otto dopfer @ institut für optik und atomare physik (tu berlin) … · 2011. 6. 4. · otto dopfer...
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Otto Dopfer @ Institut für Optik und Atomare Physik (TU Berlin)
IR & UV-vis spectroscopy (ns)photodissociationphotoionisationelectron detachment
cluster sources
electrospray
electron impact & dischargelaser desorption
tandem mass spectrometrymultipoles (quadrupole, octopole, 22-pole)ReTOFcomposition, stability & reactivity
quantum chemistryab initio (HF, MP2, CASPT2, ri-CC2, ...)density functional theory (DFT, TD-DFT)
Tools
R-r R-l L-r L-l
chiral molecule (R,L)& chiral solvent (r,l)
chiral recognition
electronic structure (excitation, ionisation)
binding energy, stability, reactivitygeometry & binding site
Questions
functional groups
potential energy surface double resonance (isomers)
isomers
solvation
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++ InteractionsIon−Ligand
chemical reactions ionosphere
Ions & Clusters
hydration & electrolytes
solvation
planetary atmospheres
molecular recognition
bio-sciences
mechanisms
adsorption & catalysis
interfaces
NH3........C O2+
NaCl + Na.(H2O)n.ClH2O
plasma & combustion
formation of soot
HCO+, H3O+, CnHm+, ...
polymers & colloids
supramolecular systems
C O2
+XY
ion−molecule reactions (SN2, SEAr, ...)
(H2O)nH+, (H2SO4)m(H2O)nH+
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++ InteractionsIon−Ligand
Tools for Potentialpotential energy surface
Quantum Chemistry
sensitivity & selectivity
Mass Spectrometry
structure & dynamics & reactivity
Spectroscopy
Bieske & Dopfer, Chem. Rev. 100 3963 (2000)
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A+
IR OPO
ion
A+...L A+ + Lhν
A+...L
QP
1
QP 2 octopole
hν
A+
λ=1500-4000 nm
EI ion source
UV OPOλ=220-2500 nm
hνUV
hνIR
photodissociation in QOQ tandem mass spectrometer
νUV
isomer
III
III
S0
S1
hνUV
F+
I II νUV
isomer
III
III
S0
S1
hνIR
F+
I
IR-UV und UV-IR double resonanceUVPD
νIR hνUV
F+
I II
hνUV fix hνIR fix
I II/ I II/
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active center in enzyme
Metal-Catalysis in Biology
Zn2+
H2O
L L L
Zn2+
OH-
L L L
H++
(L = Imidazol, Histidine, ...)
active center in enzyme Termolysin Carboxypeptidase A
pKA
Protonation and Deprotonation
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800 1000 1200
200
100
0
100
200
ν [cm-1]
I [k
m/m
ol]
DFT
n=2
n=3
800 1000 12003
2
1
0
1
2
ν [cm-1]
IRM
PD
[a.
u.]
experiment
n=2
n=3
n=2 n=3
βZn-O-H
Zn-O-H strongly cluster size dependent
Zn2+−OH−−(Im)n
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2.332.26
2.26 1.97
141°
Cp2Zr(OH)CH3CN
B3LYP/6-311G* (+ Stuttgart ECP)
Quantum Chemical Results
tetrahedral-like geometry
D0 = 417 kJ/mol (Zr-O)
D0 = 149 kJ/mol (Zr-N)
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0 500 1000 1500 2000
σZrO
βCH3
βCHσCC
γCH
γCH
βCH σCC
βZrOHγZrOH
βCH σCCβCH
x 10
ν / cm–12000 2500 3000 3500 4000
σOH
σOH
σCN
σCN
σCH
σCH
σCH
x 0.5
x 10
ν / cm–1
Quantum Chemical Results
OH-
CH3CN
Cp2Zr(OH)CH3CN
B3LYP/6-311G* (+ Stuttgart ECP)
Cp- C5H5-=
closed shell cationZr4+ (+1.62 e)OH- (-0.44 e)
C5H5- (-0.19 e)CH3CN (+0.20 e)
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0 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600
ν / cm–1
B3LYP/6–311G*
MP2/6–311G*
IRMPD (40 MeV)
σZrO
βZrOH γCH
βCH
γZrOH
IRMPD (28 MeV)
βCH
Comparison IRMPD vs calculated IR spectra
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600 800 1000 1200 1400 1600 1800
cm–1
TetraceneH+ IR Spectrum B3LYP/6-31G**(x 0.96, convolution 30 cm-1)
IRMPD H loss
TetH+ (Pos 1)
TetH+ (Pos 2)
TetH+ (Pos 3)
0 cm-1
4186 cm-1
5242 cm-1
Knorke, Langer, Oomens, Dopfer (FELIX 2008)
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CoroneneH+ IR Spectrum
600 800 1000 1200 1400 1600
cm–1
IRMPD
B3LYP/6-31G** x 0.965convolution 15 cm-1
(C24H12)H+
m = 301 u
H loss channel
Knorke, Langer, Oomens, Dopfer (FELIX 2008)Astrophys. J. Lett. (in press 2009)
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bisher keine Vorarbeiten zu chiralen Clustern
Sehr wenig (!) spektroskopische Daten zu chiralen Clustern in Literatur
Noch weniger Daten zu geladenen Systemen
Aber:
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Otto Dopfer @ Institut für Optik und Atomare Physik (TU Berlin)
IR & UV-vis spectroscopy (ns)photodissociationphotoionisationelectron detachment
cluster sources
electrospray
electron impact & dischargelaser desorption
tandem mass spectrometrymultipoles (quadrupole, octopole, 22-pole)ReTOFcomposition, stability & reactivity
quantum chemistryab initio (HF, MP2, CASPT2, ri-CC2, ...)density functional theory (DFT, TD-DFT)
Tools
R-r R-l L-r L-l
chiral molecule (R,L)& chiral solvent (r,l)
chiral recognition
electronic structure (excitation, ionisation)
binding energy, stability, reactivitygeometry & binding site
Questions
functional groups
potential energy surface double resonance (isomers)
isomers
solvation