Eu(III) Chiral Coordination Polymer with a Structural Transformation System.

A luminescent Eu(III) chiral coordination polymer with a structural transformation system, [Eu(hfa)3((R)-bidp)]n (hfa: haxafluoroacetylacetonato, (R)-bidp: (R)-1,1'-binaphthyl-2,2'-bis(diphenylphosphinate), is reported. Single-crystal X-ray analysis revealed a characteristic helical polymer structure of [Eu(hfa)3((R)-bidp)]n with hydrogen-fluorine/π interactions. [Eu(hfa)3((R)-bidp)]n shows high thermostability (decomposition temperature = 320 °C) and strong luminescence properties (the 4f-4f emission quantum yield = 76%) in the solid state due to its tight packing and asymmetric structure. [Eu(hfa)3((R)-bidp)]n is also transformed from a polymer to monomer structure in liquid media. The chiroptical properties of the monomer form in liquid media were characterized by using circular dichroism and circularly polarized luminescence spectra. In this study, structural and photophysical properties of a luminescent Eu(III) chiral coordination polymer with a structural transformation system were demonstrated.