The technique for preparing phenol formaldehyde resin from phenolated wood (PWF) and its characters were studied and analyzed. Poplar (Populus spp.) wood meal was liquefied by phenol in the presence of sulfuric acid a...The technique for preparing phenol formaldehyde resin from phenolated wood (PWF) and its characters were studied and analyzed. Poplar (Populus spp.) wood meal was liquefied by phenol in the presence of sulfuric acid as a catalyst. After the liquefied products were cooled, alkaline catalyst and formaldehyde were added. The mixture was kept at (60?) C for 1h and then was heated to (85?) C for 1h. The influence of molar ratio of formaldehyde to phenol (F/P) was investigated. The results showed when the molar ratio of formaldehyde to phenol was over 1.8, the PWF adhesives had high bond quality, bond durability and extremely low aldehydes emissions.展开更多
Single component rare earth phenolates substituted by various alkyl groups have been prepared and the correlation between the aryloxides＇ structure and catalytic activity in the ring-opening polymerization of D,L-lac...Single component rare earth phenolates substituted by various alkyl groups have been prepared and the correlation between the aryloxides＇ structure and catalytic activity in the ring-opening polymerization of D,L-lactide has also been investigated.The catalytic activity of all rare earth aryloxides,characteristics of the ring-opening polymerization as well as polymerization kinetics and mechanism were investigated.The results showed that both phenolates＇ catalytic activities and polymerization characteristics changed regularly,keeping in good concordance with variations in substitutents＇ number on phenol and structure of aryloxide ligands.The stronger ability of electron-donation of alkyl groups,the higher catalytic activity.Moreover,the more numbers of substituted alkyl on phenyl ring,the higher catalytic activity.The analyses of polymer ends revealed that the polymerization proceeded via a coordination-acyl-oxygen bond cleavage-insertion mechanism.展开更多
The neodymium chloride complex[Nd（ONN＇O）Cl（THF）]2 supported by amine-bis（phenolate） ligand was synthesized by the metathesis reaction of anhydrous NdCl3 with Li2（ONN＇O）[H2ONN＇O = Me2NCH2CH2N（CH2-3-Bu2^t-5-...The neodymium chloride complex[Nd（ONN＇O）Cl（THF）]2 supported by amine-bis（phenolate） ligand was synthesized by the metathesis reaction of anhydrous NdCl3 with Li2（ONN＇O）[H2ONN＇O = Me2NCH2CH2N（CH2-3-Bu2^t-5-Me-C6H2OH）2]in high yield.X-ray structural determination shows[Nd（ONN＇O）Cl（THF）]2 complex consists of two seven-coordinate neodymium centers linked throughμ-Cl bridges.And this complex was successfully used to initiate the ring-opening polymerization（ROP） ofε-caprolactone.展开更多
Two vanadium complexes of schiff base vith rich phenolate oxygen,o-(?)-salicylideneamino- methylphenol,had been synthesized and characterized.One is a V(Ⅳ)complex with an interaction via vanadyl oxygen and the other ...Two vanadium complexes of schiff base vith rich phenolate oxygen,o-(?)-salicylideneamino- methylphenol,had been synthesized and characterized.One is a V(Ⅳ)complex with an interaction via vanadyl oxygen and the other is a novel dinuclear V(V,V)complex with an oxo bridge.The conversion between the two complexes had been discussed.展开更多
Two d10 metal complexes Zn（NCS）2（C14HI3NO2）2 （1） and [Cd（NO3）2（CI4HI3NO2）2]. 4H20 （2） assembled by 2-methoxy-6-（phenyliminiomethyl） phenolate ligand （C14H13NO2, HL） have been synthesized and characteri...Two d10 metal complexes Zn（NCS）2（C14HI3NO2）2 （1） and [Cd（NO3）2（CI4HI3NO2）2]. 4H20 （2） assembled by 2-methoxy-6-（phenyliminiomethyl） phenolate ligand （C14H13NO2, HL） have been synthesized and characterized by elemental analysis, IR and TG The single-crystal X-ray diffraction studies demonstrated that complex 1 crystallizes in monoclinic, P21/c space group with a = 17.321（7）, b = 11.781（0）, c = 15.593（2） A, fl = 110.273（6）°, V = 2984.95 A3, Z = 4, C30H26N404SzZn, Mr = 636.04, F（000） = 1312, Dc = 1.415 g/cm3,μ（MoKa） = 1.004 mm＂1, the final R = 0.0403 and wR = 0.0900 for 21441 observed reflections with I 〉 20（/）. Complex 2 is of monoclinic system, space group C2/c with a = 16.7767（2）, b = 10.8989（2）, c = 17.4928（2） A, fl = 90.614（9）°, V= 3198.37 A3, Z = 4, C28H34N4O14Cd, Mr= 731.25, F（000） = 1528, Dc = 1.568 g＇cm^-3, μ（MoKa） = 0.757 mm-1, the final R = 0.0361 and wR = 0.0857 for 19811 observed reflections with I 〉 2σ（I）. The two complexes were formed by Schiff base 2-methoxy-6-（phenyliminiomethyl） phenolate ligand and formed a 3D supramolecular architecture by π-πstacking interactions. Moreover, the complexes are luminescent in the solid state. These observations indicate that the complexes are promising system for the development of potential photoactive materials.展开更多
Three new chiral monoanionic [ON] ancillary phenolate ligands with varying pendant arms have been synthesized in moderate to high yields (50% - 85%) via Mannich-type condensation reaction of chiral substituted phenol,...Three new chiral monoanionic [ON] ancillary phenolate ligands with varying pendant arms have been synthesized in moderate to high yields (50% - 85%) via Mannich-type condensation reaction of chiral substituted phenol, formaldehyde and (+)-bis-[(R)-1-phenylethyl]amine. These new organic compounds were fully characterized via nuclear magnetic resonance spectroscopy (1H and 13C) and elemental analysis. The newly synthesized ligands are suitable candidates for metal-catalyzed ring-opening of lactones and asymmetric catalysis.展开更多
