catena-Poly[[chloridomercury(II)]-μ-1,4-diaza-bicyclo-[2.2.2]octane-κN:N'-[chlorido-mercury(II)]-di-μ-chlorido].

In the title coordination polymer, [Hg(2)Cl(4)(C(6)H(12)N(2))](n), each Hg(II) center within the chain is four-coordinated by one terminal Cl atom, two bridging μ(2)-Cl atoms, and one N-atom donor from a μ(2)-1,4-diaza-bicyclo-[2.2.2]octane (μ(2)-daco) ligand in a distorted tetra-hedral geometry. The daco ligand acts as an end-to-end bridging ligand and bridges adjacent Hg(II) centers, forming a chain running along [001]. Weak C-H⋯Cl hydrogen-bonding inter-actions link the chains into a three-dimensional network. Comparison of the structural differences with previous findings suggests that the space between the two N donors, as well as the skeletal rigidity in N-heterocyclic linear ligands, may play an important role in the construction of such supra-molecular networks.

Related literature

For a related structure, see: Pickardt et al. (1995 ▶). For functional materials, see: Chen, Kang & Su (2006 ▶); Fang et al. (2009 ▶); Liu et al. (2007 ▶); Ma et al. (2009 ▶); Tranchemontagne et al. (2009 ▶); Uemura et al. (2009 ▶); Xue et al. (2008 ▶). For N-containing hetercyclic bridging ligands, see: Batten et al. (2002 ▶); Chen et al. (2007 ▶); Culp et al. (2008 ▶); Kaim (1983 ▶); Leininger et al. (2000 ▶); Richardson & Steel (2003 ▶); Steel (2005 ▶). For 4,4′-bipyridine and pyrazine extended assemblies, see: Arpi et al. (2006 ▶); Chen, Wang et al. (2006 ▶); Choi et al. (2009 ▶); Derossi et al. (2007 ▶); Du et al. (2007 ▶); Liu et al. (2006 ▶); Li et al.(2008 ▶); Ramírez et al. (2009 ▶); Qiu et al. (2008 ▶); Nockemann & Meyer (2004 ▶); Xie & Wu (2007 ▶). For daco complexes, see: Dybtsev et al. (2004 ▶); Li et al. (2006 ▶); Rao & Rao (2007 ▶); Steel (2005 ▶). For factors determining the crystal packing, see: Kitagawa et al. (2004 ▶). For Hg—N and Hg—Cl bond distances and bond angles about Hg, see: Orpen et al. (1989 ▶); Wang et al. (2007 ▶).

Experimental

Crystal data

[Hg2Cl4(C6H12N2)]

M = 327.58

Orthorhombic,

a = 9.2518 (9) Å

b = 8.8244 (9) Å

c = 14.7531 (8) Å

V = 1204.47 (18) Å3

Z = 8

Mo Kα radiation

μ = 26.31 mm−1

T = 293 K

0.05 × 0.04 × 0.02 mm

Data collection

Bruker SMART CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T min = 0.353, T max = 0.621

1322 measured reflections

586 independent reflections

392 reflections with I > 2σ(I)

R int = 0.040

Refinement

R[F 2 > 2σ(F 2)] = 0.037

wR(F 2) = 0.047

S = 0.96

586 reflections

39 parameters

6 restraints

H-atom parameters constrained

Δρmax = 1.41 e Å−3

Δρmin = −1.59 e Å−3

Data collection: SMART (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 ▶).

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809043839/su2148sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809043839/su2148Isup2.hkl

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

[Hg2Cl4(C6H12N2)]	F(000) = 1160
Mr = 327.58	Dx = 3.613 Mg m−3
Orthorhombic, Cmcm	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2c 2	Cell parameters from 453 reflections
a = 9.2518 (9) Å	θ = 3.2–30.3°
b = 8.8244 (9) Å	µ = 26.31 mm−1
c = 14.7531 (8) Å	T = 293 K
V = 1204.47 (18) Å3	Block, colorless
Z = 8	0.05 × 0.04 × 0.02 mm

Bruker SMART CCD area-detector diffractometer	586 independent reflections
Radiation source: fine-focus sealed tube	392 reflections with I > 2σ(I)
graphite	Rint = 0.040
φ and ω scans	θmax = 25.0°, θmin = 3.2°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −10→10
Tmin = 0.353, Tmax = 0.621	k = −10→8
1322 measured reflections	l = −17→9

