Multifunctional Luminescent Eu(III)-Based Metal–Organic Framework for Sensing Methanol and Detection and Adsorption of Fe(III) Ions in Aqueous Solution

A novel
lanthanide–organic framework (Eu–HODA), consisting of
2,2′,3,3′-oxidiphthalic acids as efficient sensitizing
units, is assembled and characterized. Eu–HODA features rare
chiral helical channels despite the achiral nature of H4ODA. It is found that this MOF shows a unique luminescent response
to methanol, in contrast to n-propanol and ethanol.
Eu–HODA reveals a turn-off luminescence switching initiated
by acetone molecules with an EC50 of 0.03 vol %, which
is below the occupational exposure limit of acetone stipulated by
the American Conference of Governmental Industrial Hygienists. Furthermore,
it also exhibits high sensitivity (Stern–Volmer constant KSV = 2.09 × 104 L/mol) and low
detection limit (6.4 ppb) for Fe3+ ions in pure water because
of the existence of uncoordinated carboxyl groups within open frameworks.
Eu–HODA-based test paper provides a simple and reliable detection
method for Fe3+ in practical applications.