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INDICATE THE EXCITED AND GROUND SINGLET AND TRIPLET STATES. INDICATE THE FOLLOWING TRANSITIONS: ABSORPTION, FLUORESCENCE, PHOSPHORESCENCE, NONRADIATIVE DECAY, INTERNAL CONVERSION AND INTERSYSTEM CROSSING. LABEL THE TRANSITIONS PROBED BY AT LEAST 4 TYPES OF SPECTROSCOPY STUDIED IN CHEM 314.

JABLONSKIDIAGRAM

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ATOMICSPECTROSCOPY

SourcespectrumEffec<vebandwidth:~0.001nm

SampleAbsorp0onEffec<vebandwidth:0.002-0.005nm

SignalatdetectorSmallerduetoabsorp<oninflameandmonothroughput

Absorp<onlinesbroadenedby:-  UncertaintyEffect-  Dopplerbroadening-  Pressurebroadening

LEARNINGCHECK1.   Howareatomicandmolecularspectroscopydifferent?

2.   DiagramanAtomicAbsorp0onSpectrophotometer

3.   DiagramandexplainhowaHollowCathodeLampworks.

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ATOMICVSMOLECULARSPECTROSCOPY

300 400 500 600 700 8000.0

0.5

1.0

1.5

2.0

Abs

orba

nce

(arb

.)

wavelength (nm)

FLAMEATOMICABSORPTIONSCHEMATIC

Ebert monochromator

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ATOMICEMISSIONSPECTROSCOPY

Excitedstatepopula<on

ATOMICFLUORESCENCESPECTROSCOPY

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HOLLOWCATHODELAMP(HCL)

MOLECULARSPECTROSCOPYCH13-15

CHEM314

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•  Differen<atebetweenatomicandmolecularspec.•  Iden<fy,diagram,anddescribehowthefollowing

instrumentcomponentsfunc<on.Alsoknowwhythesecomponentsareused.Sources:Xearc,Deuteriumarc,tungstenfilament,LEDSamplecuve/es:plas<c,glass,quartz

•  Label,diagram,describeeachofthefollowinginstruments:SinglebeamUV-VissingleelementdetectorSinglebeamUV-Vismul<-elementdetectorDoublebeamUV-Visin<meandspaceFluorimeter

OBJECTIVES

0.0 0.1 0.2 0.3 0.4 0.50.0

0.2

0.4

0.6

0.8

1.0

Abs

orba

nce

(arb

)

[Kool-aid]

A=1.9 [Kool-aid]r2=0.97

0.0 0.1 0.2 0.3 0.4 0.50.0

0.2

0.4

0.6

0.8

1.0

Abs

orba

nce

(arb

)

[Kool-aid]

A=ε b[Kool-aid]b=pathlength

y=mx+b

ε molarabsorb<vity

BEER’SLAW:THERELATIONSHIPBETWEENCONCENTRATIONANDABSORBANCE

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1.  Solu<onfactors2.  Non-monochroma<clight3.  Notanalyzingatlmax4.  Straylight5.  Mismatchedcuveles6.  Instrumentnoise

0.0 0.5 1.0 1.5 2.0 2.5 3.00.0

0.5

1.0

1.5

2.0

2.5

3.0

Abs

orba

nce

(arb

)

[Kool-aid]

SOURCESOFNONLINEARITYOFBEER’SLAW

BUILDINGASPECTROSCOPICINSTRUMENT

Components1.  Stableradia<onsource

2.Wavelengthisola<on-monochromator3.Transparentsampleholder/op<cs4.Detector-PMT,photodiode,PDA5.Signalprocessing

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BUILDINGASPECTROSCOPICINSTRUMENT

Components1.  Stableradia<onsourcedeuteriumarclamp,Tungstenfilament,LED,Xearclamp

2.Wavelengthisola<on-monochromator

3.Transparentsampleholder/op<csQuartz,glass,plas<c

4.Detector-PMT,photodiode,PDA5.Signalprocessing

Con<nuumsourceswithconstantoutputasafunc<onofwavelengthrequiredformolecularspectroscopy

SOURCES

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BLACKBODYRADIATION

hlps://docs.kde.org/stable/en/kdeedu/kstars/ai-blackbody.html

Wein’sDisplacementLaw λmax=maxoutputλT=temp(K)L=luminosityA=surfaceareaα=constant

TUNGSTENFILAMENT

Outputspectrumat2870K

100um

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DEUTERIUMARC

XEARCRange200-1000nm,peak500nm

www.wikipedia.comhlp://zeiss-campus.magnet.fsu.edu/ar<cles/lightsources/images/

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LIGHTEMITTINGDIODELightemiIngdiode(LED)

