Facile Reversibility by Design: Tuning Small Molecule Capture and Activation by Single Component Frustrated Lewis Pairs

Abstract

A series of single component FLPs has been investigated for small molecule capture, with the finding that through tuning of both the thermodynamics of binding/activation and the degree of preorganization (i.e., ΔS(⧧)) reversibility can be brought about at (or close to) room temperature. Thus, the dimethylxanthene system {(C6H4)2(O)CMe2}(PMes2)(B(C6F5)2): (i) heterolytically cleaves dihydrogen to give an equilibrium mixture of FLP and H2 activation product in solution at room temperature and (ii) reversibly captures nitrous oxide (uptake at room temperature, 1 atm; release at 323 K).

Solid frustrated-Lewis-pair catalysts constructed by regulations on surface defects of porous nanorods of CeO2

“…In general, the key features of organic molecules FLP catalysts are defined as the independent Lewis acid and base in the presence of sterically substituents on Lewis acid and base to preclude the formation of the classical Lewis acid–base adducts3061. Addition of any other small Lewis acid or base molecules results in the formation of adducts and completely blocks the catalytic activity of FLP catalysts during the catalytic process91228. On the basis of the known essentiality of molecular FLP catalysts and a strong correlation between the hydrogenation activity and surface properties of PN -CeO 2 with coexistence of Lewis acid and base in current system, it's logical to rationalize the PN -CeO 2 as all-solid FLP catalysts.…”

“…Hydrogen activation by either transition metal complexes or metal-based heterogeneous catalysts have been well developed and successfully applied for various reactions4. Recently, frustrated Lewis pairs (FLPs), Lewis acids and bases that are sterically prevented from interaction to form Lewis acid–base adjuncts, can efficiently and cooperatively activate many small molecules (for example, H 2 , CO 2 , and NO) and even strong C–H bond for important catalytic reactions including hydrogenation, hydroamination and carbon dioxide reduction5678910111213141516171819202122232425.…”

Fluorinated antimony(v) derivatives: strong Lewis acidic properties and application to the complexation of formaldehyde in aqueous solutions

“…This unique reactivity, which is accompanied by a colourimetric turn-off response, can be implemented using dilute aqueous formaldehyde solutions thereby demonstrating the potential that this frustrated Lewis pair chemistry holds in the domain of molecular recognition and sensing. 65 …”

Extending the Toolbox for the Modular Arrangement of Functions at Xanthene/Dibenzofuran Platforms: Introduction of Directly Linked Transition Metals beside Bismuthanes

“…The Bi III ··· Pd II distance in 2 is 4.0641(8) Å, which is similar to known xanthene based systems containing two functions at C4/C5 positions. [1a], [3a] Furthermore the two complex metal fragments are oriented towards each other in a way that in principal allows reactivity between the two functions: the filled d z ² orbital on the palladium atom should be oriented in the direction of the unoccupied σ* orbital of a Bi–C bond of the phenyl substituents and this is supported by Density functional calculations (B3LYP/def2‐SVP,def2‐TZVP). Figure shows the two corresponding orbitals revealed by Natural Bond Orbital (NBO) analysis, directed towards each other.…”

“…Resulting compounds proved capable of activating substrates like O 2 ,[1b], N 2 O, H 2 [1a], H 2 O,[1b] and CO 2 [1b].…”