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Aiming at intramolecular frustrated Lewis pairs (FLPs) based on soft Lewis acidic bismuth centers, a phosphine function was combined with a dichloridobismuthane unit on a phenylene backbone utilizing a scrambling approach. The reaction between two equivalents of BiCl3 and (o‐(Ph2P)C6H4)3Bi yielded (o‐(Ph2P)C6H4)BiCl2(THF), the structure of which indicated Bi...P interactions and thus a pronounced Lewis acidity at the bismuth center that was confirmed by the Gutmann‐Beckett method. However, the system turned out to be insufficient to be utilized for FLP reactivity. Hence, the chloride ligands were exchanged by iodide and C2F5 substituents, respectively. Despite a lower electronegativity the iodide compound exhibits a shorter Bi...P contact, while the C2F5 substituents led to a further decrease of the Lewis acidity, despite their high group electronegativity. DFT calculations rationalized this by a quenching of the Lewis acidity inherent to the σ*(Bi−C) orbital by negative hyperconjugation from occupied p‐orbitals at the F atoms. Furthermore, it turned out that the strength of the covalent Bi−X σ‐bond is a more important factor than the charge at Bi in determining the energetic accessibility and thus Lewis acidity of the antibonding σ*(Bi−C) orbital. [ABSTRACT FROM AUTHOR]

The strong potential of platinum single atom (PtSA) in gas sensor technology is primarily attributed to its high atomic economy. Nevertheless, it is imperative to conduct further exploration to understand the impact of PtSA on the active sites. In this study, the evolution of PtSA on (100)CeO2 and (111)CeO2 is examined, revealing notable disparities in the position and activity of surface PtSA on different crystal planes. The PtSA in (100)CeO2 surface can enhance the stability of Ce3+ and construct a frustrated Lewis pair (FLP) to form a double active site by combining the steric hindrance effect of oxygen vacancies, which increases the response value from 1.8 to 27 and reduce the response‐recovery time from 140–192 s to 25–26 s toward five ppm NO2 at room temperature. Conversely, PtSA tends to bind to terminal oxygen on the surface of (111)CeO2 and become an independent reaction site. The response value of PtSA‐(111)CeO2 surface only increased from 1.6 to 3.8. This research underscores the correlation between single atoms and crystal plane effects, laying the groundwork for designing and synthesizing ultra‐stable and efficient gas sensors. [ABSTRACT FROM AUTHOR]

Context: In silico study investigates the activation of sulfur dioxide by newly designed frustrated Lewis pairs, i.e., [P(tBu)3...B(C2NBSHF2)3], where the Lewis acid part is a super Lewis acid. The activation process involves the making of P–S and B–O bonds, leading to the formation of an FLP-SO2 adduct. The calculated results demonstrate that the activation of SO2 by the FLP is almost barrierless and exothermic. Exploration of the impact of the solvent environment on the feasibility and energetics of the reaction has been investigated. The exothermicity is increasing in nonpolar solvents. Methods: This study focuses on understanding the electronic activity of SO2 activation by FLP with the help of the Minnesota 06 functional, M06-2X (global hybrid functional with 54% HF exchange) along with Pople's basis set, 6-311G (d, p). Principal interacting orbital and extended transition state–natural orbitals for chemical valence studies, giving impactful insight into the favorable orbital interaction and electron transfer in this reaction. Furthermore, useful CDFT descriptors such as reaction force constant and reaction electronic flux profiles along the intrinsic reaction coordinate give insights into the synchronicity and total electronic activity of the reaction. [ABSTRACT FROM AUTHOR]

Due to the serious ecological problems caused by the high CO2 content in the atmosphere, reducing atmospheric CO2 has attracted widespread attention from academia and governments. Among the many ways to mitigate CO2 concentration, the capture and comprehensive utilization of CO2 through chemical methods have obvious advantages, whose key is to develop suitable adsorbents and catalysts. Frustrated Lewis pairs (FLPs) are known to bind CO2 through the interaction between unquenched Lewis acid sites/Lewis base sites with the O/C of CO2, simultaneously achieving CO2 capture and activation, which render FLP better potential for CO2 utilization. However, how to construct efficient FLP targeted for CO2 utilization and the mechanism of CO2 activation have not been systematically reported. This review firstly provides a comprehensive summary of the recent advances in the field of CO2 capture, activation, and transformation with the help of FLP, including the construction of homogeneous and heterogeneous FLPs, their interaction with CO2, reaction activity, and mechanism study. We also illustrated the challenges and opportunities faced in this field to shed light on the prospective research. [ABSTRACT FROM AUTHOR]

