Dissolved black carbon(DBC)plays a crucial role in the migration and bioavailability of iron in water.However,the properties of DBC releasing under diverse pyrolysis conditions and dissolving processes have not been s...Dissolved black carbon(DBC)plays a crucial role in the migration and bioavailability of iron in water.However,the properties of DBC releasing under diverse pyrolysis conditions and dissolving processes have not been systematically studied.Here,the compositions of DBC released from biochar through redox processes dominated by bacteria and light were thoroughly studied.It was found that the DBC released from straw biochar possess more oxygen-containing functional groups and aromatic substances.The content of phenolic and carboxylic groups in DBC was increased under influence of microorganisms and light,respectively.The concentration of phenolic hydroxyl groups increased from 10.0~57.5 mmol/gC to 6.6~65.2 mmol/gC,and the concentration of carboxyl groups increased from49.7~97.5 mmol/gC to 62.1~113.3 mmol/gC.Then the impacts of DBC on pyrite dissolution andmicroalgae growth were also investigated.The complexing Fe^(3+)was proved to play a predominant role in the dissolution of ferrous mineral in DBC solution.Due to complexing between iron ion and DBC,the amount of dissolved Fe in aquatic water may rise as a result of elevated number of aromatic components with oxygen containing groups and low molecular weight generated under light conditions.Fe-DBC complexations in solution significantly promoted microalga growth,which might be attributed to the stimulating effect of dissolved Fe on the chlorophyll synthesis.The results of study will deepen our understanding of the behavior and ultimate destiny of DBC released into an iron-rich environment under redox conditions.展开更多
This paper reports the preparation of three di‑iron complexes containing a thiazole moiety.Esterification of complex[Fe_(2)(CO)_(6)(μ‑SCH_(2)CH(CH_(2)OH)S)](1)with 4‑methylthiazole‑5‑carboxylic acid gave the correspo...This paper reports the preparation of three di‑iron complexes containing a thiazole moiety.Esterification of complex[Fe_(2)(CO)_(6)(μ‑SCH_(2)CH(CH_(2)OH)S)](1)with 4‑methylthiazole‑5‑carboxylic acid gave the corresponding ester[Fe_(2)(CO)_(6)(μ‑tedt)](2),where tedt=SCH_(2)CH(CH_(2)OOC(5‑C_(3)HNSCH_(3)))S.Further reactions of complex 2 with tri(ptolyl)phosphine(tp)or tris(4‑fluorophenyl)phosphine(fp)gave the phosphine‑substituted derivatives[Fe_(2)(CO)_(5)(tp)(μ‑tedt)](3)and[Fe_(2)(CO)_(5)(fp)(μ‑tedt)](4).The structures of the newly prepared complexes were elucidated by elemental analysis,NMR,IR,and X‑ray photoelectron spectroscopy.Moreover,single‑crystal X‑ray diffraction analysis confirmed their molecular structures,showing that they contain a di‑iron core ligated by a bridged dithiolate bearing a thiazole moiety and terminal carbonyls.The electrochemical and electrocatalytic proton reduction were probed by cyclic voltammetry,revealing that three complexes can catalyze the reduction of protons to H_(2) under the electrochemical conditions.For comparison,complex 4 possessed the best efficiency with a turnover frequency of 23.5 s^(-1)at 10 mmol·L^(-1)HOAc concentration.In addition,the fungicidal activity of these complexes was also investigated in this study.CCDC:2477511,2;2477512,3;2477513,4.展开更多
Iron deficiency anemia affects approximately 1.62 billion people worldwide,yet traditional iron supplements present bioavailability limitations and gastrointestinal side effects.This randomized,double-blind clinical t...Iron deficiency anemia affects approximately 1.62 billion people worldwide,yet traditional iron supplements present bioavailability limitations and gastrointestinal side effects.This randomized,double-blind clinical trial investigated a novel Auricularia auricula polysaccharide-iron complex(AAPIC)compared with heme iron and ferrous glycinate in 180 iron-deficient adults receiving 30 mg elemental iron daily for 12 weeks.AAPIC achieved comparable hemoglobin improvements(from 98.3±8.7 to 126.5±9.2 g/L)to heme iron(from 97.8±9.1 to 128.3±8.6 g/L)and was significantly superior to ferrous glycinate(from 98.6±8.9 to 119.7±10.3 g/L;p<0.001).Iron absorption efficiency showed AAPIC at 23.7±4.2%,heme iron at 25.1±3.8%,and ferrous glycinate at 18.4±5.1%.Toxicological assessments revealed no hepatotoxicity,nephrotoxicity,or mutagenicity.Gastrointestinal adverse events occurred in 8.3%of AAPIC recipients versus 15.0%with ferrous glycinate and 10.0%with heme iron.The polysaccharide component facilitates iron transport through enhanced intestinal uptake mechanisms.AAPIC represents a promising,well-tolerated alternative with clinical efficacy comparable to established iron formulations.展开更多
