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Frustrated Lewis pair (FLP) chemistry has undergone remarkable growth, among which rare-earth metal-based Lewis pairs have exhibited unique reactivity in recent years. Herein, treatment of the intramolecular Sc/P Lewis pair, i.e., (ArO)2ScN(tBu)PPh2 (1, Ar = 2,6-tBu2-C6H3), with pyridotetrazole resulted in the formation of an FLP nitrene adduct with N2 elimination, offering additional insights into the mechanism of transition-metal-catalyzed denitrogenative annulation of pyridotetrazole. Reactions of complex 1 with 1,3,5-triazine and benzo[c]cinnoline generated FLP-type products via Sc/P 1,2-addition to the CvN bond and the NvN bond, respectively. Furthermore, treatments of 1 with phenylacetylene, diazo, and azide compounds were also investigated, leading to the formation of a variety of metallacyclic complexes displaying typical FLP behaviors. [ABSTRACT FROM AUTHOR]

Ruthenium-based catalysts were prepared through a deposition–precipitation approach, taking beta zeolites with Si/Al ratios of 12.5, 18.5, and 150, respectively, as supports, and 1–3 wt% loadings of metal. Their activation was performed in the presence of either H2 or NaBH4. The dispersion of the Ru species and the acid–base properties were influenced by both the preparation method and the activation protocol. The catalysts reduced under H2 flow presented well-dispersed Ru(0) and RuOx nanoparticles, while the reduction with NaBH4 led to larger RuOx crystallites and highly dispersed Ru(0). These characteristics exerted an important role in the hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL). The H2 dissociation occurred via a heterolytic mechanism involving Lewis acid–base pairs associated with RuOx and the framework oxygen (Si-O-Al) located near the zeolite pore edge. The Ru(0) nanoparticles activated the –C=O bond of the LA substrate, while the presence of the carrier zeolite Brønsted acid sites promoted the ring-closure esterification of the 4-hydroxyvaleric acid (4-HVA) intermediate to GVL. An optimal combination of these features was achieved for the catalyst with 3 wt% Ru and a Si/Al ratio of 150, which selectively converted LA (XLA = 96.5%) to GVL (SGVL = 97.8%) at 130 °C and 10 bars of H2. [ABSTRACT FROM AUTHOR]

[Display omitted] • Multiscale modifications of CN into porous, curled CNA-B30 with B/–CN LABPs. • CNA-B30 extended photoabsorption edges to 470 nm (π → π*) and 715 nm (n → π*) • Planar distortion and LABPs enhanced charge redistribution and charge dynamics. • Boron centers elevated oxidation capability of CNA-B30 and reduced barrier for OER. • CNA-B30 achieved 586.5μmol g−1 h−1 O 2 evolution (λ > 420 nm) without co-catalyst. Photocatalytic oxygen evolution reaction (OER) is pivotal for sustainable energy systems yet lacks high-performance catalysts capable of strong visible light absorption, robust charge dynamics, fast reaction kinetics, and high oxidation capability. Herein, we report the multiscale optimization of carbon nitride through the construction of porous curled carbon nitride nanosheets (CNA-B30) incorporating boron center/cyano group Lewis acid-base pairs (LABPs). The unique chemical and structural features of CNA-B30 extended the photoabsorption edges of π → π* and n → π* electronic transitions to 470 nm and 715 nm, respectively. Planar distortion and LABPs induced charge redistribution, enhancing the built-in electric field to promote efficient charge dissociation and transport. Moreover, boron atoms elevated the valence band of carbon nitride and served as active oxidation sites, effectively lowering the thermodynamic barrier for water oxidation. As a result, CNA-B30 demonstrated outstanding OER activity, achieving 586.5μmol g−1 h−1 (λ > 420 nm) without co-catalysts. With the addition of a Co co-catalyst, the oxygen evolution rate increased to 2085.5 μmol g−1 h−1 (λ > 420 nm), and an apparent quantum efficiency of 5.8 % at 420 nm, surpassing most state-of-the-art OER photocatalysts. This work offers valuable insights into designing advanced OER photocatalysts for efficient solar fuel production. [ABSTRACT FROM AUTHOR]