Wood of Chinese fir and poplar were liquefied in phenol at 150℃ and atmospheric pressure. The liquefied wood were reacted with formaldehyde to synthesize the liquefied wood-based resin. The factors affecting the resi...Wood of Chinese fir and poplar were liquefied in phenol at 150℃ and atmospheric pressure. The liquefied wood were reacted with formaldehyde to synthesize the liquefied wood-based resin. The factors affecting the resinification and the properties of new resin were investigated. The results show that the formaldehyde/liquefied wood molar ratio, reaction temperature, reaction time and sodium hydroxide/liquefied wood molar ratio have important influence on the resin characteristics. With the increase of formaldehyde/liquefied wood molar ratio, the yield of resin increases, and the flee phenol content of resins decreases, showing that the resinification of liquefied wood is more complete at higher formaldehyde/liquefied wood molar ratios. The reaction temperature on the viscosity of the liquefied resin has considerable effect; the viscosity of resin increased with increasing reaction temperature, and the amount of liquefied poplar resin increased more quickly than that of liquefied Chinese fir resin. The resinification time also has obvious influence on the viscosity of resin; the viscosity of liquefied poplar resin is more sensitive to resinification time compared with that of liquefied Chinese fir. The amount of sodium hydroxide can improve the water miscibility of liquefied wood resin. The optimum sodium hydroxide/liquefied wood molar ratio for preparation of liquefied wood-based resins exceeds 0.4.展开更多
Herein,we report the application of four amino-tris(phenolate)-based metal complexes incorporating Ti(IV)or Zr(IV)centres(2a-3b)as homogeneous catalysts for the conversion of CO_(2)and epoxides into cyclic carbonates....Herein,we report the application of four amino-tris(phenolate)-based metal complexes incorporating Ti(IV)or Zr(IV)centres(2a-3b)as homogeneous catalysts for the conversion of CO_(2)and epoxides into cyclic carbonates.The four complexes were synthesised,characterised and then evaluated in combination with tetrabutylammo-nium iodide,bromide or chloride as binary catalytic systems for the reaction of CO_(2)with 1,2-epoxyhexane as epoxide substrate at 12 bar CO_(2)pressure and 90?C for 2 h.The catalytic systems comprising the two Ti(IV)complexes(2a and 2b)showed similar performance.One notable exception was the catalytic system consisting of titanium complex 2b,bearing an axial Cl-ligand,and tetrabutylammonium chloride,which displayed higher catalytic activity compared to other titanium-based systems.Even higher activity was achieved with Zr(IV)complex 3a,bearing an axial isopropoxide ligand,which reached turnover numbers(TON metal)up to 1920 for the reaction of CO_(2)with 1,2-epoxyhexane at 12 bar CO_(2)pressure and 90?C for 2 h.This performance is comparable with that of state-of-the-art catalysts for this reaction.The catalytic system consisting of complex 3a and tetra-butylammonium bromide was explored further by investigating its applicability with a broad substrate scope,achieving quantitative conversion of several epoxides with CO_(2)into cyclic carbonate products at 90?C and 12 bar CO_(2)pressure for 18 h.The selectivity towards the cyclic carbonate products was?98%for all studied terminal epoxides and?80%for all examined cyclohexene-type epoxides.展开更多
Four divalent lanthanide complexes Sm(ArO)2 -(THF)4) Yb(ArO)2(THF)3, Eu(ArO)2(THF)3 (ArO=2,6-di-tert-butyl-4-methylphenolate) and (ButCp)2Sm(THF)2 were synthesized. Their catalytic activities on the polymerization of ...Four divalent lanthanide complexes Sm(ArO)2 -(THF)4) Yb(ArO)2(THF)3, Eu(ArO)2(THF)3 (ArO=2,6-di-tert-butyl-4-methylphenolate) and (ButCp)2Sm(THF)2 were synthesized. Their catalytic activities on the polymerization of acrylonitrile were studied. The catalytic activities were influenced by the central metal ions involved. The catalytic activities of these divalent lanthanide complexes can be greatly increased by adding NaOC6H2-2,6-But2-4-Me, NaOC6H4-4-But, or NaOC10H6-2-Me. The amount of additive has apparent effect on the catalytic activity, but the additive has no effect on the tacticity of the resulting polyacryloni-trile.展开更多
The synthesis and characterization of aluminum alkoxide and alkyl complexes stabilized by piperazidine- bridged bis（phenolate） ligands are described. Treatment of ligand precursors Hz[ONNO]^1 {Hz[ONNO]^1= 1,4-bis（2...The synthesis and characterization of aluminum alkoxide and alkyl complexes stabilized by piperazidine- bridged bis（phenolate） ligands are described. Treatment of ligand precursors Hz[ONNO]^1 {Hz[ONNO]^1= 1,4-bis（2-hydroxy-3-tert-butyl-5-methylbenzyl）piperazidine} and Hz[ONNO]2 {H2[ONNO]2=1,4-bis（2-hydroxy3,5-di-tert-butylbenzyl）piperazidine} with A1Et2（OCH2Ph） and A1Etz（OPr-i）, which were generated in situ by the reactions of AIEt3 with equivalent of the corresponding alcohols, in a 1： 1 molar ratio in THF gave the corresponding aluminum alkoxide complexes [ONNO]IAI（OCH2Ph） （1） and [ONNO]2Al（OPr-i） （2）, respectively. The reaction of H2[ONNO]^1 with A1Etz（OCHzPh） in a 1 ： 2 molar ratio in THF afforded a mixture of monometallic aluminum ethyl complex [ONNO] 1A1Et （3） and complex 1, which can be isolated by stepwise crystallization. Similarly, Hz[ONNO]2 reacted with A1Etz（OPr-0 in a 1： 2 molar ratio in THF to give a mixture of aluminum ethyl complex [ONNO]2AlEt （4） and complex 2. Complexes 1 and 2 were also available via treatment of complexes 3 and 4 with 1 equiv, of benzyl alcohol and isopropyl alcohol, respectively. All of these complexes were fully characterized including X-ray structural determination. It was found that complexes 1 to 4 can initiate the ring-opening polymerization of e-caprolactone, and complexes 1 and 2 showed higher catalytic activity in comparison with com- plexes 3 and 4.展开更多
