Synthesis, Characterization and Reactivity of Diradicaloid 9,10-Bismanthrene Derivatives and Related Mixed Bi/Pn (Pn = P, As, or Sb) Species
Final Report Abstract
Efforts to synthesize stable bismanthrene derivatives are discussed, which is expected to show diradicaloid properties. Different synthetic approaches towards bulky terphenylene ligands able to kinetically stabilize the low-valent Bi centers against di- or oligomerization were unsuccessful. Using a model system with reduced steric bulk, 9,10-dihalo-9,10-dihydrobismanthrenes (Cl, Br, I) were prepared and their behavior towards reducing agents was investigated. The synthetic route involved tris(2-halophenyl)bismuthanes and 9,10-dibismatriptycenes. The latter were subject to comproportionation utilizing bismuth(III) halides BiX3 (X = Cl, Br, I). Reduction reactions of the resulting dinuclear bismuth halides led to the formation of insoluble products, potentially dimeric in nature. Also, the reduction in the presence of unsaturated substrates was unsuccessful. Salt elimination and cationization reactions were also explored, resulting in the formation of heterometallic (Bi/Se or Bi/Fe) compounds and dicationic salts. Besides the aforementioned 9,10-dibismatriptycenes, mixed 9,10-bismapnictatriptycenes (P, As, Sb) were also prepared from the respective tris(2-bromophenyl)pnictanes Pn(C6H4Br)3 (Pn = P, As, Sb) by trilithiation and treatment with BiCl3. Additionally, the combination of bismuth with redox-active ligands was investigated, demonstrating the competition between the ligands and halide atoms for coordination sites on the bismuth atom.
Publications
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Aminotroponiminates: Impact of the NO2 Functional Group on Coordination, Isomerisation, and Backbone Substitution. Chemistry – A European Journal, 27(57), 14250-14262.
Hanft, Anna; Rottschäfer, Dennis; Wieprecht, Nele; Geist, Felix; Radacki, Krzysztof & Lichtenberg, Crispin
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Sulfinyl-aminotroponiminates: alkali- (Li, Na, K) and heavy-metal (Bi) complexes. Dalton Transactions, 51(28), 10809-10817.
Hanft, Anna; Rottschäfer, Dennis; Müller, Victoria; Weinberger, Pascal; Radacki, Krzysztof; Xie, Xiulan & Lichtenberg, Crispin
