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.