General. THF was purified by distillation under nitrogen from sodium/benzophenone; dry DMF was
purchased from Fluka. The "magic mixture" eluent was a mixture of water (300 mL), NaCl (30 g), acetonitrile (1200 mL), and methanol (300 mL). Compounds 2, 3, and 4 were prepared according to literature procedures.[45,46] The IrIII chloride-bridged complexes [(ppy)2Ir(#-Cl)2Ir(ppy)2] and [(F2ppy)2Ir(#-Cl)2Ir(F2ppy)2]
were prepared according to literature procedures.[21,70] All other chemicals were purchased from Aldrich, Fluka,
or Acros and used as received. Analytical TLC was performed on Merck precoated silica gel 60 F-254 plates (layer thickness 0.25 mm) and the compounds were visualised by UV irradiation at ! = 254 and/or 366 nm and by staining with phosphomolybdic acid reagent or KMnO4. Purifications by silica gel chromatography were
Chapter 2
performed using Acros (0.035–0.070 mm, pore diameter ca. 6 nm) silica gel. All click reactions were performed in an oxygen-free atmosphere of nitrogen under Schlenk conditions and distilled solvents.
NMR spectroscopy. 1H NMR spectra were recorded at 25 °C on Varian Inova 400 or Bruker DMX-300
spectrometers operating at 400 and 300 MHz, respectively. 13C NMR spectra were recorded on a Bruker
DMX-300 spectrometer operating at 75 MHz. 1H NMR chemical shifts (") are reported in parts per million
(ppm) relative to the residual proton signal of the solvent, " = 3.31 ppm for CD3OD, and " = 7.26 ppm for
CDCl3. Multiplicities are reported as follow: s (singlet), d (doublet), t (triplet), dd (doublet of doublets), ddd
(doublet of doublet of doublets), or m (multiplet). Broad peaks are indicated by b. Coupling constants are reported as a J value in Hertz (Hz). The number of protons (n) for a given resonance is indicated as nH, and is based on spectral integration values. 13C NMR chemical shifts (") are reported in ppm relative to the residual
carbon signal of the solvent, " = 49.0 ppm for CD3OD, and " = 77 ppm for CDCl3.
Mass spectrometry (MS). All mass analyses were performed by using electrospray (ESI) techniques . High-
resolution mass spectrometry (HRMS) measurements were performed on a JEOL AccuTOF instrument by using water, acetonitrile, or methanol as solvents.
HPLC. HPLC was carried out on a Shimadzu LC-20AT HPLC system equipped with a SPD-10AV UV-vis
detector and a fraction collector. Columns were purchased from Dr. Maisch GmbH. The purity of the compounds was tested by analytical HPLC. An aliquot of solution (20 µL) was injected in a ReproSil 100 C18, 3 µm (150 $ 3 mm) column operating at 30 °C. The detection wavelengths were fixed at 254 and 215 nm. A gradient of water and acetonitrile both containing 0.1% v/v TFA was used as the mobile phase, with a flow rate of 0.4 mL min-1.
The compounds were purified on the mg scale by using a semi-preparative reversed-phase column. An aliquot of solution (2 mL) was injected in a column ReproSil 100 C8, 5 µm (250 $ 10 mm) operating at 30 °C. The detection wavelengths were fixed at 254 and 215 nm. A gradient of water and acetonitrile both containing 0.1% v/v HCl or TFA was used as the mobile phase, with a flow rate of 4 mL min-1. HCl was used to ensure that
chloride was the only counterion of the isolated compounds. In all cases, samples were prepared by dissolving the compound in mixtures of water/acetonitrile 95/5 or 1/1 v/v and filtering the solution on a Nylon syringe filter (0.2 µm).
X-ray crystallography. Single crystal of [Ir(ppy)2(pytl-ada)]Cl was grown by slow diffusion of diethyl ether
into a solution of the pure compound in chloroform. Single crystals of pytl-ada and pytl-Me were grown by slow evaporation of a solution of the respective compounds in diethyl ether/heptane. Crystal data and summaries of the data collection and structure refinement are given in Table 2.3. The selected distances and bond angles are available in the literature.[4] The atomic coordinates, and equivalent isotropic displacement parameters for the
non-hydrogen atoms, are available in the literature.[4] All measurements were performed at –65 °C. The
structures of pytl-ada and pytl-Me were solved by the CRUNCH program.[71] All non-hydrogen atoms were
refined with anisotropic temperature factors. The hydrogen atoms were placed at calculated positions and refined isotropically in riding mode. Crystallographic data (excluding structure factors) for the structure reported in this chapter has been deposited with the Cambridge Crystallographic Data Centre. CCDC-699148 (pytl-ada, MFLADA), 699149 (pytl-Me, MFLIGA), and 699147 ([Ir(ppy)2(pytl-ada)]Cl, FELIC1) contain the
supplementary crystallographic data for this chapter. These data can be obtained free of charge from the Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk.
Circular dichroism. Circular dichroism spectra were recorded on a Jasco 810 spectropolarimeter equipped
with a Jasco PTC-423S/L Peltier type temperature control unit, and were measured in MilliQ water at 20 °C.
IrIII and RuII Complexes Containing Triazole-Pyridine Ligands. Luminescence Enhancement upon Substitution with !-Cyclodextrin
Emission. Steady-state emission spectra were recorded on a Horiba Jobin-Yvon IBH FL-322 Fluorolog 3
spectrometer equipped with a 450 W xenon arc lamp, double-grating excitation and emission monochromators (2.1 nm mm-1 dispersion; 1200 grooves mm-1), and a TBX-4-X single-photon-counting detector. Emission
spectra were corrected for source intensity (lamp and grating) and emission spectral response (detector and grating) by standard correction curves. Luminescence quantum yields (#em) were measured in optically dilute
solutions (O.D. < 0.1 at excitation wavelength), using [Ru(bpy)3]Cl2 in aerated water (#em = 0.028) or
diphenylanthracene in cyclohexane (#em = 0.9) as references.
Time-resolved measurements up to %5 µs were performed by using the time-correlated single-photon- counting (TCSPC) option on the Fluorolog 3. NanoLEDs (295 or 431 nm; full-width at half maximum (fwhm) < 750 ps) with repetition rates between 10 kHz and 1 MHz were used to excite the sample. The excitation sources were mounted directly on the sample chamber at 90 °C to a double-grating emission monochromator (2.1 nm mm-1 dispersion; 1200 grooves mm-1) and collected by a TBX-4-X single-photon-
counting detector. The photons collected at the detector are correlated by a time-to-amplitude converter (TAC) to the excitation pulse. Signals were collected using an IBH DataStation Hub photon-counting module and data was analysed by the commercially available DAS6 software (Horiba Jobin Yvon IBH). The goodness of fit was assessed by minimising the reduced chi-squared function ($2) and visual inspection of the weighted residuals.