TY  - JOUR
A1  - Ramler, Jaqueline
A1  - Fantuzzi, Felipe
A1  - Geist, Felix
A1  - Hanft, Anna
A1  - Braunschweig, Holger
A1  - Engels, Bernd
A1  - Lichtenberg, Crispin
T1  - The dimethylbismuth cation: entry into dative Bi-Bi bonding and unconventional methyl exchange
JF  - Angewandte Chemie International Edition
N2  - The dimethyl bismuth cation, [BiMe\(_2\)(SbF\(_6\))], has been isolated and characterized. Reaction with BiMe\(_3\) allows access to the first compound featuring Bi→Bi donor–acceptor bonding. In solution, dynamic behavior with methyl exchange via an unusual S\(_E\)2 mechanism is observed, underlining the unique properties of bismuth species as soft Lewis acids with the ability to undergo reversible Bi−C bond cleavage.
KW  - inorganic chemistry
KW  - methyl exchange
KW  - bismuth
KW  - cationic species
KW  - electrophilic substitution
KW  - Lewis acidity
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-256543
VL  - 60
ER  - 
TY  - JOUR
A1  - Hanft, Anna
A1  - Rottschäfer, Dennis
A1  - Wieprecht, Nele
A1  - Geist, Felix
A1  - Radacki, Krzysztof
A1  - Lichtenberg, Crispin
T1  - Aminotroponiminates: Impact of the NO\(_{2}\) Functional Group on Coordination, Isomerisation, and Backbone Substitution
JF  - Chemistry—A European Journal
N2  - Aminotroponiminate (ATI) ligands are a versatile class of redox-active and potentially cooperative ligands with a rich coordination chemistry that have consequently found a wide range of applications in synthesis and catalysis. While backbone substitution of these ligands has been investigated in some detail, the impact of electron-withdrawing groups on the coordination chemistry and reactivity of ATIs has been little investigated. We report here Li, Na, and K salts of an ATI ligand with a nitro-substituent in the backbone. It is demonstrated that the NO2 group actively contributes to the coordination chemistry of these complexes, effectively competing with the N,N-binding pocket as a coordination site. This results in an unprecedented E/Z isomerisation of an ATI imino group and culminates in the isolation of the first “naked” (i. e., without directional bonding to a metal atom) ATI anion. Reactions of sodium ATIs with silver(I) and tritylium salts gave the first N,N-coordinated silver ATI complexes and unprecedented backbone substitution reactions. Analytical techniques applied in this work include multinuclear (VT-)NMR spectroscopy, single-crystal X-ray diffraction analysis, and DFT calculations.
KW  - aminotroponiminates
KW  - non-coordinate anionic ligand
KW  - isomerisation
KW  - electrophilic substitution
KW  - alkali metal
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-256988
VL  - 27
IS  - 57
ER  -