A new approach towards highly enantioselective halogen-bonding catalysis has been developed. To circumvent the intrinsic issues of the nature of the halogen-bond (XB) and the resultant unresolved limitations in asymmetric catalysis, fine-tuned halogen-halogen interactions between the substrate and XB-donor were designed to preorganize the substrate in the catalyst's cavity and boost enantiocontrol. The present strategy exploits both the electron cloud (Lewis base site) and the sigma (σ)-hole site of the halogen substituent of the substrates to form a tight catalyst-substrate-counteranion chiral complex, thus enabling a controlled induction of high levels of chirality transfer. Remarkable enantioselectivities of up to 95 : 5 e.r. (90 % ee) have been achieved in a model dearomatization reaction of halogen-substituted (iso)quinolines with tetrakis-iodotriazole multidentate anion-binding catalysts.
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http://dx.doi.org/10.1002/anie.202304781 | DOI Listing |
Inorg Chem
January 2025
School of Chemistry and Chemical Engineering, Nanchang University, Nanchang 330031, P. R. China.
Organic-inorganic hybrid lead halides have been extensively studied due to their outstanding physical properties and diverse compositional elements. However, environmentally benign tin-based hybrids with remarkable flexibility in bandgap engineering have been less investigated. Herein, we report the successful design and synthesis of three tin-based organic-inorganic hybrid compounds through precise molecular modification: [Me(i-Pr)N][SnBr] (), [MeCHCl(i-Pr)N][SnBr] (), and [MeCHBr(i-Pr-Br)N][SnBr] ().
View Article and Find Full Text PDFNano Lett
January 2025
State Key Laboratory of Solidification Processing, Center for Nano Energy Materials, School of Materials Science and Engineering, Northwestern Polytechnical University and Shaanxi Joint Laboratory of Graphene (NPU), Xi'an 710072, P. R. China.
Dion-Jacobson (DJ) perovskites are promising alternatives for Ruddlesden-Popper (RP) perovskites to fabricate blue perovskite light-emitting diodes (PeLEDs) due to their favorable structural and charge properties. However, the relatively weak hydrogen bond between the bridging diammonium group and perovskite poses huge challenges for regulating crystallization and defect density, leading to an undesirable film quality and device performance. Herein, we report the successful optimization of DJ perovskite films by introducing a new type of cesium octafluoroadipate (CsOFAA) precursor, which could strongly anchor the perovskite through coordination bonds and halogen-halogen bonds.
View Article and Find Full Text PDFJ Comput Chem
January 2025
Institute of Chemistry, Saint Petersburg State University, St. Petersburg, Russia.
In the framework of SMD approach a systematic computational study of structural, electronic and thermodynamic properties of molecular complexes of Cl, ICl and I with series of N-containing Lewis bases in solvents of different polarity was carried out. Results indicate that molecular complexes of Cl with strong and medium-strong LB undergo spontaneous ionization in the acetonitrile solution. The increase of the solvent polarity can change the nature of interaction in X'XLB systems from molecular X'X ← LB donor-acceptor complexes to 3-center 4-electron bound X'→X ← LB in solvents of medium polarity and to the contact ion pairs X'→[XLB] in polar solvents.
View Article and Find Full Text PDFACS Appl Mater Interfaces
November 2024
Department of Chemistry, UGC Sponsored-Centre of Advance Studies-II, Guru Nanak Dev University, Amritsar-143005, Punjab, India.
Photosensitizing assemblies based on twisted intramolecular charge transfer (TICT) active donor-acceptor-donor (D-A-D) system having bromine atoms at the periphery have been developed. Through strategic incorporation of bromine atoms at the -position to the nitrogen-carbon bonds of phenyl rings at the periphery, halogen-halogen interactions are induced in nanoassemblies in HO:DMSO (99:1) solution. Hence, the anti-heavy atom effect is induced, and the limitations of TICT (dark excited state) and heavy atom effect (triplet deactivation via radiative decay) could be overcome.
View Article and Find Full Text PDFRSC Adv
June 2024
Chemistry Department, Kuwait University P.O. Box 5969, Safat 13060 Kuwait +965-2481-6482 +965-2498-5631.
Halogen-halogen interactions play a pivotal role in the formation and stability of supramolecular assemblies. Herein, we investigate the assembly dynamics and dissociation pathways of linear supramolecular polymers based on pillar[5]arene-mediated by guest halogen-halogen interactions (C-X × X-C) in both the solution and solid states. The structure of the solid-state supramolecular assembly was determined by single-crystal X-ray diffraction analysis.
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