A series of neutral bimetallic lanthanide aryloxides p-C6H4[OLnL(THF)n]2 [Ln = Y(1), Yb(2), Sm(3)(n = 1) and La(4)(n = 2), L = Me2NCH2CH2N{CH2-(2-O–C6H2–tBu2-3,5)}2] and alkoxides p-C6H4CH2[OLnL(THF)]2 [Ln = Y(5), Y...A series of neutral bimetallic lanthanide aryloxides p-C6H4[OLnL(THF)n]2 [Ln = Y(1), Yb(2), Sm(3)(n = 1) and La(4)(n = 2), L = Me2NCH2CH2N{CH2-(2-O–C6H2–tBu2-3,5)}2] and alkoxides p-C6H4CH2[OLnL(THF)]2 [Ln = Y(5), Yb(6)] supported by an amine-bridged bis(phenolate) ligand have been synthesized through one-pot reactions of Ln(C5H5)3(THF), LH2 with p-benzenediol and 1,4-benzenedimethanol, respectively. All complexes have been fully characterized by elemental analyses, single-crystal X-ray diffraction analysis, and IR and multi-nuclear NMR spectroscopy(in the cases of 1, 4 and 5). Study of their catalytic behavior revealed that, in general, all complexes are efficient initiators for the polymerization of rac-lactide(LA) and rac-β-butyrolactone(BBL), except for 3 and 4 in the case of BBL. The influence imposed by lanthanides of different ionic radii and initiating groups of different structures on the activity, controllability, and stereoselectivity of polymerization were systematically studied and compared. Highly heterotactic PLA(Pr up to 0.99) and syndiotactic PHB(Pr ≈ 0.81) with high molecular weight and narrow polydispersity formed and were automatically capped with hydroxyl functionality at both ends.展开更多
Two rosamine-based pH probes 1a and 1b with pyronine-phenol skeleton were designed and synthesized by a simple one-step reaction, pH titration experiments showed that probes 1a and 1b exhibit near OFF-ON fluorescence ...Two rosamine-based pH probes 1a and 1b with pyronine-phenol skeleton were designed and synthesized by a simple one-step reaction, pH titration experiments showed that probes 1a and 1b exhibit near OFF-ON fluorescence responses around 550--750 nm towards the hydrogen ions. The pKa of the probe 1a is 8.29, while that of the probe lb increases to 12.1 because of the hydrogen bond inside it. Selective and competitive experiments indicated that both common ions and amino acids did not interfere their emission with hydrogen ions. Moreover, confocal fluorescent imaging showed that the probe la could be served as mitochondria biomarker in HeLa and Ges-1 cells.展开更多
By means of gel permeation chromatography analysis, the molecular weight of liquefied wood under different reaction conditions was investigated to trace the change in the structural characteristics of the liquefied wo...By means of gel permeation chromatography analysis, the molecular weight of liquefied wood under different reaction conditions was investigated to trace the change in the structural characteristics of the liquefied wood. The insoluble residues were analyzed by Fourier transform infrared to investigate the liquefaction order of three main wood components. The results indicate that both reaction temperature and reaction time could affect the molecular characteristics of the liquefied wood obtained. The mo...展开更多
Chinese fir (Cunninghamia lanceolata) and poplar (Populus spp.) wood meal were phenolated in the presence of sulfuric acid used as a catalyst. The effects of reaction time and reaction temperature on the wood liquefac...Chinese fir (Cunninghamia lanceolata) and poplar (Populus spp.) wood meal were phenolated in the presence of sulfuric acid used as a catalyst. The effects of reaction time and reaction temperature on the wood liquefaction were investigated. The results showed that the reaction temperature had the greater influence on the residue content than reaction time. Additionally, the liquefaction curve for the Chinese fir and Poplar were similar in general.展开更多
Due to the endocrine toxicity,neurotoxic,and reproductive toxicity to organisms,the sources and risks of brominated organic pollutants have attracted widespread attention.However,knowledge gaps remain in the brominati...Due to the endocrine toxicity,neurotoxic,and reproductive toxicity to organisms,the sources and risks of brominated organic pollutants have attracted widespread attention.However,knowledge gaps remain in the bromination processes of emerging phenolic pollutants in plants,whichmay increase the potential health risk associated with food exposure.Our study discovered that light induced generation and accumulation of more toxic brominated organic compounds(Br-org)in lettuce leaves under the stress of acetaminophen(ACE)than that without light,as evidenced by an increase in C-Br bond intensity in FTIR analysis.This result can be explained by the oxidation of bromide ions(Br^(-))by reactive species(ROS and ^(3)Chl*)of chloroplast into reactive bromine species(RBS).The main mechanism is that the redox of Br^(-)reduced the oxidative damage of ACE to the structure and function of chloroplasts,providing good conditions for light energy uptake and utilization and promoting the increase of pigments and active species.Compared with the dark group exposed to 5 mg/L Br^(-),the pigment content,H_(2)O_(2) and ^(1)O_(2) level of the light group increased by 56%,84% and 69%,respectively.On the other hand,RBS attacks certain electrophilic organic compounds in leaves to generate Br^(-)org.Triple excited state of chlorophyll(^(3)Chl^(*))was the dominant species for the transformation of ACE,while RBS is a key factor in the generation of Br-org in the Br^(-)/light/chlorophyll system.A total of six transformation products were identified by HPLC-MS/MS,which were involved in three transformation pathways:methylation,hydroxyl oxidation and hydroxylation followed by bromination.This is the first report that Br^(-)could enter the chloroplast and improved chloroplast structure under ACE stress,and elucidated the bromination mechanism of organics in terrestrial plant involving of biophotochemical bromination in chloroplast besides enzyme-catalyzed bromination.This study is beneficial for risk assessment and prevention of emerging phenolic pollutants.展开更多
