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5.4 Lighting applications

Chapter 5 Selected applications. 5.4 Lighting applications. CRI / %. 80. 60. 40. Tb III. 20. Eu III. (Eu II ). 0. -20. 400. 500. 600 nm. 400. 500. 600 nm. Chapter 5 Selected applications. Producing white light: trichromatic stimuli.

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5.4 Lighting applications

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  1. Chapter 5 Selected applications 5.4 Lighting applications MSc: f-Elements, Prof. J.-C. Bünzli, 2008

  2. CRI / % 80 60 40 TbIII 20 EuIII (EuII) 0 -20 400 500 600 nm 400 500 600 nm Chapter 5 Selected applications Producing white light: trichromatic stimuli There are three “prime”colors corresponding to thethree spectral responses ofhuman vision Color rendering index obtainedby mixing the three prime colors MSc: f-Elements, Prof. J.-C. Bünzli, 2008

  3. y Emission Reflectance Trichromatic stimuli x Chapter 5 Selected applications Trichromatic diagram MSc: f-Elements, Prof. J.-C. Bünzli, 2008

  4. Chapter 5 Selected applications W filament Hg DV e- UV (254 nm) Filling gas: Ar Coating UV photons excite phosphor-containing coating leading to a white emission thanks to an appropriate blend of phosphors (Courtesy of P. Ceintrey, Rhodia Electronics & Catalysis) MSc: f-Elements, Prof. J.-C. Bünzli, 2008

  5. Chapter 5 Selected applications Major phosphors used by lighting industry MSc: f-Elements, Prof. J.-C. Bünzli, 2008

  6. Hg 254 nm l /nm 230 280 330 380 430 480 530 580 630 680 730 Chapter 5 Selected applications Y2O3:Eu3+ 5D0→7F1 LMCT Absorption spectrum Emission spectrum f-f transitions Y2O3 features metal ion sites with Oh symmetry, e.d. transitionsare therefore forbidden MSc: f-Elements, Prof. J.-C. Bünzli, 2008

  7. Hg 254 nm 240 290 340 390 440 490 540 590 640 690 l (nm) Chapter 5 Selected applications LaPO4 : Ce,Tb 4f-5d transition Emission spectrum Absorption spectrum Ce3+→Tb3+ transfer MSc: f-Elements, Prof. J.-C. Bünzli, 2008

  8. 8 6 Volume (%) 4 2 0 0.01 0.1 1 10 100 Particle diameter /µm Chapter 5 Selected applications Synthesis Main difficulty is to reach adequate particle size Example: red phosphor 2.68 mm 2 mm (Courtesy of P. Ceintrey, Rhodia Electronics & Catalysis) MSc: f-Elements, Prof. J.-C. Bünzli, 2008

  9. 10 mm 3 mm Chapter 5 Selected applications Green phosphor is obtained by co-precipitationleading to incorporation of Ce3+ and Tb3+ in theLaPO4 lattice; allows control of morphology, particle sizeand oxidation state of Ce and Tb. Precursor After flux addition (Courtesy of P. Ceintrey, Rhodia Electronics & Catalysis) MSc: f-Elements, Prof. J.-C. Bünzli, 2008

  10. Hg 254 nm 200 300 400 500 600 nm Chapter 5 Selected applications Blue phosphor Sr4Al4O25:EuII Emission (d-f transition) excitation MSc: f-Elements, Prof. J.-C. Bünzli, 2008

  11. 80 P /mW·nm-1·lm-1 60 40 20 0 400 500 600 700 Chapter 5 Selected applications Spectral distributionof a luminescent lampwith the followingphosphors: BaMg2Al16O27:EuII CeMgAl11O19:TbIII Y2O3:EuIII J.M.P.J. Verstegen et al., J. Electrochem. Soc.1974, 121, 1627 MSc: f-Elements, Prof. J.-C. Bünzli, 2008

