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 ((11)B, (13)C, and (89)Y). 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.

We report the study of a Dy-based metal-organic framework (MOF) with unprecedented magnetic properties. The compound is made of nine-coordinated Dy magnetic building blocks (MBBs) with poor intrinsic single-molecule magnet behavior. However, the MOF architecture constrains the MBBs in a one-dimensional structure that induces a ferromagnetic coupling between them. Overall, the material shows a magnetic slow relaxation in absence of external static field and a hysteretic behavior at 0.5 K. Low-temperature magnetic studies, diamagnetic doping, and ab initio calculations highlight the crucial role played by the Dy-Dy ferromagnetic interaction. Overall, we report an original magnetic object at the frontier between single-chain magnets and single-molecule magnets that host intrachain couplings that cancel quantum tunneling between the MBBs. This compound is evidence that a bottom-up approach through MOF design can induce spontaneous organization of MBBs able to produce remarkable molecular magnetic materials.

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A spiropyran-based switchable ligand isomerizes upon reaction with lanthanide(III) precursors to generate complexes with an unusual N O coordination sphere. The air-stable dysprosium(III) complex shows a hysteresis loop at 2 K and a very strong axial magnetic anisotropy generated by the merocyanine phenolate donor.

We report the synthesis of two lanthanide complexes including a chelating merocyanine (MC) ligand obtained from the reaction of a bis(pyridinemethyl)amine substituted spiropyran with yttrium(iii) or dysprosium(iii) triflate salts, whose structures were confirmed both in the solid state and in solution by single crystal X-ray diffraction studies and NMR investigations. The obtained merocyanine metal complexes can reversibly undergo a photo-triggered transformation consisting of a partial isomerization of the trans-merocyanine ligand to its cis isomer (cis-MC) providing complexes in which the metal-phenolate bond is retained. SQUID magnetometry experiments in combination with ab initio calculations were used to evidence and rationalize the single-molecule magnet behavior of the dysprosium complex and to probe the changes in the dysprosium ion local environment upon photo-isomerization.

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A Dy(III)-based single-molecule magnet is reported. Ab initio calculations highlight that molecular symmetry plays a predominant role over site symmetry in determining the shape and orientation of Dy(III) magnetic anisotropy. Moreover the dipolar component of the electrostatic potential created by the surrounding ligands is shown to be the driving force of its magnetic behaviour.

A series of ZnCl2 complexes (compounds 1–10) with 4′-(substituted-phenyl)-2,2′:6′,2′′-terpyridine that bears hydrogen (L1), p-methyl (L2), p-methoxy (L3), p-phenyl (L4), p-tolyl (L5), p-hydroxyl (L6), m-hydroxyl (L7), o-hydroxyl (L8), p-carboxyl (L9), or p-methylsulfonyl (L10) were prepared and then characterized by 1H NMR, electrospray mass-spectra (ESI-MS), IR, elemental analysis, and single crystal X-ray diffraction. In vitro cytotoxicity assay was used to monitor the antiproliferative activities against tumor cells. Absorption spectroscopy, fluorescence titration, circular dichroism spectroscopy, and molecular modeling studied the DNA interactions. All of the compounds display interesting photoluminescent properties and different maximal emission peaks due to the difference of the substituent groups. The cell viability studies indicate that the compounds have excellent antiproliferative activity against four human carcinoma cell lines, A549, Bel-7402, MCF-7, and Eca-109, with the lowest IC50 values of 0.33 (10), 0.66 (6), 0.37 (7), and 1.05 (7) μM, respectively. The spectrophotometric results reveal that the compounds have strong affinity binding with DNA as intercalator and induce DNA conformational transition. Molecular docking studies indicate that the binding is contributed by the π…π stacking and hydrogen bonds, providing an order of nucleotide sequence binding selectivity as ATGC > ATAT > GCGC. These compounds intercalate into the base pairs of the DNA of the tumor cells to affect their replication and transcription, and the process is supposed to play an important role in the anticancer mechanism.