Star-shaped six-arm polymers with hexaaza[2_(6)]orthoparacyclophane core and arms of block copolymers of poly-2-ethyl-5,6-dihydrooxazine with poly-2-isopropyl-5,6-dihydrooxazine were synthesized successfully using cat...Star-shaped six-arm polymers with hexaaza[2_(6)]orthoparacyclophane core and arms of block copolymers of poly-2-ethyl-5,6-dihydrooxazine with poly-2-isopropyl-5,6-dihydrooxazine were synthesized successfully using cationic ring-opening polymerization.The ratio of blocks,the order of their attachment to the core,and arm length were varied.Conformation of synthesized stars was determined by methods of molecular hydrodynamics and optics.It has been shown that star-shaped molecules were characterized by high intramolecular density,and the arm folding increased with their lengthening.The influence of the structure of block copolymers and their molar mass on the critical micelle concentration has been established.Complexes of synthesized star-shaped block copolymers with curcumin were obtained and the efficient binding of curcumin to polymer molecules was demonstrated.The behavior of the aqueous solutions of the prepared polymer stars and their complexes with curcumin was investigated by light scattering and turbidimetry methods.The influence of the structure and molar mass of star polymers on their thermoresponsiveness and the phase separation temperatures in aqueous solutions was analyzed.A slight increase in the phase separation temperature was found on passage from polymer solutions to solutions of polymer complexes with hydrophobic curcumin.展开更多
Pt(Ⅱ)-salophen complexes(S-1~S-4) and 9,10-diphenylanthracene(DPA) tethering pillar[5]arene derivatives(A-1 and A-2) were synthesized to act as sensitizers and annihilators for triplet-triplet annihilation upconversi...Pt(Ⅱ)-salophen complexes(S-1~S-4) and 9,10-diphenylanthracene(DPA) tethering pillar[5]arene derivatives(A-1 and A-2) were synthesized to act as sensitizers and annihilators for triplet-triplet annihilation upconversion(TTA-UC), respectively. It turned out that the pyridine cation served as a mask for the excited state of the sensitizer, the triplet states of S-2 and S-3 were significantly quenched by photo-induced electron transfer(PET) with phosphorescence quantum yield quenched from 24.4% for S-4 to 9.3% for S-3,and therefore, both S-2 and S-3 led to negligible UC emissions when traditional annihilator DPA was used as the annihilator. Delightfully, when supramolecular annihilator A-1 and A-2 were employed to include the pyridine cation, PET was significantly inhibited and the triplet states of the sensitizers were activated,TTA-UC emission was therefore boosted. The UC quantum yield of A-2/S-3 system was up to 130 times higher than that of DPA/S-3 system, and the UC emission was switchable by the addition of competitive vips.展开更多
The authors regret that an error in Fig.3E in this article was found while we reviewing the published data.An inadvertent mistake occurred in the process of assembling images.The picture of the Ms215μg/mL group was w...The authors regret that an error in Fig.3E in this article was found while we reviewing the published data.An inadvertent mistake occurred in the process of assembling images.The picture of the Ms215μg/mL group was wrongly placed.展开更多
Based on a non-equilibrium kinetic extraction technique,the complexation kinetics of diethylenetriamine-pentaacetic acid(DTPA)with rare earth(RE)ions was investigated with different adding sequences of DTPA.The result...Based on a non-equilibrium kinetic extraction technique,the complexation kinetics of diethylenetriamine-pentaacetic acid(DTPA)with rare earth(RE)ions was investigated with different adding sequences of DTPA.The results indicated that the separation factors ofβTm/Er andβY/Er were higher when adding DTPA at the start of extraction than those before extraction.The extraction order for Y,Er and Tm was Tm>Y>Er.The root of discrepancy in complexation kinetics of Y,Er and Tm ions with DTPA and the enhanced kinetic separation mechanism were elucidated from the forward complex formation and reverse dissociation rates by the stopped-flow spectrophotometric technique.The apparent complexation rate constants began to decrease gradually with the increase of aqueous pH,while increased with increasing DTPA concentration.The emergence of extraction priority order as Tm>Y>Er was verified according to the calculated reaction kinetic constants of Y,Er and Tm at different pH values.展开更多
Humic acid(HA) as a natural reducing ligand was employed to accelerate the Fenton and Fenton-like processes, however, the potential role of photosensitivity was overlooked. This research showed that HA exhibits more s...Humic acid(HA) as a natural reducing ligand was employed to accelerate the Fenton and Fenton-like processes, however, the potential role of photosensitivity was overlooked. This research showed that HA exhibits more significant promotion for levofloxacin(LVF) degradation under light conditions compared to darkness. The study also proposed a mechanism involving complexation and photosensitization interactions. A strong inhibitor of ethylenediaminetetraacetic acid confirmed that the formation of organic-iron complexes was crucial. Firstly, it was proposed that complexed iron has a lower redox potential than free iron, which may be responsible for accelerating electron transfer from iron to peroxydisulfate(PDS). The density functional theory(DFT) calculations confirmed that complexed iron has a lower reaction energy barrier for PDS activation. Additionally, the excited state substances(^(*)HA and ^(*)LVF) can transfer electrons to Fe(Ⅲ) and PDS, and the generation of HA/LVF-Fe(Ⅲ)-PDS can accelerate this process. These findings could offer fresh perspectives on the combined elimination of contaminants through natural organic compounds and light exposure.展开更多
基金financially supported by the Russian Science Foundation(No.23-13-00205)。
文摘Star-shaped six-arm polymers with hexaaza[2_(6)]orthoparacyclophane core and arms of block copolymers of poly-2-ethyl-5,6-dihydrooxazine with poly-2-isopropyl-5,6-dihydrooxazine were synthesized successfully using cationic ring-opening polymerization.The ratio of blocks,the order of their attachment to the core,and arm length were varied.Conformation of synthesized stars was determined by methods of molecular hydrodynamics and optics.It has been shown that star-shaped molecules were characterized by high intramolecular density,and the arm folding increased with their lengthening.The influence of the structure of block copolymers and their molar mass on the critical micelle concentration has been established.Complexes of synthesized star-shaped block copolymers with curcumin were obtained and the efficient binding of curcumin to polymer molecules was demonstrated.The behavior of the aqueous solutions of the prepared polymer stars and their complexes with curcumin was investigated by light scattering and turbidimetry methods.The influence of the structure and molar mass of star polymers on their thermoresponsiveness and the phase separation temperatures in aqueous solutions was analyzed.A slight increase in the phase separation temperature was found on passage from polymer solutions to solutions of polymer complexes with hydrophobic curcumin.
