A rational synthesis of ladder-like motif in zinc-methylphosphonate from a preformed coordination assembly

摘要

The study describes the synthesis of new hybrid zinc phosphonates, {Zn(O3PMe)(4,4'-bipy)(0.5)}center dot 2H(2)O (2), {Zn (O3PMe)(1,2-bpe)(0.5)}center dot H2O (3) and Zn(O3PMe)(Im) (4) [4,4'-bipyridine (4,4'-bipy), 1,2-bis(4-pyridyl)ethane (1,2-bpe) and imidazole (Im)] by hydro(solvo)thermal reaction (140-150 degrees C, 3 days) of a preformed coordination polymer, zinc bis(O-methyl methylphosphonate), Zn{OP(O)(OMe)Me}(2) (1) with an appropriate N-donor ligand. X-ray crystallographic studies reveal structural transformation of a linear chain zinc-phosphonate framework in 1 to a ladder motif in 2-4 which is constructed by corner sharing of ZnO3N and CPO3 tetrahedra. For 2 and 3, the bifunctional N-donor ligands act as linkers to afford the formation of a layered structure. The lattice water molecules in 2 form an infinite array of cyclic tetramers via O-H center dot center dot center dot O2(P) hydrogen bonding interactions and occupy the interlayer region.