GaAlAs λmax=900nmGaAsP λmax=650nmGaP λmax=550nmGaN λmax=465nmInGaN λmax=450nm

WhiteLEDInGaNdiodeplusphosphorRange:400-800nm

www.greenprophet.comhlps://lasermom.files.wordpress.com/2012/04/ledspectrum.png

SEMICONDUCTORSBandgap(Eg)-EnergyofgapbetweenHOMOandLUMO

HOMO-highestoccupiedmolecularorbital

LUMO-lowestunoccupiedmolecularorbital

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PNJUNCTIONS

LightemiIngdiode(LED)

GaAlAs λmax=900nmGaAsP λmax=650nmGaP λmax=550nmGaN λmax=465nmInGaN λmax=450nm

WhiteLEDInGaNdiodeplusphosphorRange:400-800nm

LEDVSSILICONPHOTODIODE

LED-Source Photodiode-Detector

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WAVELENGTHSELECTION

MONOCHROMATORS1.  Entranceslit-providesrectangularop<calimage2.  Collima<nglensormirror-makeslightbeamsparallel3.  Dispersiveelement-disperseslightintocomponent

wavelengths4.  Focusingelement-reformsrectangularop<calimagefocused

onfocalplane5.  Exitslit-onfocalplane,selectsdesiredbandwidth

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OPTICSANDSAMPLEHOLDERS

01234

190 490 790 1090

Absorban

ce

Wavelength(nm)

Quartz Plas<c

DETECTORSVacuumphototube

Photomul0pliertube(PMT)

Siliconphotodiode

Photodiodearray(PDA)

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MOLECULARSPECTROSCOPICINSTRUMENTS

UV-VisSpectrophotometersinglebeamdoublebeammul<channel

Fluorimeter

SINGLEBEAMUV-VIS

PHOTODIODEARRAYUV-VIS

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DOUBLEBEAMUV-VIS

Doublebeaminspace

Doublebeamin<me

FLUORIMETER

scan monoex monoem

Excita<on scan fixedEmission fixed scan

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REVIEW

WHATKINDOFINSTRUMENTISPICTURED?HOWDOYOUKNOW?

Ebert monochromator

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WHATKINDOFINSTRUMENTISPICTURED?HOWDOYOUKNOW?

WHATKINDOFINSTRUMENTISPICTURED?HOWDOYOUKNOW?

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WHATKINDOFINSTRUMENTISPICTURED?HOWDOYOUKNOW?

Excitedstatepopula<on

WHATKINDOFINSTRUMENTISPICTURED?HOWDOYOUKNOW?

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WHATKINDOFINSTRUMENTISPICTURED?HOWDOYOUKNOW?

WHATKINDOFINSTRUMENTISPICTURED?HOWDOYOUKNOW?

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WHATKINDOFINSTRUMENTISPICTURED?HOWDOYOUKNOW?

WHATKINDOFINSTRUMENTISPICTURED?HOWDOYOUKNOW?

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WHATKINDOFINSTRUMENTISPICTURED?HOWDOYOUKNOW?

BEER’SLAWDERIVTATION

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ASIMPLEABSORPTIONEXPERIMENT

T=transmissionP0=incidentpowerP=transmiledpowerA=absorbanceε=molarabsorp<vityb=pathlengthC=analyteconcentra<on

Beer’sLaw

DERIVATIONOFBEER’SLAWT=transmissionP0=incidentpowerP=transmiledpowerA=absorbanceε=molarabsorp<vityb=pathlengthC=analyteconcentra<on

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WRITINGAPROCEDURE

1.  Descrip<veTitle2.  Purpose3.  Background4.   Safety-printMSDS5.   Sampleprepara0on6.   Instrumentparameters7.  Datatables-inlabnotebook8.  Dataanalysis9.  References10.   Whatdoyouneed?11.   Appendices

CONTRIBUTINGRESOURCESTOWEBSITE(5PTSEA)5ptseach-upto20ptsextracredit

Resources

1.   Descrip0ve0tle-Whathaveyoufound? books,ebooks,websites,anything

2.   Source-Wheretofindtheresource(cita<onorweblink)

3.   Content-Describewhatisavailable(2-3sentences)

4.   ReliabilityandUsefulness-youropinionaboutresourcereliabilityandhelpfulness

5.   Who’sContribu0ng?Yournameorpseudonym

Contribu0onsareonlyacceptedbeforetheapplicablereportisdue

Submitviaemail

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LOOKINGAHEAD

Monday(Feb8)-MolecularSpectroscopy(Ch13-15),Wri0ngProcedures

Tuesday/Thursday(Feb9,11)-Experiment1Metals

DueThursday:AnnotatedFigures1,Experiment1

Monday(Feb15)-Vibra0onalSpectroscopy

Due:ProjectOverview

Tuesday/Thursday(Feb16,18)-Experiment2-Plas0cs

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WHATKINDOFUV-VISINSTRUMENTISPICTURED?HOWDOYOUKNOW?

WHATKINDOFUV-VISINSTRUMENTISPICTURED?HOWDOYOUKNOW?