Potential of nonporous adaptive crystals for hydrocarbon separation

Chemical Society Reviews, Journal Year: 2023, Volume and Issue: 52(17), P. 6075 - 6119

Published: Jan. 1, 2023

The adsorptive separation based on nonporous adaptive crystals (NACs) is an attractive green technology. Herein, we comprehensively summarize recent advances in various supramolecular hosts-based NACs for hydrocarbon separation.

Language: Английский

---

Organocatalytic Asymmetric Synthesis of o-Carboranyl Amines

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 14, 2025

Carboranyl amines are distinct from typical organic amines. Due to the electronic influence of carborane cage, they have low nucleophilicity and reluctant alkylate. Moreover, asymmetric synthesis chiral carboranes is still in its infancy. Herein we achieved first catalytic N-alkylation o-carboranyl amine, providing general access diverse secondary with high efficiency enantioselectivity under mild conditions. For time, organocatalysis was introduced chemistry. Key success use situ generated (naphtho-)quinone methides as alkylating reagents suitable acid catalysts. This protocol also applicable S-alkylation 1-SH-o-C2B10H11. Control experiments kinetic studies provided important insights into reaction mechanism, which likely involves rate-determining generation quinone methide followed by fast enantio-determining nucleophilic addition.

Language: Английский

---

Modifying Enzymatic Substrate Binding within a Metal–Organic Capsule for Supramolecular Catalysis

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(18), P. 10136 - 10148

Published: April 27, 2023

Supramolecular catalysis is established to modify reaction kinetics by substrate encapsulation, but manipulating the thermodynamics of electron-transfer reactions remains unexplored. Herein, we reported a new microenvironment-shielding approach induce an anodic shift in redox potentials hydrazine substrates, reminiscent enzymatic activation for N–N bond cleavage within metal–organic capsule H1. Equipped with catalytic active cobalt sites and substrate-binding amide groups, H1 encapsulated hydrazines form substrate-involving clathration intermediate, triggering reduction when electrons were acquired from electron donors. Compared free hydrazines, conceptual molecular confined microenvironment decreases Gibbs energy (up −70 kJ mol–1), which relevant initial reaction. Kinetic experiments demonstrate Michaelis–Menten mechanism, involves formation pre-equilibrium substrate-binding, followed cleavage. Then, distal N released as NH3 product squeezed. Integrating fluorescein into enabled photoreduction N2H4 rate ca. 1530 nmol min–1 ammonia, comparable that natural MoFe proteins; thus, provides attractive manifold toward mimicking activation.

Language: Английский

---

Structural Switching of a Distorted Trigonal Metal‐Organic Cage to a Tetragonal Cage and Singlet Oxygen Mediated Oxidations

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(28)

Published: May 11, 2023

Construction of metal-organic cages with unique architecture and guest binding abilities is highly desirable. Herein, we report the synthesis a distorted trigonal cage (1) from twisted tetratopic ligand (L) PdII acceptor. Surprisingly, 1 exhibited complete structural reorganization its building units in presence C70 C60 to form guest-encapsulated tetragonal cages, (C70 )2 @2 (C60 @2, respectively. These guest-bound were found be potential O2 generators, former effectively catalyzing two different varieties -mediated oxidation reactions.

Language: Английский

---

Supramolecular Architectures Bearing Half-Sandwich Iridium- or Rhodium-Based Carboranes: Design, Synthesis, and Applications

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(36), P. 19440 - 19457

Published: Aug. 29, 2023

The utilization of carboranes in supramolecular chemistry has attracted considerable attention. unique spatial configuration and weak interaction forces can help to explore the properties complexes, particularly via host–guest chemistry. Additionally, certain difficulties encountered carborane development─such as controlled B–H bond activation─can be overcome by judiciously selecting metal centers their adjacent ligands. However, few studies are being conducted this nascent research area. With advances field, novel carborane-based complexes will likely prepared, structurally characterized, intrinsically investigated. To expedite these efforts, we present major findings from recent studies, including π–π interactions, associations, steric effects, which have been leveraged implement a regioselective process for activating B(2,9)–, B(2,8)–, B(2,7)–H bonds para-carboranes B(4,7)–H ortho-carboranes. Future should clarify interactions potential enhancing utility complexes. Although exhibit several (such dihydrogen-bond [Bδ+–Hδ−···Hδ+–Cδ−], Bδ+–Hδ−···M+, Bδ+–Hδ−···π interactions), manner they utilized remains unclear. Supramolecular those based on chemistry, platform demonstrating applications interactions. Owing importance alkane separation, related recognition separation isomers primarily summarized. Advances certainly lead more possibilities