Synthetic phenolic antioxidants(SPAs)are widely used in diverse industries due to their exceptional antioxidant characteristics.However,human exposure to SPAs may cause health problems.In this study,226 dust samples w...Synthetic phenolic antioxidants(SPAs)are widely used in diverse industries due to their exceptional antioxidant characteristics.However,human exposure to SPAs may cause health problems.In this study,226 dust samples were collected from 10 provinces in China,and six SPAs(three parent SPAs and their three transformation products)were analyzed.The concentrations of6SPAs(the sum of six target compounds)ranged from 15.4 to 3210 ng/g(geometric mean(GM):169 ng/g).The highest concentration of6SPAswas found in Sichuan Province(GM:349 ng/g),which was approximately 4 times higher than that in Hubei Province(81.6 ng/g)(p<0.05).The concentrations of butylated hydroxytoluene(BHT),2,2'-methylene bis(4-methyl-6–tert-butylphenol)(AO2246),2,6-di–tert–butyl–1,4-benzoquinone(BHT-Q),2,6-di–tert–butyl–4-(hydroxymethyl)phenol(BHT-OH),and ∑_(p)-SPAs were substantially higher in dust from urban areas than rural areas(p<0.05).AO2246 concentration in dust from homes(GM:0.400 ng/g)was about 4 times higher than that in workplaces(0.116 ng/g)(p<0.01).Significantly higherp-SPAs concentrations were found in dust from homes(GM:17.5 ng/g)than workplaces(11.4 ng/g)(p<0.01).The estimated daily intakes(EDIs)of ∑_(6)SPAs exposed through dust ingestion were 0.582,0.342,0.197,0.076,and 0.080 ng/kg bw/day in different age groups,and exposed through dermal contact was 0.358,0.252,0.174,0.167,and 0.177 ng/kg bw/day.EDIs showed that the exposure risks of SPAs decreased with age.This is the first work to determine SPAs in dust from10 provinces in China and investigate the spatial distribution of SPAs in those regions.展开更多
Silica gel column chromatography(CC),Sephadex LH-20 CC and high performance liquid chromatography(HPLC)were used to study the chemical constituents of the fruits of the medicine-food plant Rubus idaeus Linnaeus.A new ...Silica gel column chromatography(CC),Sephadex LH-20 CC and high performance liquid chromatography(HPLC)were used to study the chemical constituents of the fruits of the medicine-food plant Rubus idaeus Linnaeus.A new tetrahydrogenated naphthol syringic acid ester,named rubusnolicester(1),two new phenolic glycoside derivatives,4-chloro-2,6-dimethoxylphenol-1-O-β-D-glucopyranoside(2)and salicylic acid-2-O-(6'-O-acetyl)-β-D-glucopyranoside(3),together with one known salicylic acid glycoside derivative(4)and three known flavonoids derivatives(5~7),were isolated.Their structures were elucidated by HRESI-MS,NMR spectroscopy,and a comparison of optical rotation(OR).Compounds 1~7 were evaluated the inhibitory activities against the nitric oxide(NO)production induced by lipopolysaccharide(LPS)in mouse macrophage RAW264.7 cells in vitro.Compound 1 exhibited inhibitory effect with the IC50 value of(12.28±1.25)μmol/L.展开更多
The efficient mineralization of phenol and its derivatives in wastewater remains a great challenge.In this study,the bimetallic CuCeO_(2)-BTC was screened from a series of MOFs-derived MCeO_(2)-BTC(M=La,Cu,Co,Fe,and M...The efficient mineralization of phenol and its derivatives in wastewater remains a great challenge.In this study,the bimetallic CuCeO_(2)-BTC was screened from a series of MOFs-derived MCeO_(2)-BTC(M=La,Cu,Co,Fe,and Mn)catalysts,and the influence of the Cu/Ce ratio on phenol removal by catalytic ozonation was carefully examined.The results indicate that Cu_(2)Ce_(1)O_(y)-BTC was the best among the Cu_(x)Ce_(1)O_(y)-BTC(x=0,1,2,and 3)catalysts,with a phenol mineralization efficiency reaching close to 100%within 200 min,approximately 30.1%higher than CeO_(2)-BTC/O_(3)and 70.3%higher than O_(3)alone.The order of mineralization efficiency of phenol was Cu_(2)Ce_(1)O_(y)-BTC>Cu_(3)Ce_(1)O_(y)-BTC>Cu_(1)Ce_(1)O_(y)-BTC>CeO_(2)-BTC.CeO_(2)-BTC exhibited a broccoli-like morphology,and Cu_(x)Ce_(1)O_(y)-BTC(x=1,2,and 3)exhibited an urchin-like morphology.Compared with Cu_(x)Ce_(1)O_(y)-BTC(x=0,1,and 3),Cu_(2)Ce_(1)O_(y)-BTC exhibited a larger specific surface area and pore volume.This characteristic contributed to the availability of more active sites for phenol degradation.The redox ability was greatly enhanced as well.Besides,the surface of Cu_(2)Ce_(1)O_(y)-BTC exhibited a higher concentration of Ce^(3+)species and hydroxyl groups,which facilitated the dissociation of ozone and the generation of active radicals.Based on the results of radical quenching experiments and the intermediates detected by LC-MS,a potential mechanism for phenol degradation in the Cu_(2)Ce_(1)O_(y)-BTC/O_(3)system was postulated.This study offers novel perspectives on the advancement of MOFs-derived catalysts for achieving the complete mineralization of phenol in wastewater through catalytic ozonation.展开更多
This study aims to determine the phytochemical composition and antioxidant activity(AA)of different plant parts(bulbs,stalk,leaves and flowers)of wild rosy garlic(Allium roseum)from Montenegro.The flower exhibited the...This study aims to determine the phytochemical composition and antioxidant activity(AA)of different plant parts(bulbs,stalk,leaves and flowers)of wild rosy garlic(Allium roseum)from Montenegro.The flower exhibited the highest concentration of total phenols(55.7 GAE/g d.e.),followed by the leaf(25.6mg GAE/g d.e.).The leaf displayed the highest concentration of total flavonoids(41.48 mg RE/g d.e.),followed by the flower(36.26 mg RE/g d.e.)and top part of the stalk(26.80 mg RE/g d.e.).The AA of different parts of A.roseum after 60 min of incubation decreased in the following order:flower(0.15mg/cm^(3))>upper stalk(0.32mg/cm^(3))>leaf(0.36mg/cm^(3))>basal stalk(0.80mg/cm^(3))>bulb(1.53 mg/cm^(3)).The flowers exhibited the lowest EC_(50) values,indicating the highest antioxidant potential throughout the entire incubation period.Among all plant parts analyzed,the flowers demonstrated the highest ferric reducing antioxidant power(FRAP),reaching 24.99 mg Fe^(2+)/g,thereby indicating their superior antioxidant potential.Given their edibility,pleasant flavor,and high nutritional value,A.roseum flowers may be considered a promising natural additive for functional food products or culinary applications,including dish enhancement and decoration.展开更多
