Cu nanoparticles were prepared by reducing Cu2＋ ions with ascorbic acid through aqueous solution reduction method. The effects of solution pH and average size of Cu2O particles on the preparation of Cu nanoparticles ...Cu nanoparticles were prepared by reducing Cu2＋ ions with ascorbic acid through aqueous solution reduction method. The effects of solution pH and average size of Cu2O particles on the preparation of Cu nanoparticles were investigated. Cu particles were prepared at pH 3, 5 or 7, with the smallest Cu particles obtained at pH 7. However, Cu particles could not be prepared at pH 9 or 11. The average size of Cu2O particles can affect that of Cu particles. Larger Cu2O particles result in larger Cu particles. In addition, experiments were conducted to explore the reaction process by measuring the X-ray diffraction （XRD） patterns of specimens collected at different time points during the reaction. It was found that Cu（OH）2 was initially formed as a precursor, followed by the formation of Cu2O, which was finally reduced to Cu particles.展开更多
The preparation of Cu nanoparticles by the aqueous solution reduction method was investigated. The effects of different reaction parameters on the preparation of Cu nanoparticles were studied. The optimum conditions f...The preparation of Cu nanoparticles by the aqueous solution reduction method was investigated. The effects of different reaction parameters on the preparation of Cu nanoparticles were studied. The optimum conditions for preparing well-dispersed nanoparticles were found as follows: 0.4 mol/L NaBH4 was added into solution containing 0.2 mol/L Cu2+, 1.0% gelatin dispersant in mass fraction, and 1.2 mol/L NH3?H2O at pH 12 and 313 K. In addition, a series of experiments were performed to discover the reaction process. NH3?H2O was found to be able to modulate the reaction process. At pH=10, Cu2+ was transformed to Cu(NH3)42+ as precursor after the addition of NH3?H2O, and then Cu(NH3)42+ was reduced by NaBH4 solution. At pH=12, Cu2+ was transformed to Cu(OH)2 as precursor after the addition of NH3?H2O, and Cu(OH)2 was then reduced by NaBH4 solution.展开更多
Cu nanoparticles were prepared by reducing Cu2＋ ions with NaBH4 in alkaline solution. The effects of NaBH4 concentration and dripping rate on the formation of Cu nanoparticles were studied. The optimum conditions are...Cu nanoparticles were prepared by reducing Cu2＋ ions with NaBH4 in alkaline solution. The effects of NaBH4 concentration and dripping rate on the formation of Cu nanoparticles were studied. The optimum conditions are found to be 0.2 mol/L Cu2＋, solution with pH=12, temperature of 313 K and 1% gelatin as dispersant, to which 0.4 mol/L NaBH4 is added at a dripping rate of 50 mL/min. NH3-H2O is found to be the optimal complexant to form the Cu precursor. A series experiments were conducted to study the reaction process at different time points.展开更多
This study explored the extraction process of indigo pigment from Baphicacanthus cusia using aqueous enzymatic method for the first time. Through single factor tests and orthogonal tests, this study investigated the e...This study explored the extraction process of indigo pigment from Baphicacanthus cusia using aqueous enzymatic method for the first time. Through single factor tests and orthogonal tests, this study investigated the effects of extraction time, extraction temperature, enzyme concentration, pH value, and solidliquid ratio on the extraction rate of indigo pigment. The results showed that the extraction rate of indigo reached the highest(0.218%) when the solid-liquid ratio was 1:20, enzyme concentration was 6 g/L, pH value was 5, extraction temperature was 50℃, and extraction time was 3 h. The method had greatly shortened the extraction time, simplified the extraction process, and improved the extraction efficiency while producing little pollution and meeting the green environmental protection requirements.展开更多