Due to the serious ecological problems caused by the high CO2 content in the atmosphere, reducing atmospheric CO2 has attracted widespread attention from academia and governments. Among the many ways to mitigate CO2 concentration, the capture and comprehensive utilization of CO2 through chemical methods have obvious advantages, whose key is to develop suitable adsorbents and catalysts. Frustrated Lewis pairs (FLPs) are known to bind CO2 through the interaction between unquenched Lewis acid sites/Lewis base sites with the O/C of CO2, simultaneously achieving CO2 capture and activation, which render FLP better potential for CO2 utilization. However, how to construct efficient FLP targeted for CO2 utilization and the mechanism of CO2 activation have not been systematically reported. This review firstly provides a comprehensive summary of the recent advances in the field of CO2 capture, activation, and transformation with the help of FLP, including the construction of homogeneous and heterogeneous FLPs, their interaction with CO2, reaction activity, and mechanism study. We also illustrated the challenges and opportunities faced in this field to shed light on the prospective research. [ABSTRACT FROM AUTHOR]

CO2 reduction is appealing for the long‐term production of high‐value fuels and chemicals. Herein, using density functional theory (DFT) based calculations, we study the CO2 reduction pathway to formic acid using aluminum hydride and phosphine derivatives. Our primary focus is on aluminum hydride derivatives, aimed at improving the efficiency of the CO2 reduction process. Substituents with σ‐donating properties at the aluminum center are discovered to lower the activation barriers. We demonstrate how di‐tert‐butylphosphine oxide (LB‐O)/di‐tert‐butylphosphine sulfide (LB‐S)/di‐tert‐butylphosphanimine (LB‐N) work together with aluminum hydride to facilitate CO2 reduction process and generate in‐situ frustrated Lewis pairs (FLPs), such as FLP‐O, FLP‐S, and FLP‐N. The activation strain model (ASM) analysis reveals the significance of strain energy in determining activation barriers. EDA‐NOCV and PIO analyses elucidate the orbital interactions at the corresponding transition states. Furthermore, the study delves into the activation of various small molecules, such as dihydrogen, acetylene, ethylene, carbon dioxide, nitrous oxide, and acetonitrile, using those in‐situ generated FLPs. The study highlights the low activation barriers and emphasizes the potential for small molecule activation in this context. [ABSTRACT FROM AUTHOR]

Synthesizing azoles from ortho‐substituted anilines, CO2 and H2 has proved difficult due to the low nucleophilicity of anilines, which hinders their N‐formylation, i. e., the first step of the reaction. This study demonstrates that R3SnX Lewis acids (LA), N‐methylmorpholine (NMM) or DBU and polyethyleneimine (PEI) or N‐formylmorpholine efficiently catalyse the synthesis of benzimidazole and other azoles from ortho‐substituted anilines, CO2 and H2 by reductive coupling of CO2 to nucleophilic amine‐based solvents, PEI or morpholine, followed by in‐situ transfer of the formyl group to the appropriate ortho‐substituted aniline. Under these reaction conditions, spontaneous cyclization of the N‐formylated intermediate yields the corresponding azole in up to 98 % yield. [ABSTRACT FROM AUTHOR]

Synthesizing azoles from ortho‐substituted anilines, CO2 and H2 has proved difficult due to the low nucleophilicity of anilines, which hinders their N‐formylation, i. e., the first step of the reaction. This study demonstrates that R3SnX Lewis acids (LA), N‐methylmorpholine (NMM) or DBU and polyethyleneimine (PEI) or N‐formylmorpholine efficiently catalyse the synthesis of benzimidazole and other azoles from ortho‐substituted anilines, CO2 and H2 by reductive coupling of CO2 to nucleophilic amine‐based solvents, PEI or morpholine, followed by in‐situ transfer of the formyl group to the appropriate ortho‐substituted aniline. Under these reaction conditions, spontaneous cyclization of the N‐formylated intermediate yields the corresponding azole in up to 98 % yield. [ABSTRACT FROM AUTHOR]

The possible existence of nonagermanide deltahedral Zintl ion (Ge94−) as a nine-folded Lewis base is investigated from first principles calculations. It is observed that all nine centres, Ge94−, can make an adduct with Lewis acid. The presence of lone pairs is confirmed from the 1c–2e AdNDP calculation. It is further noticed that the bulky group functionalized organo-Zintl cluster, [Ge9(tBu)3]− , can potentially act as a Lewis base and can make an intermolecular frustrated Lewis pair (FLP) with a well-known Lewis acid Tris[2,4,6-tris(trifluoromethyl)phenyl] borane, [B{C6H2(CF3)3}3]. [ABSTRACT FROM AUTHOR]