  12. Hg Energy saving Chapter 5 Selected applications The future of lighting Incandescent lamp Light Emitting Diodes Fluorescent lamp 1970 1995 * Heat loss: 100 W gives only 18 W for lighting * Elimination of heat loss but * 55% of energy is lost during conversion of UV excitation into visible photons * 35% of energy is lost during conversion of UV excitation into visible photons 18 % 60-70 % 25-30 % (Courtesy of P. Ceintrey, Rhodia Electronics & Catalysis) MSc: f-Elements, Prof. J.-C. Bünzli, 2008

  13. » 200 nm Chapter 5 Selected applications Eliminating mercury from lamps: quantum cutting Eu Gd 6 G J b a 6 P Ardischarge190 nm J 3 5 D J 2 1 0 b a 8 7 S F 7/2 J MSc: f-Elements, Prof. J.-C. Bünzli, 2008

  14. UV Chapter 5 Selected applications 5.5 Security inks Euro bills MSc: f-Elements, Prof. J.-C. Bünzli, 2008

  15. lexc EuIII 2 370.5 nm 5D07FJ J = l / nm 1 0 4 3 560 580 600 620 640 660 680 700 720 Chapter 5 Selected applications The euro is protected by the luminescence from europium: red from EuIII Europium was discovered byEugène A. Demarçay in 1901 in Paris MSc: f-Elements, Prof. J.-C. Bünzli, 2008

  16. l/nm 450 500 550 600 650 700 Chapter 5 Selected applications Possibly EuII ? lexc= 375 nm MSc: f-Elements, Prof. J.-C. Bünzli, 2008

  17. Chapter 5 Selected applications 5.6 Luminescent chemical sensors The specific spectroscopic properties of LnIII ions makethem ideal luminescent probes: - easily recognizable line-like spectra - long lifetimes of excited states - large Stokes’ shift upon ligand excitation Time-resolved luminescence allows high signal-to-noiseratios, henceforth high sensitivity Lanthanide-containing luminescent probes can be used as: - structural probe (site symmetry) - analytical probes (mainly for bio-analyses) - imaging probe for medical diagnosis (tumorimaging) MSc: f-Elements, Prof. J.-C. Bünzli, 2008

  18. I em 2-4 ms measurement Chapter 5 Selected applications Time-resolved luminescence: an essential tool Background luminescence UV pulse Eu emission Detection limits Ion lexce/103 lem/nm t/ms QDet. lim. Eu 340 36 613 730 0.69 0.05 pM Sm 340 36 643 50 0.02 3.5 pM time MSc: f-Elements, Prof. J.-C. Bünzli, 2008

  19. hn hn an + an Chapter 5 Selected applications LnIII luminescence as signaling method a) Direct binding of the analyte modifies the LnIII inner co-ordination sphere hn hn Here, water molecules are expelled, lifting theluminescence quenching. J.-C. Bünzli & C. Piguet, Chem. Soc. Rev. 2005, 34, 1048 MSc: f-Elements, Prof. J.-C. Bünzli, 2008

  20. hn an hn an Chapter 5 Selected applications b) Binding of the analyte to a ligand modifies its energy- transfer properties Here, binding of the analyte results in a quenching of themetal-centered luminescence. Alternatively, luminescence can be activated by such abinding. MSc: f-Elements, Prof. J.-C. Bünzli, 2008

  21. hn hn an an hn hn Chapter 5 Selected applications c) Binding of the analyte to a ligand initiates an energy- transfer process to the metal ion Note: in bio-analyses, specific biochemical reactionsare usually used to render the analysis target specific. MSc: f-Elements, Prof. J.-C. Bünzli, 2008

  22. OH2 OTf2 O OTf2 Eu P N N N N O N O O O OTf2 Eu P N N N N Chapter 5 Selected applications a) Modification of inner coordination sphere: anion analysis In acetonitrile: Q = 2.6 % t = 0.86 ms OTf = CF3SO3- Q = 30 % t = 1.45 ms Kassoc = 106 L. J. Charbonnière et al., J. Am. Chem. Soc.2002, 124, 7779 MSc: f-Elements, Prof. J.-C. Bünzli, 2008