The preparation of polyaniline nanofibers in aqueous solution was studied as functions of the concentrations and ratios of reactants. The morphology and microstructure of polyaniline nanofibers are affected by the con...The preparation of polyaniline nanofibers in aqueous solution was studied as functions of the concentrations and ratios of reactants. The morphology and microstructure of polyaniline nanofibers are affected by the concentrations and proportions of the reactants. A special kind of sea cucumber-like polyaniline nanofibers can be prepared under control of reaction conditions. Secondary growth is the formation mechanism. In addition, the bulk electrical conductivity of these sea cucumber-like polyaniline nanofibers was higher than that of other common polyaniline nanofibers.展开更多
Taken kiwi fruit as raw material, this paper extracted kiwi fruit seed oil with ultrasonic-assisted enzyme, researched the influence of factors such as liquid-to-solid ratio, granularity, type of enzyme, ultrasonic po...Taken kiwi fruit as raw material, this paper extracted kiwi fruit seed oil with ultrasonic-assisted enzyme, researched the influence of factors such as liquid-to-solid ratio, granularity, type of enzyme, ultrasonic power, treating time, enzymolysis temperature, enzymolysis time, pH and enzyme additive on oil extraction, and optimized the extracting technology of kiwi fruit seed oil with response surface method. The result shows that the best technical parameter is: material granularity: 60, liquid-to-solid ratio: 1:10 (g/mL), ultrasonic power: 400 W, treating time: 30 min, enzyme amount: 2.50%, pH: 9.2, enzymolysis temperature: 53°C, enzymolysis time: 2.80 h;and the extracting ratio under such condition is 92.57%.展开更多
An efficient and green method has been developed for the synthesis of 2H-indazolo[2,1-b]phthalazinetriones derivatives by employing 15 mol%β-cyclodextrinvia a one-pot multicomponent reaction of aldehyde,dimedone,hydr...An efficient and green method has been developed for the synthesis of 2H-indazolo[2,1-b]phthalazinetriones derivatives by employing 15 mol%β-cyclodextrinvia a one-pot multicomponent reaction of aldehyde,dimedone,hydrazine hydrate with succinic anhydride/phthalic anhydride in water at 80 ℃ for first time.The catalyst could be recovered and reused for four consecutive cycles without appreciable loss in catalytic activity and evaluated for in vitro antimicrobial activity against different Gram-positive and Gram-negative bacterial strains.The outcome of the screening study showed that compound 6d,6f and7 n exhibited excellent activity against E.coil.Whereas,compound 6f and 6h exhibited excellent activity against P.aeurginosa,and compound 6c,and 6e displayed again excellent activity against Staphylococcus aureus whereas compound 7o shows excellent activity against S.aureus and B.subtilis when compared with Ampicillin（standard control）.The results indicated that maximum compounds are moderately effective against bacterial growth and their effectiveness is highest against standard drugs.展开更多
Bismuth-based fluoride nanocrystalline materials are an emerging class of host matrixes for luminescent ions with promising applications in optoelectronic devices and medical diagnosis.However,rapid aqueous-phase synt...Bismuth-based fluoride nanocrystalline materials are an emerging class of host matrixes for luminescent ions with promising applications in optoelectronic devices and medical diagnosis.However,rapid aqueous-phase synthesis of highly stable bismuth-based fluoride nanocrystals at low temperature(room temperature∼90℃)is still a significant challenge.Herein we report an ultrafast(1 min only)and economical aqueous method to synthesize lanthanide-doped K_(0.3)Bi_(0.7)F_(2.4)upconversion nanocrystalline particles at low temperature.The resultant materials show exceptional upconversion luminescence performance under the excitation of a 980 nm near-infrared laser.More importantly,these fluoride nanocrystalline particles show excellent stability against high temperature up to 200℃,high excitation power density(80 W cm^(−2))and prolonged water soaking(60 days or more).The proposed simple synthesis route,rare-earth free fluoride matrix,commendable upconversion luminescence performance and excellent chemical and thermal stability opens the door to access these lanthanide-doped K0.3Bi0.7F2.4 upconversion nanocrystalline particles for anti-counterfeiting and other daily applications.展开更多