SAPO-5 zeolite supported RuMn was a highly efficient catalyst for the aqueous-phase selective hydrodeoxygenation of guaiacol to cyclohexanol.The optimal catalyst achieved a high cyclohexanol yield of 93.7%at full guai...SAPO-5 zeolite supported RuMn was a highly efficient catalyst for the aqueous-phase selective hydrodeoxygenation of guaiacol to cyclohexanol.The optimal catalyst achieved a high cyclohexanol yield of 93.7%at full guaiacol conversion under mild conditions,with a high TOF of 920 h^(-1).Moreover,the catalyst displayed remarkable performance for the hydrogenation of phenol to cyclohexanol,where a 100%yield of cyclohexanol was obtained at a phenol-to-Ru molar ratio of about 17900.In particular,the catalyst exhibited excellent recyclability and could be recycled for 20 times without obvious activity loss.The as-prepared RuMn/SAPO-5 catalyst exhibited higher performance than most of the reported Rubased catalysts.展开更多
文摘The technique for preparing phenol formaldehyde resin from phenolated wood (PWF) and its characters were studied and analyzed. Poplar (Populus spp.) wood meal was liquefied by phenol in the presence of sulfuric acid as a catalyst. After the liquefied products were cooled, alkaline catalyst and formaldehyde were added. The mixture was kept at (60?) C for 1h and then was heated to (85?) C for 1h. The influence of molar ratio of formaldehyde to phenol (F/P) was investigated. The results showed when the molar ratio of formaldehyde to phenol was over 1.8, the PWF adhesives had high bond quality, bond durability and extremely low aldehydes emissions.
基金Funded by the Natural Science Foundation of Shanxi Province (No.2006011069)the Opening Foundation of Key Laboratory of Shanxi Province (No.2009011059-7)
文摘Single component rare earth phenolates substituted by various alkyl groups have been prepared and the correlation between the aryloxides＇ structure and catalytic activity in the ring-opening polymerization of D,L-lactide has also been investigated.The catalytic activity of all rare earth aryloxides,characteristics of the ring-opening polymerization as well as polymerization kinetics and mechanism were investigated.The results showed that both phenolates＇ catalytic activities and polymerization characteristics changed regularly,keeping in good concordance with variations in substitutents＇ number on phenol and structure of aryloxide ligands.The stronger ability of electron-donation of alkyl groups,the higher catalytic activity.Moreover,the more numbers of substituted alkyl on phenyl ring,the higher catalytic activity.The analyses of polymer ends revealed that the polymerization proceeded via a coordination-acyl-oxygen bond cleavage-insertion mechanism.
基金the financial supports of the National Natural Science Foundation of China (No.20774078)the Special Funds for Major Basic Research Projects(No.2005CB623802)Scientific Research Foundation for Returned Scholars,Ministry of Education of China
文摘The neodymium chloride complex[Nd（ONN＇O）Cl（THF）]2 supported by amine-bis（phenolate） ligand was synthesized by the metathesis reaction of anhydrous NdCl3 with Li2（ONN＇O）[H2ONN＇O = Me2NCH2CH2N（CH2-3-Bu2^t-5-Me-C6H2OH）2]in high yield.X-ray structural determination shows[Nd（ONN＇O）Cl（THF）]2 complex consists of two seven-coordinate neodymium centers linked throughμ-Cl bridges.And this complex was successfully used to initiate the ring-opening polymerization（ROP） ofε-caprolactone.
文摘Two vanadium complexes of schiff base vith rich phenolate oxygen,o-(?)-salicylideneamino- methylphenol,had been synthesized and characterized.One is a V(Ⅳ)complex with an interaction via vanadyl oxygen and the other is a novel dinuclear V(V,V)complex with an oxo bridge.The conversion between the two complexes had been discussed.
基金supported by the Natural Science Foundation of Zhejiang Province (LY12B01003)
文摘Two d10 metal complexes Zn（NCS）2（C14HI3NO2）2 （1） and [Cd（NO3）2（CI4HI3NO2）2]. 4H20 （2） assembled by 2-methoxy-6-（phenyliminiomethyl） phenolate ligand （C14H13NO2, HL） have been synthesized and characterized by elemental analysis, IR and TG The single-crystal X-ray diffraction studies demonstrated that complex 1 crystallizes in monoclinic, P21/c space group with a = 17.321（7）, b = 11.781（0）, c = 15.593（2） A, fl = 110.273（6）°, V = 2984.95 A3, Z = 4, C30H26N404SzZn, Mr = 636.04, F（000） = 1312, Dc = 1.415 g/cm3,μ（MoKa） = 1.004 mm＂1, the final R = 0.0403 and wR = 0.0900 for 21441 observed reflections with I 〉 20（/）. Complex 2 is of monoclinic system, space group C2/c with a = 16.7767（2）, b = 10.8989（2）, c = 17.4928（2） A, fl = 90.614（9）°, V= 3198.37 A3, Z = 4, C28H34N4O14Cd, Mr= 731.25, F（000） = 1528, Dc = 1.568 g＇cm^-3, μ（MoKa） = 0.757 mm-1, the final R = 0.0361 and wR = 0.0857 for 19811 observed reflections with I 〉 2σ（I）. The two complexes were formed by Schiff base 2-methoxy-6-（phenyliminiomethyl） phenolate ligand and formed a 3D supramolecular architecture by π-πstacking interactions. Moreover, the complexes are luminescent in the solid state. These observations indicate that the complexes are promising system for the development of potential photoactive materials.
