Location of Repository

Luminescent Cyclometallated Ir(III) Complexes: Synthesis, Characterisation and Applications

By Shalini Singh

Abstract

A range of luminescent Ir(III) complexes [Ir(C^N)2(X^Y)]n+ (n = 0, 1) containing different cyclometallated (C^N) and ancillary (X^Y) ligands has been synthesised. All new compounds were fully characterised by 1H and 13C NMR spectroscopy, mass spectrometry and elemental analyses and several compounds have been structurally characterised by X-ray crystallography. The photophysical and electrochemical properties of the complexes were also studied.\ud Chapter one provides an introduction to luminescent transition metal complexes, in particular Ru(II) and Ir(III) complexes and gives an overview of the factors controlling the emission wavelengths of cyclometallated Ir(III) complexes and their applications, particularly as biological labels and probes. Chapter two discusses the synthesis and properties of [Ir(C^N)2(bipy)]+ and shows that substituents para to the metal on the cyclometallated phenyl have a significant effect on the emission wavelength. Chapter three describes complexes [Ir(C^N)2(X^Y)]n+ (n = 1, X^Y = pyridine imine; n = 0, X^Y = pyrrolylimine) and the effect of substituents on the redox properties and emission wavelength. Some of these complexes have been employed in live-cell imaging. In Chapter four the synthesis, characterisation and application of [Ir(C^N)2(phencat-OH)]+ complexes as molybdate sensors is discussed.\ud Chapter five describes the synthesis of [Ir(C^N)2(X^Y)]n+ (n = 0, 1) containing a homochiral X^Y ligand i.e. (S)-soxH, (S)-pepH, (S)-phglyH, (+)-tfacH and (S)-ppea. The complexes are all formed as 1:1 mixtures of diastereomers with Δ or Λ chirality at the metal. Diastereomers containing the (S)-sox and (S)-pep ligands can often be separated via crystallisation or column chromatography. Treatment of a single diastereomer (ΛS or ΔS) with an appropriate acid removes the sox or pep ligand hence provides a route to complexes with only metal-centred chirality, for example Λ- and Δ-[Ir(ppz)2(bipy)]+

Publisher: University of Leicester
Year: 2011
OAI identifier: oai:lra.le.ac.uk:2381/9067