Ammonia is important for industrial development and human life.The traditional Haber Bosch method converts nitrogen into ammonia gas at high temperatures and pressures,causing serious pollution and greenhouse gas emis...Ammonia is important for industrial development and human life.The traditional Haber Bosch method converts nitrogen into ammonia gas at high temperatures and pressures,causing serious pollution and greenhouse gas emissions.These problems prompt the nitrogen fixation method to proceed in a sustainable way.Ultrathin Ni/V-layered double hydroxides(Ni/V-LDHs)nanosheets with different proportions were prepared successfully for photocatalystic reduction of nitrogen to ammonia,through aqueous miscible organic solvent method(AMO)to achieve the higher surface area and rich oxygen vacancies,containing more carriers and active sites to enhance nitrogen reduction.And the optimal catalyst of Ni/V-LDHs 11 AMO possesses the highest photocatalytic efficiency(176μmol·g^(-1)·h^(-1)),indicating its potential application prospects in catalyst fields.Consequently,this work achieves an environmentally friendly,low-cost and efficient conversion method for nitrogen reduction to ammonia through solar energy.展开更多
Aqueous lead monosulfide(PbS)quantum dots(QDs)fabricated by conventional approaches display poor photodetection performance and unsatisfactory chemical stability,so various strategies for well-defined PbS QD-based het...Aqueous lead monosulfide(PbS)quantum dots(QDs)fabricated by conventional approaches display poor photodetection performance and unsatisfactory chemical stability,so various strategies for well-defined PbS QD-based heterostructures have been developed,which are usually complicated and unsuitable for largescale production.In this work,homogeneous ultrasmall,uniform ternary Pb_(1−x)Cd_(x)S QDs are rationally designed and successfully fabricated by an in situ aqueous coprecipitation method.展开更多
In this paper,a novel electrochemical sensor based on a functionalized multi-walled carbon nanotube(f-MWCNT)decorated ruskin michelle-like zinc oxide(ZnO)nanocomposite for the determination of the environmental pollut...In this paper,a novel electrochemical sensor based on a functionalized multi-walled carbon nanotube(f-MWCNT)decorated ruskin michelle-like zinc oxide(ZnO)nanocomposite for the determination of the environmental pollutant hydroquinone(HQ)is reported.We have followed a new aqueous solution method for the synthesis of ruskin michelle-like ZnO nanoparticles and they are characterized by scanning electron microscopy(SEM),X-ray diffraction(XRD),Raman spectroscopy,Fourier transform infrared(FT-IR)spectroscopy and UV visible spectroscopy.Cyclic voltammetry(CV),differential pulse voltammetry(DPV)and amperometric techniques are used for the electrochemical analysis of a f-MWCNT decorated ruskin michelle-like ZnO nanocomposite modified glassy carbon electrode(GCE).The fabricated f-MWCNT/ZnO GCE showcased excellent electrocatalytic activity in the determination of HQ and we obtained a sharp anodic and cathodic peak current at a low potential value of 0.11 V and 0.05 V,respectively.Efficient reproducibility and stability,anti-interference property and good repeatability,which are the traits of a good electrochemical sensor,are exhibited by the fabricated sensor.We have obtained a very low limit of detection(LOD)for the fabricated f-MWCNT/ZnO GCE of 0.02μM,a linear response in the range of 0.1-190μM and a sensitivity of 6.37μAμM^(-1)cm^(-2).These results obtained from the electrochemical analysis reveal the excellent performance of the f-MWCNT decorated ruskin michelle-like ZnO nanocomposite modified GCE in the effective determination of HQ.展开更多
