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Ferroptosis, a type of programmed cell death induced by the iron-dependent lipid hydroperoxide pathway, has attracted widespread attention. However, Fenton response-dependent ferroptosis has many limitations, such as insufficient reaction conditions in the tumor micro-environment. Here, we propose an all-in-one phototherapy nanoplatform consisting of iron-polydopamine (Fe-PDA), a folic acid-modified red blood cell membrane (FA-RBCm), and epirubicin (EPI), namely, Fe-PDA-EPI@FA-RBCm NPs, to achieve enhanced photothermal-ferroptosis effects via overcoming the limitations of the Fenton-like reaction. The results showed that the synthesized biomimetic nanoparticles could decompose hydrogen peroxide (H2O2) to generate hydroxyl radicals (˙OH), and further induce the non-apoptotic ferroptosis pathway. After irradiation with near-infrared (NIR) light, the uptake of Fe-PDA-EPI@FA-RBCm NPs by cells could be effectively promoted, and it presented impressive in vitro and in vivo photothermal properties. In vitro and in vivo results showed that laser irradiation could enhance ferroptosis by promoting the production of reactive oxygen species (ROS) and lipid peroxides, down-regulating the expression of glutathione peroxidase 4 (GPX4), and reducing the mitochondrial membrane potential. Furthermore, the photothermal-promoted ferroptosis and apoptosis pathways (photothermal therapy and chemotherapy) exhibited outstanding synergistic antitumor efficacy in vitro and in vivo, with an in vivo tumor inhibition rate as high as 76.95%. In conclusion, the construction of tumor-targeted biomimetic nanocarriers utilizing the advantageous properties of RBCm has been investigated as a potential anticancer strategy. [ABSTRACT FROM AUTHOR]

Copolymerization of urea and small molecules is an effective strategy to modify g-C3N4. To study in depth the important effects of the introduction of a small molecule moiety on the structure–property relationship of g-C3N4, in this paper, the copolymers MxCN (x = 5, 15, 25, 50, 100 mg) were synthesized from urea melt and different amounts of small molecule murexide by a one-pot method. The experimental results confirm that the addition of small molecule murexide can evoke the synergistic effect of reduced band gaps, enhanced visible light absorption and improved separation efficiency of photogenerated carriers. Benefiting from these merits, the optimized M25CN exhibits superior photocatalytic hydrogen production performance (6.1 mmol g−1 h−1) with an apparent quantum efficiency of about 7.5% at 420 nm, which is about five times higher than that of pristine CN. The degradation rate of tetracycline is about 97.6% in 2 h, and a possible degradation mechanism is proposed. This work provides a reference for the study of the effect of small molecule modified g-C3N4 on the photocatalytic performance. [ABSTRACT FROM AUTHOR]

The atom thickness of two-dimensional materials (2D) makes their physical and chemical properties vulnerable to external influences. In this study, we show that the electronic and optical properties of the MoS2 monolayer can be tuned by substrates (BN, g-GeC, and graphite). Based on first-principles calculations with the GW and GW plus Bethe–Salpeter equation (GW–BSE) approaches, we find that substrates provide effective dielectric screening to the electron–hole Coulomb interaction and result in reduced exciton binding energies in the MoS2 monolayer, which is more pronounced on graphite and GeC, due to more effective screening and stronger interfacial interaction, respectively. We further demonstrate that when the thickness of the substrate is increased, the exciton binding energy converges slowly due to the nonlocal nature of the screened Coulomb interaction, and encapsulating the MoS2 monolayer with the same substrate material further decreases the exciton binding energy due to increased screening. These results highlight the importance of substrate effects on the electronic and optical properties of a 2D semiconducting monolayer, and might offer an efficient way to tailor the performance of the relevant electronic and optoelectronic devices. [ABSTRACT FROM AUTHOR]

