Chapter 11. Basics in spin-orbit couplings
|
|
- Eustacia Maxwell
- 5 years ago
- Views:
Transcription
1 1- The Jablonski diagram (or the state diagram of diamagnetic molecules) 2- Various natures of excited states and basics in molecular orbitals 3- Vibronic coupling and the Franck-Condon term 4- Excited state distortion vs bond order 5- The radiative and non-radiative processes 6- The Kasha rule and its exceptions 7- Photo-induced emission, excitation spectra and electroluminescence 8- Polarized emission and excitation spectra (tool for assignments) 9- Delayed fluorescence 10- Excimers and exciplexes 11- Basics in spin-orbit couplings 12- The measurements of some of the photophysical parameters 13- Bimolecular reactions, Stern-Volmer plots, and sensors 14- Time-resolved spectroscopy 15-2-Photon spectroscopy, flash photolysis and transient spectra 16- Exciton coupling and delocalized exciton in extended systems 17- Photo-induced energy transfer and the antenna effect 18- Photo-induced electron transfer and the Marcus inverted region Chapter 11. Basics in spin-orbit couplings What is spin-orbit couplings? It is the coupling (also called mixing) of the spin and electron wavefunctions. What is the consequence of spin-orbit couplings? The excited states are not pure singlets or triplets but they are mixed, so that the selection rules for multiplicity are no longer rigorous (larger S-T absorptivities, more intense T 1 emissions shorter triplet lifetimes).
2 What promotes spin-orbit couplings? Heavy elements promote more couplings. Magnitude of the spin-orbit couplings: Measurements of the spin-orbit splittings in photoelectron spectra. Molecule(g) + energy Molecule + (g) + 1 electron F F + 2 π g,1/2 2 π g,3/2 Spin-orbit constant Stretching frequency of the cation Spin-orbit constant F cm -1 Cl cm -1 Br cm -1 I cm -1
3 Heavy atom effect on the S 0 T 1 absorption spectra Internal heavy atom effect External heavy atom effect I Cl I Cl. J. Turro, Modern Molecular Photochemistry, Benjamen/Cummings, Menlo Park, M = Zn Fluo Fluo M = Zn M S Fluo M Phosphorescence M = Pd
4 1- The Jablonski diagram (or the state diagram of diamagnetic molecules) 2- Various natures of excited states and basics in molecular orbitals 3- Vibronic coupling and the Franck-Condon term 4- Excited state distortion vs bond order 5- The radiative and non-radiative processes 6- The Kasha rule and its exceptions 7- Photo-induced emission, excitation spectra and electroluminescence 8- Polarized emission and excitation spectra (tool for assignments) 9- Delayed fluorescence 10- Excimers and exciplexes 11- Basics in spin-orbit couplings 12- The measurements of some of the photophysical parameters 13- Bimolecular reactions, Stern-Volmer plots, and sensors 14- Time-resolved spectroscopy 15-2-Photon spectroscopy, flash photolysis and transient spectra 16- Exciton coupling and delocalized exciton in extended systems 17- Photo-induced energy transfer and the antenna effect 18- Photo-induced electron transfer and the Marcus inverted region Chapter 12: The measurements of some of the photophysical parameters Excited state lifetimes Radiative (emission decay traces) on-radiative (transient absorption decay traces) Quantum yields (Chapter 14) Radiative (absolute or comparison with a standard) on-radiative (intersystem crossing & photochemical)
5 Measurements of the singlet (and triplet) lifetimes from the emission decay traces -d[s 1 ]/dt = Σ k i [S 1 ], with: Σ k i = k F + k c +k isc + k RS k isc (order 1 reaction i.e.: ln[s 1 ] = Σ k i ) and +d[s 1 ]/dt = I a With [S 1 ] α I F, then one can monitor I F vs time: Excitation pulse then: a graph of ln(i F ) vs time gives a slope = Σ k i. Decay trace τ F = 1/Σ k i.
6 then: a graph of ln(i F ) vs time gives a slope = Σ k i. residual (raw data fit), also considered as a criteria of quality Small problem There! ln (I F ) calculated fit τ F = 1/Σ k i. excitation pulse raw data time (ns) Modified image from: The residual is evenly distributed all along the decay trace: This is a good fit of the experimental data Picture from:
7 Sometime there are multiple decays! B short component α B x e -t/τ` A long component α A x e -t/τ Deconvolution of very short emission lifetimes Picture from a technical report:
8 Possible techniques a) laser spectroscopy, b) photocounting Photon counting is based on the fact that there are «slow» and «fast» photons. The instrument counts the number of photons it sees at a given time and so the decay grows from bottom to top. sample 1 Photon Count (In scale) sample 2 flash pulse Emission quantum yields There is the absolute and comparative methods. Definition: Φ e = number of emitted photons number of absorbed photons sample Laser beam Spherical detector
9 Exemples of fluorescence quantum yields (Φ F ): n π* Benzene 0.2 aphtalene 0.2 Antracene 0.4 9,10-diphenylanthracence 1.0 Pyrene 0.7 Perylene 1.0 Stilbene 0.05 Biacetyl Diaza bicycloheptane light Photochemical isomerization (non-radiative) There is also the comparative method. Quantum Yield Standards [%] Conditions Excitation [nm] Cy3 4 PBS 540 9,10-DPA 100 toluene 380 Cresyl Violet 53 Methanol 580 Fluorescein M ah 496 PPP 97 Cyclohexane 300 Quinine Sulfate M H 2 S Rhodamine Ethanol 450 Rhodamine 6G 95 Water 488 Rhodamine B 31 Water 514 Tryptophan 13 Water, 20 C 280 L-Tyrosine 14 Water 275 PBS = phosphate-buffered saline PPP = 1, 4-bis(5-phenyloxazole-2-yl)benzene
