Cover
Circular Dichroism in the Photoelectron Angular Distribution
of 2-amino-1-propanol in gas phase
Daniele Catone
Istituto di Struttura della Materia CNR, Area della Ricerca di Roma , Italy
Transizione
The Chirality
"I call any geometrical figure, or group of points, chiral, and
say it has chirality, if its image in a plane mirror, ideally
realized, cannot be brought to coincide with itself."
Lord Kelvin, 1904
Enantiomers
9Mirror Image
Molecules
9Identical ChemicalPhysics Properties
SS-Penicillamine
-Penicillamine
Antiarthritic
Antiarthriticdrug
drug
RR-Penicillamine
-Penicillamine
Toxic
Toxicdrug
drug
The Asymmetric Probe
Enantiomeric System
Asymmetric Probe
Circularly
Polarized
Light
Spectroscopy
Angle
Resolved
PhotoElectron
Spectroscopy
ARPES:
9Valence band Spectra
9Circular Dichroism
The Circular Dichroism
Photoelectron Current in Angular Distribution
mr
⎡
⎤
σ (ω )
⎛ 1⎞
I (θ ) =
⎢1 + ⎜ − ⎟ β (ω )P2 (cos θ ) + mr D(ω )P1 (cos θ )⎥
4π ⎢⎣ ⎝ 2 ⎠
⎥⎦
B. Ritchie, Phys.l Rev. A 1976, 13, 1411
The Circular Dichroism
Photoelectron Current in Angular Distribution
⎤
σ (ω ) ⎡ β (ω ) ⎛ 3 2
1⎞
I (θ ) =
1−
⎜ cos θ − ⎟ + mr D(ω ) cos θ ⎥
⎢
4π ⎣
2 ⎝2
2⎠
⎦
Magic Angle → θm=54.7°
ACDAD
I + (θ m ) − I − (θ m )
= +
I (θ m ) + I − (θ m )
D = 3 ACDAD
B. Ritchie, Phys.l Rev. A 1976, 13, 1411
ARPES Experimental Apparatus
Angle Resolved PhotonElectron Spectroscopy
PES Spectrum and Dichroism
2-Amino-1-Propanol
R(-)- and S(+)-2-amino-1-propanol
Dynamics in Circular Dichroism
2-Amino-1-Propanol
Conclusions
9The CD in PES on randomly oriented chiral molecules gives the
opportunity to have a fingerprint of the interplay between
asymmetry and electronic structure.
9The CD effect in photoelectron spectroscopy is very sensitive to the
electronic structure of the system as demonstrated by the various
shapes showed by D parameters for the different orbitals investigated.
9The photoemission dichroism appears to be sensitive also to
conformational structures. It can be used probably as a probe for
studying the conformations of chiral systems in gas phase.
9The CD should be a good probe for the determination of the
absolute conformation of chiral systems.
Groups and People
Institute of Structure of Matter
(ISM – CNR Rome):
9T. Prosperi
9N. Zema
9S. Turchini
9G. Contini
9D. Catone
9S. Irrera
9S.Sanna
9M.Brolatti
Cover
Circular Dichroism in the Photoelectron Angular Distribution
of 2-amino-1-propanol
Daniele Catone
Istituto di Struttura della Materia CNR, Area della Ricerca di Roma , Italy
σ, β and D – Conformational Sensibility
3-Hydroxytetrahydrofuran - HOMO
A0 →
B2 →
LCAO B-Spline DFT Method
Configurational Discrimination
3-Hydroxytetrahydrofuran
A0 →
B2 →
LCAO B-Spline DFT Method
Studied Systems
H3C
H
O
H
O
H
H
Methyl-Oxirane
[Propylene Oxide]
H
H
HO
H
H
H
H
3-Hydroxytetrahydrofuran
PES Spectrum
Methyl-Oxirane
Circular Dichroism at 22 eV
Methyl-Oxirane
S. Turchini, N. Zema, G. Contini, G. Alberti,
M. Alagia, S. Stranges, G. Fronzoni, M. Stener,
P. Decleva, and T. Prosperi,
Phys. Rev. A, 2004, 70, 14502.
LCAO B-Spline DFT Method
Dynamics in Circular Dichroism
Methyl-Oxirane
PES Spectrum
3-Hydroxytetrahydrofuran
MP2/6-31G* Level of Theory.
Dynamics in Circular Dichroism
3-Hydroxytetrahydrofuran
hν=14 eV
hν=16 eV
hν=19 eV
hν=22 eV
A. Giardini, D. Catone, S. Stranges, M.
Satta, M. Tacconi, S. Piccirillo, S. Turchini, N.
Zema, G. Contini, T. Prosperi, P. Decleva, D.
Ditommaso, G. Fronzoni, M. Stener, A.
Filippi, and M. Speranza. To be published
Chem. Phys. Chem., 2005.