The substitution effect in chemistry is a concept that is probably too common to mention, while for a molecule with an elusive electronic structure, substitution can introduce an unusual effect that dramatically tunes the chemical process. To reveal the substitution effects on the photodynamics of Criegee Intermediates (CIs), we carried out the multireference CASSCF trajectory surface-hopping (TSH) molecular dynamics and CASPT2 electronic-structure calculations for a methyl-substituted CI (MCI) and a vinyl-substituted CI (VCI). The results show that for different substituents, the hydrogen bond, ring tension and π-conjugation not only alter the relative stabilities of the conformers/configurations, but also dramatically change the photo-induced channel of CIs. For an anti-MCI, the dominant channel starting from the S1 state is the ring-closure process leading to dioxirane, while in the syn configuration, the intramolecular CH⋯O hydrogen bond hinders the rotation around the C–O bond and thus leads to a high yield of in-plane O–O dissociation towards acetaldehyde (X1A′) and the O(1D) atom. In a VCI with an unsaturated substituent, the π-conjugation greatly strengthens the O–O bond and therefore no O–O dissociation is observed in all configurations. In addition, the CH⋯O hydrogen bond in the syn(CO)-VCI further stabilizes the S1-state intermediates and makes them less reactive; in contrast, isomerization to dioxirane becomes the globally dominant channel in the anti(CO)-VCI. The dramatic substitution effects by saturated and unsaturated substituents on CIs found here will deepen the understanding of Criegee-intermediate chemistry. [ABSTRACT FROM AUTHOR]

Increased nitrogen doping in TiO2(B) with obviously enhanced visible light absorption ability was achieved via a facile pretreatment of HF followed by an annealing process in NH3. The optimized samples showed a 2.8 times photocatalytic hydrogen evolution rate and 4.2 times RhB degradation rate compared with the original TiO2(B). [ABSTRACT FROM AUTHOR]

A new ortho-dimethylaminomethylphenyl-tetramethylcyclopentadienyl ligand C5Me4H-C6H4-o-CH2NMe2 (HL) and a series of rare-earth metal complexes bearing this ligand were synthesized. Of these complexes, two binuclear alkyl complexes [(C5Me4-C6H4-o-CH2N(Me)CH2-μ)Ln(CH2SiMe3)]2 (Ln = Sc (1a) and Y (1b)) were obtained from the alkane elimination reaction of the free ligand with Ln(CH2SiMe3)3(THF)2, followed by an intramolecular C–H activation process of a NMe group in the ligand with a CH2SiMe3 group, two binuclear dichloro complexes (C5Me4-C6H4-o-CH2NMe2)2Y2Cl4[LiCl(THF)2] (2a) and [(C5Me4-C6H4-o-CH2NMe2)LuCl(μ-Cl)]2 (2b) were synthesized by the reaction of anhydrous yttrium or lutetium trichloride with the lithium salt of the ligand LiL, and the binuclear bis(borohydrido) complexes [(C5Me4-C6H4-o-CH2NMe2)Ln(μ-BH4)BH4]2 (Ln = Sm (3a) and Nd (3b)) were synthesized by the reaction of Ln(BH4)3(THF)3 (Ln = Sm and Nd) with the lithium salt of the ligand. The molecular structures of all complexes 1a, 1b, 2a, 2b, 3a and 3b were determined by single-crystal X-ray crystallography. Upon activation with AlR3/Ph3CB(C6F5)4, MAO or MMAO, the binuclear alkyl complexes 1a and 1b show good catalytic activity for isoprene cis-1,4 enriched regioselective polymerization and moderate catalytic activity for 1-hexene polymerization. Complexes 3a and 3b were studied as catalysts for methyl methacrylate polymerization reaction under different conditions and were found to show moderate to high catalytic activity. [ABSTRACT FROM AUTHOR]

