Competition between coordination network and halogen bond network formation: towards halogen-bond functionalised network materials using copper-iodobenzoate units

Abstract

The Cu2(3-iodobenzoate)4 paddlewheel has been investigated as a secondary building unit (SBU I) in the design and synthesis of a linear coordination network. The SBU was found to form halogen-bonded networks rather than coordination networks with simple short linkers such as 1,4-dioxane and diazabicyclo(2.2.2)octane (dabco). Increasing the linker size to 4,4′-bipyridine (bipy) resulted in a linear network containing both the paddlewheel SBU I and a new mononuclear SBU II. Further increase of linker size to 4,4′-bipyridylethane (bpe) results in two crystalline phases. The first consists of linear chains of SBU II and the second contains two types of network chain in one single crystal, single chains of SBU II along with double chains of a new dinuclear SBU III.