Jennifer K. Molloy

Silicon Nanocrystals Functionalized with Pyrene Units: Efficient Light-Harvesting Antennae with Bright Near-Infrared Emission.

Pyrene chromophores were attached to silicon nanocrystals (SiNCs) with diameters of 2.6 and 5.0 nm to provide light-harvesting antennae for enhanced optical absorption. Efficient energy transfer from the pyrene moieties to the SiNCs was observed to induce bright visible (2.6 nm) or near-infrared (NIR) (5.0 nm) photoluminescence (PL). The 5.0 nm diameter pyrene-derivatized SiNCs exhibited NIR PL emission that was insensitive to dioxygen, with a 40% quantum yield and long lifetime (hundreds of μs).

A Strongly Emitting Liquid-Crystalline Derivative of Y3N@C80: Bright and Long-Lived Near-IR Luminescence from a Charge Transfer State†

Great balls of fire: C60 and Y3 N@C80 were connected to the same oligo(phenyleneethynylene) unit to investigate their structural and photophysical properties. NMR investigations revealed a fulleroid structure for the Y3 N@C80 derivative, and both dyads gave rise to columnar phases with core-shell cylinders. The black and gray spheres represent the fullerene core units of the Y3 N@C80 derivative, which is an ideal candidate to be involved in energy and electron transfer processes.

Bispidines for Dual Imaging

The efficient transformation of the hexadentate bispidinol 1 into carbamate derivatives yields functional bispidines enabling convenient functionalization for targeted imaging. The BODIPY-substituted bispidine 3 combines a coordination site for metal ions, such as radioactive (64) Cu(II) , with a fluorescent unit. Product 3 was thoroughly characterized by standard analytical methods, single crystal X-ray diffraction, radiolabeling, and photophysical analysis. The luminescence of ligand 3 was found to be strongly dependent on metal ion coordination: Cu(II) quenches the BODIPY fluorescence, whereas Ni(II) and Zn(II) ions do not affect it. It follows that, in imaging applications with the positron emitter (64) Cu(II) , residues of its origin from enriched (64) Ni and the decay products (64) Ni(II) and (64) Zn(II) , efficiently restore the fluorescence of the ligand. This allows for monitoring of the emitted radiation as well as the fluorescence signal. The stability of the (64) Cu(II) 3 complex is investigated by transmetalation experiments with Zn(II) and Ni(II) , using fluorescence and radioactivity detection, and the results confirm the high stability of (64) Cu(II) 3. In addition, metal complexes of ligand 3 with the lanthanide ions Tb(III) , Eu(III) , and Nd(III) are shown to exhibit emission of the BODIPY ligand and the lanthanide ion, thus enabling dual emission detection.

A tailored RAFT copolymer for the dispersion of single walled carbon nanotubes in aqueous media

The Reversible Addition-Fragmentation chain-Transfer (RAFT) synthesis of poly(glycidyl methacrylate) (PGMA) copolymers followed by the post-polymerisation treatment with morpholine allows the rational design of amphiphilic block copolymers that are capable of efficiently dispersing single walled carbon nanotubes (SWCNTs) in aqueous media, as shown by comparative photophysical characterisation and AFM analysis.

Self-assembly of nanocrystalline tetra-terpyridine complexes: from molecules to mesoscopic objects†

We report the properties of a shape-persistent tetra-terpyridine ligand whose coordination to transition metal ions guides its three-dimensional self-assembly in two steps: at first, nanoscale objects form, which with time, self-assemble into micrometer structures. This work highlights the potential for control of the molecular self-assembly of molecules on the nanoscale, and the successive self-assembly of the formed supramolecular nanosystems to yield mesoscopic objects.

Diazapyrenium cored dendrimers: electron poor guests for a molecular clip host

Dendrimers containing a luminescent and redox-active diazapyrenium core have been synthesized. Changes in the photophysical and electrochemical properties provide evidence for the formation of a stable adduct with an anthracene based molecular clip in acetonitrile solution.

Dendronised diazapyrenium derivatives: host–guest complexes in aqueous solution

Dendronised diazapyrenium derivatives were synthesised with glycol-appended dendrons to confer water solubility. These dendrimers form self-assembled supramolecular structures with cucurbituril hosts. The self-assembly process could be monitored by changes in the absorption spectra and redox properties of the dendrimers due to electronic interactions of the electron-accepting diazapyrenium core with the electron-rich inner cavity of cucurbiturils.