1 msc: f-elements, prof. j.-c. bünzli, 2008 5.4 lighting applications chapter 5 selected...
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1MSc: f-Elements, Prof. J.-C. Bünzli, 2008
5.4 Lighting applications
Chapter 5 Selected applications
2MSc: f-Elements, Prof. J.-C. Bünzli, 2008
Producing white light: trichromatic stimuli
There are three “prime”colors corresponding to thethree spectral responses ofhuman vision
400 500 600 nm
80
40
60
20
0
-20
CRI / %
400 500 600 nm
Color rendering index obtainedby mixing the three prime colors
EuIII
TbIII
(EuII)
Chapter 5 Selected applications
3MSc: f-Elements, Prof. J.-C. Bünzli, 2008
x
y
Trichromatic diagram
Xx
X Y Z=
+ +
Yy
X Y Z=
+ +
780
380
780
380
780
380
( )
( )
(
1d( ( )
(
)
( )
( )
)
)1
( d)
1d
x
y
XK
YK
ZK
z
P
P
P
= ⋅ ⋅ ⋅ λ
= ⋅ ⋅ ⋅ λ
= ⋅
ρ λ
⋅ ⋅ λ
ρ λ
ρ λ
λ λ
λ
λ
λ
λ
∫
∫
∫780
380( )() ) d(K P y= ⋅ ⋅ ⋅ λλ ρ λλ∫
EmissionReflectanceTrichromatic stimuli
Chapter 5 Selected applications
4MSc: f-Elements, Prof. J.-C. Bünzli, 2008
Coating
W filament
V
Filling gas: Ar UV (254 nm)
e-
Hg
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)
Chapter 5 Selected applications
5MSc: f-Elements, Prof. J.-C. Bünzli, 2008
Year Phosphor
1960 Ca5(PO4)3Cl:Sb3+,Mn2+ (white)
1974 BaMg2Al16O27:Eu2+ CeMgAl10O19:Tb3+ Y2O3:Eu3+
1990 BaMgAl10O17:Eu2+
(Sr,Ca)5(PO4)3Cl:Eu2+
(La,Ce)PO4:Tb3+
CeMgAl10O19:Tb3+
(Gd,Ce)MgB5O10:Tb3+
Y2O3:Eu3+
2005 BaMgAl10O17:Eu2+ (La,Ce)PO4:Tb3+ Y2O3:Eu3+
Major phosphors used by lighting industry
Chapter 5 Selected applications
6MSc: f-Elements, Prof. J.-C. Bünzli, 2008
5D0→7F1LMCT
f-f transitions
Absorption spectrum
Y2O3 features metal ion sites with Oh symmetry, e.d. transitionsare therefore forbidden
230 280 330 380 430 480 530 580 630 680 730
λ /nm
Emission spectrum
Y2O3:Eu3+Y2O3:Eu3+
Hg 254 nm
Chapter 5 Selected applications
7MSc: f-Elements, Prof. J.-C. Bünzli, 2008
LaPO4 : Ce,TbLaPO4 : Ce,Tb
240 290 340 390 440 490 540 590 640 690
λ (nm)
Absorption spectrum
4f-5dtransition Emission spectrum
Hg 254 nmCe3+→Tb3+
transfer
Chapter 5 Selected applications
8MSc: f-Elements, Prof. J.-C. Bünzli, 2008
SynthesisMain difficulty is to reach adequate particle size
Example: red phosphor
(Courtesy of P. Ceintrey, Rhodia Electronics & Catalysis)
2 m Volu
me (
%)
0
2
4
6
8
0.01 0.1 1 10 100
Particle diameter /µm
2.68 m
Chapter 5 Selected applications
9MSc: f-Elements, Prof. J.-C. Bünzli, 2008
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.