A number of new sulfur-bridged tridentate [OSO] bisphenolato-based ligand precursors S(2-CH2-4-tBu-6-R-C6H2OH)2 [R = CMe3 (H2L1), CMe2Ph (H2L2), CMePh2 (H2L3), CPh3 (H2L4), and C(p-Tol)3 (H2L5)] were synthesized by reactions of Na2S·9H2O with 2 eq. of the corresponding 2-(bromomethyl)-4-(tert-butyl)-6-R-phenol. Their neutral titanium complexes [S(2-CH2-4-tBu-6-R-C6H2O)2]TiCl2 [R = CMe3 (1), CMe2Ph (2), CMePh2 (3), CPh3 (4), and C(p-Tol)3 (5)] were synthesized in high yields by direct HCl-elimination reactions of TiCl4 with the corresponding ligand precursors in toluene. Ionic titanium complexes [NHEt3][S(2-CH2-4-tBu-6-R-C6H2O)2TiCl3] [R = CMe3 (6), CMePh2 (7)] and [NH2Et2][S(2-CH2-4-tBu-6-R-C6H2O)2TiCl3] [R = CMe3 (8) and CMePh2 (9)] were obtained in high yields from the reactions of TiCl4 with the corresponding ligand precursors in the presence of 2 eq. of triethylamine or diethylamine. Neutral zirconium complexes [S(2-CH2-4-tBu-6-R-C6H2O)2]ZrCl2(THF) [R = CMe2Ph (10·THF), and CMePh2 (11·THF)] were synthesized by reactions of ZrCl4 with 1 eq. of the dilithium salt of the corresponding ligand precursors Li2L in THF. The new titanium and zirconium complexes were characterized by 1H and 13C NMR, IR and elemental analyses. The molecular structures of complexes 4, 6 and 10·THF were determined by single-crystal X-ray diffraction analysis. The X-ray crystallography analysis reveals that titanium complex 4 has a five-coordinating environment surrounding the central metal atom, while the titanium complex 6 and the THF-solvated zirconium complex 10·THF possess a six-coordinating pseudo-octahedral environment around the central metal atom. Upon activation with MAO or AliBu3/Ph3CB(C6F5)4, all these titanium and zirconium complexes exhibit moderate to high catalytic activities for ethylene polymerization and ethylene/1-hexene copolymerization with moderate to high comonomer incorporation, and the ionic titanium complexes 6, 7, 8 and 9 show lower catalytic activity than their corresponding neutral complexes under similar conditions. [ABSTRACT FROM AUTHOR]

Three novel furanacenes (5/D5c) have been synthesized and characterized. Single-crystal analyses suggested that the as-prepared molecules 5a/5b formed twisted configurations. The absorption and emission spectra of these compounds (5/D5c) and their precursors, alkynyl-modified acenes (3), were measured to uncover the substituent effect on their optoelectronic properties. Twistfuranacenes 5a/5b and substituted twistacenes 3 emit strong blue light, and the triphenylamine-decorated π-system D5c exhibited obviously red-shifted fluorescence. Nonlinear spectroscopic investigation illustrated that the cyclized furanacenes 5/D5c presented larger two-photon absorption cross section than twistacenes 3, being attributed to the introduction of more delocalized electrons from electron-rich furan units. Apparently, these observations might be beneficial for the design of novel twistacenes/heteroacenes and the development of organic photonic materials. [ABSTRACT FROM AUTHOR]

A series of new half-sandwich secondary amine-coordinated dichlorochromium complexes chelated by 2-(tetramethylcyclopentadienyl)benzylamine ligands, 2-Me4CpC6H4CH2(R)NHCrCl2 [R = iPr (1), Cy (2), Ph (3), 4-MePh (4), 2,6-Me2Ph (5), 2,6-Et2Ph (6)], have been synthesized from the reactions of CrCl3(THF)3 with the dilithium salts of the corresponding ligands in THF, followed by the addition of 1/2 eq. of H2O to the reaction mixtures. The isolated yields of the chromium complexes were found to increase with the increase in the amount of H2O introduced and reach the highest values (66–76%) when 1/2 eq. of H2O is added. Attempts to isolate the 2-(tetramethylcyclopentadienyl)benzylamidochromium complexes, 2-Me4CpC6H4CH2(R)NCrCl, were not successful. The new dichlorochromium complexes were characterized by IR, 1H NMR, EPR, and UV/Vis spectroscopy and elemental analyses, and the molecular structures of complexes 1, 5 and 6 were determined by X-ray crystallography. The X-ray crystallographic analysis reveals that these chromium complexes possess a three-legged piano-stool geometry with the amine N atom in a mitered six-membered chelating ring and the two chloride atoms as the legs. Upon activation with AlR3 and Ph3CB(C6F5)4, complexes 1–6 exhibit reasonable catalytic activity for ethylene polymerization and copolymerization with 1-hexene, producing polyethylenes with moderate to high molecular weights and poly(ethylene-co-1-hexene)s with moderate comonomer incorporation which are typical linear low-density polyethylenes (LLDPE). Complex 4 was found to show higher catalytic activity for ethylene homo- and co-polymerization than other complexes under similar conditions, while complex 3 produced poly(ethylene-co-1-hexene)s with the highest comonomer incorporation. [ABSTRACT FROM AUTHOR]

Increased nitrogen doping in TiO2(B) with obviously enhanced visible light absorption ability was achieved via a facile pretreatment of HF followed by an annealing process in NH3. The optimized samples showed a 2.8 times photocatalytic hydrogen evolution rate and 4.2 times RhB degradation rate compared with the original TiO2(B).