The industrial production of methyl propionate synthesized via methoxycarbonyl esterification of ethylene achieved 100% atom economy. In this study, we synthesized ruthenium-loaded praseodymium–cerium oxide (Pr–CeO2) catalysts by precipitation impregnation and evaluated their performance in the methoxycarbonylation reaction of ethylene. The effect of Pr doping on the reaction results was analyzed by characterization and mechanistic studies. Pr doping increased the concentration of localized oxygen vacancies in the catalysts and thus modulated the catalytic effect of Lewis acid–base pairs. The increase of local oxygen vacancies significantly enhanced the activation and dissociation of CH3OH. At the same time, since the dissociation activation of the other two feedstock molecules, ethylene and CO, occurred at the Ru site, Pr doping facilitated the dispersion of Ru to a certain extent, thus increasing the dissociation activation of CO and ethylene, which, in combination with Pr doping, further increased the content of oxygen vacancies in the active site as methanol, resulting in a substantial enhancement of the dissociation activation of the feedstock molecules, which then increased the catalytic reaction rate through synergistic effects. The results provide a new perspective for the future study of methoxycarbonylation. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Urea plays a vital role in human society, which has various applications in organic synthesis, medicine, materials chemistry, and other fields. Conventional industrial urea production process is energy−intensive and environmentally damaging. Recently, electrosynthesis offers a greener alternative to efficient urea synthesis involving coupling CO2 and nitrogen sources at ambient conditions, which affords an achievable way for diminishing the energy consumption and CO2 emissions. Additionally, urea electrolysis, namely the electrocatalytic urea oxidation reaction (UOR), is another emerging approach very recently. When coupling with hydrogen evolution reaction, the UOR route potentially utilizes 93% less energy than water electrolysis. Although there have been many individual reviews discussing urea electrosynthesis and urea electrooxidation, there is a critical need for a comprehensive review on urea electrocatalysis. The review will serve as a valuable reference for the design of advanced electrocatalysts to enhance the electrochemical urea electrocatalysis performance. In the review, we present a thorough review on two aspects: the electrocatalytic urea synthesis and urea oxidation reaction. We summarize in turn the recently reported catalyst materials, multiple catalysis mechanisms and catalyst design principles for electrocatalytic urea synthesis and urea electrolysis. Finally, major challenges and opportunities are also proposed to inspire further development of urea electrocatalysis technology. Key Scientists: For urea electrosynthesis, Furuya et al. firstly investigated the electrochemical coreduction of CO2 and NO3−/NO2− using gas‐diffusion electrodes in 1995. Then, Wang et al. effectively achieved C—N bond formation and urea synthesis on PdCu alloy nanoparticles in 2020. Shortly, Yan and Yu et al. proposed the formation of *CO2NO2 from *NO2 and *CO2 intermediates at early stage on In(OH)3 electrocatalyst in 2021, and employed defect engineering strategy to facilitate the *CO2NH2 protonation in 2022. Amal et al. Investigated the role that Cu‐N‐C coordination plays for both the CO2RR and NO3RR. After that, Zhang's group developed In‐based electrocatalysts with artificial frustrated Lewis pairs for urea, and they offered a systematic screening approach for catalyst design in urea electrosynthesis in 2023. And sargent et al. reported a strategy that increased selectivity to urea using a hybrid catalyst. For urea electrooxidation, Stevenson et al. investigated the effect of Sr substitution toward the urea oxidation reaction. Wang et al. provided insights into the urea electrooxidation process using a β‐Ni(OH)2 electrode and Qiao et al. elucidated a two‐stage reaction pathway for UOR in 2021. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Urea plays a vital role in human society, which has various applications in organic synthesis, medicine, materials chemistry, and other fields. Conventional industrial urea production process is energy−intensive and environmentally damaging. Recently, electrosynthesis offers a greener alternative to efficient urea synthesis involving coupling CO2 and nitrogen sources at ambient conditions, which affords an achievable way for diminishing the energy consumption and CO2 emissions. Additionally, urea electrolysis, namely the electrocatalytic urea oxidation reaction (UOR), is another emerging approach very recently. When coupling with hydrogen evolution reaction, the UOR route potentially utilizes 93% less energy than water electrolysis. Although there have been many individual reviews discussing urea electrosynthesis and urea electrooxidation, there is a critical need for a comprehensive review on urea electrocatalysis. The review will serve as a valuable reference for the design of advanced electrocatalysts to enhance the electrochemical urea electrocatalysis performance. In the review, we present a thorough review on two aspects: the electrocatalytic urea synthesis and urea oxidation reaction. We summarize in turn the recently reported catalyst materials, multiple catalysis mechanisms and catalyst design principles for electrocatalytic urea synthesis and urea electrolysis. Finally, major challenges and opportunities are also proposed to inspire further development of urea electrocatalysis technology. Key Scientists: For urea electrosynthesis, Furuya et al. firstly investigated the electrochemical coreduction of CO2 and NO3−/NO2− using gas‐diffusion electrodes in 1995. Then, Wang et al. effectively achieved C—N bond formation and urea synthesis on PdCu alloy nanoparticles in 2020. Shortly, Yan and Yu et al. proposed the formation of *CO2NO2 from *NO2 and *CO2 intermediates at early stage on In(OH)3 electrocatalyst in 2021, and employed defect engineering strategy to facilitate the *CO2NH2 protonation in 2022. Amal et al. Investigated the role that Cu‐N‐C coordination plays for both the CO2RR and NO3RR. After that, Zhang's group developed In‐based electrocatalysts with artificial frustrated Lewis pairs for urea, and they offered a systematic screening approach for catalyst design in urea electrosynthesis in 2023. And sargent et al. reported a strategy that increased selectivity to urea using a hybrid catalyst. For urea electrooxidation, Stevenson et al. investigated the effect of Sr substitution toward the urea oxidation reaction. Wang et al. provided insights into the urea electrooxidation process using a β‐Ni(OH)2 electrode and Qiao et al. elucidated a two‐stage reaction pathway for UOR in 2021. [ABSTRACT FROM AUTHOR]

Frustrated Lewis Pairs (FLP) have found exciting access in catalysis and small molecule activation. Here, we describe the potential of two vanadium(V) oxido complexes with monoanionic bidentate N,O donors, [VOCl(LCF3)2] (1 a), [VOCl(LH)2] (1 b) as bases in FLPs. Upon reaction of 1 a with the Lewis acid B(C6F5)3 the FLP [VOCl(LCF3)2]/B(C6F5)3 (1 a/B(C6F5)3) was observed. Addition of Ph3SiH led to the reduction of VV to VIV under formation of the adduct [V{OB(C6F5)3}(LCF3)2] (2 a) while FLP reactivity was not observed. Dissolving 2 a in CH3CN leads to the VIV oxido complex, [VO(LCF3)2] (3 a). In contrast, when 1 b was reacted with B(C6F5)3, a VIV oxido complex [VO(LH)2] (3 b) was obtained. Upon addition of B(C6F5)3 to 3 b no reaction leading to the expected adduct such as 2 a could be observed. Only few crystals deriving from a disproportion reaction could be identified as an adduct dimer [V{OB(C6F5)3}LH(μ‐O)]2. While FLP reactivity could not be found yet with the described systems, the redox labile nature and versatility of the metal complexes are demonstrated. [ABSTRACT FROM AUTHOR]

Hydroboranes are versatile reagents in synthetic chemistry, but their synthesis relies on energy‐intensive processes. Herein, we report a new method for the preparation of hydroboranes from hydrogen and the corresponding haloboranes. Triethylamine (NEt3) form with dialkylchloroboranes a Frustrated Lewis Pair (FLP) able to split H2 and afford the desired hydroborane with ammonium salts. Unreactive haloboranes were unlocked using a catalytic amount of Cy2BCl, enabling the synthesis of commonly used hydroboranes such as pinacolborane or catecholborane. The mechanisms of these reactions have been examined by DFT studies, highlighting the importance of the base selection. Finally, the system's robustness has been evaluated in one‐pot B−Cl hydrogenolysis/hydroboration reactions of C=C unsaturated bonds. [ABSTRACT FROM AUTHOR]

Herein, we simultaneously synthesized three different double B←N Lewis pair‐functionalized naphthalenes including the asymmetric BNNY and BNNO and the mirror‐symmetric BNNR, via a one‐pot method. The annulation modes of the B←N Lewis pairs and the substituents on the boron atoms efficiently tune the molecular frontier orbitals and emission colors. α‐Position fusion leads to a significant enhancement of the HOMO energy level and a decrease in the HOMO‐LUMO gap, while the electron‐withdrawing groups attached to the boron atom make the LUMO energy level more stable. In particular, the LUMO energy level of BNNO is as low as −3.12 eV. BNNY, BNNO, and BNNR emit cyan, green, and red fluorescence at 509, 534, and 620 nm, respectively, with fluorescence quantum yields of 24 %, 49 %, and 30 %, respectively. [ABSTRACT FROM AUTHOR]

Several complexes of the intramolecular frustrated Lewis pair (FLP)‐supported P(−1) ligand [iPr2P(C6H4)BCy2{P}]− are presented (Cy=cyclohexyl). Chief among these is the first example of a monomeric zinc bis(phosphido) complex, which was synthesized as a potential precursor for the solution‐phase deposition of Zn3P2. While this goal was ultimately unsuccessful, the Zn(II) complex acts as a convenient springboard to other metal phosphide species via transmetallation: affording a tellurium bis(phosphido) complex and a formal adduct of the phosphorus subhalide PPCl2. Trapping experiments show that the PPCl2 adduct can also be prepared directly through the in situ reduction of PCl3 in the presence of an intramolecular FLP ligand. Lastly, we report a formal η2‐phosphaborene complex of cobalt(−1) which is isoelectronic to olefin complexes, and explore its bonding via density functional theory (DFT) computations. [ABSTRACT FROM AUTHOR]

