TY  - JOUR
A1  - Knorr, Johannes
A1  - Sokkar, Pandian
A1  - Schott, Sebastian
A1  - Costa, Paolo
A1  - Thiel, Walter
A1  - Sander, Wolfram
A1  - Sanchez-Garcia, Elsa
A1  - Nuernberger, Patrick
T1  - Competitive solvent-molecule interactions govern primary processes of diphenylcarbene in solvent mixtures
JF  - Nature Communications
N2  - Photochemical reactions in solution often proceed via competing reaction pathways
comprising intermediates that capture a solvent molecule. A disclosure of the underlying
reaction mechanisms is challenging due to the rapid nature of these processes and the
intricate identification of how many solvent molecules are involved. Here combining
broadband femtosecond transient absorption and quantum mechanics/molecular mechanics
simulations, we show for one of the most reactive species, diphenylcarbene, that the
decision-maker is not the nearest solvent molecule but its neighbour. The hydrogen bonding
dynamics determine which reaction channels are accessible in binary solvent mixtures at
room temperature. In-depth analysis of the amount of nascent intermediates corroborates
the importance of a hydrogen-bonded complex with a protic solvent molecule, in striking
analogy to complexes found at cryogenic temperatures. Our results show that adjacent
solvent molecules take the role of key abettors rather than bystanders for the fate of the
reactive intermediate.
KW  - Reaction kinetics and dynamics
KW  - Photochemistry
Y1  - 2016
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-165954
VL  - 7
ER  - 
TY  - JOUR
A1  - Kim, E.
A1  - Christl, Manfred
A1  - Kochl, J. K.
T1  - Charge-Transfer Cycloaddition of Homobenzvalene with Tetracyanoethylene
N2  - The transient yellow color observed in the cycloaddition of homobenzvalene (HB) with tetracyanoethylene (TCNE) is associated with the charge-transfer complex [HB, TCNE). The deliberate photoexcitation of [HB,TCNE) affords a mixture of charge-transfer cycloadducts (1, 2, and 3) that differs from that obtained in thermal cycloaddition. The relationship of {HB t TCNE•) radical-ion pair (as the critical reactive intermediate in charge-transfer cycloaddition) to the activation process for thermal cycloaddition is discussed.
KW  - Organische Chemie
KW  - Electron transfer
KW  - photochemical
KW  - Radical-ion pair
KW  - Photochemistry
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58537
ER  -