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

++ 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+

++ InteractionsIon−Ligand

Tools for Potentialpotential energy surface

Quantum Chemistry

sensitivity & selectivity

Mass Spectrometry

structure & dynamics & reactivity

Spectroscopy

Bieske & Dopfer, Chem. Rev. 100 3963 (2000)

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/

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

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

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)

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)

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

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)

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)

bisher keine Vorarbeiten zu chiralen Clustern

Sehr wenig (!) spektroskopische Daten zu chiralen Clustern in Literatur

Noch weniger Daten zu geladenen Systemen

Aber:

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