This work reports boron and oxygen dual‐doped carbon nitride nanotubes (B/O‐CNNTs) prepared via a copolymerization process for electrocatalytic ammonia synthesis from nitrogen gas (NRR) and nitrate (NO3RR) sources, respectively. By adjusting the dosage of boron oxide precursor, the texture and content of B/O dual dopants and the coordination environment in the resulting 1D CNNTs can be tuned. The best B/O‐CNNTs can achieve maximum Faradaic efficiencies of 35% and 96% at −1.1 V versus RHE with corresponding ammonia yields of 16.7 and 211.4 µg h−1 mg−1, respectively. A comparatively higher selectivity is achieved in the NRR process compared to NO3RR. The B/O‐induced coordinations boost electron transfer rates along the longitudinal axis. The presence of carbon vacancies and the unique 1D nanotubular structure enhance interactions among reactants. Concurrently, the formed frustrated Lewis pairs are pivotal in activating chemisorbed nitrogen gas or nitrate, resulting in notable accelerations of ammonia generation kinetics. In situ UV–vis spectroscopy reveals that the ideal potential of −1.1 V versus RHE facilitates the involvement of free electrons in the reaction, as it aligns with the conduction potential of B/O‐CNNTs. This study paves the way for the design of non‐metal‐based electrocatalysts with dual dopants for sustainable electrocatalysis toward ammonia synthesis. [ABSTRACT FROM AUTHOR]

The tin-containing Lewis acid group (C2F5)3Sn was combined with a phosphonium ylide as base function in one molecule: o-[(C2F5)3Sn]-C6H4(Ph)2PCMe2. It was prepared by reacting the ortho-lithiated triphenylphosphoniumdimethylmethylide (o-Li-C6H4)(Ph)2PCMe2 with the stannyl chloride (C2F5)3SnCl to afford o-[(C2F5)3Sn]-C6H4(Ph)2PCMe2 in 86 % yield. It forms a ring structure with a bond between tin and the ylidic carbon atom both in solution and in the solid state and can thus be considered as a hidden frustrated Lewis pair. The title compound is unreactive towards H2, CO2, CS2, PhNCO and decomposes in the presence of SO2 or NH3. However, it is active in the catalytic reduction of CO2 with pinacolborane, H–BPin. The title compound reacts slowly with H–BPin in an unselective reaction from which a reduction product with cleaved C2F5 group, the phosphonium stannate (II) o-[(C2F5)2Sn]-C6H4(Ph)2PCHMe2, could be obtained in small amounts. [ABSTRACT FROM AUTHOR]

Thermodynamic parameters of the process of dissociation of the donor-acceptor complexes of bidentate Lewis acids R[OE(C6F5)2]2 (E = B, Al; R = C2H4, p-C6H4, m-C6H4) with pyrazine (pyz) and 3,3′-bipyridine (bipy) have been determined by means of quantum-chemical simulation (M06-2X/def2-TZVP). A combination of the bidentate Lewis acid and the bidentate Lewis base may result in the formation of one or two donor-acceptor bonds. The formation of the hos-guest type complexes can be observed in the case of the formation of two donor-acceptor bonds. The non-optimal size of the donor and the acceptor molecules has led to the strain in the formed cyclic compound, which can be reflected in the possibility of the heterolytic rupture of hydrogen molecule (into the Н+ and Н– ions), analogous to the Frustrated Lewis Pairs (FLP). The performed quantum-chemical simulations of the energy and thermodynamic parameters of the processes of activation of molecular hydrogen with the R[OE(C6F5)2]2·LB (E = B, Al; LB = pyz, bipy; R = C2H4, p-C6H4, m-C6H4) complexes in the gas phase have evidenced the prospects of further optimization of the size and acid-base properties of the bidentate donor and acceptor. [ABSTRACT FROM AUTHOR]

Gas-phase heterogeneous catalytic CO2 hydrogenation to commodity chemicals and fuels via surface frustrated Lewis pairs is a growing focus of scientific and technological interest. Traditional gas-phase heterogeneous surface frustrated Lewis pair catalysts primarily involve metal oxide-hydroxides (MOH•••M). An avenue to improve the process performance metrics lies in replacing the Lewis base MOH with a stronger alternative; an intriguing example being the amine MNH2 in metal nitrides. This study establishes a proof-of-concept that an amine-type photoactive surface frustrated Lewis pair (MNH2•••M) can be constructed in titanium nitride (TiNxOy) when integrated with a nanoscale platinum spillover co-catalyst. This surface frustrated Lewis pair, comprising Ti-NH2 as the Lewis base and low-valent Ti as the Lewis acid, facilitates the gas-phase light-assisted heterogeneous reverse water-gas shift reaction. The reaction proceeds via a surface-active carbamate intermediate, Ti-(H2N-COO)-Ti, whereby the synergism of Lewis acidic and Lewis basic sites endows it with superior performance indicators compared to TiNxOy alone, as well as conventional platinum supported metal oxides. Heterogeneous surface frustrated Lewis pairs catalysis have been predominantly focused on metal oxide hydroxides. This study instead explores a different chemical composition space by shifting from metal oxides to metal nitrides for CO2 photoreduction. [ABSTRACT FROM AUTHOR]

Developing novel sorbents for effective removal of heavy metals and organic dyes from industrial wastewater remains a central theme for water research. We modified hydrochar derived from the hydrothermal carbonization of wheat straw at 180 °C with 3-Aminopropyl triethoxysilane (APTES) to enhance its versatile adsorption of Pb(II), Cu(II), methylene blue (MB), and reactive red (Red). Pristine and modified hydrochar (HyC and APTES-HyC) were characterized and tested for sorption performance. Characterization results revealed an enriched presence of N-functional groups, mainly -NH2 and C-N, on APTES-HyC, in addition to an increased specific surface area from 1.14 m2/g (HyC) to 4.51 m2/g. APTES-HyC exhibited a faster adsorption rate than HyC, reaching equilibrium approximately 4 h after initiation. The Langmuir adsorption capacities of APTES-HyC were 49.6, 14.8, 31.7, and 18.3 mg/g for Pb(II), Cu(II), MB, and Red, respectively, about 8.5, 5.0, 1.3, and 9.5 times higher than for HyC. The enhanced adsorption performance of APTES-HyC is attributed to the increased N-functional groups, which facilitated adsorption mechanisms specific to the pollutant of concern such as formation of frustrated Lewis pairs and cation–π interactions for metal ions and π–π interactions and hydrogen bond for dyes. This study offers a novel and facile approach to the synthesis of N-doped carbon materials for practical applications. [ABSTRACT FROM AUTHOR]