10 The comparative method; conditions of application: 1- The standard must be strongly luminescent. 2- The standard must absorb and emit at the same place as the sample (n). 3- The absorbtivity of both standard and sample must be below 0.05 abs (B&L law). Wavelength (nm) 4- The excitation wavelength must be the same for both also. 5- The spectra should corrected for instrumental responses. 6- The spectra must be recorded in S/E (for lamp fluctuations). 7- The spectra must be plotted in energy scale (cm -1 ) before calculating the area under the curve. The standard should absorb and emit in the same region as the sample (to minimize the effect of the difference of the refractive index) Φ sample = Φ standard x Area(sam) x Absorbance(sta) Area(sta) x Absorbance(sam) From corrected spectra in linear energy scale (cm -1 ). At the same wavelength of excitation with identical absorbance and < 0.05 (linear region of the Beer-Lambert law
11 9,10-diphenylanthracene Φ F = 1.0 Quinine sulfate, 0.1 M H 2 S 4 Me H H H H 2 S 4 ΦF = 0.54 H CH 2 Photo from Zn Φ F = 0.30
12 Φ F = 0.14 Chlorophyll A Tryptophan, water ph = 7.2 H Mg H C 20 H 39 CH 3 Φ F = 0.32 The photophysical parameters are temperature dependent L C Pt C L Au Au L C Pt C L M = Pd gives activation energy M = Pt Wavelength (nm) Harvey & Gray Polyhedron, 1990, 9, Harvey & coll. Inorg. Chem., 1999, 38, 4928
13 Some useful relationships k nr = k c + k i + k isc + k RS k F Φ F = τ k F + k F = nr 1 k F + k nr Φ F = k F τ F k nr = (k F /Φ F )(1 Φ F ) Quantum yields Radiative (absolute or comparison with a standard) on-radiative (intersystem crossing & photochemical) Φ isc = k isc k F + k nr k Φ RS RS = k F + k nr k Φ RT RT = k F + k nr
14 Measurements of the photochemical quantum yields: actinometry Example: photolabilisation of L (C-2,6-(i-Pr) 2 C 6 H 3 ) t = 0 s t = 60 s L L L Cr L L L + hν L L Cr L L L + L The actinometer: K 3 [Fe(C 2 4 )] K 3 [Fe(C 2 4 ) 3 ] + H 2 S 4 "[Fe(C 2 4 )] + " + "[Fe(C 2 4 ) 2 ] - + Fe Fe C C 2 Pale green complex (d-d transition) Φ reaction = 1.0 at 436 nm. ne can measure the exact time that is necessary for that 10% of the materials disappears upon irradiation for both the sample and the standard at the same irradiation wavelength if possible using the same optical density at this wavelength, but the actinometer is a weak absorber. For more precision, one uses phenantroline.
15 Fe phenantroline Fe(Phen) 3 2+ ε = M -1 cm -1 Fe(Phen) 3 2+ A = ε l c Fe 2+ Example Φ reaction = 0.1 Ph 2 P PPh 2 2+ Ph 2 P Pd Pd PPh 2 Ph 2 Ph 2 P Pd P C Pd 3 (dppm) 3 (µ-c) 2+ Products + C [Host-guest complex] Stable
16 1- The Jablonski diagram (or the state diagram of diamagnetic molecules) 2- Various natures of excited states and basics in molecular orbitals 3- Vibronic coupling and the Franck-Condon term 4- Excited state distortion vs bond order 5- The radiative and non-radiative processes 6- The Kasha rule and its exceptions 7- Photo-induced emission, excitation spectra and electroluminescence 8- Polarized emission and excitation spectra (tool for assignments) 9- Delayed fluorescence 10- Excimers and exciplexes 11- Basics in spin-orbit couplings 12- The measurements of some of the photophysical parameters 13- Bimolecular reactions, Stern-Volmer plots, and sensors 14- Time-resolved spectroscopy 15-2-Photon spectroscopy, flash photolysis and transient spectra 16- Exciton coupling and delocalized exciton in extended systems 17- Photo-induced energy transfer and the antenna effect 18- Photo-induced electron transfer and the Marcus inverted region Chapter 13: General aspects of bimolecular reactions, Stern-Volmer plots, and sensors Energy transfer Molecule* + Quencher Molecule + Quencher* Electron transfer Molecule* + Quencher Molecule + + Quencher - Molecule* + Quencher Molecule - + Quencher + Atom transfer, bond cleavage, photochemistry! Molecule* + Quencher Products
17 The effect of quenching on the emission intensity o quencher More quencher Even more quencher The effect of quenching on the emission lifetime o quencher More quencher Even more quencher Image from
18 Fluorescence quenching of quinine by bromide ions In the absence of a quencher In the presence of a quencher S 1 S 1 k RS A k F k nr A k F k nr S 0 S 0 o τ F = 1 kf + k nr τ F = 1 kf + k nr + k Q Q o τ F = τ F 1 o + τ F k Q Q
19 The Stern-Volmer plots o τ F = τ F 1 o + τ F k Q Q Also o Φ F o = 1 + τ F k Q Q Φ F Bimolecular emission quenching by 2 A diffusional (collision) energy transfer process absorption spectrum of dioxygen low-energy excited state Molecule* + 2 ( 3 Σ g- ) Molecule + 2 *( 1 g )
20 Diffusion Coefficients at 25 C Tryptophan = 0.66 x 10-5 cm/s xygen = 2.5 x 10-5 cm/s Collision radius = 5Å Lifetime without quencher; τ ο = 2.70 ns = 2.7 x 10-9 s Bi-molecular collision rate constant; k q = 1.27 x M -1 s -1 Stern-Volmer Constant; K D = 32.5 = k q τ o Efficiency of quenching per collision; f q = 1 Diffusion controlled constant; k o = k q f q = 1.27 x M -1 s τ o /τ = 32.5 M -1 [Q] τ ο /τ τ = ns [ 2 ], M Example: quenching of the Pd(TPP) phosphorescence by 2 M S M «Shield» Pd Harvey & coll., Inorg. Chem. 2005, 44, Pd(TPP)