(Courtesy of P. Ceintrey, Rhodia Electronics & Catalysis)
After flux additionPrecursor
10 m 3 m
Chapter 5 Selected applications
10MSc: f-Elements, Prof. J.-C. Bünzli, 2008
Blue phosphorSr4Al4O25:EuII
200 300 400 500 600 nm
excitationEmission(d-f transition)
Hg 254 nm
Chapter 5 Selected applications
11MSc: f-Elements, Prof. J.-C. Bünzli, 2008
80
60
40
20
0600 700500400
P /W·nm-1·lm-1
J.M.P.J. Verstegen et al., J. Electrochem. Soc. 1974, 121, 1627
Spectral distributionof a luminescent lampwith the followingphosphors:
BaMg2Al16O27:EuII
CeMgAl11O19:TbIII
Y2O3:EuIII
Chapter 5 Selected applications
12MSc: f-Elements, Prof. J.-C. Bünzli, 2008
19951970Hg
Fluorescent lampIncandescent lamp
Light Emitting Diodes
* 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
Energy saving
* 35% of energy is lost during conversion of UV excitation into visible photons
The future of lighting
(Courtesy of P. Ceintrey, Rhodia Electronics & Catalysis)
18 % 25-30 % 60-70 %
Chapter 5 Selected applications
13MSc: f-Elements, Prof. J.-C. Bünzli, 2008
Eliminating mercury from lamps: quantum cutting
6G J
6P J
8S7/27FJ
a
a
5DJ01
2
3
Eu Gd
b
b 200 nm
Ardischarge190 nm
Ardischarge190 nm
Chapter 5 Selected applications
14MSc: f-Elements, Prof. J.-C. Bünzli, 2008
UV
5.5 Security inks
Euro bills
Chapter 5 Selected applications
15MSc: f-Elements, Prof. J.-C. Bünzli, 2008
The euro isprotected by theluminescencefrom europium:red from EuIII
Europium wasdiscovered byEugène A. Demarçayin 1901 in Paris
560 580 600 620 640 660 680 700 720λ / nm
5D0 7FJ
EuIII2
J =
0 13 4
Chapter 5 Selected applications
370.5 nm
λexc
16MSc: f-Elements, Prof. J.-C. Bünzli, 2008
λexc= 375 nm
450 500 550 600 650 700
λ/nm
Possibly EuII ?
Chapter 5 Selected applications
17MSc: f-Elements, Prof. J.-C. Bünzli, 2008
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 (tumor imaging)
Chapter 5 Selected applications
18MSc: f-Elements, Prof. J.-C. Bünzli, 2008
Time-resolved luminescence:an essential tool
Detection limits
Ion lexc /103 lem/nm /s Q Det. lim.
Eu 340 36 613 730 0.69 0.05 pM
Sm 340 36 643 50 0.02 3.5 pM
UV pulse
2-4 ms
Backgroundluminescence
Eu emission
measurement
time
Iem
Chapter 5 Selected applications
19MSc: f-Elements, Prof. J.-C. Bünzli, 2008
LnIII luminescence as signaling method
h
hh
h
an
+
an
a) Direct binding of the analyte modifies the LnIII inner co-ordination sphere
Here, water molecules are expelled, lifting theluminescence quenching.
Chapter 5 Selected applications
J.-C. Bünzli & C. Piguet, Chem. Soc. Rev. 2005, 34, 1048
20MSc: f-Elements, Prof. J.-C. Bünzli, 2008
an
h h an
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.
Chapter 5 Selected applications
21MSc: f-Elements, Prof. J.-C. Bünzli, 2008
an
h
h
h
anh
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.
