TY - THES A1 - Hanft, Anna T1 - Aminotroponiminate: Koordinationschemie, Reaktivität und Redoxverhalten von Alkalimetall-, Silber-, und Bismut-Komplexen T1 - Aminotroponiminates: Coordination Chemistry, Reactivity and Redox Behaviour of Alkali Metal, Silver and Bismut Complexes N2 - Die Koordinationschemie, die Reaktivität und das Redoxverhalten von Alkalimetall-, Silber- und Bismut-Aminotroponiminat(ATI)-Komplexen wurde untersucht N2 - The coordination chemistry, the reactivity and the redox behaviour of alkali metal, silver and bismut aminotroponiminate (ATI) complexes has been investigated KW - Reaktivität KW - Alkalimetall KW - Silber KW - Bismut KW - Komplexe KW - Aminotroponiminate KW - Redoxverhalten KW - Koordinationschemie KW - Koordinationslehre Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-232049 N1 - Teile der Arbeit wurden veröffentlicht in: WILEY-VCH Verlag GmbH & Co. KGaA; The Royal Society of Chemistry; American Chemical Society; Zeitschrift für Kristallographie - New Crystal Structures 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 - 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 - TY - JOUR A1 - Hanft, Anna A1 - Lichtenberg, Crispin T1 - Dimerization of 2-[(2-((2-aminophenyl)thio)phenyl)amino]-cyclohepta-2,4,6-trien-1-one through hydrogen bonding, C\(_{19}\)H\(_{16}\)N\(_2\)OS JF - Zeitschrift für Kristallographie - New Crystal Structures N2 - C\(_{19}\)H\(_{16}\)N\(_2\)OS, triclinic, P (1) over bar (no. 2), a= 8.1510(3) angstrom, b = 8.8021(3) angstrom, c =11.3953(5) angstrom, alpha =72.546(2)degrees, beta=84.568(2)degrees, gamma =80.760(2)degrees, V =768.86(5) angstrom(3), Z =2, R\(_{gt}\)(F) = 0.0491, WR\(_{ref}\)(F-2) = 0.1494, T =100 K. KW - crystal structure KW - complexes KW - ligands KW - tropocoronands KW - mononuclear KW - chemistry Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-229482 VL - 235 IS - 4 ER - 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 -