Gold nanoparticles coated with fluorinated ligands (F-MPCs) present features suitable for ¹⁹F MRI as observed from phantom experiments. Cellular uptake, by HeLa cells, and toxicity of fluorescent dye-decorated F-MPCs are presented together with their ability to bind hydrophobic molecules allowing for a potential combination of targeting, delivery and imaging features.

Gold nanoparticles carrying fluorinated ligands in their monolayer are, by themselves, contrast agents for ¹⁹F magnetic resonance imaging displaying high sensitivity because of the high density of fluorine nuclei achievable by grafting suitable ligands on the gold core surface. Functionalization of these nanoparticles with Gd(III) chelates allows adding a further functional activity to these systems, developing materials also acting as contrast agents for proton magnetic resonance imaging. These dual mode contrast agents may allow capitalizing on the benefits of ¹H and ¹⁹F magnetic resonance imaging in a single diagnostic session. In this work, we describe a proof of principle of this approach by studying these nanoparticles in a high field preclinical scanner. The Gd(III) centers within the nanoparticles monolayer shorten considerably the ¹⁹F T1 of the ligands but, nevertheless, these systems display strong and sharp NMR signals which allow recording good quality ¹⁹F MRI phantom images at nanoparticle concentration of 20 mg/mL after proper adjustment of the imaging sequence. The Gd(III) centers also influence the T1 relaxation time of the water protons and high quality ¹H MRI images could be obtained. Gold nanoparticles protected by hydrogenated ligands and decorated with Gd(III) chelates are reported for comparison as ¹H MRI contrast agents.

The [Pd(dppp)(OTf)₂] complex acts as an efficient transporter of halide anions, in particular the biologically relevant chloride anion, across a phospholipid bilayer.

The reaction between 5-(4-pyridyl)dipyrrylmethane and aromatic aldehydes affords meso-arylsubstituted trans-A₂B₂ di(4-pyridyl)porphyrins which are key building blocks in the metal-mediated self-assembling of supramolecular structures. A careful optimization of the reaction conditions allowed us to obtain 5,15-diphenyl-10,20-di(4-pyridyl)porphyrin (P1), and two analogues bearing on the meso-phenyl substituents two dipropyl- (P4) or dihexyl-alkyl chains (P5), with yields ranging from 53 to 63%. Porphyrin P1 reacts with Re(CO₅)Br to give the expected 4 + 4 Re(I)–porphyrin metallacycle which has been fully characterized by means of infrared, NMR and UV-Vis (absorption and emission) spectroscopies and by guest inclusion studies. Unexpectedly the addition of alkyl chains to the porphyrin fragment, which increase the solubility of the porphyrin in organic solvents, has the opposite effect on the adduct with Re(I). Indeed, the reaction between Re(CO₅)Br and porphyrins P4,5 gives very insoluble materials, hampering their complete characterization.