@phdthesis{Hanft2023, author = {Hanft, Anna}, title = {Aminotroponiminate: Koordinationschemie, Reaktivit{\"a}t und Redoxverhalten von Alkalimetall-, Silber-, und Bismut-Komplexen}, doi = {10.25972/OPUS-23204}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-232049}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {Die Koordinationschemie, die Reaktivit{\"a}t und das Redoxverhalten von Alkalimetall-, Silber- und Bismut-Aminotroponiminat(ATI)-Komplexen wurde untersucht}, subject = {Reaktivit{\"a}t}, language = {de} } @article{HanftLichtenberg2020, author = {Hanft, Anna and Lichtenberg, Crispin}, title = {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}, series = {Zeitschrift f{\"u}r Kristallographie - New Crystal Structures}, volume = {235}, journal = {Zeitschrift f{\"u}r Kristallographie - New Crystal Structures}, number = {4}, doi = {10.1515/ncrs-2020-0124}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-229482}, pages = {963-966}, year = {2020}, abstract = {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.}, language = {en} } @article{HanftRadackiLichtenberg2021, author = {Hanft, Anna and Radacki, Krzysztof and Lichtenberg, Crispin}, title = {Cationic Bismuth Aminotroponiminates: Charge Controls Redox Properties}, series = {Chemistry - A European Journal}, volume = {27}, journal = {Chemistry - A European Journal}, number = {20}, doi = {10.1002/chem.202005186}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-225669}, pages = {6230 -- 6239}, year = {2021}, abstract = {The behavior of the redox-active aminotroponiminate (ATI) ligand in the coordination sphere of bismuth has been investigated in neutral and cationic compounds, [Bi(ATI)\(_{3}\)] and [Bi(ATI)\(_{2}\)L\(_{n}\)][A] (L=neutral ligand; n=0, 1; A=counteranion). Their coordination chemistry in solution and in the solid state has been analyzed through (variable-temperature) NMR spectroscopy, line-shape analysis, and single-crystal X-ray diffraction analyses, and their Lewis acidity has been evaluated by using the Gutmann-Beckett method (and modifications thereof). Cyclic voltammetry, in combination with DFT calculations, indicates that switching between ligand- and metal-centered redox events is possible by altering the charge of the compounds from 0 in neutral species to +1 in cationic compounds. This adds important facets to the rich redox chemistry of ATIs and to the redox chemistry of bismuth compounds, which is, so far, largely unexplored.}, language = {en} } @article{OberdorfHanftRamleretal.2021, author = {Oberdorf, Kai and Hanft, Anna and Ramler, Jacqueline and Krummenacher, Ivo and Bickelhaupt, Matthias and Poater, Jordi and Lichtenberg, Crispin}, title = {Bismuth Amides Mediate Facile and Highly Selective Pn-Pn Radical-Coupling Reactions (Pn=N, P, As)}, series = {Angewandte Chemie, International Edition}, volume = {60}, journal = {Angewandte Chemie, International Edition}, number = {12}, doi = {10.1002/anie.202015514}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-236582}, pages = {6441-6445}, year = {2021}, abstract = {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.}, language = {en} } @article{RamlerFantuzziGeistetal.2021, author = {Ramler, Jaqueline and Fantuzzi, Felipe and Geist, Felix and Hanft, Anna and Braunschweig, Holger and Engels, Bernd and Lichtenberg, Crispin}, title = {The dimethylbismuth cation: entry into dative Bi-Bi bonding and unconventional methyl exchange}, series = {Angewandte Chemie International Edition}, volume = {60}, journal = {Angewandte Chemie International Edition}, doi = {10.1002/anie.202109545}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-256543}, pages = {24388-24394}, year = {2021}, abstract = {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.}, language = {en} } @article{HanftRottschaeferWieprechtetal.2021, author = {Hanft, Anna and Rottsch{\"a}fer, Dennis and Wieprecht, Nele and Geist, Felix and Radacki, Krzysztof and Lichtenberg, Crispin}, title = {Aminotroponiminates: Impact of the NO\(_{2}\) Functional Group on Coordination, Isomerisation, and Backbone Substitution}, series = {Chemistry—A European Journal}, volume = {27}, journal = {Chemistry—A European Journal}, number = {57}, doi = {10.1002/chem.202102324}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-256988}, pages = {14250-14262}, year = {2021}, abstract = {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.}, language = {en} }