Frustrated Lewis pairs (FLPs) composed of acidic alane and basic phosphane functions, separated by a xanthene linker, can be prepared through the corresponding Me3Sn derivative and methyl aluminum compounds with elimination of Me4Sn. This way MeClAl‐, Cl2Al‐ and (C6F5)2Al‐ moieties could be introduced and the resulting FLPs are stabilized by a further equivalent of the alane precursors. In contact with the FLPs CO2 is bound via the C atom at the phosphane functions and the two O atoms at the Al centers. The residues at the latter determine the binding strength. Hence, in case of MeClAl CO2 capture occurs at higher pressure and under ambient conditions CO2 is released again, while for Cl2Al and (C6F5)2Al CO2 binding becomes irreversible. The results of DFT calculations rationalize these findings by the high thermodynamic stabilization in case of more electronegative residues, which concomitantly lead to higher barriers, and in case of (C6F5)2Al further stabilization is achieved through a low reorganization energy. [ABSTRACT FROM AUTHOR]

Frustrated Lewis pairs (FLPs) composed of acidic alane and basic phosphane functions, separated by a xanthene linker, can be prepared through the corresponding Me3Sn derivative and methyl aluminum compounds with elimination of Me4Sn. This way MeClAl‐, Cl2Al‐ and (C6F5)2Al‐ moieties could be introduced and the resulting FLPs are stabilized by a further equivalent of the alane precursors. In contact with the FLPs CO2 is bound via the C atom at the phosphane functions and the two O atoms at the Al centers. The residues at the latter determine the binding strength. Hence, in case of MeClAl CO2 capture occurs at higher pressure and under ambient conditions CO2 is released again, while for Cl2Al and (C6F5)2Al CO2 binding becomes irreversible. The results of DFT calculations rationalize these findings by the high thermodynamic stabilization in case of more electronegative residues, which concomitantly lead to higher barriers, and in case of (C6F5)2Al further stabilization is achieved through a low reorganization energy. [ABSTRACT FROM AUTHOR]

New Frustrated Lewis Pairs (FLPs) are designed and are attempted to activate molecular hydrogen. The new FLPs are modeled by changing the ligands in the Lewis acid (LA) part of the TPFPB (Tris(pentafluorophenyl)borane) molecule. The modifications are done by replacing the phenyl group in TPFPB with three different aromatic heterocyclic ligands. The stability and reactivity of FLPs: [(C2BNSHF2)]3B−P(tBu)3, [(C2BNSF3)]3B−P(tBu)3 and [C2BNO(CN)3]3B−P(tBu)3 is analysed in terms of the dual descriptors, NBO/Hirshfeld charges, VDE, hardness (η) and electrophilicity (ω). Although all three modeled FLPs show their capability towards activating molecular hydrogen, the [C2BNO(CN)3]3B−P(tBu)3 shows better performance than the conventionally used FLP: (C6F5)3B−P(tBu)3. [ABSTRACT FROM AUTHOR]

Graphical abstract Quantum chemical calculations have been carried out to design some frustrated Lewis pairs (FLPs) based on the carbene borane system. The designed FLPs have been found to possess high catalytic activity for H 2 activation. Abstract Activation of small molecules by metal-free frustrated Lewis pairs (FLPs) is gaining much attention. In this regard, quantum chemical calculations have been carried out in benzene medium to design some intramolecular FLPs based on a carbene–borane system for activation of dihydrogen. Different carbenes, such as normal, abnormal and remote, has been considered in designing these FLPs. The designed FLPs are found to have lower activation barriers compared to the previously reported analogous systems. A FLP having a remote carbene is found to have the lowest activation barrier. However, the reversibility is most pronounced in case of normal carbene based FLPs, having a lower aromatization effect. The electronic feature associated with the activation process has been thoroughly studied and it is found that the synergism between donation and back-donation is responsible for activation of the H H bond. [ABSTRACT FROM AUTHOR]

