We report a pair of fluorinated, redox-active copper complexes for potential use as (19)F MRI contrast agents for detecting cellular hypoxia. Trifluorinated Cu(II) ATSM-F3 displays the appropriate redox potential for selective accumulation in hypoxic cells and a completely quenched (19)F NMR signal that is "turned on" following reduction to Cu(I). Incubation of cancer cells with CuATSM-F3 resulted in a selective detection of (19)F signal in cells grown under hypoxic conditions.

Two series of Cd-Ln and Ni-Ln clusters [Ln8Cd24L12(OAc)44(48)Cl4(0)] and [Ln8Ni6L6(OAc)24(EtOH)6(H2O)2] were constructed using a flexible ligand. The Cd-Ln clusters exhibit interesting nano-drum-like structures which allows direct visualization by TEM. Luminex MicroPlex Microspheres loaded with the Cd-Sm cluster were visualized using epifluorescence microscopy. Cytotoxicity studies on A549 and AGS cancer cell lines showed that the materials have mild to moderate cytotoxicity.

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We have developed a new class of lanthanide nano-clusters that self-assemble using flexible Schiff base ligands. Cd–Ln and Ni–Ln clusters, [Ln8Cd24(L1)12(OAc)39Cl7(OH)2] (Ln = Nd, Eu), [Eu8Cd24(L1)12(OAc)44], [Ln8Cd24(L2)12(OAc)44] (Ln = Nd, Yb, Sm) and [Nd2Ni4(L3)2(acac)6(NO3)2(OH)2], were constructed using different types of flexible Schiff base ligands. These molecular nano-clusters exhibit anisotropic architectures that differ considerably depending upon the presence of Cd (nano-drum) or Ni (square-like nano-cluster). Structural characterization of the self-assembled particles has been undertaken using crystallography, transmission electron microscopy and small-angle X-ray scattering. Comparison of the metric dimensions of the nano-drums shows a consistency of size using these techniques, suggesting that these molecules may share similar structural features in both solid and solution states. Photophysical properties were studied by excitation of the ligand-centered absorption bands in the solid state and in solution, and using confocal microscopy of microspheres loaded with the compounds. The emissive properties of these compounds vary depending upon the combination of lanthanide and Cd or Ni present in these clusters. The results provide new insights into the construction of novel high-nuclearity nano-clusters and offer a promising foundation for the development of new functional nanomaterials.