LUMINESCENT LEAD COMPLEXES Haina Li Joshua Pan Professor James - - PowerPoint PPT Presentation

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LUMINESCENT LEAD COMPLEXES Haina Li Joshua Pan Professor James - - PowerPoint PPT Presentation

Oct 02, 2023 327 likes •468 views

ANALYTICAL APPLICATIONS OF LUMINESCENT LEAD COMPLEXES Haina Li Joshua Pan Professor James Demas UVa Chemistry October 23, 2013 OUTLINE Previous Work What is Luminescence? Identifying Emitting Species PREVIOUS WORK Pb 2+ + Br -

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ANALYTICAL APPLICATIONS OF LUMINESCENT LEAD COMPLEXES

Haina Li Joshua Pan Professor James Demas UVa Chemistry October 23, 2013

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OUTLINE

 Previous Work  What is Luminescence?  Identifying Emitting Species

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PREVIOUS WORK

Pb2+ + Br- ⇿ Pb4Br11

3-

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 Emits green (550nm),

peak absorption at 350nm

 Jobin Yvon

Spectrofluorometer

LUMINESCENCE

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PREVIOUS WORK

0.00E+00 1.00E+05 2.00E+05 3.00E+05 4.00E+05 5.00E+05 6.00E+05 420 470 520 570 620 Intensity (CPS) Wavelength (nm) [Pb2+]

0 nM lead 450 nM lead 1000 nM lead

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ZINC

Zn2+ + Pb4Br11

3- ⇿ PbwBrx + ZnyBrz

50000 100000 150000 200000 250000 300000 450 500 550 600 650 Inten ensity sity (CPS) Wavel elen ength gth (nm)

[Zn2+]

0 mM Zinc 1 mM Zinc

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SLIDE 7

BROMIDE IONS

[Bromide ion] 100000 200000 300000 400000 500000 600000 700000 450 500 550 600 650 Intens ensit ity y (CPS) Wavel elen ength gth (nm) 0.03 M 0.003 M

PbxBry ⇿ Br- + PbaBrb

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PbxBry ⇿ Br- +PbaBrb PbBr4

2- ⇿ Br- +PbBr3

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550 350 320 600 0.2 0.4 0.6 0.8 1 1.2 300 350 400 450 500 550 600 Norma malized ized Inten ensity ty Wavele velength gth (nm) 0.2 0.4 0.6 0.8 1 1.2 150 350 550 Normali malized ed Intens ensity ty Wavel elen ength gth (nm)

PbBr3

  • PbBr4

2-

550 350 320 600

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Pb4Br11

3-

Pb2+ + Br- ⇿ Pb4Br11

3-

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PbBr4

2-

PbBr3

  • Pb2+ + Br-

PbBr4

2- ⇿ Br- +PbBr3

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CONCLUSION

 PbBr3

  • and PbBr4

2-

 No Pb4Br11

3-

 Does not affect our previous

methods for lead quantification

 Future Work: Better Design

the System

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ACKNOWLEDGEMENT

 Dr. James Demas, Joshua Pan  UVA Chemistry Department  UVA College Science Scholars Program:

Many thanks go to the generous donors to the College Science Scholars program who make these summer research awards possible: Charles Henry Leach, II, Foundation, Mr. Steve Van Besien; Entigence Corporation; Lois A. Fitton & W. Christopher Draper, Jr.; Sharon B. Parente & John W. Risner; The Jefferson Trust; Robert Atkinson; Dean’s discretionary gifts