21 Phosphorescence quenching of Bis(Pd-Porph) and (Pd)TPP Compound τ P (µs) k Q (10 9 M -1. s -1 ) k SV (10 6 M -1 ) Lowest detection (ppm) (Pd) 2 DPX (Pd)TPP (Pd) 2 DPS (Pd) 2 DPS (Pd) 2 DPB Protection against 2 quenching Shield no emission quenching by 2! HH 2 C HH 2 C R R R R HH 2 C R R R CH 2 H R R R R R CH 2 H R CH 2 H R CH 2 H
22 Emission quenching by photo-induced electron transfer H Ru 2+ e- H H H 2- Mo Q = Mo 4 2- Image from: ne application of the bimolecular photo-induced electron transfer: the photovoltaic cells π π*
23 Prof. Mihai Scarlete Thin Film Research Solar panel production
24 Action spectrum Soret Zinc(porphyrin) Zn Q-region 1- The Jablonski diagram (or the state diagram of diamagnetic molecules) 2- Various natures of excited states and basics in molecular orbitals 3- Vibronic coupling and the Franck-Condon term 4- Excited state distortion vs bond order 5- The radiative and non-radiative processes 6- The Kasha rule and its exceptions 7- Photo-induced emission, excitation spectra and electroluminescence 8- Polarized emission and excitation spectra (tool for assignments) 9- Delayed fluorescence 10- Excimers and exciplexes 11- Basics in spin-orbit couplings 12- The measurements of some of the photophysical parameters 13- Bimolecular reactions, Stern-Volmer plots, and sensors 14- Time-resolved spectroscopy 15-2-Photon spectroscopy, flash photolysis and transient spectra 16- Exciton coupling and delocalized exciton in extended systems 17- Photo-induced energy transfer and the antenna effect 18- Photo-induced electron transfer and the Marcus inverted region
25 Chapter 14: Time-resolved spectroscopy Eximers and Exciplex! Molecule(S 1 )* + Molecule (S 0 ) (Molecule) 2 *
26 CH 3 + CH 3 + Cu Cu Cu Cu + P P P P P P P P Major Minor (not observable in absorption) Harvey and collaborators, Inorg. Chem. 1997, 36, hν Excitonic processes in 1D polymers * * * hν` Emission Properties hν` hν` {Ag(dmb) 2+ } n 0.1 ms 2.0 ms 4.0 ms 6.0 ms
27 It is also good for slow processes such as phosphorescence Rel. Int Wavelength (nm) 1- The Jablonski diagram (or the state diagram of diamagnetic molecules) 2- Various natures of excited states and basics in molecular orbitals 3- Vibronic coupling and the Franck-Condon term 4- Excited state distortion vs bond order 5- The radiative and non-radiative processes 6- The Kasha rule and its exceptions 7- Photo-induced emission, excitation spectra and electroluminescence 8- Polarized emission and excitation spectra (tool for assignments) 9- Delayed fluorescence 10- Excimers and exciplexes 11- Basics in spin-orbit couplings 12- The measurements of some of the photophysical parameters 13- Bimolecular reactions, Stern-Volmer plots, and sensors 14- Time-resolved spectroscopy 15-2-Photon spectroscopy, flash photolysis and transient spectra 16- Exciton coupling and delocalized exciton in extended systems 17- Photo-induced energy transfer and the antenna effect 18- Photo-induced electron transfer and the Marcus inverted region
28 Chapter 15: 2-Photon spectroscopy (intense laser) S 2 S 1 S 0 virtual state Fps-null mouse colon stained with β-catenin 1 antibody and Alexa 488 secondary. n the right is normal tissue and on the left is a tumour. S 3 S 2 S 1 S 0
29 Absorption (T 1 -T n ) T n Inter-system crossing (very fast) Probe (lamp) S 1 T 1 Pump (laser) spectrum with pump excitation -spectrum without pump excitation transient spectrum S 0 Transient absorption S 1 inter-system crossing (very fast) very fast reaction electron or energy transfer Probe (lamp) Pump (laser) T 1 Products S 0 spectrum with pump excitation -spectrum without pump excitation transient spectrum
30 Schematic drawing of a transient absorption set-up Probe lamp Pump laser spectrum with pump excitation -spectrum without pump excitation transient spectrum anosecond Flash Photolysis Laser System (Harvey Group) scilloscope Laser Fan Screen Probe lamp Computer
31 Sample P Laser ( nm) Pump excitation nm nm YAG laser nm Growth and decay of the transient species Bleach and recovery of the ground state species The decay give the lifetime of the non-luminescing transient species
32 Delta A A 0,12 0,1 0,08 0,06 0,04 0,02 65 ns 80 ns 100 ns Wavelength(nm) Xanthone 0,11 0,07 A 0,03-0, ,05 Time(ns) Charge separated states S 1 inter-system crossing (very fast) fast reaction electron transfer + electron acceptor Probe (lamp) Pump (laser) T 1 electron recombination electron donor + electron acceptor - S 0 electron donor
33 10 9 W/cm W/cm W/cm 2 Requires very powerful lasers
Advanced Organic Chemistry Chm 512/412 Spring Handout I Photochemistry Part 1. Photophysical Processes Quenching Alkene cis-trans Isomerization
Advanced rganic Chemistry Chm 512/412 Spring 2010 Handout I Photochemistry Part 1 Photophysical Processes Quenching Alkene cis-trans Isomerization Importance of Photochemistry/Photophysics rganic Synthesis
More informationPHOTOCHEMISTRY NOTES - 1 -