Suggested articles

Preview

Citations

  1. (+)-tfacH (37.2 mg, 31.8 µL, 0.150 mmol), and Na2CO3 (31.8 mg, 0.300 mmol) and after work up gave ∆(+)/Λ(+)-5.4g as a yellow solid (combined yield 92 mg, 82%). ∆(+)/Λ(+)-5.4g could not be separated. Anal. Calcd for C34H31F3IrN2O2: C,
  2. (+)-tfacH (38.7 mg, 33 µL, 0.156 mmol), and Na2CO3 (33.1 mg, 0.312 mmol) and after work up gave ∆(+)/Λ(+)-5.4a as a yellow solid (combined yield 92 mg, 82%). ∆(+)/Λ(+)-5.4a could not be separated. Anal. Calcd for C30H29F3IrN4O2: C, 49.58, H,
  3. (quaternary C could not be assigned). MS (FAB): m/z 630 [M+H]+. Synthesis of ∆S-5.3a This was prepared from dimer ∆∆-5.6a (30 mg,
  4. [α]D -560° in DCM. 1H NMR (CDCl3) ΛS: δ 8.08 (1H, dd,
  5. 1.2, Hb), 6.84 (2H, d,
  6. 1.2, Hd, d′), doi
  7. 1.6, 0.8, Hh(ΛS)), doi
  8. 1.6, Hg′(∆S)),
  9. 1H NMR (CDCl3) ∆S: δ 8.02 (1H, s, H5), 7.99 (1H, d, doi
  10. 1H NMR (CDCl3) ∆S: δ 8.06 (1H, s, H5), 8.02 (1H, d, doi
  11. 1H NMR (CDCl3) ∆S: δ 8.90 (1H, dt, doi
  12. 1H NMR (CDCl3): δ 9.71 (1H, d, doi
  13. 2.85 (1H, t, J = 3.1, H8(∆S)), 2.82 (1H, t,
  14. 22.15 (Me). [α]D -535° in DCM. 1H NMR (CDCl3) ΛS: δ 9.02 (1H, ddd,
  15. 3.86 (1H, dd, doi
  16. 37 mg, 65%). 1H NMR (CDCl3): δ 10.84 (1H, s, H5(ΛS)), 10.76 (1H, s, H5(∆S)), 9.44, 9.37 (2H, 2 X d,
  17. 3a as a grey solid (combined yield 66 mg, 78%). ∆S/ΛS-5.3a could not be separated. Anal. Calcd for C26H22IrN5O2: C, 49.67,
  18. 3f as a grey solid (combined yield 52 mg, 87%). ∆S/ΛS-5.3f could not be separated. Anal. Calcd for
  19. 4.73 (1H, q, doi
  20. 4.94 (1H, q, doi
  21. 5.34 (1H, dd, doi
  22. 6.20 (2H, d, doi
  23. 6.60 (1H, d, doi
  24. 6.75 (4H, t, doi
  25. 6.88 – 6.84 (4H, m, H9, 9′, b, b′), 6.74 (2H, m, H1, d), 6.61 (1H, t,
  26. a, a′(ΛS)), 2.83 (1H, t,
  27. (2001). Analytica Chimica Acta, doi
  28. (2003). Applications of Coordination Complexes, doi
  29. (2000). Bioconjugate Chemistry, doi
  30. Bioorganometallics: biomolecules, labelling, doi
  31. Cc, c′(∆S), c, c′(ΛS)), 111.68, 111.41 (Cd, d′(∆S), d, d′(ΛS)), 108.51, 108.17, 107.91, 107.63 (Cf, f′(∆S), f, f′(ΛS)), 69.90 (C6(∆S)), 69.81 (C6(ΛS)), 22.98 (Me(∆S)),
  32. (2008). Chem Commun (Camb), doi
  33. (2009). Chem Soc Rev, doi
  34. (2005). Chemistry of Materials, doi
  35. could not be assigned). MS (FAB): m/z 686 [M+H]+. Synthesis of ∆S/ΛS-5.3g This was prepared from dimer 2.6g (70 mg,
  36. d,
  37. dd,
  38. dd, J = 7.8, 1.2, Hd′), 7.12 (1H, ddd, J = 8.2, 7.1, 1.2, H2), 7.10 (1H, ddd,
  39. (2004). Fish on the occasion of his 65th birthday,
  40. Found (∆(+):Λ(+) 1:1): C, doi
  41. Fundamentals of Analytical Chemistry, doi
  42. H1(∆S)), 4.28 (1H, dd,
  43. H2), 7.12 (1H, d,
  44. H6), 0.82 (3H, d,
  45. Ha′(ΛS)), 6.07 (1H, dd,
  46. (1993). Handbook of photochemistry,
  47. Hg′(ΛS)), 6.59 (1H, t,
  48. (1995). jpn. kokai tokkyo koho, doi
  49. m, H4, b, b′), 6.74 (1H, t,
  50. m, H9, 9′, 10, b, b′, c, c′, doi
  51. m, Ha, a′(∆S), a(ΛS)), 5.93 (1H, dd,
  52. m, He, e′(∆S), e, e′(ΛS)), 7.54 (1H, d,
  53. (2004). Mendeleev Commun., doi
  54. (1996). Metal Ions in Biological Systems: Probing Nucleic Acids by Metal Complexes of Small Molecules, Marcel Decker,
  55. mg, 0.061 mmol), and NaOMe (3.3 mg, 0.061 mmol) and after work up gave ∆S-5.3a as a grey solid (23 mg, 72%). 1H NMR (MeOD): δ 8.54 (1H, dd,
  56. mg, 0.106 mmol) and after work up gave ∆S/ΛS-
  57. mg, 0.157 mmol), and NaOMe (8.5 mg, 0.157 mmol) and after work up gave ∆S/ΛS-5.3g as a yellow solid (combined yield 63 mg, 74%). ∆S/ΛS-5.3g could not be separated.
  58. mg, 0.164 mmol) and after work up gave ∆S/ΛS-
  59. (2009). Molecular Imaging,
  60. (2009). Molecular Structure, doi
  61. MS (FAB): m/z 1071 [M-CF3CO2]+. MS (ES): m/z 561 [Ir(ppz)2(MeCN)2]+. Synthesis of ∆-2.7a TFA (40.5 mg, 27.4 µL, 0.356 mmol) was added to a solution of ∆S-5.2a (50 mg, 0.071 mmol) and bipy (12.2 mg,
  62. (2007). Photochemistry and photophysics of coordination compounds: Iridium, doi
  63. (2007). Photofunctional transition metal complexes, doi
  64. prepared from dimer 2.6a (70 mg, 0.068 mmol),
  65. prepared from dimer 2.6b (70 mg, 0.065 mmol),
  66. prepared from dimer 2.6c (70 mg, 0.054 mmol),
  67. prepared from dimer 2.6g (70 mg, 0.065 mmol),
  68. q,
  69. t,
  70. td,
  71. (2005). Transition Met. Chem., doi

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.