Marco Flock

University of Wuerzburg | JMU · Institute of Physical and Theoretical Chemistry

We investigated the excited-state dynamics of 4-(dimethylamino)benzethyne (4-DMABE) in a combined theoretical and experimental study using surface-hopping simulations and time-resolved ionisation experiments. The simulations predict a decay of the initially excited S2 state into the S1 state in only a few femtoseconds, inducing a subsequent partial...

The understanding of excimer formation and its interplay with the singlet-correlated triplet pair state¹(TT) is of high significance for the development of efficient organic electronics. Here, we study the photoinduced dynamics of the tetracene dimer in the gas phase by time-resolved photoionisation and photoion imaging experiments as well as nonad...

Das erste Ziel der vorliegenden Dissertation bestand darin, ein bereits bestehendes TOF-MS-Setup dahingehend zu erweitern, um damit Velocity Map Imaging-Experimente durchführen zu können. Dies erforderte zunächst die Konzipierung und Programmierung einiger für die Datenaufnahme, -verarbeitung und -analyse benötigter LabView-Anwendungen. Anschließen...

The three isomers of the xylyl radical, C8H9 are possible intermediates in the formation of soot and polycyclic aromatic hydrocarbons (PAH). Their infrared spectra have been recorded by IR/UV ion dip spectroscopy using free electron laser radiation. The radicals were generated by flash pyrolysis from the corresponding nitrites and resonantly ionize...

Tolane (diphenylacetylene, C14H10) was studied by picosecond time-resolved photoionisation and photoelectron imaging in a supersonic jet. The low-energy part of the 1B1u <- S0 REMPI spectrum is very similar to an earlier LIF spectrum, however additional bands were observed at higher energies above the fluorescence cut-off. For a number of bands the...

The ultrafast photophysics and photochemistry of benzocyclobutenedione (BCBD) dissolved in dichloromethane is investigated by transient absorption spectroscopy in both the IR and the UV/Vis regime. The molecule is excited at 300 nm to the S3 (ππ*) state and a time scale from roughly 100 fs to several nanoseconds is covered. The initially excited S3...

We report a picosecond time-resolved photoionization and photoelectron spectroscopic study of acenaphthylene, C12H8 in a free jet. The origin for the A ¹B2 (S1) ← X ¹A1 (S0) transition is found at 21,757 ± 15 cm⁻¹, while the one for the B ²A1 ← X ¹A1 transition is observed at 30,076 ± 27 cm⁻¹. For both transitions vibrational bands are resolved and...

The reactivity of N-heterocyclic carbenes (NHCs) and cyclic alkyl amino carbenes (cAACs) with arylboronate esters is reported. The reaction with NHCs leads to the reversible formation of thermally stable Lewis acid/base adducts Ar-B(OR)2 ⋅NHC (Add1-Add6). Addition of cAAC(Me) to the catecholboronate esters 4-R-C6 H4 -Bcat (R=Me, OMe) also afforded...

Es wird die Reaktivität N-heterocyclischer Carbene (NHCs) und cyclischer Alkylaminocarbene (cAACs) gegenüber Arylboronsäureestern vorgestellt. Die Reaktionen mit NHCs führen zur reversiblen Bildung thermisch stabiler Lewis-Säure-Base-Addukte Ar-B(OR)2⋅NHC (Add1–Add6). Die Umsetzungen von cAACMe mit den Catecholboronsäureestern 4-R-C6H4Bcat (R=Me, O...

In this paper we describe an investigation of the excited-state dynamics of isolated 1,3-di-tert-butyl-imidazoline-2-ylidene (tBu2Im, C11H20N2, m/z=180), an Arduengo-type carbene, by time- and frequency-resolved photoionization using a picosecond laser system. The energies of several singlet and triplet excited states were calculated by time-depend...