Two new crystalline materials[Cu_(3)(μ_(2)-H_(3)bis-tris)_(2)(μ_(2)-Hhpa)_(2)]·H_(2)O(1)and[Cu_(3)(μ_(2)-H_(2)tea)_(2)(μ_(2)-hpa)-(μ_(3)-hpa)]_(n)(2)bearing distinct tricopper(Ⅱ)cores were easily generated ...Two new crystalline materials[Cu_(3)(μ_(2)-H_(3)bis-tris)_(2)(μ_(2)-Hhpa)_(2)]·H_(2)O(1)and[Cu_(3)(μ_(2)-H_(2)tea)_(2)(μ_(2)-hpa)-(μ_(3)-hpa)]_(n)(2)bearing distinct tricopper(Ⅱ)cores were easily generated by the aqueous medium selfassembly method from copper(Ⅱ)nitrate,bis(2-hydroxyethyl)amino-tris(hydroxymethyl)methane(H_(5)bistris)or triethanolamine(H_(3)tea)aminoalcohol biobuffers and homophthalic acid(H_(2)hpa).The obtained products were characterised by IR,UV-vis and EPR spectroscopy,ESI-MS(±),thermogravimetric,elemental and single crystal X-ray diffraction analysis.Apart from possessing different dimensionality,the crystal structures of the discrete 0D trimer 1 and the zigzag 1D coordination polymer 2 show distinct symmetric[Cu_(3)(μ-O)_(4)(μ-COO)_(2)]and asymmetric[Cu_(3)(μ-O)_(3)(μ-COO)_(2)]tricopper(Ⅱ)cores,respectively.An intense pattern of intermolecular O-H…O hydrogen bonds provides a 0D→3D(1)or 1D→2D(2)extension of the structures into intricate topologically unique H-bonded nets.After additional simplification,these were classified as a uninodal 6-connected 3D framework with the snk topology in 1 and a binodal 3,5-connected 2D layer with the 3,5L50 topology in 2.Variable-temperature magnetic susceptibility studies indicate a predominant ferromagnetic coupling[J=39.1(1)and 29.5(1)cm^(−1)for 1 and 2,respectively]within the mixed-bridged tricopper(Ⅱ)cores.Both compounds 1 and 2 were also applied as rather efficient bio-inspired pre-catalysts for the mild homogeneous oxidation,by aqueous H_(2)O_(2)at 50℃in acidic MeCN-H_(2)O medium,of cyclic(cyclopentane,cyclohexane,cycloheptane and cyclooctane)and linear(n-pentane,n-hexane,n-heptane and n-octane)alkanes to the corresponding alcohols and ketones with overall yields up to 26%based on the alkane.The effects of different reaction parameters(type of pre-catalyst and acid promoter,reaction time and substrate scope)and various selectivity features were investigated and discussed,supporting a free-radical mechanism in the present alkane oxidations.展开更多
文摘Cu nanoparticles were prepared by reducing Cu2＋ ions with ascorbic acid through aqueous solution reduction method. The effects of solution pH and average size of Cu2O particles on the preparation of Cu nanoparticles were investigated. Cu particles were prepared at pH 3, 5 or 7, with the smallest Cu particles obtained at pH 7. However, Cu particles could not be prepared at pH 9 or 11. The average size of Cu2O particles can affect that of Cu particles. Larger Cu2O particles result in larger Cu particles. In addition, experiments were conducted to explore the reaction process by measuring the X-ray diffraction （XRD） patterns of specimens collected at different time points during the reaction. It was found that Cu（OH）2 was initially formed as a precursor, followed by the formation of Cu2O, which was finally reduced to Cu particles.
文摘The preparation of Cu nanoparticles by the aqueous solution reduction method was investigated. The effects of different reaction parameters on the preparation of Cu nanoparticles were studied. The optimum conditions for preparing well-dispersed nanoparticles were found as follows: 0.4 mol/L NaBH4 was added into solution containing 0.2 mol/L Cu2+, 1.0% gelatin dispersant in mass fraction, and 1.2 mol/L NH3?H2O at pH 12 and 313 K. In addition, a series of experiments were performed to discover the reaction process. NH3?H2O was found to be able to modulate the reaction process. At pH=10, Cu2+ was transformed to Cu(NH3)42+ as precursor after the addition of NH3?H2O, and then Cu(NH3)42+ was reduced by NaBH4 solution. At pH=12, Cu2+ was transformed to Cu(OH)2 as precursor after the addition of NH3?H2O, and Cu(OH)2 was then reduced by NaBH4 solution.