Selective hydrogenation of C C double bond in α, β-unsaturated carbonyl compounds is of great significance in the production of fine chemicals, and the design and preparation of hydrogenation catalysts with high selectivity is the key to realize the industrialization of this reaction. Controlling and adjusting the steric hindrance between substrate molecules and active center of catalysts is an effective strategy to achieve high selectivity. In this work, the spatially hindered "Frustrated Lewis pairs" (FLPs) was used as the active component and metal-organic frameworks (MOFs) materials with a certain window size were used as the catalyst support. We designed and synthesized a heterogeneous hydrogenation catalyst B(C 6 F 5) 3 /DO-MIL-101 by immobilizing FLP onto metal-organic frameworks (MIL-101). Characterizations and catalytic performance tests revealed that the catalytically active species B(C 6 F 5) 3 /DO was confined in MIL-101 nanocavities via Cr–O coordination bond. The resulting B(C 6 F 5) 3 /DO-MIL-101 catalyst not only realized the recycling of FLP, but also showed excellent catalytic activity and high selectivity in the selective hydrogenation of C C double bond in α, β-unsaturated carbonyl ketones. It should be noted that the steric hindrance between FLP and substrate molecules, as well as the shape selectivity of MOFs nanocages, are the principal factors for the high selectivity of the catalyst. [Display omitted] • FLP-MOFs heterogeneous catalyst was prepared by post-synthetic modification. • An excellent catalyst for the selective hydrogenation of C＝C double bond in α, β-unsaturated ketones. • The steric effect between FLP and substrates and the shape selectivity of MOFs nanocages were the key to high selectivity. [ABSTRACT FROM AUTHOR]

Organoboranes carrying electron-withdrawing substituents are commonly used as Lewis acidic catalysts or cocatalysts in a variety of organic processes. These Lewis acids also became popular through their application in `frustrated Lewis pairs', i.e. combinations of Lewis acids and bases that are unable to fully neutralize each other due to steric or electronic effects. We have determined the crystal and molecular structures of four heteroleptic arylboranes carrying 2-(trifluoromethyl)phenyl, 2,6-bis(trifluoromethyl)phenyl, 3,5-bis(trifluoromethyl)phenyl or mesityl substituents. [3,5-Bis(trifluoromethyl)phenyl]bis[2-(trifluoromethyl)phenyl]borane, C22H11BF12, (I), crystallizes with two molecules in the asymmetric unit which show very similar geometric parameters. In one of the two molecules, both trifluoromethyl groups of the 3,5-bis(trifluoromethyl)phenyl substituent are disordered over two positions. In [3,5-bis(trifluoromethyl)phenyl]bis[2,6-bis(trifluoromethyl)phenyl]borane, C24H9BF18, (II), only one of the two meta-trifluoromethyl groups is disordered. In [2,6-bis(trifluoromethyl)phenyl]bis[3,5-bis(trifluoromethyl)phenyl]borane, C24H9BF18, (III), both meta-trifluoromethyl groups of only one 3,5-bis(trifluoromethyl)phenyl ring are disordered. [3,5-Bis(trifluoromethyl)phenyl]dimesitylborane, C26H25BF6, (IV), carries only one meta-trifluoromethyl-substituted phenyl ring, with one of the two trifluoromethyl groups disordered over two positions. In addition to compounds (I)-(IV), the structure of bis[2,6-bis(trifluoromethyl)phenyl]fluoroborane, C16H6BF13, (V), is presented. None of the ortho-trifluoromethyl groups is disordered in any of the five compounds. In all the structures, the boron centre is in a trigonal planar coordination. Nevertheless, the bond angles around this atom vary according to the bulkiness and mutual repulsion of the substituents of the phenyl rings. Also, the ortho-trifluoromethyl-substituted phenyl rings usually show longer B-C bonds and tend to be tilted out of the BC3 plane by a higher degree than the phenyl rings carrying ortho H atoms. A comparison with related structures corroborates the conclusions regarding the geometric parameters of the boron centre drawn from the five structures in this paper. On the other hand, CF3 groups in meta positions do not seem to have a marked effect on the geometry involving the boron centre. Furthermore, it has been observed for the structures reported here and those reported previously that for CF3 groups in ortho positions of the aromatic ring, disorder of the F atoms is less probable than for CF3 groups in meta or para positions of the ring. [ABSTRACT FROM AUTHOR]

The isolable silylene 1 forms a frustrated Lewis pair with silylium ion 2 that is able to split hydrogen under ambient conditions. The protonated silylene 3 obtained in this reaction isomerizes to yield the hydrogen-bridged disilyl cation 4. Cation 4 is fully characterized by NMR spectroscopy and by XRD analysis. Its formation via the protonated silylene 3 is indicated by independent synthesis of cation 3 by hydride abstraction from the corresponding dihydridosilane 11 and is further supported by the results of density functional calculations. [ABSTRACT FROM AUTHOR]

Diarylphosphino-substituted alkynes undergo a 1, 1-carboboration reaction with tris(pentafluorophenyl)borane to yield 2-diarylphosphino-substituted alkenylboranes. These unsaturated systems show a P/B interaction. Nevertheless, they feature a limited frustrated Lewis pair (FLP) reactivity. Four such unsaturated vicinal FLPs were shown to react with benzaldehyde to give the respective six-membered heterocyclic P/B FLP 1, 2-addition products, which were characterized by X-ray diffraction. [ABSTRACT FROM AUTHOR]