Methane is a vital feedstock while the intrinsic inertness of CH4 molecule hinders the conversion of methane under mild conditions. Investigating and understanding the mechanism of methane activation is of great importance in chemistry. In this study, tantalum sulfide anions TaS3− were generated by laser ablation method and mass-selected by a quadrupole mass filter to react with methane, ethane, and propane in an ion funnel trap reactor under thermal collision conditions. The reactant and product ions were detected by a time-of-flight mass spectrometer. Experimental results demonstrate that TaS3− is able to adsorb all of the alkane molecules and break the robust C-H bonds. Further density functional theory calculations reveal that TaS3− is a closed-shell species and effectively activates methane via the Ta/δ+–Sδ− Lewis acid-base pair (LABP, CH4+Taδ+−Sδ− → CH3-Ta-S-H). With a comparative study with NbS3− that contains the Nbδ+–Sδ− LABP, the higher reactivity of TaS3− than that of NbS3− can be attributed to the more acidity of Taδ+ than that of Nbδ+. To the best of our knowledge, this study reports the first example of gas phase species TaS3− to activate methane through the metal-sulfur LABP under thermal collision conditions. [ABSTRACT FROM AUTHOR]

Hydrolytic nanozyme–based visual colorimetry has emerged as a promising strategy for the detection of aluminum ions. However, most studies focus on simulating the structure of natural enzymes while neglecting to regulate the rate of hydrolysis-related steps, leading to low enzyme-like activity for hydrolytic nanozymes. Herein, we constructed a ruthenium dioxide (RuO2) in situ embedded cerium oxide (CeO2) nanozyme (RuO2/CeO2) with a Lewis acid–base pair (Ce–O-Ru-OH), which can simulate the catalytic behavior of phosphatase (PPase) and can be quantitatively quenched by Al3+ to achieve accurate and sensitive Al3+ colorimetric sensing detection. The incorporation of Ru into CeO2 nanorods accelerates the dissociation of H2O, followed by subsequent combination of hydroxide species to Lewis acidic Ce–O sites. This synergistic effect facilitates substrate activation and significantly enhances the hydrolysis activity of the nanozyme. The results show that the RuO2/CeO2 nanozyme exhibits a limit of detection as low as 0.5 ng/mL. We also demonstrate their efficacy in detecting Al3+ in various practical food samples. This study offers novel insights into the advancement of highly sensitive hydrolytic nanozyme engineering for sensing applications. [ABSTRACT FROM AUTHOR]

The potassium aluminyl K[Al(NON)] ([NON]2−=[O(SiMe2NDipp)2]2−, Dipp=2,6‐iPr2C6H3) reacts with group 14 chloroamidinates E{14}(Am)Cl (E{14}=Ge, Sn, Pb. [Am]−=[tBuC(NDipp)2]−) to form (NON)Al−E{14}(Am) Lewis pairs with unsupported Al−E{14} bonds, including the first structurally authenticated Al−Pb bond. Analysis using spectroscopic (NMR, UV‐vis and Mössbauer for E{14}=Sn), X‐ray diffraction and computational (DFT, QTAIM, TD‐DFT) methods conclude an Al−E{14} σ‐bond derived from a Lewis basic Al and a Lewis acidic tetrylene, with back‐donation from the E{14} s‐orbital lone pair donor NBO to acceptor NBOs on Al that are derived from s/p‐orbitals. The reaction of the Al−Ge compound with CO2 forms the dioxocarbene (NON)Al(μ‐O2C)Ge(Am), whilst under the same conditions the Al−Sn compound reacts with additional CO2 to form the carbonate, (NON)Al(μ‐CO3)Sn(Am). Addition of ethene to the Al−E{14} (E{14}=Ge, Sn) compounds introduces an ethylene bridge between the aluminium and group 14 atoms forming a frustrated Lewis pair (FLP). Reaction of the (Al/Ge) FLP with CO2 forms an activation product with new Al−O and Ge−C bonds, whilst reaction with iPrN=C=NiPr proceeds with insertion into the Al−C bond to form an aluminium amidinate. [ABSTRACT FROM AUTHOR]

Photo‐driven cross‐coupling of o‐arylenediamines and alcohols has emerged as an alternative for the synthesis of bio‐active benzimidazoles. However, tackling the key problem related to efficient adsorption and activation of both coupling partners over photocatalysts towards activity enhancement remains a challenge. Here, we demonstrate an efficient interface synergy strategy by coupling exposed oxygen vacancies (VO) and Pd Lewis acid sites for benzimidazole and hydrogen (H2) coproduction over Pd‐loaded TiO2 nanospheres with the highest photoredox activity compared to previous works so far. The results show that the introduction of VO optimizes the energy band structure and supplies coordinatively unsaturated sites for adsorbing and activating ethanol molecules, affording acetaldehyde active intermediates. Pd acts as a Lewis acid site, enhancing the adsorption of alkaline amine molecules via Lewis acid‐base pair interactions and driving the condensation process. Furthermore, VO and Pd synergistically promote interfacial charge transfer and separation. This work offers new insightful guidance for the rational design of semiconductor‐based photocatalysts with interface synergy at the molecular level towards the high‐performance coproduction of renewable fuels and value‐added feedstocks. [ABSTRACT FROM AUTHOR]

Metal single‐atom catalysts (SACs) have emerged as a promising class of catalysts in various fields, owing to their well‐defined active centers, tunable coordination environments, and high reaction selectivity. Among the diverse supports, graphene‐based SACs have garnered significant attention due to their exceptional properties in hydrogenation reactions. This review elucidates recent advancements in theoretical investigations of the electronic and geometric structures of metal SACs, with a focus on modulation strategies such as coordination number adjustment, heteroatom doping, defect site engineering, and frustrated Lewis pair construction. This review emphasizes atomic‐level insights into the hydrogenation reaction mechanism in thermocatalysis, including the activation of the H‐source molecules, hydrogen diffusion, and elementary reaction steps. Strategies for modulating the catalytic activity of SACs are summarized. Lastly, this review offers perspectives on the design of effective graphene‐based SACs from theoretical standpoint, paving the way for future research in this exciting field. [ABSTRACT FROM AUTHOR]

Interest is growing in transition metal‐free compounds for small molecule activation and catalysis. We discuss the opportunities arising from synthesizing sodium‐doped amorphous silicon‐boron‐nitride (Na‐doped a‐SiBN). Na+ cations and 3‐fold coordinated BIII moieties were incorporated into an amorphous silicon nitride network via chemical modification of a polysilazane followed by pyrolysis in ammonia (NH3) at 1000 °C. Emphasis is placed on the mechanisms of hydrogen (H2) activation within Na‐doped a‐SiBN structure. This material design approach allows the homogeneous distribution of Na+ and BIII moieties surrounded by SiN4 units contributing to the transformation of the BIII moieties into 4‐fold coordinated geometry upon encountering H2, potentially serving as frustrated Lewis acid (FLA) sites. Exposure to H2 induced formation of frustrated Lewis base (FLB) N−= sites with Na+ as a charge‐compensating cation, resulting in the in situ formation of a frustrated Lewis pair (FLP) motif (≡BFLA⋅⋅⋅Hδ−⋅⋅⋅Hδ+⋅⋅⋅:N−(Na+)=). Reversible H2 adsorption‐desorption behavior with high activation energy for H2 desorption (124 kJ mol−1) suggested the H2 chemisorption on Na‐doped a‐SiBN. These findings highlight a future landscape full of possibilities within our reach, where we anticipate main‐group‐mediated small molecule activation will have an important impact on the design of more efficient catalytic processes and the discovery of new catalytic transformations. [ABSTRACT FROM AUTHOR]

