Novel Au(I) and Re(I) luminescent complexes towards sensing, imaging and therapeutics

Two novel quinolinyl/pyridinyl bis-urea ligands were coordinated to Au(I) and Re(I). Emission was ligand-centred (Au(I)) or 3MLCT (Re(I)).  Two fac{[Re(CO)3(di-imine)]2L} 2+ complexes demonstrated luminescent responses to anions in two organic solvents.  Emission quenching and modulated 3MLCT lifetimes, characteristic of each anion, were observed.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Gold(I) complexes incorporating emissive mercapto-pteridine ligands: Syntheses, X-ray structure, luminescence and preliminary cytotoxic evaluation

The syntheses of six new mixed P/S-donor two-coordinate AuI complexes are described. The complexes incorporate a pteridinyl ligand coordinated through a thiolate donor, and an ancillary tertiary phosphane (PPh3 or PCy3). The mercapto-pteridine ligands (L1–L3) differ in the nature of the substituents on the pteridine core. An X-ray crystal structure was obtained for one of the examples, [(L1)Au(PPh3)], revealing weak intermolecular interactions between two molecules of the complex: π–π contacts between aromatic rings appear to support an intermolecular Au–Au contact of approximately 3.05 Å. All of the complexes are luminescent in solution, with emission arising from tuneable ligand-based excited states, and characterised as a perturbed fluorescence in nature. In this context, complexes of L3 displayed useful visible absorption and emission. Preliminary cytotoxicity assessments were conducted using the MTT assay, and the complexes each displayed impressive anti-proliferative activities (IC50 < 5 μm) with respect to four different adenocarcinoma cell lines (MCF7, A549, PC3 and LOVO). For a given pteridine moiety, triphenylphosphane appeared to be the co-ligand of choice for enhancing biological activity

Rhenium complexes of chromophore-appended dipicolylamine ligands: syntheses, spectroscopic properties, DNA binding and X-ray crystal structure

The syntheses of two chromophore-appended dipicolylamine-derived ligands and their reactivity with pentacarbonylchlororhenium have been studied. The resultant complexes each possess the fac-Re(CO)3 core. The ligands L1 1-[bis(pyridine-2-ylmethyl)amino]methylpyrene and L2 2-[bis(pyridine-2-ylmethyl)amino]methylquinoxaline were isolated via a one-pot reductive amination in moderate yield. The corresponding rhenium complexes were isolated in good yields and characterised by 1H NMR, MS, IR and UV-Vis studies. X-Ray crystallographic data were obtained for fac-{Re(CO)3( L1)}(BF4), C34H26BF4N4O3Re: monoclinic, P2(1)/c, a = 18.327(2) , = 90.00°, b = 14.1537(14) , = 96.263(6)°, c = 23.511(3) , = 90.00°, 6062.4(11) 3, Z = 8. The luminescence properties of the ligands and complexes were also investigated, with the emission attributed to the appended chromophore in each case. Isothermal titration calorimetry suggests that fac-{Re(CO)3( L1)}(BF4) self-aggregates cooperatively in aqueous solution, probably forming micelle-like aggregates with a cmc of 0.18 mM. Investigations into the DNA-binding properties of fac-{Re(CO)3( L1)}(BF4) were undertaken and revealed that fac-{Re(CO)3( L1)}(BF4) binding to fish sperm DNA (binding constant 1.5 ± 0.2 × 105 M-1, binding site size 3.2 ± 0.3 base pairs) is accompanied by changes in the UV-Vis spectrum as typically observed for pyrene-based intercalators while the calorimetrically determined binding enthalpy (-14 ± 2 kcal mol-1) also agrees favourably with values as typically found for intercalator