文摘Three new chiral monoanionic [ON] ancillary phenolate ligands with varying pendant arms have been synthesized in moderate to high yields (50% - 85%) via Mannich-type condensation reaction of chiral substituted phenol, formaldehyde and (+)-bis-[(R)-1-phenylethyl]amine. These new organic compounds were fully characterized via nuclear magnetic resonance spectroscopy (1H and 13C) and elemental analysis. The newly synthesized ligands are suitable candidates for metal-catalyzed ring-opening of lactones and asymmetric catalysis.
基金Supported by the Key Research Program Foundation, Ministry of Education of China (Grant No. 02021)and the National Science Foundation of China (Grant No. 30471351)
文摘Wood of Chinese fir and poplar were liquefied in phenol at 150℃ and atmospheric pressure. The liquefied wood were reacted with formaldehyde to synthesize the liquefied wood-based resin. The factors affecting the resinification and the properties of new resin were investigated. The results show that the formaldehyde/liquefied wood molar ratio, reaction temperature, reaction time and sodium hydroxide/liquefied wood molar ratio have important influence on the resin characteristics. With the increase of formaldehyde/liquefied wood molar ratio, the yield of resin increases, and the flee phenol content of resins decreases, showing that the resinification of liquefied wood is more complete at higher formaldehyde/liquefied wood molar ratios. The reaction temperature on the viscosity of the liquefied resin has considerable effect; the viscosity of resin increased with increasing reaction temperature, and the amount of liquefied poplar resin increased more quickly than that of liquefied Chinese fir resin. The resinification time also has obvious influence on the viscosity of resin; the viscosity of liquefied poplar resin is more sensitive to resinification time compared with that of liquefied Chinese fir. The amount of sodium hydroxide can improve the water miscibility of liquefied wood resin. The optimum sodium hydroxide/liquefied wood molar ratio for preparation of liquefied wood-based resins exceeds 0.4.
文摘Herein,we report the application of four amino-tris(phenolate)-based metal complexes incorporating Ti(IV)or Zr(IV)centres(2a-3b)as homogeneous catalysts for the conversion of CO_(2)and epoxides into cyclic carbonates.The four complexes were synthesised,characterised and then evaluated in combination with tetrabutylammo-nium iodide,bromide or chloride as binary catalytic systems for the reaction of CO_(2)with 1,2-epoxyhexane as epoxide substrate at 12 bar CO_(2)pressure and 90?C for 2 h.The catalytic systems comprising the two Ti(IV)complexes(2a and 2b)showed similar performance.One notable exception was the catalytic system consisting of titanium complex 2b,bearing an axial Cl-ligand,and tetrabutylammonium chloride,which displayed higher catalytic activity compared to other titanium-based systems.Even higher activity was achieved with Zr(IV)complex 3a,bearing an axial isopropoxide ligand,which reached turnover numbers(TON metal)up to 1920 for the reaction of CO_(2)with 1,2-epoxyhexane at 12 bar CO_(2)pressure and 90?C for 2 h.This performance is comparable with that of state-of-the-art catalysts for this reaction.The catalytic system consisting of complex 3a and tetra-butylammonium bromide was explored further by investigating its applicability with a broad substrate scope,achieving quantitative conversion of several epoxides with CO_(2)into cyclic carbonate products at 90?C and 12 bar CO_(2)pressure for 18 h.The selectivity towards the cyclic carbonate products was?98%for all studied terminal epoxides and?80%for all examined cyclohexene-type epoxides.
基金the National Natural Science Foundation of China (Grant No. 20072027).
文摘Four divalent lanthanide complexes Sm(ArO)2 -(THF)4) Yb(ArO)2(THF)3, Eu(ArO)2(THF)3 (ArO=2,6-di-tert-butyl-4-methylphenolate) and (ButCp)2Sm(THF)2 were synthesized. Their catalytic activities on the polymerization of acrylonitrile were studied. The catalytic activities were influenced by the central metal ions involved. The catalytic activities of these divalent lanthanide complexes can be greatly increased by adding NaOC6H2-2,6-But2-4-Me, NaOC6H4-4-But, or NaOC10H6-2-Me. The amount of additive has apparent effect on the catalytic activity, but the additive has no effect on the tacticity of the resulting polyacryloni-trile.
文摘The synthesis and characterization of aluminum alkoxide and alkyl complexes stabilized by piperazidine- bridged bis（phenolate） ligands are described. Treatment of ligand precursors Hz[ONNO]^1 {Hz[ONNO]^1= 1,4-bis（2-hydroxy-3-tert-butyl-5-methylbenzyl）piperazidine} and Hz[ONNO]2 {H2[ONNO]2=1,4-bis（2-hydroxy3,5-di-tert-butylbenzyl）piperazidine} with A1Et2（OCH2Ph） and A1Etz（OPr-i）, which were generated in situ by the reactions of AIEt3 with equivalent of the corresponding alcohols, in a 1： 1 molar ratio in THF gave the corresponding aluminum alkoxide complexes [ONNO]IAI（OCH2Ph） （1） and [ONNO]2Al（OPr-i） （2）, respectively. The reaction of H2[ONNO]^1 with A1Etz（OCHzPh） in a 1 ： 2 molar ratio in THF afforded a mixture of monometallic aluminum ethyl complex [ONNO] 1A1Et （3） and complex 1, which can be isolated by stepwise crystallization. Similarly, Hz[ONNO]2 reacted with A1Etz（OPr-0 in a 1： 2 molar ratio in THF to give a mixture of aluminum ethyl complex [ONNO]2AlEt （4） and complex 2. Complexes 1 and 2 were also available via treatment of complexes 3 and 4 with 1 equiv, of benzyl alcohol and isopropyl alcohol, respectively. All of these complexes were fully characterized including X-ray structural determination. It was found that complexes 1 to 4 can initiate the ring-opening polymerization of e-caprolactone, and complexes 1 and 2 showed higher catalytic activity in comparison with com- plexes 3 and 4.