- 1 - PHOTOCHEMISTRY NOTES 1 st Law (Grotthus-Draper Law) Only absorbed radiation produces chemical change. Exception inelastic scattering of X- or γ-rays (electronic Raman effect). 2 nd Law (Star-Einstein
More informationWhat the Einstein Relations Tell Us
What the Einstein Relations Tell Us 1. The rate of spontaneous emission A21 is proportional to υ 3. At higher frequencies A21 >> B(υ) and all emission is spontaneous. A 21 = 8π hν3 c 3 B(ν) 2. Although
More information1. Photoreduction of Benzophenone in 2-Propanol
1. Photoreduction of Benzophenone in 2-Propanol Topic: photochemistry, photophysics, kinetics, physical-organic chemistry Level: undergraduate physical chemistry Time: 2 x 2 hours (separated by ~24 hours)
More informationsingle-molecule fluorescence resonance energy transfer
single-molecule fluorescence resonance energy transfer (2) determing the Förster radius: quantum yield, donor lifetime, spectral overlap, anisotropy michael börsch 26/05/2004 1 fluorescence (1) absorbance
More informationExcited State Processes
Excited State Processes Photophysics Fluorescence (singlet state emission) Phosphorescence (triplet state emission) Internal conversion (transition to singlet gr. state) Intersystem crossing (transition
More informationLABORATORY OF ELEMENTARY BIOPHYSICS
LABORATORY OF ELEMENTARY BIOPHYSICS Experimental exercises for III year of the First cycle studies Field: Applications of physics in biology and medicine Specialization: Molecular Biophysics Fluorescence
More informationChap. 12 Photochemistry
Chap. 12 Photochemistry Photochemical processes Jablonski diagram 2nd singlet excited state 3rd triplet excited state 1st singlet excited state 2nd triplet excited state 1st triplet excited state Ground
More informationFluorescence (Notes 16)
Fluorescence - 2014 (Notes 16) XV 74 Jablonski diagram Where does the energy go? Can be viewed like multistep kinetic pathway 1) Excite system through A Absorbance S 0 S n Excite from ground excited singlet
More informationCD Basis Set of Spectra that is used is that derived from comparing the spectra of globular proteins whose secondary structures are known from X-ray
CD Basis Set of Spectra that is used is that derived from comparing the spectra of globular proteins whose secondary structures are known from X-ray crystallography An example of the use of CD Modeling
More informationCHEM Outline (Part 15) - Luminescence 2013
CHEM 524 -- Outline (Part 15) - Luminescence 2013 XI. Molecular Luminescence Spectra (Chapter 15) Kinetic process, competing pathways fluorescence, phosphorescence, non-radiative decay Jablonski diagram
More informationModern Optical Spectroscopy
Modern Optical Spectroscopy With Exercises and Examples from Biophysics and Biochemistry von William W Parson 1. Auflage Springer-Verlag Berlin Heidelberg 2006 Verlag C.H. Beck im Internet: www.beck.de
More informationMolecular Luminescence. Absorption Instrumentation. UV absorption spectrum. lg ε. A = εbc. monochromator. light source. Rotating mirror (beam chopper)
Molecular Luminescence Absorption Instrumentation light source I 0 sample I detector light source Rotating mirror (beam chopper) motor b sample I detector reference I 0 UV absorption spectrum lg ε A =
More informationIntroduction ENERGY. Heat Electricity Electromagnetic irradiation (light)
Photochemistry Introduction ENERGY Heat Electricity Electromagnetic irradiation (light) Vision: Triggered by a photochemical reaction Is red in the dark? The answer must be NO - Since what we see as colour
More informationChapter 15 Molecular Luminescence Spectrometry
Chapter 15 Molecular Luminescence Spectrometry Two types of Luminescence methods are: 1) Photoluminescence, Light is directed onto a sample, where it is absorbed and imparts excess energy into the material
More informationLuminescence. Photoluminescence (PL) is luminescence that results from optically exciting a sample.
Luminescence Topics Radiative transitions between electronic states Absorption and Light emission (spontaneous, stimulated) Excitons (singlets and triplets) Franck-Condon shift(stokes shift) and vibrational
More informationChem G8316_10 Supramolecular Organic Chemistry
Chem G8316_10 Supramolecular Organic Chemistry Lecture 5, Wednesday, February 3, 2010 Photophysics of aromatic hydrocarbons Supramolecular effects on the photophysics of aromatic hydrocarbons 1 Course
More informationSinglet. Fluorescence Spectroscopy * LUMO
Fluorescence Spectroscopy Light can be absorbed and re-emitted by matter luminescence (photo-luminescence). There are two types of luminescence, in this discussion: fluorescence and phosphorescence. A
More informationChapter 6 Photoluminescence Spectroscopy
Chapter 6 Photoluminescence Spectroscopy Course Code: SSCP 4473 Course Name: Spectroscopy & Materials Analysis Sib Krishna Ghoshal (PhD) Advanced Optical Materials Research Group Physics Department, Faculty
More informationGeneration of light Light sources
Generation of light Light sources Black-body radiation Luminescence Luminescence Laser Repetition Types of energy states in atoms and molecules are independent (not coupled) Energy states are non-continuous,
More informationChemistry 2. Molecular Photophysics
