Boronate Covalent and Hybrid Organic Frameworks Featuring P^III and P=O Lewis Base Sites

Abstract

Two covalent organic frameworks comprising Lewis basic P III centers and Lewis acidic boron atoms were prepared by poly-condensation reactions of newly obtained tris(4-diisopropoxyborylphenyl)phosphine with 2,3,6,7,10,11hexahydroxytriphenylene and 2,3,6,7-tetrahydroxy-9,10-dimethylanthracene. Obtained materials exhibit significant sorption of dihydrogen (100 cm 3 g À1 at 1 bar at 77 K), methane (20 cm 3 g À1 at 1 bar at 273 K) and carbon dioxide (50 cm 3 g À1 at 1 bar at 273 K). They were exploited as solidstate ligands for coordination of Pd 0 centers. Alternatively, in a bottom-up approach, boronated phosphine was treated with Pd 2 dba 3 and poly-condensated, yielding hybrid materials where the polymer networks are formed by means of covalent boronate linkages and coordination PÀPd bonds. In addition, the analogous materials based on phosphine oxide were synthesized. The DFT calculations on framework-guest interactions revealed that the behavior of adjacent boron and phosphorus/phosphine oxide centers is reminiscent of that found in Frustrated Lewis Pairs and may improve sorption of selected molecules.

Covalent organic frameworks anchored with frustrated Lewis pairs for hydrogenation of alkynes with H2

“…Generally, there are two routes to introduce the catalyst into COFs, pre-synthetic functionalization and post-synthetic functionalization. 38,39 It is well known that the solubility, spatial conguration and reactivity of linkers containing functional groups are essentially different from those of original linkers, which is very challenging for the synthesis of COFs. 40 In order to avoid these obstacles, the postsynthetic modication strategy has been extensively investigated to introduce catalytic functional groups onto the pore walls of COFs, paving the way for the synthesis of COF supported heterogeneous catalysts.…”

Palladium Nanoparticles Inset into the Carbon Sphere with Robust Acid Resistance for Selective Hydrogenation of Chloronitrobenzene

“…3 Clearly, compared with CS, the pyrrolic-N peak of Pd/SCS7 positively shifts 0.2 eV from 400 to 400.2 eV. Meanwhile, a negative shift for Pd 0 , compared with previous reports, 53,54 is observed. These shifts of binding energy indicate the electron transfer from pyrrolic-N to Pd nanoparticles, and electron-rich Pd nanoparticles are beneficial to improve the selectivity of halogenated nitrobenzenes.…”

Phosphine‐Functionalized Porous Materials for Catalytic Organic Synthesis

“…[34] Tris(pbromophenyl)phosphine underwent triple halogen-metal exchange and subsequent borylation with triisopropyl borate and treatment with Me 3 SiCl to yield the desired product. It was used in the ester form since the free acid was in equilibrium with the hydrated zwitterion and thus not suitable [56] .…”

“…The solids were poorly crystalline, showing only short-range order by synchrotron-light PXRD, and porous, with BET surface area of 669 and 530 m 2 /g respectively and broad pore size distribution. [56] Palladium-functionalized BP1 and BP2 were prepared with two different approaches: by polymerizing palladium complexes with phosphine monomers and by PSM of the P-COFs with Pd 2 (dba) 3 . XPS analyses demonstrated that the PSM strategy introduces a larger amount of palladium in the solids but promotes the formation of metal NPs instead of palladium-phosphine complexes.…”