TY  - JOUR
A1  - Ji, Lei
A1  - Griesbeck, Stefanie
A1  - Marder, Todd B.
T1  - Recent developments in and perspectives on three-coordinate boron materials: a bright future
JF  - Chemical Science
N2  - The empty p\(_z\)-orbital of a three-coordinate organoboron compound leads to its electron-deficient properties, which make it an excellent π-acceptor in conjugated organic chromophores. The empty p-orbital in such Lewis acids can be attacked by nucleophiles, so bulky groups are often employed to provide air-stable materials. However, many of these can still bind fluoride and cyanide anions leading to applications as anion-selective sensors. One electron reduction generates radical anions. The π-acceptor strength can be easily tuned by varying the organic substituents. Many of these compounds show strong two-photon absorption (TPA) and two-photon excited fluorescence (TPEF) behaviour, which can be applied for e.g. biological imaging. Furthermore, these chromophores can be used as emitters and electron transporters in OLEDs, and examples have recently been found to exhibit efficient thermally activated delayed fluorescence (TADF). The three-coordinate organoboron unit can also be incorporated into polycyclic aromatic hydrocarbons. Such boron-doped compounds exhibit very interesting properties, distinct from their all-carbon analogues. Significant developments have been made in all of these areas in recent years and new applications are rapidly emerging for this class of boron compounds.
KW  - anorganic chemistry
KW  - boron
KW  - 3-coordinate boron
KW  - Lewis acids
KW  - OLED
KW  - polycyclic aromatic hydrocarbons
KW  - chromophore
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-171912
VL  - 8
IS  - 2
ER  - 
TY  - JOUR
A1  - Ramler, Jacqueline
A1  - Lichtenberg, Crispin
T1  - Molecular Bismuth Cations: Assessment of Soft Lewis Acidity
JF  - Chemistry – A European Journal
N2  - Three‐coordinate cationic bismuth compounds [Bi(diaryl)(EPMe\(_{3}\))][SbF\(_{6}\)] have been isolated and fully characterized (diaryl=[(C\(_{6}\)H\(_{4}\))\(_{2}\)C\(_{2}\)H\(_{1}\)]\(^{2-}\), E=S, Se). They represent rare examples of molecular complexes with Bi⋅⋅⋅EPR\(_{3}\) interactions (R=monoanionic substituent). The \(^{31}\)P NMR chemical shift of EPMe3 has been found to be sensitive to the formation of LA⋅⋅⋅EPMe\(_{3}\) Lewis acid/base interactions (LA=Lewis acid). This corresponds to a modification of the Gutmann–Beckett method and reveals information about the hardness/softness of the Lewis acid under investigation. A series of organobismuth compounds, bismuth halides, and cationic bismuth species have been investigated with this approach and compared to traditional group 13 and cationic group 14 Lewis acids. Especially cationic bismuth species have been shown to be potent soft Lewis acids that may prefer Lewis pair formation with a soft (S/Se‐based) rather than a hard (O/N‐based) donor. Analytical techniques applied in this work include (heteronuclear) NMR spectroscopy, single‐crystal X‐ray diffraction analysis, and DFT calculations.
KW  - bismuth
KW  - bonding analysis
KW  - cationic species
KW  - HSAB principle
KW  - Lewis acids
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-225808
VL  - 26
IS  - 45
SP  - 10250
EP  - 10258
ER  - 
TY  - JOUR
A1  - Su, Wei
A1  - Rajeshkumar, Thayalan
A1  - Xiang, Libo
A1  - Maron, Laurent
A1  - Ye, Qing
T1  - Facile Synthesis of Uranium Complexes with a Pendant Borane Lewis Acid and 1,2‐Insertion of CO into a U−N Bond
JF  - Angewandte Chemie International Edition
N2  - In this contribution, we illustrate uranium complexes bearing a pendant borate (i.e. 1 and 2) or a pendant borane (i.e. 3 and 4) moiety via reaction of the highly strained uranacycle I with various 3‐coordinate boranes. Complexes 3 and 4 represent the first examples of uranium complexes with a pendant borane Lewis acid. Moreover, complex 3 was capable of activation of CO, delivering a new CO activation mode, and an abnormal CO 1,2‐insertion pathway into a U−N bond. The importance of the pendant borane moiety was confirmed by the controlled experiments.
KW  - Boranes
KW  - Boron
KW  - Carbon Monoxide
KW  - Lewis acids
KW  - Uranium
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-312197
VL  - 61
IS  - 51
ER  -