We present the design and comprehensive investigation of stable para‐substituted triarylamine–2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ) radical ion pairs (RIPs) generated via single‐electron transfer (SET). We quantified the degree of SET in both solution and solid phases, utilising a suite of spectroscopic techniques including IR, EPR, NMR, and single‐crystal X‐ray diffraction (SC–XRD). Our findings reveal that the extent of SET is significantly influenced by the nature of the substituents (MeO > tBu > Br) and the polarity of the solvent (MeCN > DCM > toluene). The radical ion pair [(pMeOPh)3N]⋅+[DDQ]⋅− was unambiguously identified using EPR and UV–vis spectroscopy, and its structure was confirmed by SC–XRD. Detailed analysis indicates an open‐shell singlet ground state with a thermally accessible triplet state, as corroborated by EPR, magnetic susceptibility measurements, and DFT calculations. This study offers crucial insights into the mechanistic pathways of RIP formation and tuning both in solution and solid states, laying the groundwork for future exploration of their reactivity and potential applications. [ABSTRACT FROM AUTHOR]

The capture of formaldehyde (HCHO) is a crucial step in the HCHO purification system that requires an adjustable surface structure of adsorbent to enhance the HCHO adsorption ability. Carbon material, known to contain high surface area and structural tunability, provides an extremely valuable candidate to eliminate indoor HCHO pollutant. Herein, a novel electron acceptor–donor structure is constructed to the surface of nanoporous carbon based on the B, N doping theory. The mechanism of HCHO adsorption and activation on the surface of B, N co-doped nanoporous carbon (BNC) is systematically investigated by experimental tests that the B–N Lewis pair sites contribute a larger adsorption capacity than that of nitrogen-doping and non-doping samples. The present study gives an in-depth understanding about the contribution of the B–N Lewis pair for HCHO adsorption, and also corresponding positive impacts on the transformation into less toxic intermediate species of adsorbed HCHO at room temperature. [ABSTRACT FROM AUTHOR]

The conversion of CO2 into valuable chemicals remains a significant challenge for achieving environmental sustainability, primarily due to the stability of the CO2 molecule. This necessitates the development of efficient and ecofriendly catalysts. In recent years, frustrated Lewis pairs (FLPs) have shown promise for CO2 utilization. In this study, we introduce α‐aminodiboronic acid (DBA), a novel trifunctional aminoboronic acid, as an intramolecular FLP for converting CO2 into cyclic carbonate and formic acid. Using density functional theory (DFT) calculations, we explored the reaction mechanism and investigated DBA's electronic structure through molecular electrostatic potential surface (MESP) and natural bond orbital (NBO) analyses. Our results reveal that one −B (OH)2 group induces an unusual state of frustration in the molecule due to charge transfer from the nitrogen atom's lone pair to the π* orbitals, enhancing catalytic performance. The additional −B (OH)2 group serves as an anchoring site for reactive species. The epoxide activation energy is reduced by approximately 27 kcal/mol compared to the uncatalyzed reaction, and the reduction of CO2 occurs with a requirement of 26 kcal/mol. The additional −B (OH)2 plays a crucial role in the catalytic mechanism and minimizes the energies of various structures observed in the reaction path. The reaction energetics align with structural analysis observations, marking this study as the first report on single‐molecule trifunctional FLPs for transforming CO2 into valuable chemicals. [ABSTRACT FROM AUTHOR]

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 development of oxygen evolution reaction (OER) electrocatalyst for seawater electrolysis plays a crucial role in producing renewable hydrogen energy. However, during the seawater electrolysis process, the anode inevitably undergoes chloride oxidation reaction (ClOR) due to Cl− adsorption, making the seawater electrolysis process difficult to sustain. Inspired by the selective permeability of cell membranes, we propose a biomimetic design of frustrated Lewis pairs (FLPs) layers for selective seawater oxidation. Combining experimental results and molecular dynamics simulations, it has been demonstrated that cerium dioxide layers with FLPs sites can decompose water molecules, capture hydroxyl anions, and repel chloride ions simultaneously. DFT theoretical analysis indicates that the FLP sites regulate the Ce 4 f−O 2p−Ni 3d gradient orbital coupling, providing additional oxygen non‐bonding (ONB) to stabilize the Ni−O bond and optimize the adsorption strength of intermediates, thereby breaking the *OH and *OOH scaling relationship. The assembled anion exchange membrane electrolyzers exhibit an efficiency of 95.7 % at a current density of 0.1 A cm−2 and can stably operate for 250 hours at a current density of 0.2 A cm−2. [ABSTRACT FROM AUTHOR]

The reduction of CO and CO 2 by hydrogen to form formaldehyde and methanoic acid is a common way for renewable resources. In the recent decade, Frustrated Lewis Pairs provides a synergetic reaction based on the cooperative Lewis acidity and Lewis basicity to capture small molecules, such as H 2 , CO and CO 2. Generally, the energy barrier is used as the only way to evaluate the performance of different catalyst, lacking a common rule to connect the structure of catalyst and the corresponding properties. However, CO/CO 2 is polarized as the Lewis pairs by Frustrated Lewis Pairs in the activation, the degradation can be viewed as the hydrogenation of activated CO/CO 2. Herein, we learn three classic Frustrated Lewis Pairs composed by Pier's acid and different N-heterocyclic groups to understand the Lewis acidy and basicity in capture of CO and CO 2. By comparing the hydrogenation ability of pristine Frustrated Lewis Pairs and activated CO/CO 2 , the hydrogenation model based on the Lewis acidity or basicity, including the pristine Frustrated Lewis Pairs and the activated CO/CO 2 , can be a common rule to clarify the performances of the degradation of CO/CO 2. [Display omitted] • Establish the hydrogenation model to evaluate the CO/CO 2 degradation efficiency. • CO/CO 2 absorption can be improved by enhanced basicity/acidity of Lewis pairs. • Strong acidity of Lewis pairs catalyst benefits the degradation of CO. • Hydrogenation of CO 2 is determined by stability and basicity of absorbed CO 2. [ABSTRACT FROM AUTHOR]

Electroreduction of CO2 into high‐value chemicals and fuels driven is an effective way to alleviate the environmental crisis, but it suffers from poor activity and low selectivity of the catalyst. Single‐atom catalysts have excellent selectivity and the highest atomic efficiency, and are widely used in the 2‐electron transfer to produce CO. However, electroreduction of CO2 to C2+ products involves complex processes such as multi‐electron reaction and competitive adsorption, so single‐atom catalysis is often powerless. Herein, a single‐atom Ga‐anchored F‐doped Cu2O catalyst with dual active sites is reported. The Lewis acid‐base pairs and Ga single atom sites promote the adsorption/activation of CO2 and the dissociation of water molecules, respectively, enhance the coverage of *CO and *H, and their synergy optimizes the reaction path. At a high current density of 600 mA cm−2, the FEC2+ reached 72.8 ± 3.2% with remarkable stability. Experiments and theory calculations demonstrate that the dual sites increase the coverage of *CO and *H, and the key intermediate *CO is transformed into *CHO through protonation reaction, which changes the reaction path from the C─C coupling (*OCCO) to the protonation followed by C─C coupling (*OCCHO) with low energy barrier, greatly improving the selectivity for C2+ products. [ABSTRACT FROM AUTHOR]