Chemistry 2 Lecture 12 Molecular Photophysics Assumed knowledge Electronic states are labelled using their spin multiplicity with singlets having all electron spins paired and triplets having two unpaired
More informationEffects of Temperature and Concentration on the Rate of Photo-bleaching of Erythrosine in Water
Supporting Information for: Effects of Temperature and Concentration on the Rate of Photo-bleaching of Erythrosine in Water Joshua K. G. Karlsson, Owen J. Woodford, Roza Al-Aqar and Anthony Harriman* Molecular
More informationFluorescence 2009 update
XV 74 Fluorescence 2009 update Jablonski diagram Where does the energy go? Can be viewed like multistep kinetic pathway 1) Excite system through A Absorbance S 0 S n Excite from ground excited singlet
More informationAula 5 e 6 Transferência de Energia e Transferência de Elétron Caminhos de espécies fotoexcitadas
Fotoquímica Aula 5 e 6 Transferência de Energia e Transferência de Elétron Prof. Amilcar Machulek Junior IQ/USP - CEPEMA Caminhos de espécies fotoexcitadas 1 Diagrama de Jablonski S 2 Relaxation (τ < 1ps)
More informationSupporting Information for. Metallonaphthalocyanines as Triplet Sensitizers for Near-Infrared. Photon Upconversion beyond 850 nm
Electronic Supplementary Material (ESI) for Physical Chemistry Chemical Physics. This journal is the Owner Societies 2015 Supporting Information for Metallonaphthalocyanines as Triplet Sensitizers for
More informationPART VI : MOLECULAR LUMINESCENCE SPECTROSCOPY (Recommendations 1985)
PART VI : MOLECULAR LUMINESCENCE SPECTROSCOPY (Recommendations 1985) 1. INTRODUCTION This document does not aim to be completely self-contained since many of the terms and units needed for describing Molecular
More informationFluorescence Spectroscopy
Fluorescence Spectroscopy Frequency and time dependent emission Emission and Excitation fluorescence spectra Stokes Shift: influence of molecular vibrations and solvent Time resolved fluorescence measurements
More information10. 6 Photochemistry. Out-class reading: Levine, pp photochemistry
Out-class reading: Levine, pp. 800-804 photochemistry 6.1 Brief introduction of light 1) Photochemistry The branch of chemistry which deals with the study of chemical reaction initiated by light. 2) Energy
More informationPulsed lasers. To induce new chemistry, different from that initiated by conventional sources
Pulsed lasers As part of a method to study photoinitiated chemical reactions To induce new chemistry, different from that initiated by conventional sources As a light source, to initiate the same chemistry
More informationA Guide to Recording Fluorescence Quantum Yields
Oa~äëíçåd~êÇÉåëIpí~åãçêÉIjáÇÇäÉëÉñe^TN_nIrh A Guide to Recording Fluorescence Quantum Yields Introduction: When a fluorophore absorbs a photon of light, an energetically excited state is formed. The fate
More informationSupporting Information
Supporting Information Cyclodextrin Supramolecular Complex as Water Soluble Ratiometric Sensor for ferric Ion Sensing Meiyun Xu, Shuizhu Wu,* Fang Zeng, Changmin Yu College of Materials Science & Engineering,
More information1. Transition dipole moment
1. Transition dipole moment You have measured absorption spectra of aqueous (n=1.33) solutions of two different chromophores (A and B). The concentrations of the solutions were the same. The absorption
More informationModel Answer (Paper code: AR-7112) M. Sc. (Physics) IV Semester Paper I: Laser Physics and Spectroscopy
Model Answer (Paper code: AR-7112) M. Sc. (Physics) IV Semester Paper I: Laser Physics and Spectroscopy Section I Q1. Answer (i) (b) (ii) (d) (iii) (c) (iv) (c) (v) (a) (vi) (b) (vii) (b) (viii) (a) (ix)
More informationwith Long-lived Triplet Excited State for Triplet-Triplet-Annihilation Based Upconversion
Supporting nformation for: Organic Triplet Sensitizer Library Derived rom a Single Chromophore (ODPY) with Long-lived Triplet Excited State for Triplet-Triplet-Annihilation ased Upconversion Wanhua Wu,
More information5 questions, 3 points each, 15 points total possible. 26 Fe Cu Ni Co Pd Ag Ru 101.
Physical Chemistry II Lab CHEM 4644 spring 2017 final exam KEY 5 questions, 3 points each, 15 points total possible h = 6.626 10-34 J s c = 3.00 10 8 m/s 1 GHz = 10 9 s -1. B= h 8π 2 I ν= 1 2 π k μ 6 P
More informationComplex Reaction Mechanisms Chapter 36
Reaction Mechanisms: Complex Reaction Mechanisms Chapter 36 Reaction mechanism is a collection o elementary (one step) reactions that would add up to result in the overall reaction. Generally elementary
More informationSupporting Information for:
Supporting Information for: High Efficiency Low-Power Upconverting Soft Materials Jae-Hyuk Kim, Fan Deng, Felix N. Castellano,*, and Jae-Hong Kim*, School of Civil and Environmental Engineering, Georgia
More informationE L E C T R O P H O S P H O R E S C E N C E
Organic LEDs part 4 E L E C T R O P H O S P H O R E S C E C E. OLED efficiency 2. Spin 3. Energy transfer 4. Organic phosphors 5. Singlet/triplet ratios 6. Phosphor sensitized fluorescence 7. Endothermic
More informationXV 74. Flouorescence-Polarization-Circular-Dichroism- Jablonski diagram Where does the energy go?