文摘Cu nanoparticles were prepared by reducing Cu2＋ ions with NaBH4 in alkaline solution. The effects of NaBH4 concentration and dripping rate on the formation of Cu nanoparticles were studied. The optimum conditions are found to be 0.2 mol/L Cu2＋, solution with pH=12, temperature of 313 K and 1% gelatin as dispersant, to which 0.4 mol/L NaBH4 is added at a dripping rate of 50 mL/min. NH3-H2O is found to be the optimal complexant to form the Cu precursor. A series experiments were conducted to study the reaction process at different time points.
文摘This study explored the extraction process of indigo pigment from Baphicacanthus cusia using aqueous enzymatic method for the first time. Through single factor tests and orthogonal tests, this study investigated the effects of extraction time, extraction temperature, enzyme concentration, pH value, and solidliquid ratio on the extraction rate of indigo pigment. The results showed that the extraction rate of indigo reached the highest(0.218%) when the solid-liquid ratio was 1:20, enzyme concentration was 6 g/L, pH value was 5, extraction temperature was 50℃, and extraction time was 3 h. The method had greatly shortened the extraction time, simplified the extraction process, and improved the extraction efficiency while producing little pollution and meeting the green environmental protection requirements.
基金supported by the National Advanced Materials Committee of China (No. 2008AA03Z409)
文摘The preparation of polyaniline nanofibers in aqueous solution was studied as functions of the concentrations and ratios of reactants. The morphology and microstructure of polyaniline nanofibers are affected by the concentrations and proportions of the reactants. A special kind of sea cucumber-like polyaniline nanofibers can be prepared under control of reaction conditions. Secondary growth is the formation mechanism. In addition, the bulk electrical conductivity of these sea cucumber-like polyaniline nanofibers was higher than that of other common polyaniline nanofibers.
文摘Taken kiwi fruit as raw material, this paper extracted kiwi fruit seed oil with ultrasonic-assisted enzyme, researched the influence of factors such as liquid-to-solid ratio, granularity, type of enzyme, ultrasonic power, treating time, enzymolysis temperature, enzymolysis time, pH and enzyme additive on oil extraction, and optimized the extracting technology of kiwi fruit seed oil with response surface method. The result shows that the best technical parameter is: material granularity: 60, liquid-to-solid ratio: 1:10 (g/mL), ultrasonic power: 400 W, treating time: 30 min, enzyme amount: 2.50%, pH: 9.2, enzymolysis temperature: 53°C, enzymolysis time: 2.80 h;and the extracting ratio under such condition is 92.57%.
基金supported by Special Assistance Programme SAP,University Grants Commission,New Delhi,India
文摘An efficient and green method has been developed for the synthesis of 2H-indazolo[2,1-b]phthalazinetriones derivatives by employing 15 mol%β-cyclodextrinvia a one-pot multicomponent reaction of aldehyde,dimedone,hydrazine hydrate with succinic anhydride/phthalic anhydride in water at 80 ℃ for first time.The catalyst could be recovered and reused for four consecutive cycles without appreciable loss in catalytic activity and evaluated for in vitro antimicrobial activity against different Gram-positive and Gram-negative bacterial strains.The outcome of the screening study showed that compound 6d,6f and7 n exhibited excellent activity against E.coil.Whereas,compound 6f and 6h exhibited excellent activity against P.aeurginosa,and compound 6c,and 6e displayed again excellent activity against Staphylococcus aureus whereas compound 7o shows excellent activity against S.aureus and B.subtilis when compared with Ampicillin（standard control）.The results indicated that maximum compounds are moderately effective against bacterial growth and their effectiveness is highest against standard drugs.
