One-dimensional halide-bridged polymers of metal cations with mono-heterocyclic donor ligands or cations: A review correlating chemical composition, connectivity and chain conformation

•One-dimensional halide-bridged polymers of metal cations with mono-heterocyclic organic ligands/cations are reviewed.•The metal cations include alkali-, alkaline-earth, transition-, post-transition metals and metalloids with no restriction on oxidation state.•Structural trends between related systems are identified.•Identified trends are interpreted by correlating chemical composition, connectivity and chain conformation.•The role of hydrogen bonding on chain conformation is discussed in detail.

Since the diverse range of properties ascribed to ionic- and coordination compounds containing one-dimensional halide-bridged polymers of metal cations is controlled by their varied but unique one-dimensional structural characteristics, comprehension of the factors controlling connectivity and conformation will ultimately enable the inclusion of specific structural characteristics in the design of such materials. In this review, structures of one-dimensional halide-bridged polymers of alkali-, alkaline-earth, transition-, post-transition metals and metalloids, with no restriction on oxidation state, with neutral coordinated- or cationic mono-heterocyclic type donor ligands or cations are reviewed. The work is prearranged topologically, firstly according to the coordination geometries around the metal centres and then according to connectivity. Structural trends between related systems are identified and interpreted by correlating chemical composition, connectivity and conformation, with specific focus on the role of hydrogen bonding interactions. A brief overview of properties and possible applications of these compounds, with slight relaxation of boundary conditions, is given.