XV 74 Flouorescence-Polarization-Circular-Dichroism- Jablonski diagram Where does the energy go? 1) Excite system through A Absorbance S 0 S n Excite from ground excited singlet S = 0 could be any of them
More informationLAB #3: FLUROESCENCE SPECTROSCOPY AND ELECTRON TRANSFER (This lab is adapted from the U of MN Phsyical Chemistry lab manual)
Chemistry 372 Gustavus Adolphus College A. Purpose LAB #3: FLUROESCENCE SPECTROSCOPY AND ELECTRON TRANSFER (This lab is adapted from the U of MN Phsyical Chemistry lab manual) In this experiment, you will
More informationDepartment of Chemistry Physical Chemistry Göteborg University
Department of Chemistry Physical Chemistry Göteborg University &RQVWUXFWLRQRIDSXOVHGG\HODVHU 3OHDVHREVHUYHWKDWWKHVDIHW\SUHFDXWLRQVRQSDJHPXVW EHIROORZHGRWKHUZLVHWKHUHLVDULVNRIH\HGDPDJH Renée Andersson -97,
More informationChapter 17: Fundamentals of Spectrophotometry
Chapter 17: Fundamentals of Spectrophotometry Spectroscopy: the science that deals with interactions of matter with electromagnetic radiation or other forms energy acoustic waves, beams of particles such
More informationChapter 17: Fundamentals of Spectrophotometry
Chapter 17: Fundamentals of Spectrophotometry Spectroscopy: the science that deals with interactions of matter with electromagnetic radiation or other forms energy acoustic waves, beams of particles such
More informationTHE ROLE OF ENERGY TRANSFER IN THE
THE ROLE OF ENERGY TRANSFER IN THE STABILIZATION OF POLYMERS Department of Chemistry. University of Toronto, Toronto 181, Canada ABSTRACT Energy transfer processes can, in principle, represent a powerful
More informationFluorescence Quenching
Summary Fluorescence Quenching The emission of light from the excited state of a molecule (fluorescence or phosphorescence) can be quenched by interaction with another molecule. The stationary and time-dependent
More informationHaiyang Sun, Huimin Guo,* Wenting Wu, Xin Liu, Jianzhang Zhao*
Electronic Supplementary Information for: Coumarin phosphorescence observed with ^ Pt(II) bisacetylide complex and its applications for luminescent oxygen sensing and triplet-triplet-annihilation based
More information4 Single molecule FRET
4 Single molecule FRET FRET basics Energie Dipole-dipole interaction Teil I SM Fluo, Kap. 4 FRET FRET basics transfer rate (from Fermis Golden Rule) k t = 1 0 1 r 6 apple 2 9 ln(10) n 4 N A 128 5 Z d f
More informationElectronic Spectra of Complexes
Electronic Spectra of Complexes Interpret electronic spectra of coordination compounds Correlate with bonding Orbital filling and electronic transitions Electron-electron repulsion Application of MO theory
More informationNPTEL/IITM. Molecular Spectroscopy Lectures 1 & 2. Prof.K. Mangala Sunder Page 1 of 15. Topics. Part I : Introductory concepts Topics
Molecular Spectroscopy Lectures 1 & 2 Part I : Introductory concepts Topics Why spectroscopy? Introduction to electromagnetic radiation Interaction of radiation with matter What are spectra? Beer-Lambert
More informationUltraviolet-Visible Spectroscopy
Ultraviolet-Visible Spectroscopy Introduction to UV-Visible Absorption spectroscopy from 160 nm to 780 nm Measurement of transmittance Conversion to absorbance * A=-logT=εbc Measurement of transmittance
More informationIntroduction to Fluorescence Spectroscopies I. Theory
March 22, 2006; Revised January 26, 2011 for CHMY 374 Adapted for CHMY 362 November 13, 2011 Edited by Lauren Woods December 2, 2011 17mar14, P.Callis; 1feb17 P. Callis, 29jan18 P. Callis Introduction
More informationPrinciples and Applications of Photochemistry
Principles and Applications of Photochemistry Brian Wardle Manchester Metropolitan University, Manchester, UK A John Wiley & Sons, Ltd., Publication Principles and Applications of Photochemistry Principles
More informationChem 442 Review of Spectroscopy
Chem 44 Review of Spectroscopy General spectroscopy Wavelength (nm), frequency (s -1 ), wavenumber (cm -1 ) Frequency (s -1 ): n= c l Wavenumbers (cm -1 ): n =1 l Chart of photon energies and spectroscopies
More informationTime Resolved Pulsed Laser Photolysis Study of Pyrene Fluorescence Quenching by I - Anion
1 Time Resolved Pulsed Laser Photolysis Study of Pyrene Fluorescence Quenching by I - Anion Cameron Incognito, Ryan Bella, Cassandra Smith, Brandon Alexander Department of Chemistry, The Pennsylvania State
More informationExcited States in Organic Light-Emitting Diodes
Excited States in Organic Light-Emitting Diodes The metal-to-ligand charge transfer (MLCT) excited states of d 6 π coordination compounds have emerged as the most efficient for solar harvesting and sensitization
More informationCHAPTER 13 Molecular Spectroscopy 2: Electronic Transitions
CHAPTER 13 Molecular Spectroscopy 2: Electronic Transitions I. General Features of Electronic spectroscopy. A. Visible and ultraviolet photons excite electronic state transitions. ε photon = 120 to 1200
More informationFluorescence polarisation, anisotropy FRAP
Fluorescence polarisation, anisotropy FRAP Reminder: fluorescence spectra Definitions! a. Emission sp. b. Excitation sp. Stokes-shift The difference (measured in nm) between the peak of the excitation
More information"Molecular Photochemistry - how to study mechanisms of photochemical reactions?"
