Phosphine Oxide Porous Organic Polymers Incorporating Cobalt(II) Ions: Synthesis, Characterization, and Investigation of H₂ Production

Abstract

Suitably functionalized porous matrices represent versatile platforms to support well-dispersed catalytic centers. In the present study, porous organic polymers (POPs) containing phosphine oxide groups were fabricated to bind transition metals and to be investigated for potential electrocatalytic applications. Cross-linking of mono- and di-phosphine monomers with multiple phenyl substituents was subject to the Friedel–Crafts (F-C) reaction and the oxidation process, which generated phosphine oxide porous polymers with pore capacity up to 0.92 cm3/g and a surface area of about 990 m2/g. The formation of the R3P·BH3 borohydride adduct during synthesis allows to extend the library of phosphine-based monomeric entities when using FeCl3. The porous polymers were loaded with 0.8–4.2 w/w % of cobalt­(II) and behaved as hydrogen evolution reaction (HER) catalysts with a Faradaic efficiency of up to 95% (5.81 × 10–5 mol H2 per 11.76 C) and a stable current density during repeated controlled potential experiments (CPE), even though with high overpotentials (0.53–0.68 V to reach a current density of 1 mA·cm–2). These studies open the way to the effectiveness of tailored phosphine oxide POPs produced through an inexpensive and ecofriendly iron-based catalyst and for the insertion of transition metals in a porous architecture, enabling electrochemically driven activation of small molecules.

Facile Hydrogenolysis of Sugars to 1,2-Glycols by Ru@PPh3/OPPh3 Confined Large-Pore Mesoporous Silica

“…31 P of the SiP polymer shows chemical shift values of −5.9 and 25.7 ppm corresponding to tertiary phosphorus and quaternary phosphorus sites. 44 The larger peak resonating at 25.7 ppm is dominating in SiP, which agrees with the presence of P−O, apart from free PPh 3 . After Ruincorporation, chemical shift values of the corresponding P−O and C−P bands in Ru@SiP becomes slightly red-shifted, possibly due to the interaction among functional ligands and Ru.…”

“…31 P solid-state NMR spectra of SiP and Ru@SiP are shown in Figure . 31 P of the SiP polymer shows chemical shift values of −5.9 and 25.7 ppm corresponding to tertiary phosphorus and quaternary phosphorus sites . The larger peak resonating at 25.7 ppm is dominating in SiP, which agrees with the presence of P–O, apart from free PPh 3 .…”

A cobalt harnessed phenanthroline and triphenylamine-based conjugated mesoporous polymer designed by a donor–acceptor approach for trifunctional electrocatalysis

“…1 and S5 †). [16][17][18] The cobalt tends to exist in Co(0) and Co(II) states near the TBPA unit and phenanthroline moiety, 19,20 respectively.…”

C- and N-Phosphorylated Enamines—An Avenue to Heterocycles: NMR Spectroscopy

“…The development of efficient and reliable methods for the formation of carbon-phosphorus bonds is of great importance in connection with the widespread use of organophosphorus compounds in chemistry, materials science and biology. In recent years, interest in functionalized organophosphorus compounds has been steadily increasing, as evidenced by a large number of publications in the field of their chemical and structural studies [86][87][88][89][90][91][92]. It should be noted that the skillful use of phosphorus pentachloride as a phosphorylating agent for derivatives of enamines, enamides, tertiary amines, acetyl ureas and other nucleophiles leads to the production of various Cand N-chlorophosphorylated compounds, which, under certain conditions, are transformed to form promising nitrogen-and phosphoruscontaining heterocyclic systems of diverse structures.…”