Université de Fribourg

One-pot synthesis and AFM imaging of a triangular aramide macrocycle

Storz, Christof ; Badoux, Michael ; Hauke, Christopher M. ; Šolomek, Tomáš ; Kühnle, Angelika ; Bally, Thomas ; Kilbinger, Andreas F. M.

In: Journal of the American Chemical Society, 2014, vol. 136, no. 37, p. 12832–12835

Macrocyclizations in exceptionally good yields were observed during the self-condensation of N-benzylated phenyl p-aminobenzoates in the presence of LiHMDS to yield three-membered cyclic aramides that adopt a triangular shape. An ortho-alkyloxy side chain on the N-benzyl protecting group is necessary for the macrocyclization to occur. Linear polymers are formed exclusively in the absence of this...

Université de Fribourg

The Primary steps in excited-state hydrogen transfer: the phototautomerization of o-nitrobenzyl derivatives

Šolomek, Tomáš ; Bochet, Christian G. ; Bally, Thomas

In: Chemistry – A European Journal, 2014, vol. 20, no. 26, p. 8062–8067

The quantum yield for the release of leaving groups from o-nitrobenzyl “caged” compounds varies greatly with the nature of these leaving groups, for reasons that have never been well understood. We found that the barriers for the primary hydrogen-atom transfer step and the efficient nonradiative processes on the excited singlet and triplet surfaces determine the quantum yields. The...

Université de Fribourg

Photolysis of ortho-nitrobenzylic derivatives: the importance of the leaving group

Šolomek, Tomáš ; Mercier, Sébastien ; Bally, Thomas ; Bochet, Christian G.

In: Photochemical & Photobiological Sciences, 2012, vol. 11, no. 3, p. 548-555

Quantum yields for the photoinduced release of seven different commonly used leaving groups (LGs) from the o-nitroveratryl protecting group were measured. It was found that these quantum yields depend strongly on the nature of the LGs. We show that the quantum efficiency with which the LGs are released correlates with the stabilization that these LGs provide to o-nitrobenzyl-type radicals because...