5)	0.036 (3)	0.038 (4)	0.015 (3)	−0.006 (3)	0.011 (3)
C2	0.055 (4)	0.042 (4)	0.037 (3)	0.004 (3)	−0.009 (3)	0.014 (3)
C3	0.056 (4)	0.039 (3)	0.030 (3)	0.013 (3)	−0.006 (3)	0.006 (3)
C4	0.048 (4)	0.037 (3)	0.028 (3)	0.006 (3)	−0.005 (3)	0.004 (3)
C5	0.055 (4)	0.041 (4)	0.029 (3)	0.011 (3)	−0.002 (3)	0.009 (3)
N1	0.062 (4)	0.031 (3)	0.032 (3)	0.007 (3)	−0.007 (3)	0.007 (2)
N2	0.057 (3)	0.040 (3)	0.029 (3)	0.007 (3)	−0.007 (2)	0.010 (2)
N3	0.085 (5)	0.045 (3)	0.030 (3)	0.023 (4)	−0.005 (3)	0.009 (3)
O1	0.095 (6)	0.049 (3)	0.031 (3)	0.032 (4)	−0.005 (3)	0.007 (2)
Hg1	0.0387 (3)	0.0433 (3)	0.0380 (3)	0.01479 (17)	−0.00149 (16)	0.01255 (19)
Br1	0.0390 (4)	0.0374 (4)	0.0453 (5)	0.0116 (3)	0.0000 (3)	0.0146 (3)

C1—N1	1.356 (10)	C5—O1	1.224 (11)
C1—C2	1.378 (12)	C5—N3	1.313 (10)
C1—H1	0.93	N3—H3A	0.86
C2—N2	1.325 (11)	N3—H3B	0.86
C2—H2	0.93	Hg1—Br1	2.4775 (8)
C3—N2	1.323 (9)	Hg1—Br1i	2.4775 (8)
C3—C4	1.402 (11)	Hg1—Br1ii	3.1122 (8)
C3—H3	0.93	Hg1—Br1iii	3.1122 (8)
C4—N1	1.321 (12)	Hg1—N2	2.758 (6)
C4—C5	1.505 (12)	Hg1—N2i	2.758 (6)
N1—C1—C2	121.2 (8)	N3—C5—C4	116.1 (8)
N1—C1—H1	119.4	C4—N1—C1	116.5 (7)
C2—C1—H1	119.4	C3—N2—C2	116.8 (7)
N2—C2—C1	122.2 (7)	C5—N3—H3A	120
N2—C2—H2	118.9	C5—N3—H3B	120
C1—C2—H2	118.9	H3A—N3—H3B	120
N2—C3—C4	121.7 (8)	Br1—Hg1—Br1i	180.00 (4)
N2—C3—H3	119.1	Br1—Hg1—Br1ii	90.44 (2)
C4—C3—H3	119.1	Br1i—Hg1—Br1ii	89.56 (2)
N1—C4—C3	121.5 (8)	Br1—Hg1—Br1iii	89.56 (2)
N1—C4—C5	120.1 (7)	Br1i—Hg1—Br1iii	90.44 (2)
C3—C4—C5	118.4 (8)	Br1ii—Hg1—Br1iii	180.000 (17)
O1—C5—N3	124.2 (8)	Hg1—Br1—Hg1iv	89.56 (2)
O1—C5—C4	119.7 (7)
N1—C1—C2—N2	−0.7 (15)	C3—C4—C5—N3	−177.2 (9)
N2—C3—C4—N1	2.9 (14)	C3—C4—N1—C1	−2.6 (12)
N2—C3—C4—C5	−176.4 (8)	C5—C4—N1—C1	176.7 (9)
N1—C4—C5—O1	−176.4 (8)	C2—C1—N1—C4	1.6 (13)
C3—C4—C5—O1	3.0 (14)	C4—C3—N2—C2	−1.9 (12)
N1—C4—C5—N3	3.4 (13)	C1—C2—N2—C3	0.8 (13)

D—H···A	D—H	H···A	D···A	D—H···A
N3—H3A···O1v	0.86	2.02	2.881 (11)	174
N3—H3B···N1vi	0.86	2.53	3.214 (11)	137

Table 1

Selected bond lengths (Å)

Hg1—Br1	2.4775 (8)
Hg1—Br1i	3.1122 (8)
Hg1—N2	2.758 (6)

Symmetry code: (i) .

Table 2

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N3—H3A⋯O1ii	0.86	2.02	2.881 (11)	174
N3—H3B⋯N1iii	0.86	2.53	3.214 (11)	137

Symmetry codes: (ii) ; (iii) .