The photo‐assisted strategy is regarded as a crucial approach to enhance the conversion kinetics of polysulfides in lithium–sulfur (Li–S) batteries. However, the development of photo‐assisted Li–S batteries still faces important challenges, such as the rapid recombination of photogenerated electron−holes on cathode and more severe shuttle effect. Herein, a breakthrough in overcoming the challenges has been made by constructing a promising photo‐assisted Li−S battery based on semiconducted metal−organic frameworks. During the discharging progress, the photoexcited electrons generated by H2BPDC ligand based on ligand‐to‐metal charge transfer (LMCT) effect, are injected into the Ti‐oxo clusters in Ti‐MOF, thereby facilitating the sulfur reduction to Li2S. And photoexcited holes are capable of promoting the decomposition kinetics of Li2S during charging. More importantly, the stronger chemical interaction between Ti‐BPDC‐d and polysulfides under light inhibits the polysulfides dissolution and shuttling, which fundamentally addresses the issue of light‐accelerated shuttling. As a result, the photo‐assisted Li–S batteries deliver a reversible capability of 1090.21 mAh g−1 at 0.2 C with a capacity retention of 82.91% over 150 cycles, and a superior rate capability of 673.58 mAh g−1 at 5 C. The findings are promising in advancing the design principles for photo‐rechargeable Li−S batteries. [ABSTRACT FROM AUTHOR]

The document is a contents list for the journal Chemical Society Reviews. It provides the ISSN, CODEN, and date of publication. The contents list includes tutorial reviews, cover images, and various review articles on topics such as lectin ligands, fluorescent labeling of cellular proteins, conducting MOFs, C-N cross-coupling, proteolysis-targeting drug delivery systems, closed-loop recyclable polymers, structured liquids, and metal chalcogenide nanocrystals. The document also mentions approved training courses offered by the Royal Society of Chemistry. [Extracted from the article]

Catalysis plays a crucial role in advancing sustainability. The unique reactivity of frustrated Lewis pairs (FLPs) is driving an ever-growing interest in the transition metal-free transformation of small molecules like CO2 into valuable products. In this area, there is a recent growing incentive to heterogenize molecular FLPs into porous solids, merging the benefits of homogeneous and heterogeneous catalysis – high activity, selectivity, and recyclability. Despite the progress, challenges remain in preventing deactivation, poisoning, and simplifying catalyst-product separation. This review explores the expanding field of FLPs in catalysis, covering existing molecular FLPs for CO2 hydrogenation and recent efforts to design heterogeneous porous systems from both experimental and theoretical perspectives. Section 2 discusses experimental examples of CO2 hydrogenation by molecular FLPs, starting with stoichiometric reactions and advancing to catalytic ones. It then examines attempts to immobilize FLPs in porous matrices, including siliceous solids, metal–organic frameworks (MOFs), covalent organic frameworks, and disordered polymers, highlighting current limitations and challenges. Section 3 then reviews computational studies on the mechanistic details of CO2 hydrogenation, focusing on H2 splitting and hydride/proton transfer steps, summarizing efforts to establish structure–activity relationships. It also covers the computational aspects on grafting FLPs inside MOFs. Finally, Section 4 summarizes the main design principles established so far, while addressing the complexities of translating computational approaches into the experimental realm, particularly in heterogeneous systems. This section underscores the need to strengthen the dialogue between theoretical and experimental approaches in this field. [ABSTRACT FROM AUTHOR]

Unreactive C‐H bond activation is a new horizon for frustrated Lewis pairs (FLPs) chemistry. Although concerted mechanism (Science 2015, 349, 513) and stepwise carbene mechanism (Org. Lett. 2018, 20, 1102) have been proposed for the FLPs catalyzed C‐H bond activation of 1‐methylpyrrole, the influence of electronic properties of FLPs on the reaction mechanism is far away from well‐understood. In this study, an assortment of P‐B type FLPs with different electronic characteristic was employed to study the catalyzed C‐H bond activation of 1‐methylpyrrole by using density functional theory calculations. Detailed calculations demonstrated that the reactivity variation and the reaction mechanism binary of FLPs catalyzed C‐H activation can be varied by tuning electronic effect of Lewis base center. On the one hand, the concerted C‐H activation reactivity is mainly controlled by the electron donation of the lone pair of Lewis base center; thus, the FLPs with electron‐donating substituents (FLP1, FLP2, and FLP3) catalyzed the C‐H bond activation through concerted mechanism. On the other hand, the reactivity of stepwise carbene mechanism is mostly attributed to the vacant orbital of Lewis acid center; as a result, the FLP5 bearing ‐P(C6F5)2 preferred to catalyzed the bond activation through concerted mechanism. In contrast, a metathesis mechanism through strained four‐membered ring transition state is less feasible. These results should provide deeper insight and broader perspective to understand the structure and function of FLPs for rational design of FLPs catalyzed C‐H bond activation. [ABSTRACT FROM AUTHOR]

Heterocycles containing both phosphorus and nitrogen have seen increasing use in recent years in luminescent materials, coordination chemistry and as building blocks for inorganic polymers, yet their chemistry is currently dominated by five- and six-membered derivatives. Seven-membered P/N heterocycles are comparatively scarce and lack general, high yielding syntheses. Here, we explore the synthesis and characterisation of 1,2,5-diazaphosphepines from azophosphines. The mechanism has been probed in detail with both computational and experimental studies supporting a stepwise mechanism to form a five-membered ring, and subsequent ring expansion to the diazaphosphepine. Regioselective synthesis of five- and seven-membered rings is possible using asymmetric alkynes. The Lewis acidic borane B(C6F5)3 could either catalyse the formation of the seven-membered ring (iPr derivative) or trap out a key intermediate via a frustrated Lewis pair (FLP) mechanism (tBu derivative). [ABSTRACT FROM AUTHOR]

Due to their molecular topology, atropisomers serve as highly valuable chiral frameworks for diverse applications across academic research and industry. Despite the availability of numerous established catalytic methods for their synthesis, there is still a high demand for the development of novel and resourceful strategies. In this concept article, we will detail our studies on the use of transient Lewis acid‐base interactions (LABI) as a dynamization strategy for the synthesis of (hetero)biaryl atropisomers by Dynamic Kinetic Resolution (DKR). The formation of cyclic transition states, resulting from the interaction between an acidic functionality and a basic counterpart, plays a key role in facilitating racemization by substantially reducing the barrier to atropisomerization. In this scenario, we have employed transformations aimed at neutralizing the acidic nature of the Lewis acid, ultimately leading to the formation of configurationally stable enantioenriched compounds. The design of substrates and the employment of stereoselective strategies based on transition metal and biocatalysis for their resolution is detailed. Specific emphasis on the preparation of axially chiral motifs commonly found in catalysis or medicinal chemistry will also be given. [ABSTRACT FROM AUTHOR]