"Molecular Photochemistry - how to study mechanisms of photochemical reactions?" Bronislaw Marciniak Faculty of Chemistry, Adam Mickiewicz University, Poznan, Poland 2014/2015 - lecture 4 Contents 1. Introduction
More informationMaking OLEDs efficient
Making OLEDs efficient cathode anode light-emitting layer η = γ EL r ηpl k st External Efficiency Outcoupling Internal efficiency of LEDs η = γ EL r ηpl k st γ = excitons formed per charge flowing in the
More informationFluorescence spectra of 1-Pyrenebutyric acid, concentration dependence and dynamic quenching phenomena
Practicum Spectroscopy Fall 2010 Fluorescence spectra of 1-Pyrenebutyric acid, concentration dependence and dynamic quenching phenomena LUM Jorge Ferreiro, study degree Chemistry, 5 th semester, fjorge@student.ethz.ch
More informationLaser Dissociation of Protonated PAHs
100 Chapter 5 Laser Dissociation of Protonated PAHs 5.1 Experiments The photodissociation experiments were performed with protonated PAHs using different laser sources. The calculations from Chapter 3
More informationMeasurement Examples. Excitation and Emission Scans. Steady State Fluorescence Anisotropy. Kinetic Measurements
Measurement Examples A division of Edinburgh Instruments Ltd. Excitation and Emission Scans Excitation and emission spectra are standard measurements in fluorescence spectroscopy. The figure demonstrates
More informationLecture 5. Anisotropy decay/data analysis. Enrico Gratton
Lecture 5. Anisotropy decay/data analysis Enrico Gratton Anisotropy decay Energy-transfer distance distributions Time resolved spectra Excited-state reactions Basic physics concept in polarization The
More informationCHAPTER 7 SUMMARY OF THE PRESENT WORK AND SUGGESTIONS FOR FUTURE WORK
161 CHAPTER 7 SUMMARY OF THE PRESENT WORK AND SUGGESTIONS FOR FUTURE WORK 7.1 SUMMARY OF THE PRESENT WORK Nonlinear optical materials are required in a wide range of important applications, such as optical
More informationFluorescence Workshop UMN Physics June 8-10, 2006 Quantum Yield and Polarization (1) Joachim Mueller
Fluorescence Workshop UMN Physics June 8-10, 2006 Quantum Yield and Polarization (1) Joachim Mueller Quantum yield, polarized light, dipole moment, photoselection, dipole radiation, polarization and anisotropy
More informationP. Lambrev October 10, 2018
TIME-RESOLVED OPTICAL SPECTROSCOPY Petar Lambrev Laboratory of Photosynthetic Membranes Institute of Plant Biology The Essence of Spectroscopy spectro-scopy: seeing the ghosts of molecules Kirchhoff s
More informationGeneral Considerations on the Radiation and Photochemistry of Resists
Chapter 8 General Considerations on the Radiation and otochemistry of Resists Here the boundaries meet and all contradictions exist side by side. Fyodor Dostoevsky, The Brothers Karamazov 8.1 Interaction
More informationLast Updated: April 22, 2012 at 7:49pm
Page 1 Electronic Properties of d 6 π Coordination Compounds The metal-to-ligand charge transfer (MLCT) excited states of d 6 π coordination compounds have emerged as the most efficient for both solar
More informationPhotochemistry and Photophysics Concepts, Research, Applications. V. Balzani, Paolo Ceroni e Alberto Jurin. Wiley VCH. Preface
Photochemistry and Photophysics Concepts, Research, Applications V. Balzani, Paolo Ceroni e Alberto Jurin Wiley VCH Preface Chapter 1. Introduction 1.1 Photochemistry and photophysics in science and technology
More informationIntroduction to scintillators
Introduction to scintillators M. Kobayashi (KEK) 17 November, 2003 1. Luminescence, fluorescence, scintillation, phosphorescence, etc. 2. Scintillation mechanism 3. Scintillation efficiency 4. Main characteristics
More informationSpectroscopy Problem Set February 22, 2018
Spectroscopy Problem Set February, 018 4 3 5 1 6 7 8 1. In the diagram above which of the following represent vibrational relaxations? 1. Which of the following represent an absorbance? 3. Which of following
More informationi) impact of interchain interactions
i) impact of interchain interactions multiple experimental observations: in dilute solutions or inert matrices: the photoluminescence quantum yield of a given conjugated polymers can be very large: up
More informationChem 344 Final Exam Tuesday, Dec. 11, 2007, 3-?? PM
Chem 344 Final Exam Tuesday, Dec. 11, 2007, 3-?? PM Closed book exam, only pencils and calculators permitted. You may bring and use one 8 1/2 x 11" paper with anything on it. No Computers. Put all of your
More informationTIME-RESOLVED OPTICAL SPECTROSCOPY
TIME-RESOLVED OPTICAL SPECTROSCOPY Petar Lambrev Laboratory of Photosynthetic Membranes Institute of Plant Biology The Essence of Spectroscopy spectro-scopy: seeing the ghosts of molecules Kirchhoff s
More informationReflection = EM strikes a boundary between two media differing in η and bounces back
Reflection = EM strikes a boundary between two media differing in η and bounces back Incident ray θ 1 θ 2 Reflected ray Medium 1 (air) η = 1.00 Medium 2 (glass) η = 1.50 Specular reflection = situation
More information1 Electronic Process in Organic Solids
1 1 Electronic Process in Organic Solids ongzhen Lin, Fenglian Bai Organic solids, in a broad sense, include all solid - state materials consisting of organic molecules or polymers, namely, compounds with
More informationLuminescence Spectroscopy Excitation is very rapid (10-15 s). Vibrational relaxation is a non-radiational process. It involves vibrational levels of
Luminescence Spectroscopy Excitation is very rapid (10-15 s). Vibrational relaxation is a non-radiational process. It involves vibrational levels of the same electronic state. The excess of vibrational
More informationTheoretical Photochemistry WiSe 2016/17
Theoretical Photochemistry WiSe 2016/17 Lecture 8 Irene Burghardt burghardt@chemie.uni-frankfurt.de) http://www.theochem.uni-frankfurt.de/teaching/ Theoretical Photochemistry 1 Topics 1. Photophysical
More informationOptical and Photonic Glasses. Lecture 31. Rare Earth Doped Glasses I. Professor Rui Almeida
Optical and Photonic Glasses : Rare Earth Doped Glasses I Professor Rui Almeida International Materials Institute For New Functionality in Glass Lehigh University Rare-earth doped glasses The lanthanide
