title: Anion-directed self-assembly in coordination networks: architectural control via cooperative noncovalent interactions.
abstract: The self-assembly of a new flexible tritopic pyrazine-pyridine ligand (pz-3-py) with HgX(2) (X = Cl, Br) was investigated. The results show that coordinated chloride and bromide anions play different roles, and two architecturally different coordination polymers were obtained with the anions used. Where X = Cl, in [Hg(μ(3)-pz-3-py)Cl(2)](n) (1), the 2D network is isolated, while for X = Br, in [Hg(μ-pz-3-py)Br(2)](n) (2), a 1D zigzag chain is constructed. Our results show that noncovalent interactions such as hydrogen bond, halogen···halogen, and halogen···π interactions, when acting cooperatively, are driving forces for the selection of different structures.
authors.affiliation: Chemistry Department, Shahid Beheshti University, G. C., Evin, Tehran 1983963113, Iran.
authors.forename: Behrouz
authors.initials: B
authors.lastname: Notash
authors.forename: Nasser
authors.initials: N
authors.lastname: Safari
authors.forename: Hamid Reza
authors.initials: HR
authors.lastname: Khavasi