基金financial supported by the National Natural Science Foundation of China (20972108, 21174095, 21132002)a project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)the Qing Lan Project is gratefully acknowledged
文摘A series of neutral bimetallic lanthanide aryloxides p-C6H4[OLnL(THF)n]2 [Ln = Y(1), Yb(2), Sm(3)(n = 1) and La(4)(n = 2), L = Me2NCH2CH2N{CH2-(2-O–C6H2–tBu2-3,5)}2] and alkoxides p-C6H4CH2[OLnL(THF)]2 [Ln = Y(5), Yb(6)] supported by an amine-bridged bis(phenolate) ligand have been synthesized through one-pot reactions of Ln(C5H5)3(THF), LH2 with p-benzenediol and 1,4-benzenedimethanol, respectively. All complexes have been fully characterized by elemental analyses, single-crystal X-ray diffraction analysis, and IR and multi-nuclear NMR spectroscopy(in the cases of 1, 4 and 5). Study of their catalytic behavior revealed that, in general, all complexes are efficient initiators for the polymerization of rac-lactide(LA) and rac-β-butyrolactone(BBL), except for 3 and 4 in the case of BBL. The influence imposed by lanthanides of different ionic radii and initiating groups of different structures on the activity, controllability, and stereoselectivity of polymerization were systematically studied and compared. Highly heterotactic PLA(Pr up to 0.99) and syndiotactic PHB(Pr ≈ 0.81) with high molecular weight and narrow polydispersity formed and were automatically capped with hydroxyl functionality at both ends.
基金This work was financially supported by the National Natural Science Foundation of China （51273136）, Natural Science Fund of Jiangsu Province （BK20151262）, a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions （PAPD）, the Project of Scientific and Technologic Infrastructure of Suzhou （SZS201708） and Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions.
文摘Two rosamine-based pH probes 1a and 1b with pyronine-phenol skeleton were designed and synthesized by a simple one-step reaction, pH titration experiments showed that probes 1a and 1b exhibit near OFF-ON fluorescence responses around 550--750 nm towards the hydrogen ions. The pKa of the probe 1a is 8.29, while that of the probe lb increases to 12.1 because of the hydrogen bond inside it. Selective and competitive experiments indicated that both common ions and amino acids did not interfere their emission with hydrogen ions. Moreover, confocal fluorescent imaging showed that the probe la could be served as mitochondria biomarker in HeLa and Ges-1 cells.
文摘By means of gel permeation chromatography analysis, the molecular weight of liquefied wood under different reaction conditions was investigated to trace the change in the structural characteristics of the liquefied wood. The insoluble residues were analyzed by Fourier transform infrared to investigate the liquefaction order of three main wood components. The results indicate that both reaction temperature and reaction time could affect the molecular characteristics of the liquefied wood obtained. The mo...
文摘Chinese fir (Cunninghamia lanceolata) and poplar (Populus spp.) wood meal were phenolated in the presence of sulfuric acid used as a catalyst. The effects of reaction time and reaction temperature on the wood liquefaction were investigated. The results showed that the reaction temperature had the greater influence on the residue content than reaction time. Additionally, the liquefaction curve for the Chinese fir and Poplar were similar in general.
基金supported by the National Natural Science Foundation of China(Nos.42377428 and 42077391)the National Key Research&Developmental Program of China(No.2022YFC3701301)+1 种基金the Shandong Provincial Natural Science Foundation,China(Nos.ZR2020ZD34 and ZR2023YQ031)the Instrument Improvement Funds of Shandong University Public Technology Platform(No.ts20230108).
文摘Due to the endocrine toxicity,neurotoxic,and reproductive toxicity to organisms,the sources and risks of brominated organic pollutants have attracted widespread attention.However,knowledge gaps remain in the bromination processes of emerging phenolic pollutants in plants,whichmay increase the potential health risk associated with food exposure.Our study discovered that light induced generation and accumulation of more toxic brominated organic compounds(Br-org)in lettuce leaves under the stress of acetaminophen(ACE)than that without light,as evidenced by an increase in C-Br bond intensity in FTIR analysis.This result can be explained by the oxidation of bromide ions(Br^(-))by reactive species(ROS and ^(3)Chl*)of chloroplast into reactive bromine species(RBS).The main mechanism is that the redox of Br^(-)reduced the oxidative damage of ACE to the structure and function of chloroplasts,providing good conditions for light energy uptake and utilization and promoting the increase of pigments and active species.Compared with the dark group exposed to 5 mg/L Br^(-),the pigment content,H_(2)O_(2) and ^(1)O_(2) level of the light group increased by 56%,84% and 69%,respectively.On the other hand,RBS attacks certain electrophilic organic compounds in leaves to generate Br^(-)org.Triple excited state of chlorophyll(^(3)Chl^(*))was the dominant species for the transformation of ACE,while RBS is a key factor in the generation of Br-org in the Br^(-)/light/chlorophyll system.A total of six transformation products were identified by HPLC-MS/MS,which were involved in three transformation pathways:methylation,hydroxyl oxidation and hydroxylation followed by bromination.This is the first report that Br^(-)could enter the chloroplast and improved chloroplast structure under ACE stress,and elucidated the bromination mechanism of organics in terrestrial plant involving of biophotochemical bromination in chloroplast besides enzyme-catalyzed bromination.This study is beneficial for risk assessment and prevention of emerging phenolic pollutants.
基金supported by the National Key Research and Development Program of China(No.2023YFC3706602)the National Natural Science Foundation of China(Nos.22225605 and 22193051)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0750200).
文摘Synthetic phenolic antioxidants(SPAs)are widely used in diverse industries due to their exceptional antioxidant characteristics.However,human exposure to SPAs may cause health problems.In this study,226 dust samples were collected from 10 provinces in China,and six SPAs(three parent SPAs and their three transformation products)were analyzed.The concentrations of6SPAs(the sum of six target compounds)ranged from 15.4 to 3210 ng/g(geometric mean(GM):169 ng/g).The highest concentration of6SPAswas found in Sichuan Province(GM:349 ng/g),which was approximately 4 times higher than that in Hubei Province(81.6 ng/g)(p<0.05).The concentrations of butylated hydroxytoluene(BHT),2,2'-methylene bis(4-methyl-6–tert-butylphenol)(AO2246),2,6-di–tert–butyl–1,4-benzoquinone(BHT-Q),2,6-di–tert–butyl–4-(hydroxymethyl)phenol(BHT-OH),and ∑_(p)-SPAs were substantially higher in dust from urban areas than rural areas(p<0.05).AO2246 concentration in dust from homes(GM:0.400 ng/g)was about 4 times higher than that in workplaces(0.116 ng/g)(p<0.01).Significantly higherp-SPAs concentrations were found in dust from homes(GM:17.5 ng/g)than workplaces(11.4 ng/g)(p<0.01).The estimated daily intakes(EDIs)of ∑_(6)SPAs exposed through dust ingestion were 0.582,0.342,0.197,0.076,and 0.080 ng/kg bw/day in different age groups,and exposed through dermal contact was 0.358,0.252,0.174,0.167,and 0.177 ng/kg bw/day.EDIs showed that the exposure risks of SPAs decreased with age.This is the first work to determine SPAs in dust from10 provinces in China and investigate the spatial distribution of SPAs in those regions.
