In situ synthesis of a zwitterionic ligand and formation of a Eu(III) coordination polymer with double-bridged connectors

The zwitterionic ligand H2Bci [H2Bci = 1,3-bis(4-carboxybenzyl)-1H-imidazolium] was formed via in situ reaction. Its Eu(III)-organic framework, {[Eu(Bci)2]Cl}n (1), was obtained under hydrothermal conditions. Complex 1 exhibits a 3-fold interpenetrated diamondoid network with double-bridged connectors. Its solid-state luminescent behavior was investigated at room temperature.