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)] = 0.037	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.047	H-atom parameters constrained
S = 0.96	w = 1/[σ2(Fo2) + (0.0085P)2] where P = (Fo2 + 2Fc2)/3
586 reflections	(Δ/σ)max < 0.001
39 parameters	Δρmax = 1.41 e Å−3
6 restraints	Δρmin = −1.59 e Å−3

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.

	x	y	z	Uiso*/Ueq	Occ. (<1)
Hg1	0.5000	0.22915 (6)	0.51455 (3)	0.0533 (2)
C1	0.5000	0.0735 (12)	0.6983 (7)	0.036 (3)
H1A	0.5849	0.0205	0.6763	0.043*	0.50
H1B	0.4151	0.0205	0.6763	0.043*	0.50
C2	0.3708 (8)	0.3114 (9)	0.6975 (5)	0.032 (2)
H2A	0.2843	0.2615	0.6754	0.039*
H2B	0.3704	0.4150	0.6754	0.039*
Cl1	0.2906 (3)	0.0000	0.5000	0.0344 (8)
Cl2	0.5000	0.3087 (3)	0.3653 (2)	0.0349 (9)
N1	0.5000	0.2318 (11)	0.6631 (6)	0.022 (2)

	U11	U22	U33	U12	U13	U23
Hg1	0.0692 (4)	0.0785 (5)	0.0122 (3)	0.000	0.000	0.0076 (3)
C1	0.055 (9)	0.017 (6)	0.036 (8)	0.000	0.000	0.006 (5)
C2	0.016 (5)	0.050 (6)	0.031 (5)	−0.003 (4)	−0.003 (4)	0.008 (4)
Cl1	0.0244 (17)	0.0511 (18)	0.028 (2)	0.000	0.000	−0.0067 (17)
Cl2	0.042 (2)	0.043 (2)	0.0198 (16)	0.000	0.000	0.0094 (13)
N1	0.022 (2)	0.022 (2)	0.022 (2)	0.000	0.000	0.0000 (10)

Hg1—N1	2.192 (8)	C1—H1B	0.9700
Hg1—Cl2	2.311 (3)	C2—N1	1.476 (9)
Hg1—Cl1i	2.8083 (17)	C2—C2ii	1.549 (15)
Hg1—Cl1	2.8083 (17)	C2—H2A	0.9700
C1—N1	1.490 (13)	C2—H2B	0.9700
C1—C1ii	1.52 (2)	Cl1—Hg1i	2.8083 (17)
C1—H1A	0.9700	N1—C2iii	1.476 (9)
N1—Hg1—Cl2	161.7 (3)	N1—C2—H2A	109.6
N1—Hg1—Cl1i	94.82 (18)	C2ii—C2—H2A	109.6
Cl2—Hg1—Cl1i	98.39 (5)	N1—C2—H2B	109.6
N1—Hg1—Cl1	94.82 (18)	C2ii—C2—H2B	109.6
Cl2—Hg1—Cl1	98.39 (5)	H2A—C2—H2B	108.2
Cl1i—Hg1—Cl1	87.21 (7)	Hg1—Cl1—Hg1i	92.79 (7)
N1—C1—C1ii	110.4 (5)	C2iii—N1—C2	108.1 (8)
N1—C1—H1A	109.6	C2iii—N1—C1	109.1 (6)
C1ii—C1—H1A	109.6	C2—N1—C1	109.1 (6)
N1—C1—H1B	109.6	C2iii—N1—Hg1	110.4 (5)
C1ii—C1—H1B	109.6	C2—N1—Hg1	110.4 (5)
H1A—C1—H1B	108.1	C1—N1—Hg1	109.8 (6)
N1—C2—C2ii	110.1 (4)

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2A···Cl2iv	0.97	2.77	3.708 (8)	163
C2—H2B···Cl2v	0.97	2.78	3.678 (8)	154

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C2—H2A⋯Cl2i	0.97	2.77	3.708 (8)	163
C2—H2B⋯Cl2ii	0.97	2.78	3.678 (8)	154

Symmetry codes: (i) ; (ii) .