TY  - JOUR
A1  - Ramler, Jacqueline
A1  - Schwarzmann, Johannes
A1  - Stoy, Andreas
A1  - Lichtenberg, Crispin
T1  - Two Faces of the Bi−O Bond: Photochemically and Thermally Induced Dehydrocoupling for Si−O Bond Formation
JF  - European Journal of Inorganic Chemistry
N2  - The diorgano(bismuth)alcoholate [Bi((C\(_{6}\)H\(_{4}\)CH\(_{2}\))\(_{2}\)S)OPh] (1-OPh) has been synthesized and fully characterized. Stoichiometric reactions, UV/Vis spectroscopy, and (TD-)DFT calculations suggest its susceptibility to homolytic and heterolytic Bi−O bond cleavage under given reaction conditions. Using the dehydrocoupling of silanes with either TEMPO or phenol as model reactions, the catalytic competency of 1-OPh has been investigated (TEMPO=(tetramethyl-piperidin-1-yl)-oxyl). Different reaction pathways can deliberately be addressed by applying photochemical or thermal reaction conditions and by choosing radical or closed-shell substrates (TEMPO vs. phenol). Applied analytical techniques include NMR, UV/Vis, and EPR spectroscopy, mass spectrometry, single-crystal X-ray diffraction analysis, and (TD)-DFT calculations.
KW  - Bismuth
KW  - dehydrocoupling
KW  - radical reactions
KW  - chalcogens
KW  - catalysis
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-257428
VL  - 2022
IS  - 7
ER  - 
TY  - JOUR
A1  - Oberdorf, Kai
A1  - Hanft, Anna
A1  - Ramler, Jacqueline
A1  - Krummenacher, Ivo
A1  - Bickelhaupt, Matthias
A1  - Poater, Jordi
A1  - Lichtenberg, Crispin
T1  - Bismuth Amides Mediate Facile and Highly Selective Pn–Pn Radical‐Coupling Reactions (Pn=N, P, As)
JF  - Angewandte Chemie, International Edition
N2  - The controlled release of well‐defined radical species under mild conditions for subsequent use in selective reactions is an important and challenging task in synthetic chemistry. We show here that simple bismuth amide species [Bi(NAr\(_2\))\(_3\)] readily release aminyl radicals [NAr\(_2\)]. at ambient temperature in solution. These reactions yield the corresponding hydrazines, Ar\(_2\)N−NAr\(_2\), as a result of highly selective N−N coupling. The exploitation of facile homolytic Bi−Pn bond cleavage for Pn−Pn bond formation was extended to higher homologues of the pnictogens (Pn=N–As): homoleptic bismuth amides mediate the highly selective dehydrocoupling of HPnR\(_2\) to give R\(_2\)Pn−PnR\(_2\). Analyses by NMR and EPR spectroscopy, single‐crystal X‐ray diffraction, and DFT calculations reveal low Bi−N homolytic bond‐dissociation energies, suggest radical coupling in the coordination sphere of bismuth, and reveal electronic and steric parameters as effective tools to control these reactions.
KW  - bismuth amides
KW  - radical species
KW  - pnictogen coupling
KW  - aminyl radicals
KW  - diphosphanes
KW  - heavier pnictogens
KW  - radical coupling
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-236582
VL  - 60
IS  - 12
ER  -