基金support from the National Natural Science Foundation of China(grant no.51902184)the Shandong Provincial Natural Science Foundation(grant no.ZR2019BEM028)+2 种基金the“Qi-Lu Young Scholar Fund”(grant no.31370088963167)from Shandong Universitysupport from the Major Basic Research Projects of Shandong Natural Science Foundation(ZR2018ZB0104)supported by the National Natural Science Foundation of China(grant no.21805111)and the Taishan Scholar Fund.
文摘Bismuth-based fluoride nanocrystalline materials are an emerging class of host matrixes for luminescent ions with promising applications in optoelectronic devices and medical diagnosis.However,rapid aqueous-phase synthesis of highly stable bismuth-based fluoride nanocrystals at low temperature(room temperature∼90℃)is still a significant challenge.Herein we report an ultrafast(1 min only)and economical aqueous method to synthesize lanthanide-doped K_(0.3)Bi_(0.7)F_(2.4)upconversion nanocrystalline particles at low temperature.The resultant materials show exceptional upconversion luminescence performance under the excitation of a 980 nm near-infrared laser.More importantly,these fluoride nanocrystalline particles show excellent stability against high temperature up to 200℃,high excitation power density(80 W cm^(−2))and prolonged water soaking(60 days or more).The proposed simple synthesis route,rare-earth free fluoride matrix,commendable upconversion luminescence performance and excellent chemical and thermal stability opens the door to access these lanthanide-doped K0.3Bi0.7F2.4 upconversion nanocrystalline particles for anti-counterfeiting and other daily applications.
基金This work was financially supported by the National Basic Research Program of China(No.2014CB932101)the National Natural Science Foundation of China,111 Project(No.B07004)+1 种基金Program for Changjiang Scholars and Innovative Research Team in University(No.IRT1205)the Fundamental Research Funds for the Central Universities(No.buctrc201527).
文摘Ammonia is important for industrial development and human life.The traditional Haber Bosch method converts nitrogen into ammonia gas at high temperatures and pressures,causing serious pollution and greenhouse gas emissions.These problems prompt the nitrogen fixation method to proceed in a sustainable way.Ultrathin Ni/V-layered double hydroxides(Ni/V-LDHs)nanosheets with different proportions were prepared successfully for photocatalystic reduction of nitrogen to ammonia,through aqueous miscible organic solvent method(AMO)to achieve the higher surface area and rich oxygen vacancies,containing more carriers and active sites to enhance nitrogen reduction.And the optimal catalyst of Ni/V-LDHs 11 AMO possesses the highest photocatalytic efficiency(176μmol·g^(-1)·h^(-1)),indicating its potential application prospects in catalyst fields.Consequently,this work achieves an environmentally friendly,low-cost and efficient conversion method for nitrogen reduction to ammonia through solar energy.
基金supported by the National Natural Science Foundation of China(grant no.61805147 and 52103316).
文摘Aqueous lead monosulfide(PbS)quantum dots(QDs)fabricated by conventional approaches display poor photodetection performance and unsatisfactory chemical stability,so various strategies for well-defined PbS QD-based heterostructures have been developed,which are usually complicated and unsuitable for largescale production.In this work,homogeneous ultrasmall,uniform ternary Pb_(1−x)Cd_(x)S QDs are rationally designed and successfully fabricated by an in situ aqueous coprecipitation method.
基金supported by the Ministry of Science and Technology,ROC,under grant no.105-2221-E-027-061.
