The development of responsive, luminescent lifetime probes based upon axially functionalised fac-[Re(CO)3(di-imine)(L)]+ complexes.

The syntheses of four new ditopic ligands (L1-4), based on N,N-functionalised 4-aminomethylpyridine, was achieved via a reductive amination methodology. The ligands react with fac-[Re(CO)(3)(di-imine)(MeCN)](OTf) to give the mixed-ligand species fac-[Re(CO)(3)(di-imine)(L1-4)](OTf). X-Ray crystallography has been used to structurally characterise one of the complexes confirming that the axial ligand (L4) coordinates via the pyridine unit: by adopting this binding mode the axial ligand therefore provides an additional binding site for metal cations. Each of the complexes displayed room temperature phosphorescence from (3)MLCT excited states. In addition the complexes based upon L1-3 also possessed ligand-centred fluorescence, originating from either the quinoline or 8-hydroxyquinoline units of the axial ligands. The luminescent properties of the complexes were monitored in the presence of metal dications of physiological and toxicological importance (Cu(II), Zn(II) and Hg(II)). As well as emission intensity changes the results show that these probes firstly, display highly modulated (3)MLCT lifetimes thus allowing differentiation between the different dications and secondly, can demonstrate selectivity in an ionic mixture, as judged by (3)MLCT lifetime measurements.

The coordination chemistry of fluorescent pyridinyl- and quinolinyl-phthalimide ligands with the {Au(I)-PPh(3)} cationic unit.

The new mono-dentate ligands, 2-(2-aminoethyl)-N-phthalimido-pyridine () and 8-amino-N-phthalimido-quinoline (), were synthesised using a solvent-free melt method. These ligands together with (3-amino-N-phthalimido-pyridine; 3-aminomethyl-N-phthalimido-pyridine; 4-aminomethyl-N-phthalimido-pyridine; 3-amino-N-phthalimido-quinoline) were then used to access six luminescent Au(I) complexes of the generic type {Ph(3)P-Au-L(n)}(OTf). X-Ray crystallography has been used to structurally characterise three of the complexes showing that in the cases of and the complexes adopt an approximately linear P-Au-N coordination geometry. However, in the case of the sterically demanding the structure shows distortions within the ligand and deviations from a linear coordination geometry. Solution state (1)H and (31)P{(1)H} NMR confirmed that the proposed formulations and coordination modes exist in solution. At room temperature the photophysical studies showed that the emission from each of the six complexes was in the visible region (395-475 nm) and assigned to a ligand-centred fluorescence (tau < 10 ns) in each case.