A new ortho-dimethylaminomethylphenyl-tetramethylcyclopentadienyl ligand C 5 Me 4 H-C 6 H 4 -o-CH 2 NMe 2 (HL) and a series of rare-earth metal complexes bearing this ligand were synthesized. Of these complexes, two binuclear alkyl complexes [(C 5 Me 4 -C 6 H 4 -o-CH 2 N(Me)CH 2 -μ)Ln(CH 2 SiMe 3 )] 2 (Ln = Sc (1a) and Y (1b)) were obtained from the alkane elimination reaction of the free ligand with Ln(CH 2 SiMe 3 ) 3 (THF) 2 , followed by an intramolecular C-H activation process of a NMe group in the ligand with a CH 2 SiMe 3 group, two binuclear dichloro complexes (C 5 Me 4 -C 6 H 4 -o-CH 2 NMe 2 ) 2 Y 2 Cl 4 [LiCl(THF) 2 ] (2a) and [(C 5 Me 4 -C 6 H 4 -o-CH 2 NMe 2 )LuCl(μ-Cl)] 2 (2b) were synthesized by the reaction of anhydrous yttrium or lutetium trichloride with the lithium salt of the ligand LiL, and the binuclear bis(borohydrido) complexes [(C 5 Me 4 -C 6 H 4 -o-CH 2 NMe 2 )Ln(μ-BH 4 )BH 4 ] 2 (Ln = Sm (3a) and Nd (3b)) were synthesized by the reaction of Ln(BH 4 ) 3 (THF) 3 (Ln = Sm and Nd) with the lithium salt of the ligand. The molecular structures of all complexes 1a, 1b, 2a, 2b, 3a and 3b were determined by single-crystal X-ray crystallography. Upon activation with AlR 3 /Ph 3 CB(C 6 F 5 ) 4 , MAO or MMAO, the binuclear alkyl complexes 1a and 1b show good catalytic activity for isoprene cis-1,4 enriched regioselective polymerization and moderate catalytic activity for 1-hexene polymerization. Complexes 3a and 3b were studied as catalysts for methyl methacrylate polymerization reaction under different conditions and were found to show moderate to high catalytic activity.

A series of new half-sandwich secondary amine-coordinated dichlorochromium complexes chelated by 2-(tetramethylcyclopentadienyl)benzylamine ligands, 2-Me4CpC6H4CH2(R)NHCrCl2 [R = iPr (1), Cy (2), Ph (3), 4-MePh (4), 2,6-Me2Ph (5), 2,6-Et2Ph (6)], have been synthesized from the reactions of CrCl3(THF)3 with the dilithium salts of the corresponding ligands in THF, followed by the addition of 1/2 eq. of H2O to the reaction mixtures. The isolated yields of the chromium complexes were found to increase with the increase in the amount of H2O introduced and reach the highest values (66-76%) when 1/2 eq. of H2O is added. Attempts to isolate the 2-(tetramethylcyclopentadienyl)benzylamidochromium complexes, 2-Me4CpC6H4CH2(R)NCrCl, were not successful. The new dichlorochromium complexes were characterized by IR, 1H NMR, EPR, and UV/Vis spectroscopy and elemental analyses, and the molecular structures of complexes 1, 5 and 6 were determined by X-ray crystallography. The X-ray crystallographic analysis reveals that these chromium complexes possess a three-legged piano-stool geometry with the amine N atom in a mitered six-membered chelating ring and the two chloride atoms as the legs. Upon activation with AlR3 and Ph3CB(C6F5)4, complexes 1-6 exhibit reasonable catalytic activity for ethylene polymerization and copolymerization with 1-hexene, producing polyethylenes with moderate to high molecular weights and poly(ethylene-co-1-hexene)s with moderate comonomer incorporation which are typical linear low-density polyethylenes (LLDPE). Complex 4 was found to show higher catalytic activity for ethylene homo- and co-polymerization than other complexes under similar conditions, while complex 3 produced poly(ethylene-co-1-hexene)s with the highest comonomer incorporation.