文摘In this paper,a novel electrochemical sensor based on a functionalized multi-walled carbon nanotube(f-MWCNT)decorated ruskin michelle-like zinc oxide(ZnO)nanocomposite for the determination of the environmental pollutant hydroquinone(HQ)is reported.We have followed a new aqueous solution method for the synthesis of ruskin michelle-like ZnO nanoparticles and they are characterized by scanning electron microscopy(SEM),X-ray diffraction(XRD),Raman spectroscopy,Fourier transform infrared(FT-IR)spectroscopy and UV visible spectroscopy.Cyclic voltammetry(CV),differential pulse voltammetry(DPV)and amperometric techniques are used for the electrochemical analysis of a f-MWCNT decorated ruskin michelle-like ZnO nanocomposite modified glassy carbon electrode(GCE).The fabricated f-MWCNT/ZnO GCE showcased excellent electrocatalytic activity in the determination of HQ and we obtained a sharp anodic and cathodic peak current at a low potential value of 0.11 V and 0.05 V,respectively.Efficient reproducibility and stability,anti-interference property and good repeatability,which are the traits of a good electrochemical sensor,are exhibited by the fabricated sensor.We have obtained a very low limit of detection(LOD)for the fabricated f-MWCNT/ZnO GCE of 0.02μM,a linear response in the range of 0.1-190μM and a sensitivity of 6.37μAμM^(-1)cm^(-2).These results obtained from the electrochemical analysis reveal the excellent performance of the f-MWCNT decorated ruskin michelle-like ZnO nanocomposite modified GCE in the effective determination of HQ.
基金supported by the Foundation for Science and Technology(FCT)(projects PTDC/QUI-QUI/121526/2010,RECI/QEQ-QIN/0189/2012,PEst-OE/QUI/UI0100/2013,IF/01395/2013 and SFRH/BPD/78854/2011),Portugal.
文摘Two new crystalline materials[Cu_(3)(μ_(2)-H_(3)bis-tris)_(2)(μ_(2)-Hhpa)_(2)]·H_(2)O(1)and[Cu_(3)(μ_(2)-H_(2)tea)_(2)(μ_(2)-hpa)-(μ_(3)-hpa)]_(n)(2)bearing distinct tricopper(Ⅱ)cores were easily generated by the aqueous medium selfassembly method from copper(Ⅱ)nitrate,bis(2-hydroxyethyl)amino-tris(hydroxymethyl)methane(H_(5)bistris)or triethanolamine(H_(3)tea)aminoalcohol biobuffers and homophthalic acid(H_(2)hpa).The obtained products were characterised by IR,UV-vis and EPR spectroscopy,ESI-MS(±),thermogravimetric,elemental and single crystal X-ray diffraction analysis.Apart from possessing different dimensionality,the crystal structures of the discrete 0D trimer 1 and the zigzag 1D coordination polymer 2 show distinct symmetric[Cu_(3)(μ-O)_(4)(μ-COO)_(2)]and asymmetric[Cu_(3)(μ-O)_(3)(μ-COO)_(2)]tricopper(Ⅱ)cores,respectively.An intense pattern of intermolecular O-H…O hydrogen bonds provides a 0D→3D(1)or 1D→2D(2)extension of the structures into intricate topologically unique H-bonded nets.After additional simplification,these were classified as a uninodal 6-connected 3D framework with the snk topology in 1 and a binodal 3,5-connected 2D layer with the 3,5L50 topology in 2.Variable-temperature magnetic susceptibility studies indicate a predominant ferromagnetic coupling[J=39.1(1)and 29.5(1)cm^(−1)for 1 and 2,respectively]within the mixed-bridged tricopper(Ⅱ)cores.Both compounds 1 and 2 were also applied as rather efficient bio-inspired pre-catalysts for the mild homogeneous oxidation,by aqueous H_(2)O_(2)at 50℃in acidic MeCN-H_(2)O medium,of cyclic(cyclopentane,cyclohexane,cycloheptane and cyclooctane)and linear(n-pentane,n-hexane,n-heptane and n-octane)alkanes to the corresponding alcohols and ketones with overall yields up to 26%based on the alkane.The effects of different reaction parameters(type of pre-catalyst and acid promoter,reaction time and substrate scope)and various selectivity features were investigated and discussed,supporting a free-radical mechanism in the present alkane oxidations.
