Positively charged heteroboranes
Provider: Ministerstvo školství, mládeže a tělovýchovy
Programme: ERC_CZ
Implementation period: 01.09.23 - 31.08.25
Workplace:
Fakulta chemicko-technologická - Katedra obecné a anorganické chemie
Investigator: Vrána Jan
Description:
The chemistry of boranes and heteroboranes has become a self-consistent field of chemistry with tens of thousands of compounds published up to date and numerous applications including materials, medicinal as well as organometallic chemistry. Despite their electron deficiency, these clusters are extremely stable in both neutral and anionic forms. Nevertheless, thermally robust cationic boranes remained elusive for a long time. Recently, our group has reported the first synthesis of such species using N-heterocyclic carbenes as powerful electron donors. The cationic heteroboranes are surprisingly air-stable and can be easily prepared in a multigram scale. The main focus of this project is to prepare a wide range of cationic clusters with different backbones as well as stabilising moieties. The subsequent investigation of the chemical properties of the compounds prepared will be of high interest because there is no comparison in the literature yet. Even redox chemistry could bring exciting results, because formal one-electron reduction should lead to neutral radicals. Higher Lewis acidity in comparison with neutral species will show a different reaction pattern in the reactions with bases and acids as well. There are a plethora of other reactions that should be investigated to understand the nature of this novel class of compounds, e.g. methylation, halogenation, reaction with small molecules and others. Another great challenge is posed by the synthesis of a dicationic heteroborane, which would exhibit even more interesting properties. The above-mentioned stability combined with the possibility of releasing and again accepting the proton indicates plausible use in catalytic transformation. Moreover, the cationic species has shown reasonable solubility and stability in water, which encourages us to test these compounds for interactions with biomolecules, for which heteroboranes have been extensively investigated in the last years.
The chemistry of boranes and heteroboranes has become a self-consistent field of chemistry with tens of thousands of compounds published up to date and numerous applications including materials, medicinal as well as organometallic chemistry. Despite their electron deficiency, these clusters are extremely stable in both neutral and anionic forms. Nevertheless, thermally robust cationic boranes remained elusive for a long time. Recently, our group has reported the first synthesis of such species using N-heterocyclic carbenes as powerful electron donors. The cationic heteroboranes are surprisingly air-stable and can be easily prepared in a multigram scale. The main focus of this project is to prepare a wide range of cationic clusters with different backbones as well as stabilising moieties. The subsequent investigation of the chemical properties of the compounds prepared will be of high interest because there is no comparison in the literature yet. Even redox chemistry could bring exciting results, because formal one-electron reduction should lead to neutral radicals. Higher Lewis acidity in comparison with neutral species will show a different reaction pattern in the reactions with bases and acids as well. There are a plethora of other reactions that should be investigated to understand the nature of this novel class of compounds, e.g. methylation, halogenation, reaction with small molecules and others. Another great challenge is posed by the synthesis of a dicationic heteroborane, which would exhibit even more interesting properties. The above-mentioned stability combined with the possibility of releasing and again accepting the proton indicates plausible use in catalytic transformation. Moreover, the cationic species has shown reasonable solubility and stability in water, which encourages us to test these compounds for interactions with biomolecules, for which heteroboranes have been extensively investigated in the last years.