  23. H3O+ -H3O+ (H2O) Chapter 5 Selected applications Supramolecular pH sensor pH sensor pHrange 5–7.5 modulates electrondensity ofN-atom D. Parker et al, J. Am. Chem. Soc. 2001, 123, 7601 MSc: f-Elements, Prof. J.-C. Bünzli, 2008

  24. Chapter 2 Physico-chemical properties Supramolecular pH sensor EuIIILuminescence MSc: f-Elements, Prof. J.-C. Bünzli, 2008

  25. Ln binding unit O O O O O O O O O O O O N N N N N N O O O O O O O O O O O O O O O O O O K+ receptor K+ receptor Chapter 5 Selected applications b) Removal of a quenching process electronic relays Eu logK = 4.8 (MeOH) A.P. de Silva et al., Chem. Commun.1997, 1891 MSc: f-Elements, Prof. J.-C. Bünzli, 2008

  26. UV-irradiation O O O O N N O O O O N N N N O O O O O O O O N N N N O O O O Eu Eu Eu Eu M M e e O O O O O O M M e e O O EuII EuIII Luminescence quenched by PET process Chapter 5 Selected applications Q = 2.6% in MeOH A.P. de Silva et al., Chem. Commun.1997, 1891 MSc: f-Elements, Prof. J.-C. Bünzli, 2008

  27. UV-irradiation Chapter 5 Selected applications K K Eu logK = 4.3 (MeOH) Q = 47 % in MeOH light emission A.P. de Silva et al., Chem. Commun.1997, 1891 MSc: f-Elements, Prof. J.-C. Bünzli, 2008

  28. H H O O N N N N O O OH OH OH OH 2 2 2 2 Tb Tb Tb Tb Tb Tb N N O O O O O O N N N N O O H H O O Chapter 5 Selected applications c) Initiating an energy transfer process Strong Tb emission in H2O due to efficient energy transfer from host b-CD coupled to dtpa weak Tb emission in H2O Nocera et al., Coord. Chem. Rev. 1998, 171, 115 MSc: f-Elements, Prof. J.-C. Bünzli, 2008

  29. H O N N O OH OH 2 2 Tb Tb Tb N O O O N N O H O c / ppm Chapter 5 Selected applications Supramolecular PAH sensor 40 Irel 30 20 Tb luminescence enhancement 10 0 0 5 10 15 20 MSc: f-Elements, Prof. J.-C. Bünzli, 2008

  30. H O N N O OH OH 2 2 Tb Tb Tb N O O O N N O H O Chapter 5 Selected applications Supramolecular PAH sensor 34.9 S1 kisc = 5.2·108 s-1 ket = 8.3·104 s-1 22.9 3T E / 103 cm-1 20.4 5D4 kr = 1.7·104 s-1 Tb3+ 7FJ S0 0 Nocera et al., Coord. Chem. Rev. 1998, 171, 115 MSc: f-Elements, Prof. J.-C. Bünzli, 2008

  31. Chapter 5 Selected applications Supramolecular PAH sensor (2) Enhancement of the Tb luminescence in de-oxygenated solution by supramolecular fixation ofnaphtalene sensitised Tb3+ emission permethylated b-CD Large association constant: logK = 4 D. Parker et al., J. C. S., Perkin Trans. 2, 2000, 1329 MSc: f-Elements, Prof. J.-C. Bünzli, 2008

  32. ( O M e ) 7 ( O M e ) 7 logKnapht = 4 H O O N O H 2 ( O M e ) 6 N N O T b O N N O O O Chapter 5 Selected applications Supramolecular PAH sensor (2) Benesi-Hildebrand analysis (I - I0)-1 c-1 / 104 M-1 D. Parker et al., J. C. S., Perkin Trans. 2, 2000, 1329 MSc: f-Elements, Prof. J.-C. Bünzli, 2008

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