Language: Английский

---

B(9)-OH-o-Carboranes: Synthesis, Mechanism, and Property Exploration

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(13), P. 7331 - 7342

Published: March 24, 2023

Herein, we present a chemically robust and efficient synthesis route for B(9)-OH-o-carboranes by the oxidation of o-carboranes with commercially available 68% HNO3 under assistance trifluoromethanesulfonic acid (HOTf) hexafluoroisopropanol (HFIP). The reaction is highly wide scope carboranes, selectivity B(9)/B(8) up to 98:2. success this transformation relies on strong electrophilicity oxidizability HNO3, promoted through hydrogen bonds Brønsted HOTf solvent HFIP. Mechanism studies reveal that o-carborane involves an initial electrophilic attack atom at most electronegative B(9) o-carborane. In transformation, B-H bond nucleophilic site, which different from substitution reaction, where boron site. Therefore, oxidation-reduction mild conditions in N(V) → N(III) H(-I) H(I). derivatization 9-OH-o-carborane was further examined, carboranyl group successfully introduced amino acid, polyethylene glycol, biotin, deoxyuridine, saccharide. Undoubtedly, approach provides selective way rapid incorporation carborane moieties into small molecules application neutron capture therapy, requires targeted delivery boron-rich groups.

Language: Английский

---

Selective Synthesis and Structural Transformation of a 4‐Ravel Containing Four Crossings and Featuring Cp*Rh/Ir Fragments

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(20)

Published: March 17, 2023

Intricately interwoven topologies are continually being synthesized and ultimately equally versatile significant at the nanoscale level; however, reports concerning ravel structures, which highly entwined new topological species, extremely rare fraught with tremendous synthesis challenges. To solve problem, a tetrapodontic pyridine ligand L1 two types of olefinic bond units Cp*M-based building blocks (E1, M=Rh; E2, M=Ir) featuring large conjugated planes was prepared to perform self-assembly. Two unprecedented [5+10] icosanuclear molecular 4-ravels containing four crossings were obtained by parallel-displaced π⋅⋅⋅π interactions in single-step strategy. Remarkably, reversible structural transformations between 4-ravel corresponding metallocage could be realized concentration changes solvent- guest-induced effects. X-ray crystallographic data NMR spectroscopy provide full confirmation these phenomena.

Language: Английский

---

Dative Bonding Activation Enables Precise Functionalization of the Remote B–H Bond of nido-Carborane Clusters

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: unknown

Published: Sept. 13, 2024

The innovation of synthetic strategies for selective B-H functionalization is a pivotal objective in the realm boron cluster chemistry. However, precise, efficient, and rapid bond carboranes that distant from existing functional groups remains intractable owing to limited approaches site-selective control established methods. Herein, we report dative bonding activation strategy nonclassical remote site

Language: Английский

---

Host–Guest Interactions Induced Enhancement in Oxidase-Like Activity of a Benzothiadiazole Dye Inside an Aqueous Pd₈L₄ Barrel

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(36), P. 24901 - 24910

Published: Aug. 28, 2024

The effect of host–guest interactions on the chemistry encapsulated molecules is a fascinating field research that has gained momentum in recent years. Much work this been focused such catalysis and photoluminescence dyes. However, related photoinduced processes, as photoregulated oxidase-mimicking activity, not explored much. Herein, we report unique example enhancement oxidase-like activity benzothiadiazole dye (G1) water through encapsulation within M8L4 molecular barrel (1). Favorable helped guest G1 to have better electron transfer oxygen leading increased production superoxide radical anions activity. Furthermore, inside 1 also caused change redox potentials which after produced oxidizing agent than free G1. These phenomena combined enhance upon cage 1. present demonstrates processes.

Language: Английский

---

Copper Azide-based Complexes without Repulsive Steric Clashes between Azides for Advanced Primary Explosives

Chemical Engineering Journal, Journal Year: 2023, Volume and Issue: 472, P. 144982 - 144982

Published: July 22, 2023

Language: Английский

---