Poly[di-μ-chlorido-μ-(1,2,3,9-tetrahydropyrrolo[2,1-b]quinazolin-9-one-κ2 N:O)-mercury(II)]

In the crystal structure of the title two-dimensional network, [HgCl2(C11H10N2O)]n, the asymmetric unit consists of HgCl2 dumbbells and one molecule of the quinazoline unit. Pseudo-octahedrally coordinated HgII cations are chloride-bridged via a crystallographic inversion centre leading to different Hg—Cl bonds (short and long) and linked by other Cl atoms via translation along the a axis. The quinazoline ligands connect the Hg—Cl—Hg—Cl chains by N and O atoms along the b axis, forming the two-dimensional network structure. The crystal structure is stabilized by weak non-classical C—H⋯Cl hydrogen bonds and aromatic π–π stacking interactions [centroid–centroid distances = 3.942 (4) and 3.621 (4) Å].

In the crystal structure of the title two-dimensional network, [HgCl 2 (C 11 H 10 N 2 O)] n , the asymmetric unit consists of HgCl 2 dumbbells and one molecule of the quinazoline unit. Pseudooctahedrally coordinated Hg II cations are chloride-bridged via a crystallographic inversion centre leading to different Hg-Cl bonds (short and long) and linked by other Cl atoms via translation along the a axis. The quinazoline ligands connect the Hg-Cl-Hg-Cl chains by N and O atoms along the b axis, forming the two-dimensional network structure. The crystal structure is stabilized by weak non-classical C-HÁ Á ÁCl hydrogen bonds and aromaticstacking interactions [centroid-centroid distances = 3.942 (4) and 3.621 (4) Å ].

Related literature
For the synthesis of the ligand, see: Chatterjee & Ganguly (1968). For the crystal structure of the ligand, see: Turgunov et al. (1995). For the crystal structure of the pure octahedral Hg II ion and halide-bridged complex, see: Hu et al. (2007). For the crystal structure of a Hg II complex with asymmetric Hg-Cl bonds, see: Batten et al. (2002); Hu et al. (2007); Merkens et al. (2010). For a general review of halide-bridged chain and crosslinking polymers, see: Englert (2010).
The bridging chlorido ligands form zigzag Hg-Cl-Hg-Cl ring chains in the direction of the shortest lattice parameter.
The chlorido-bridged Hg···Hg distances amount to 3.9342 (7) and 3.9442 (7) Å. As the result of halide bridging in the [100] and bridging of the ditopic organic ligand in the [010] direction, an overall two-dimensional sheet is formed which is depicted in Fig. 2.
The observed structure is stabilized by weak C-H···Cl hydrogen bonds (Table 2). Cooperative π-π stacking interactions between neighbouring quinazolone ring systems also contribute to the stability of this layer structure (Cg1···Cg1 i =3.942 (4) Cg1···Cg2 i =3.621 (4) Å, where Cg1 represents the centroid of the pyrimidinone and Cg2 that of the benzo ring centroid, The ligand molecule is essentially planar with a maximum deviation of 0.044 (7) Å for atom C10 and an r.m.s. deviation of 0.015 Å.

Experimental
A solution of 27.15 mg (0.1 mmol) of mercury (II) chloride in 2 ml water was added to a solution of 18.62 mg (0.1 mmol) of 1,2,3,9-tetrahydropyrrolo(2,1 -b)quinazolin-9-one in 2 ml acetone. The solution was allowed for slow evaporation at the room temperature. Colourless needle shaped crystals were obtained after several days.

quinazolin-9-one-κ 2 N:O)-mercury(II)]
Crystal data [HgCl 2 (C 11  Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating Rfactors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.