Frustrated Lewis pairs (FLPs), composed of spatially hindered Lewis acids and bases, are promising catalysts for the catalytic hydrogenation of unsaturated organic substrates, but the lack of reusability limits their development. The functionalization of solid materials with molecular FLP is a promising method for preparing heterogeneous FLP catalysts. In this work, a magnetically recyclable FLP catalyst was successfully prepared for the reductive carbonyl compounds to the corresponding alcohols. FLP of 2‐Ph2PPhCHO/B(C6F5)3 was grafted into NH2‐MIL‐101@Fe3O4 composite material through an aldehyde‐amine condensation reaction. The as‐prepared FLP‐NH‐MIL‐101@Fe3O4 exhibited remarkable catalytic activity for aldehyde/ketone carbonyl compounds. In addition, FLP‐NH‐MIL‐101@Fe3O4 displays outstanding magnetic recyclability and can be reused 8 times without loss of activity. [ABSTRACT FROM AUTHOR]

Kinetic frustrated Lewis pairs (FLP) allow facile cleavage of a number of E-H bonds (E = H, Si, C, B) where both the Lewis base and Lewis acid are involved in the bond activation transition state. More recently, kinetic FLP systems have been extended to the cleavage of C-X (X = F, Cl, Br) bonds. We report on the role of sodium tetrakis(pentafluorophenyl)borate in the benzylation of triarylphosphines, where the sodium cation and phosphine support a kinetic FLP type transition state. [ABSTRACT FROM AUTHOR]

A series of new luminescent bimetallic platinum(II) complexes with stimuli‐responsive flexible Lewis pair (FlexLP) ligands are described. The FlexLP ligands consist of a dimesitylboron Lewis acid and diphenylphosphine oxide Lewis base which are in equilibrium between the unbound open form and the Lewis adduct, controlled by the hydrogen bond donating strength of the solvent. Spectroscopic techniques and density functional theory (DFT) calculations were used to interpret the photophysics of the platinum(II) complexes. All complexes exhibit tunable absorption in the region of 300–500 nm and green to orange photoluminescence, depending on the ratio of weak (THF) to strong (MeOH) hydrogen bond donating solvent employed. Spectroscopic and computational data shows that phosphine and peripheral acetylide ligands on the platinum(II) centers have limited influence on the emission energy, indicating the emission originates from the FlexLP‐dominated fluorescence. Using time‐resolved transient absorption spectroscopy it is shown that the complexes undergo intersystem crossing (ISC) to the triplet excited state upon photoexcitation, and the ISC efficiency is affected by the peripheral acetylide ligands. The triplet excited state lifetime can also be manipulated by the state of the FlexLP ligand, with the closed form complexes having longer lifetimes than the open form complexes. [ABSTRACT FROM AUTHOR]

The adducts 2M,R of general formula trans‐[(L)M{R2P(CH2)2PR2}2{N2B(C6F5)3}] (L=ø or N2, M=Mo or W, R=Et or Ph), formed from Lewis acid‐base pairing of B(C6F5)3 to a dinitrogen ligand of zero‐valent group 6 bis(phosphine) complexes trans‐[M{R2P(CH2)2PR2}2(N2)2] are shown to react with dihydrogen to afford hepta‐coordinated bis(hydride) complexes [M(H)2{R2P(CH2)2PR2}{N2B(C6F5)3}] 3M,R which feature the rare ability to activate both dinitrogen and dihydrogen at a single metal center, except in the case where M=Mo and R=Ph for which fast precipitation of insoluble [Mo(H)4(dppe)2] (dppe=1,2‐bis(diphenylphosphino)ethane) occurs. The frustrated Lewis pair (FLP)‐related reactivity of the B−N linkage in compounds 3W,R was explored and led to distal N functionalization without involvement of the hydride ligands. It is shown in one example that the resulting bis(hydride) diazenido compounds may also be obtained through a sequence involving first FLP‐type N‐functionalization followed by oxidative addition of H2. Those oily compounds were found to have limited stability in solution or in their isolated states. Finally, treatment of 3W,Et with the Lewis base N,N‐dimethylaminopyridine (DMAP) affords the simple but unknown bis(hydride)‐dinitrogen species [W(H)2(depe)2(N2)] 11Et (depe=1,2‐bis(diethylphosphino)ethane) which direct, selective formation from trans‐[W(N2)2(depe)2] is not possible. [ABSTRACT FROM AUTHOR]

The electrochemical reduction of nitrates (NO3RR) for ammonia synthesis at room temperature holds immense potential. One key challenge is the adsorption and activation of NO3−, along with the provision of sufficient active hydrogen to accelerate the hydrogenation process. Here, the study prepares N‐doped TiO2‐x supported by Zr single atoms (Zr‐TiON) with rich oxygen vacancies (Ov), in which unsaturated Zr (Lewis acidic, LA) sites together with oxygen atoms around Ov (Lewis base, LB) form frustrated Lewis acid‐base pairs (FLPs). At −60 mA cm−2, NH3 Faradaic efficiency reaches 94.8%, corresponding to the production rate of 663.15 µmol h−1 mgcat−1. The yield rate is up to 26.16 mmol h−1mgcat−1 at −1 A cm−2 in flowing electrolyzer. Theoretical calculations and in situ spectroscopy analysis reveal that the interaction between LA and LB sites in FLPs plays a crucial role in facilitating adsorption and activation of electron‐rich NO3− and electron‐deficient *H. The presence of enhanced FLPs significantly reduces the energy barrier for H2O dissociation, lowering it to 0.20 eV, which facilitates subsequent hydrogenation reactions. The abundance of *H accelerates hydrogenation process, thereby enhancing the activity of NO3RR. This FLP design offers a promising approach for paving the way for the development of highly efficient NO3RR catalysts. [ABSTRACT FROM AUTHOR]

The creation of frustrated Lewis pairs on catalyst surface is an effective strategy for tuning CO2 activation. The critical step in the formation of frustrated Lewis pairs is the spatial effect of proximal Lewis acid‐Lewis base pairs. Here, we demonstrate a facile surface functionalization methodology that enables hydrogen bonding between N and H atoms to mediate the construction of frustrated Lewis pairs in poly(heptazine imide), thereby increasing the propensity to activate CO2 molecules. Experimental and theoretical results show that the construction of active hydrogen bonding regions can facilitate the bending of CO2 molecules. Furthermore, the delocalization of electron clouds induced by the hydrogen bonding‐mediated frustrated Lewis pairs can promote the heterolytic cleavage and photocatalytic conversion of CO2. This work highlights the potential of utilizing hydrogen bonding‐mediated strategy in heterogeneously photocatalytic activation of CO2 over polymer materials. [ABSTRACT FROM AUTHOR]

