A Family of Lanthanide-Based Coordination Polymers with Boronic Acid as Ligand

Reactions
in water between the sodium salt of 4-carboxyphenylboronic
acid (Hcpb) and lanthanide ions (Pr–Nd, Sm–Lu, and Y)
led to a family of lanthanide-based coordination polymers with general
chemical formula {[Ln­(cpbOH)­(H2O)2]­(cpb)}∞. Structural characterizations were ensured by single-crystal
X-ray diffraction and solid-state NMR spectroscopy (11B, 13C, and 89Y). This family of compounds constitutes
the first example of lanthanide-based coordination polymers involving
4-carboxyphenylboronic acid as ligand. To evaluate their
potential usefulness, luminescent and magnetic properties of some
of the compounds that constitute this family were explored. From a
magnetic point of view, the Yb­(III) compound is the more promising.
On the other hand, upon UV irradiation (λexc = 303
nm) ligand phosphorescence is quite intense and offers a sizable blue
component to emission spectra. This is quite unusual and can constitute
an asset as far as white emission is targeted. Moreover, luminescence
properties of these compounds are highly temperature-dependent, and
some of them seem promising as molecular thermometers.