基金supported by the National Natural Science Foundation of China (Nos. 22171194, 21971169, 92056116 and 21871194)the Fundamental Research Funds for the Central Universities (No. 20826041D4117)the Science & Technology Department of Sichuan Province (Nos. 2022YFH0095 and 2021ZYD0052)。
文摘Pt(Ⅱ)-salophen complexes(S-1~S-4) and 9,10-diphenylanthracene(DPA) tethering pillar[5]arene derivatives(A-1 and A-2) were synthesized to act as sensitizers and annihilators for triplet-triplet annihilation upconversion(TTA-UC), respectively. It turned out that the pyridine cation served as a mask for the excited state of the sensitizer, the triplet states of S-2 and S-3 were significantly quenched by photo-induced electron transfer(PET) with phosphorescence quantum yield quenched from 24.4% for S-4 to 9.3% for S-3,and therefore, both S-2 and S-3 led to negligible UC emissions when traditional annihilator DPA was used as the annihilator. Delightfully, when supramolecular annihilator A-1 and A-2 were employed to include the pyridine cation, PET was significantly inhibited and the triplet states of the sensitizers were activated,TTA-UC emission was therefore boosted. The UC quantum yield of A-2/S-3 system was up to 130 times higher than that of DPA/S-3 system, and the UC emission was switchable by the addition of competitive vips.
文摘The authors regret that an error in Fig.3E in this article was found while we reviewing the published data.An inadvertent mistake occurred in the process of assembling images.The picture of the Ms215μg/mL group was wrongly placed.
基金funded by Key Laboratory of Ionic Rare Earth Resources and Environment,Ministry of Natural Resources,China(No.2022IRERE206)financially supported by the National Natural Science Foundation of China(Nos.51904027,52074031)。
文摘Based on a non-equilibrium kinetic extraction technique,the complexation kinetics of diethylenetriamine-pentaacetic acid(DTPA)with rare earth(RE)ions was investigated with different adding sequences of DTPA.The results indicated that the separation factors ofβTm/Er andβY/Er were higher when adding DTPA at the start of extraction than those before extraction.The extraction order for Y,Er and Tm was Tm>Y>Er.The root of discrepancy in complexation kinetics of Y,Er and Tm ions with DTPA and the enhanced kinetic separation mechanism were elucidated from the forward complex formation and reverse dissociation rates by the stopped-flow spectrophotometric technique.The apparent complexation rate constants began to decrease gradually with the increase of aqueous pH,while increased with increasing DTPA concentration.The emergence of extraction priority order as Tm>Y>Er was verified according to the calculated reaction kinetic constants of Y,Er and Tm at different pH values.
基金supported by the Natural Science Foundation of China (No. 42107073)Central Guidance for Local Science and Technology Development Fund Projects (No. 2024ZYD0030)+1 种基金Natural Science Foundation of Sichuan Province (No. 2024NSFSC0130)the Sichuan Science and Technology Program (No. 2024NSFTD0014)。
文摘Humic acid(HA) as a natural reducing ligand was employed to accelerate the Fenton and Fenton-like processes, however, the potential role of photosensitivity was overlooked. This research showed that HA exhibits more significant promotion for levofloxacin(LVF) degradation under light conditions compared to darkness. The study also proposed a mechanism involving complexation and photosensitization interactions. A strong inhibitor of ethylenediaminetetraacetic acid confirmed that the formation of organic-iron complexes was crucial. Firstly, it was proposed that complexed iron has a lower redox potential than free iron, which may be responsible for accelerating electron transfer from iron to peroxydisulfate(PDS). The density functional theory(DFT) calculations confirmed that complexed iron has a lower reaction energy barrier for PDS activation. Additionally, the excited state substances(^(*)HA and ^(*)LVF) can transfer electrons to Fe(Ⅲ) and PDS, and the generation of HA/LVF-Fe(Ⅲ)-PDS can accelerate this process. These findings could offer fresh perspectives on the combined elimination of contaminants through natural organic compounds and light exposure.