Dihydrogen activation is the paradigmatic reaction of frustrated Lewis pairs (FLPs). While trigonal‐planar Lewis acids have been well established in this transformation, tetrahedral Lewis acids are surprisingly limited. Indeed, several cases were computed as thermodynamically and kinetically feasible but exhibit puzzling discrepancies with experimental results. In the present study, a computational investigation of the factors influencing dihydrogen activation are considered by large ensemble sampling of encounter complexes, deformation energies and the activation strain model for a silicon/nitrogen FLP and compared with a boron/phosphorous FLP. The analysis adds the previously missing dimension of Lewis acids' structural flexibility as a factor that influences preexponential terms beyond pure transition state energies. It sheds light on the origin of "overfrustration" (defined herein), indicates structural constraint in Lewis acids as a linchpin for activation of weak donor substrates, and allows drawing a more refined mechanistic picture of this emblematic reactivity. [ABSTRACT FROM AUTHOR]

Reaction of a nucleophilic germylene Ge[CH(SiMe3)2]2 with the phosphanyl phosphaketene [{(H2C)(NDipp)}2P]PCO induces decarbonylation to form a phosphanyl phosphagermene [{(H2C)(NDipp)}2P]P=Ge[CH(SiMe3)2]2 (1; Dipp=2,6‐diisopropyl‐phenyl). Addition of CO2 or MeCN to 1 results in [3+2]‐cycloaddition reactions to afford five‐membered heterocycles. This mode of reactivity is reminiscent of that observed for frustrated Lewis pairs, with the pendant phosphanyl group acting as a base and the germanium center as a Lewis acid. Contrastingly, 1,2‐addition across the P=Ge bond was observed when using ammonia, small primary amines (NH2nP), or metal complexes (e. g. Au(PPh3)Cl and ZnEt2). These latter reactions allow for the one‐step synthesis of metal phosphide complexes. [ABSTRACT FROM AUTHOR]

This review article describes the development of the use of aluminum compounds in the chemistry of frustrated Lewis pairs (FLPs) over the last 14 years. It also discusses the synthesis, reactivity and catalytic applications of intermolecular, intramolecular and so‐called hidden FLPs with phosphorus, nitrogen and carbon Lewis bases. The intrinsically higher acidity of aluminum compounds compared to their boron analogs opens up different reaction pathways. The results are presented in a more or less chronological order. It is shown that Al FLPs react with a variety of polar and non‐polar substrates and form both stable adducts and reversibly activate bonds. Consequently, some catalytic applications of the title compounds were presented such as dimerization of alkynes, hydrogenation of tert‐butyl ethylene and imines, C−F bond activation, reduction of CO2, dehydrogenation of amine borane and transfer of ammonia. In addition, various Al FLPs were used as initiators in polymerization reactions. [ABSTRACT FROM AUTHOR]

The first examples of RE/Si FLPs (RE: rare-earth metal, FLPs: frustrated Lewis pairs), namely Yb/Si FLPs were synthesized, where Yb⋯Si distances are in the range of 3.55 to 3.72 Å. These FLPs react with triphenylphosphine sulfide and aryl isocyanide to produce novel silylyne group transfer products through dissociation of naphthalene. [ABSTRACT FROM AUTHOR]

Xanthene‐backbone FLPs featuring secondary borane functions −B(ArX)H (where ArX=C6F5 (ArF) or C6Cl5 (ArCl)) have been targeted through reactions of the dihydroboranes Me2S ⋅ BArXH2 with [4,5‐xanth(PR2)Li]2 (R=Ph, iPr), and investigated in the synthesis of related cationic systems via hydride abstraction. The reactivity of these systems (both cationic and charge neutral) with ammonia have been probed, with a view to probing the potential for proton shuttling via N−H bond 'activation.' We find that in the case of four‐coordinate boron systems (cationic or change neutral), the N−H linkage remains intact, supported by a NH⋅⋅⋅P hydrogen bond which is worth up to 17 kcal mol−1 thermodynamically, and enabled by planarization of the flexible xanthene scaffold. For cationic three coordinate systems, N‐to‐P proton transfer is viable, driven by the ability of the boron centre to stabilise the [NH2]− conjugate base through N‐to‐B π bonding. This proton transfer can be shown to be reversible in the presence of excess ammonia, depending on the nature of the B‐bound ArX group. It is viable in the case of C6F5 substituents, but is prevented by the more sterically encumbering and secondary donor‐stabilising capabilities of the C6Cl5 substituent. [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]

Sterically hindered pyridines embedded in a three‐dimensional triptycene framework have been synthesized, and their resolution by chiral HPLC enabled access to unprecedented enantiopure pyridines exceeding the known steric limits. The design principles for new axially chiral pyridine derivatives are then described. To rationalize their associations with Lewis acids and transition metals, a comprehensive determination of the steric and electronic parameters for this new class of pyridines was performed. This led to the general parameterization of the steric parameters (percent buried volume %VBur, Tolman cone angle θ, and He8_steric descriptor) for a large set of two‐ and three‐dimensional pyridine derivatives. These parameters are shown to describe quantitatively their interactions with carbon‐ and boron‐centered Lewis acids and were used to predict the ΔG° of association with the prototypical B(C6F5)3 Lewis acid widely used in frustrated Lewis pair catalysis. This first parameterization of pyridine sterics is a fundamental basis for the future development of predictive reactivity models and for guiding new applications of bulky and chiral pyridines in organocatalysis, frustrated Lewis pairs, and transition‐metal catalysis. [ABSTRACT FROM AUTHOR]

B(C6F5)3 and the corresponding anion [B(C6F5)4]− are ubiquitous in main group and transition metal chemistry. Known derivatives are generally limited to the incorporation of electron donating substituents. Herein we describe electrophilic fluorination and dearomatization of such species using XeF2 in the presence of BF3 or Lewis acidic cations. In this fashion the anions [HB(C6F5)3]−, [B(C6F5)4]− and [(C6F5)3BC≡NB(C6F5)3]−, are converted to [FB(C6F7)3]−, [B(C6F7)4]−, and [(C6F7)3BC≡NB(C6F7)3]−, respectively. Similarly, the borane adducts (L)B(C6F7)3 (L=MeCN, OPEt3) are produced. These rare examples of electrophilic attack of electron deficient rings proceed as [XeF][BF4] acts as a frustrated Lewis pair effecting fluorination and dearomatization of C6F5 rings. [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]

The reactions of the frustrated Lewis pair (F5C2)2SbCH2P(tBu)2 with oxygen, sulphur, selenium and tellurium led to the mono-oxidation products (F5C2)2SbCH2P(E)(tBu)2 (E = O, S, Se, Te). Further oxidation of these chalcogen adducts with tetrachloro-ortho-benzoquinone (o-chloranil) gave (F5C2)2Sb(CH2)(μ-E)P(tBu)2·CatCl (CatCl = o-O2C6Cl4) with a central four-membered ring heterocycle for E = O, S, and Se. For E = Te the elimination of elemental tellurium led to an oxidation product with two equivalents of o-chloranil, (F5C2)2SbCH2P(tBu)2·2CatCl, which is also accessible by reaction of (F5C2)2SbCH2P(tBu)2 with o-chloranil. The synthesised compounds were characterised by NMR spectroscopy and X-ray structure analyses, and the structural properties were analysed in the light of the altered Lewis acidity due to the oxidation of the antimony atoms. [ABSTRACT FROM AUTHOR]