Catalysts with Co nanoparticles (NPs) entrapped in N,S‐codoped carbon shells were successfully fabricated by pyrolysis of porous organic polymers (POPs) with cobalt salts. The encapsulated structure consisting of Co NPs and N,S‐codoped carbon layers was verified by TEM, XRD, and X‐ray photoelectron spectroscopy. The catalysts displayed excellent activity and stability for the catalytic transfer hydrogenation (CTH) of nitrobenzene with formic acid under base‐free conditions. Furthermore, the resultant catalysts allowed for highly efficient and selective transfer hydrogenation of various functionalized nitroarenes to the corresponding anilines. Through control experiments, the covered Co NPs were identified as active sites for CTH. The incorporation of S into the N‐doped carbon lattice promoted the electron transfer from metallic cobalt NPs to their shells, which played a significant role in the acceleration of CTH. Moreover, the Co‐NSPC‐850 catalyst pyrolyzed at 850 °C showed excellent stability in the recycling experiments.

The first examples of porphyrin analogues incorporating pyrene units are reported. Acid-catalyzed condensation of a pyrene dialdehyde with a tripyrrane, followed by oxidation with DDQ, afforded a polycyclic aromatic hydrocarbon (PAH)-porphyrin hybrid in 38% yield. Pyreniporphyrin proved to be devoid of global aromatic character, but upon protonation aromatic mono- and dicationic species were generated. In the proton NMR spectrum for the dication, the internal CH was shifted upfield to approximately +3 ppm. NICS calculations and ACID plots confirmed the diatropic nature of these structures. Pyreniporphyrin reacted with palladium(II) acetate to give excellent yields of a palladium(II) complex that showed weakly diatropic properties. Treatment of the pyrene dialdehyde with phenylmagnesium bromide generated a dicarbinol that reacted with excess pyrrole in the presence of boron trifluoride etherate to give a tripyrrane analogue. Lewis acid catalyzed ring closure with a thiophene dialcohol in 2% ethanol-dichloromethane afforded a tetraphenylthiapyreniporphyrin in 31% yield. This porphyrinoid was nonaromatic in the free-base form but showed significant diatropicity upon protonation. These results demonstrate that PAH-porphyrin hybrids are easily accessible, and this strategy may allow the incorporation of even larger aromatic subunits.

Herein, N,S-codoped carbon materials embedded with ultrafine and well-distributed Co nanoparticles (1.14 wt % Co) were prepared through pyrolysis of the hybrids of SNW-1 and Co(Ac) 2 coated with glucose. It was observed by TEM and XRD that Co nanoparticles (NPs) were entrapped in doped carbon shells uniformly. The glucose coating presented a significant impact on the size distribution of Co NPs and doped modes of heteroatoms, especially the S species. The catalyst displayed outstanding activity for catalytic transfer hydrogenation (CTH) with formic acid under the base-free system. Encouragingly, diverse secondary amines were produced in excellent yields through the domino reaction of hydrogenation and reductive amination. Remarkably, the catalyst with ultrafine Co NPs showed good durability under harsh reaction conditions and displayed no significant loss in both activity and selectivity in 5 runs. This was attributed to the protection of constructed N,S dual-doped carbon shells. Hence, we offer an alternative strategy for the construction of dualdoped carbon materials trapped with ultrafine transition metal, which can be further applied in various catalytic processes.

A diiron hexacarbonyl complex containing bridging phenanthrene‐4,5‐dithiolate ligand is prepared by oxidative addition of Phenanthro[4,5‐cde][1,2]dithiin to Fe2(CO)9. The complex is investigated as a model for the active site of the [Fe–Fe] hydrogenase enzyme. The compound, [(μ‐PNT)Fe2(CO)6]; (PNT = phenanthrene‐4,5‐dithiolate), was characterized by spectroscopic methods (IR, UV/Vis and NMR) and X‐ray crystallography. The IR and proton NMR spectra of [(μ‐PNT)Fe2(CO)6] (4) are in agreement with a PNT ligand attached to a Fe2(CO)6 core. The infrared spectrum of 4 recorded in dichloromethane contains three peaks at 2001, 2040, and 2075 cm–1 corresponding to the stretching frequency of terminal metal carbonyls. X‐ray crystallographic study unequivocally confirms the structure of the complex having a butterfly shape with an Fe–Fe bond length of 2.5365 Å close to that of the enzyme (2.6 Å). Electrochemical properties of [(μ‐PNT)Fe2(CO)6] have been investigated by cyclic voltammetry. The cyclic voltammogram of [(μ‐PNT)Fe2(CO)6] recorded in acetonitrile contains one quasi‐irreversible reduction (E1/2 = –0.84 V vs. Ag/AgCl, Ipc/Ipa = 0.6, ΔEp = 131 V at 0.1 V·s–1) and one irreversible oxidation (Epa = 0.86 V vs. Ag/AgCl). The redox of [(μ‐PNT)Fe2(CO)6] at E1/2 = –0.84 V can be assigned to the one‐electron transfer processes; [FeI–FeI] → [FeI–Fe0] and [FeI–Fe0] → [FeI–FeI].

Ceria promoted Co@NC (NC, N doped carbon) catalysts are prepared by pyrolysis of biomass materials. Characterization results indicate ceria and Co species facilitate the distribution of each other due to...