文摘Silica gel column chromatography(CC),Sephadex LH-20 CC and high performance liquid chromatography(HPLC)were used to study the chemical constituents of the fruits of the medicine-food plant Rubus idaeus Linnaeus.A new tetrahydrogenated naphthol syringic acid ester,named rubusnolicester(1),two new phenolic glycoside derivatives,4-chloro-2,6-dimethoxylphenol-1-O-β-D-glucopyranoside(2)and salicylic acid-2-O-(6'-O-acetyl)-β-D-glucopyranoside(3),together with one known salicylic acid glycoside derivative(4)and three known flavonoids derivatives(5~7),were isolated.Their structures were elucidated by HRESI-MS,NMR spectroscopy,and a comparison of optical rotation(OR).Compounds 1~7 were evaluated the inhibitory activities against the nitric oxide(NO)production induced by lipopolysaccharide(LPS)in mouse macrophage RAW264.7 cells in vitro.Compound 1 exhibited inhibitory effect with the IC50 value of(12.28±1.25)μmol/L.
基金supported by the National Natural Science Foundation of China(No.22206013).
文摘The efficient mineralization of phenol and its derivatives in wastewater remains a great challenge.In this study,the bimetallic CuCeO_(2)-BTC was screened from a series of MOFs-derived MCeO_(2)-BTC(M=La,Cu,Co,Fe,and Mn)catalysts,and the influence of the Cu/Ce ratio on phenol removal by catalytic ozonation was carefully examined.The results indicate that Cu_(2)Ce_(1)O_(y)-BTC was the best among the Cu_(x)Ce_(1)O_(y)-BTC(x=0,1,2,and 3)catalysts,with a phenol mineralization efficiency reaching close to 100%within 200 min,approximately 30.1%higher than CeO_(2)-BTC/O_(3)and 70.3%higher than O_(3)alone.The order of mineralization efficiency of phenol was Cu_(2)Ce_(1)O_(y)-BTC>Cu_(3)Ce_(1)O_(y)-BTC>Cu_(1)Ce_(1)O_(y)-BTC>CeO_(2)-BTC.CeO_(2)-BTC exhibited a broccoli-like morphology,and Cu_(x)Ce_(1)O_(y)-BTC(x=1,2,and 3)exhibited an urchin-like morphology.Compared with Cu_(x)Ce_(1)O_(y)-BTC(x=0,1,and 3),Cu_(2)Ce_(1)O_(y)-BTC exhibited a larger specific surface area and pore volume.This characteristic contributed to the availability of more active sites for phenol degradation.The redox ability was greatly enhanced as well.Besides,the surface of Cu_(2)Ce_(1)O_(y)-BTC exhibited a higher concentration of Ce^(3+)species and hydroxyl groups,which facilitated the dissociation of ozone and the generation of active radicals.Based on the results of radical quenching experiments and the intermediates detected by LC-MS,a potential mechanism for phenol degradation in the Cu_(2)Ce_(1)O_(y)-BTC/O_(3)system was postulated.This study offers novel perspectives on the advancement of MOFs-derived catalysts for achieving the complete mineralization of phenol in wastewater through catalytic ozonation.
基金funded by the Ministry of Education Science and Technological Development of the Republic of Serbia with grant numbers 451-03-47/2025-01/200133 and 451-34403-47/2025-01/200189.
文摘This study aims to determine the phytochemical composition and antioxidant activity(AA)of different plant parts(bulbs,stalk,leaves and flowers)of wild rosy garlic(Allium roseum)from Montenegro.The flower exhibited the highest concentration of total phenols(55.7 GAE/g d.e.),followed by the leaf(25.6mg GAE/g d.e.).The leaf displayed the highest concentration of total flavonoids(41.48 mg RE/g d.e.),followed by the flower(36.26 mg RE/g d.e.)and top part of the stalk(26.80 mg RE/g d.e.).The AA of different parts of A.roseum after 60 min of incubation decreased in the following order:flower(0.15mg/cm^(3))>upper stalk(0.32mg/cm^(3))>leaf(0.36mg/cm^(3))>basal stalk(0.80mg/cm^(3))>bulb(1.53 mg/cm^(3)).The flowers exhibited the lowest EC_(50) values,indicating the highest antioxidant potential throughout the entire incubation period.Among all plant parts analyzed,the flowers demonstrated the highest ferric reducing antioxidant power(FRAP),reaching 24.99 mg Fe^(2+)/g,thereby indicating their superior antioxidant potential.Given their edibility,pleasant flavor,and high nutritional value,A.roseum flowers may be considered a promising natural additive for functional food products or culinary applications,including dish enhancement and decoration.
基金supported by the Zhejiang Provincial Natural Science Foundation of China(LY23B060006 and LY18B060016).
文摘SAPO-5 zeolite supported RuMn was a highly efficient catalyst for the aqueous-phase selective hydrodeoxygenation of guaiacol to cyclohexanol.The optimal catalyst achieved a high cyclohexanol yield of 93.7%at full guaiacol conversion under mild conditions,with a high TOF of 920 h^(-1).Moreover,the catalyst displayed remarkable performance for the hydrogenation of phenol to cyclohexanol,where a 100%yield of cyclohexanol was obtained at a phenol-to-Ru molar ratio of about 17900.In particular,the catalyst exhibited excellent recyclability and could be recycled for 20 times without obvious activity loss.The as-prepared RuMn/SAPO-5 catalyst exhibited higher performance than most of the reported Rubased catalysts.
