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6205334 無機光譜化學Inorganic Spectroscopic Chemistry

Time : Thursday 9:00 - 11:45 Classroom : Chem 430 Textbooks : ˙ F.A. Cotton “Chemical Applications of Group

Theory, 3rd ed.”, 1990, Wiley.˙ E.A.V. Ebsworth, D.W.H. Rankin, S. Cradock “Structural Methods in Inorganic Chemistry, 2nd ed.”, 1991, CRC.˙ R.S. Drago “Physical Methods for Chemists, 2nd ed.”, 1992, Saunders.˙ A.K. Brisdon “Inorganic Spectroscopic Methods” 1998, Oxford.

Contents : ˙ UV-visible (electronic) spectroscopyCotton Chapter 9Ebsworth/Rankin/Cradock Chapter 6Brisdon Chapter 4

˙ IR/Raman (vibrational) spectroscopyCotton Chapter 10Ebsworth/Rankin/Cradock Chapter 5Brisdon Chapter 2

˙ Mass SpectrometryEbsworth/Rankin/Cradock Chapter 9Drago Chapter 16Brisdon Chapter 5

˙ NMR SpectroscopyEbsworth/Rankin/Cradock Chapter 2Drago Chapter 7, 8Brisdon Chapter 3

˙ ESR SpectroscopyEbsworth/Rankin/Cradock Chapter 3Drago Chapter 9Brisdon Chapter 3

Grade : Mid-term 40% Final 40% Quiz 20%

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Introduction

Determining structure

˙ contain any known compound?

˙ is it pure?

˙ what functional group it contains?

˙ what is its composition and molecular

weight?

˙ how the functional groups linked together?

˙ what is molecular symmetry?

˙ what are the bond lengths and bond angles?

˙ what is its electronic structure?

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Some physical techniques in determining structure

Fingerprint

Group present

Molecular symmetry

Bond lengths and angles

Electronicstructure

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excited state

electronic transition

vibrational transition rotational transition

ground state

E = Eelectronic + Evibration + Erotation + Etranslation

population distribution

Nupper ——— = exp(-E/kT) k =1.381 10-23 J/K Nlower

radiation E = h = hc/

unit 1 nm = 10-9 m 1 cm-1 = 11.98 J/mol = 2.86 cal/mol 1 eV = 96500 J/mol = 23060 cal/mol

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spectrum of electromagnetic radiation

timescales associated with some spectroscopic techniques

Energy of excited state Typical relaxation Typical

Technique (Hz) time (seconds) linewidth (Hz)

NMR (solution) 108 10 10-1

ESR (solution) 1010 10-5 105

rotationalspectroscopy (gas) 1011 10-4 104

vibrationalspectroscopy (gas) 1014 10-8 108

electronic spectroscopy (solution) 1016 10-15 1015

Mössbauerspectroscopy (solid) 1019 10-8 108

Nuclear energies Chemical energies Molecular energies Spin energies XRF Electronic∣ ∣ ∣ Rotational ∣Mössbauer XPS UPS Vibrational ∣ ∣ ESR NMR NQR GED XRD

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glossary of spectroscopic and structural techniques

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Symmetry – group theorysymmetry operation

identity E

inversion i

reflection rotation C

rotation and reflection S

point group

character table

ex. What is the point group for [PtCl4]2-?

Cl

Cl –– Pt –– Cl

Cl

symmetry element: E, C4, C2, i, h, v, d, S4

point group: D4h

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character table of D4h