More informationTriplet state diffusion in organometallic and organic semiconductors
Triplet state diffusion in organometallic and organic semiconductors Prof. Anna Köhler Experimental Physik II University of Bayreuth Germany From materials properties To device applications Organic semiconductors
More informationSupporting Information for. Near infrared-to-blue photon upconversion by exploiting direct. S-T absorption of a molecular sensitizer
Electronic Supplementary Material (ESI) for Journal of Materials Chemistry C. This journal is The Royal Society of Chemistry 2017 Supporting Information for Near infrared-to-blue photon upconversion by
More informationChemistry Instrumental Analysis Lecture 3. Chem 4631
Chemistry 4631 Instrumental Analysis Lecture 3 Quantum Transitions The energy of a photon can also be transferred to an elementary particle by adsorption if the energy of the photon exactly matches the
More informationA Fluorometric Analysis of Quinine in Tonic Water
A Fluorometric Analysis of Quinine in Tonic Water Introduction In this Laboratory Exercise, we will determine the amount of quinine in Tonic Water using a fluorometric analysis. Fluorescence Spectroscopy
More informationSupporting Information
Supporting Information For Bioinspired Orientation of β-substituents on Porphyrin Antenna Ligands Switches Ytterbium(III) NIR Emission with Thermosensitivity Yingying Ning, Xian-Sheng Ke, Ji-Yun Hu, Yi-Wei
More informationLuminescence spectroscopy
Febr. 203 Luminescence spectroscopy Biophysics 2 nd semester Józse Orbán University o Pécs, Department o Biophysics Deinitions, laws FUNDAMENTALS o SPECTROSCY review - Spectral types (absorbtion/emission
More informationPlatinum resistance. also wirewound versions. eg
Platinum resistance Platinum resistance Very stable and reproducible, wide T range (~ -200 C to 1000 C) T coefficient ~ +0.4%/ C Bulky and expensive for some applications (~ 2-3) need wires (R) or local
More informationLuminescence basics. Slide # 1
Luminescence basics Types of luminescence Cathodoluminescence: Luminescence due to recombination of EHPs created by energetic electrons. Example: CL mapping system Photoluminescence: Luminescence due to
More informationSupporting Information. Evaluating steady-state and time-resolved fluorescence as a tool to study the behavior of asphaltene in toluene
Electronic Supplementary Material (ESI) for Photochemical & Photobiological Sciences. This journal is The Royal Society of Chemistry and Owner Societies 2014 Supporting Information Evaluating steady-state
More informationSupplementary Figures
Supplementary Figures Supplementary Figure. X-ray diffraction pattern of CH 3 NH 3 PbI 3 film. Strong reflections of the () family of planes is characteristics of the preferred orientation of the perovskite
More informationSignaling preferences of substituted pyrrole coupled six-membered spirocyclic rhodamine probes towards Hg 2+ ion detection
Electronic Supplementary Material (ESI) for rganic & Biomolecular Chemistry. This journal is The Royal Society of Chemistry 6 Signaling preferences of substituted pyrrole coupled six-membered spirocyclic
More informationAssumed knowledge. Chemistry 2. Learning outcomes. Electronic spectroscopy of polyatomic molecules. Franck-Condon Principle (reprise)
Chemistry 2 Lecture 11 Electronic spectroscopy of polyatomic molecules Assumed knowledge For bound excited states, transitions to the individual vibrational levels of the excited state are observed with
More informationHow does a polymer LED OPERATE?
How does a polymer LED OPERATE? Now that we have covered many basic issues we can try and put together a few concepts as they appear in a working device. We start with an LED:. Charge injection a. Hole
More informationFluorescence Polarization Anisotropy FPA
Fluorescence Polarization Anisotropy FPA Optics study of light Spectroscopy = light interacts the study of the interaction between matter & electro-magnetic radiation matter Spectroscopy Atomic Spectroscopy
More informationFluorescence Spectrophotometry
Chemistry 422L Manual Page 27 I. Introduction Fluorescence Spectrophotometry Ru(bpy) 3 2+, where bpy = 2, 2' bipyridine, has been one of the most widely studied metal complexes in recent years. Interest
More informationSupporting Information for
Supporting Information for Molecular Rectification in Conjugated Block Copolymer Photovoltaics Christopher Grieco 1, Melissa P. Aplan 2, Adam Rimshaw 1, Youngmin Lee 2, Thinh P. Le 2, Wenlin Zhang 2, Qing
More informationBoosting Transport Distances for Molecular Excitons within Photo-excited Metal Organic Framework Films
Supporting Information Boosting Transport Distances for Molecular Excitons within Photo-excited Metal Organic Framework Films Subhadip Goswami, a Michelle Chen, a Michael R. Wasielewski, a Omar K. Farha,
More information[Supporting Information]
Transmittance (a.u.) Intensity (a.u.) Intensity (a.u.) [Supporting Information] New methods of synthesis and varied properties of carbon quantum dots with high nitrogen content Sunita Dey, P. Chithaiah,
More informationModeling of S-N Bond Breaking in an Aromatic Sulfilimine. By Jacob Brunsvold & Katrina Hanson Advisor: Stacey Stoffregen
Modeling of S-N Bond Breaking in an Aromatic Sulfilimine By Jacob Brunsvold & Katrina Hanson Advisor: Stacey Stoffregen Outline! Background Photochemical Reaction! Introduction to Photochemistry and Quantum
More informationPhotoperoxidation of a Diamino Zinc Porphyrazine to the seco-zinc Porphyrazine: Suicide or Murder?
4352 J. Phys. Chem. A 999, 03, 4352-4358 Photoperoxidation of a Diamino Zinc Porphyrazine to the seco-zinc Porphyrazine: Suicide or Murder? A. Garrido Montalban, H. G. Meunier,, R. B. Ostler, A. G. M.
More informationLecture 6 Radiative Transition in Atoms, Molecules & Insulators/Semiconductors
Lecture 6 Radiative Transition in Atoms, Molecules & Insulators/Semiconductors Read: FQ 4, FS 3 Purdue University Spring 2016 Prof. Yong P. Chen (yongchen@purdue.edu) Lecture 6 (1/28/2016) Slide 1 Textbook
More information