Chapter 5 Selected applications
22MSc: f-Elements, Prof. J.-C. Bünzli, 2008
a) Modification of inner coordination sphere: anion analysis
N NN N
P
O
Eu
OTf2
OTf2
OH2 In acetonitrile:
Q = 2.6 %= 0.86 ms
N NN N
P
O
Eu
O
OTf2
O
O
N Q = 30 % = 1.45 msKassoc = 106
L. J. Charbonnière et al., J. Am. Chem. Soc.2002, 124, 7779
OTf = CF3SO3
-
Chapter 5 Selected applications
23MSc: f-Elements, Prof. J.-C. Bünzli, 2008
Supramolecular pH sensor
D. Parker et al, J. Am. Chem. Soc. 2001, 123, 7601
O
HO
O
N
NN
N N
HO
O OH
H
S
R
O
O
pH sensor
NN
SO2R
H3O+
NN
H
SO2R
(H2O)
-H3O+
modulateselectron densityof N-atom
pH range5 – 7.5
Chapter 5 Selected applications
24MSc: f-Elements, Prof. J.-C. Bünzli, 2008
4 5 6 7 8 9 10 11
6
7
8
9
10
11
pH
EuIII
Luminescence
Supramolecular pH sensor
Chapter 2 Physico-chemical properties
25MSc: f-Elements, Prof. J.-C. Bünzli, 2008
electronic relays
A.P. de Silva et al., Chem. Commun. 1997, 1891
Ln binding unit
EuEu
logK = 4.8 (MeOH)
N N
N
OMeO O OMe
N
N
b) Removal of a quenching process
OO
N
O OO
OO
N
O OO
OO
N
O OO
K+ receptor
Chapter 5 Selected applications
OO
N
OOO
OO
N
OOO
OO
N
OOO
K+ receptor
N
N
26MSc: f-Elements, Prof. J.-C. Bünzli, 2008
A.P. de Silva et al., Chem. Commun. 1997, 1891
UV-irradiation
EuEuIIIIII EuEuIIIILuminescence quenchedby PET process Q = 2.6% in MeOH
O
ON
OO
ON N
N
N
O
O
OO
O
OMeO O OMe
EuEu
O
ON
OO
ON N
N
N
O
O
OO
O
OMeO O OMe
EuEu
Chapter 5 Selected applications
27MSc: f-Elements, Prof. J.-C. Bünzli, 2008
KK KK
EuEu
UV-irradiation
light emissionQ = 47 % in MeOH
logK = 4.3 (MeOH)
O
ON
OO
ON N
N
N
O
O
OO
O
OMeO O OMe
A.P. de Silva et al., Chem. Commun. 1997, 1891
Chapter 5 Selected applications
28MSc: f-Elements, Prof. J.-C. Bünzli, 2008
-CD coupled to dtpaweak Tb emission in H2O
Strong Tb emission in H2Odue to efficient energy transferfrom host
Nocera et al., Coord. Chem. Rev. 1998, 171, 115
TbTb
N
ON
N
NO
N
O
O
OO
O
H
H
TbOH2OH2
c) Initiating an energy transfer process
TbTb
N
ON
N
NO
N
O
O
OO
O
H
H
TbOH2OH2
Chapter 5 Selected applications
29MSc: f-Elements, Prof. J.-C. Bünzli, 2008
0
10
20
30
40
0 5 10 15 20
c / ppm
Irel
Supramolecular PAH sensor
Tb luminescenceenhancement
TbTb
N
ON
N
NO
N
O
O
OO
O
H
H
TbOH2OH2
Chapter 5 Selected applications
30MSc: f-Elements, Prof. J.-C. Bünzli, 2008
kisc = 5.2·108 s-1
ket = 8.3·104 s-1
E /
103
cm
-1
0
34.9
22.9
20.4
SS00
SS11
33TT
Tb3+
5D4
7FJ
kr = 1.7·104 s-1
Nocera et al., Coord. Chem. Rev. 1998, 171, 115
Supramolecular PAH sensor
TbTb
N
ON
N
NO
N
O
O
OO
O
H
H
TbOH2OH2
Chapter 5 Selected applications
31MSc: f-Elements, Prof. J.-C. Bünzli, 2008
Supramolecular PAH sensor (2)
Enhancement of the Tbluminescence in de-oxygenatedsolution by supramolecularfixation of naphtalene
D. Parker et al., J. C. S., Perkin Trans. 2, 2000, 1329
Large associationconstant: logK = 4
permethylated -CD
OO
O
O
O
N
NN
N N
OO
H
(OMe)6
(OMe)7 (OMe)7
Tb
OH2sensitised Tb3+ emission
Chapter 5 Selected applications
32MSc: f-Elements, Prof. J.-C. Bünzli, 2008
0 2 4 6 8 10 12
0.2
0.4
0.6
0.8
1.0
1.2
Supramolecular Supramolecular PAH sensor (2)PAH sensor (2)
c-1 / 104 M-1
(I -
I0)-1
Benesi-Hildebrand analysis
logKnapht = 4OO
O
O
O
N
NN
N N
OO
H
(OMe)6
(OMe)7(OMe)7
Tb
OH2
D. Parker et al., J. C. S., Perkin Trans. 2, 2000, 1329
Chapter 5 Selected applications