Leveraging the modularity and efficiency of click chemistry,a series of chiral diamine-triazole tetradentate nitrogen donor ligands and their corresponding nonheme iron complexes were synthesized.These iron-based cata...Leveraging the modularity and efficiency of click chemistry,a series of chiral diamine-triazole tetradentate nitrogen donor ligands and their corresponding nonheme iron complexes were synthesized.These iron-based catalysts demonstrated excellent catalytic activity and enantioselectivity in the asymmetric epoxidation of electron-deficient olefins using H_(2)O_(2) as the terminal oxidant.展开更多
The methylene-selective oxidation of simple alkanes catalyzed by a nonheme iron(Ⅲ)-monoamidate complex using H_(2)O_(2)as the terminal oxidant is reported.Mechanistic studies suggest that iron(V)-oxo species is the a...The methylene-selective oxidation of simple alkanes catalyzed by a nonheme iron(Ⅲ)-monoamidate complex using H_(2)O_(2)as the terminal oxidant is reported.Mechanistic studies suggest that iron(V)-oxo species is the active intermediate,undergoing hydrogen atom abstraction(HAA)as the rate-determining step to initiate C-H bond activation.展开更多
Two mono iron complexes Fe（CO）2PR3（NN） （R = Cy （3）, Ph （4）, NN = o-phenylenediamine dianion ligand, N2H2Ph2-） derived from the ligand substitution of Fe（CO）3hPR3 by the NN ligand were isolated and structur...Two mono iron complexes Fe（CO）2PR3（NN） （R = Cy （3）, Ph （4）, NN = o-phenylenediamine dianion ligand, N2H2Ph2-） derived from the ligand substitution of Fe（CO）3hPR3 by the NN ligand were isolated and structurally characterized by single crystal X-ray diffraction. They have a similar first coordination sphere and oxidation state of the iron center as the [Fe]-hydrogenase active site, and can be a model of it IR demonstrated that the effect of the NN ligand on the coordinated CO stretch- ing frequencies was due to its excellent electron donating ability. The reversible protonation/deprotonation of the NN ligand was identified by infrared spectroscopy and density functional theory computation. The NN ligand is an effective proton acceptor as the internal base of the cysteine thiolate ligand in [Fe]-hydrogenase. The electrochemical properties of complexes 3, 4 were investigated by cyclic voltammograms. Complex 3 catalyzed the transfer hydrogenation of benzoquinone to hydroquinone effectively under mild conditions.展开更多
A robust voltammetric method has been developed and validated for the determination of Fe（Ⅱ） and Fe（Ⅲ） in pharmaceutical iron polysaccharidic complexes. Undesirable low molecular weight iron complexes, at concen...A robust voltammetric method has been developed and validated for the determination of Fe（Ⅱ） and Fe（Ⅲ） in pharmaceutical iron polysaccharidic complexes. Undesirable low molecular weight iron complexes, at concentration about 3% in the pharmaceutical formulation, can be easily determined with good accuracy and precision. This methodology can be proposed as a viable, environmentally sustainable substitute for the conventional Normal Pulse Polarographic method in US Pharmacopeia, with better analytical figures of merit, and reduced Hg consumption. A deeper insight in Fe（Ⅱ） and Fe（Ⅲ） composition can be gained by the combined use of a new potentiometric technique after chemical decomposition of the complex.展开更多
The cerium iron complex oxides oxygen carrier was prepared by the co-precipitation method. The reactions between methane and lattice oxygen from the complex oxides were investigated in a fixed micro-reactor system. Th...The cerium iron complex oxides oxygen carrier was prepared by the co-precipitation method. The reactions between methane and lattice oxygen from the complex oxides were investigated in a fixed micro-reactor system. The reduced oxygen carder could be re-oxidized by air and its initial state could be restored. The characterizations of the oxygen carders were studied using XRD, O2-TPD, and H2-TPR. The results showed that the bulk lattice oxygen of CeO2-Fe2O3 was found to be suitable for the partial oxidation of methane to synthesis gas. There were two kinds of oxygen species on the oxygen carrier： the stronger oxygen species that was responsible for the complete oxidation of methane, and the weaker oxygen species （bulk lattice oxygen） that was responsible for the selective oxidation of methane to CO and H2 at a higher temperature. Then, the lost bulk lattice oxygen could be selectively supplemented by air re-oxidation at an appropriate reaction condition. CeFeO3 appeared on the oxygen carrier after 10 successive redox cycles, however, it was not bad for the selectivity of CO and H2.展开更多
The kinetics of isothermal reduction of the carbon bearing pellets, which were mainly composed of Bayanobo complex iron ore and pulverized coal, was investigated by thermogravimetry at the temperature of 1 273-1 673 K...The kinetics of isothermal reduction of the carbon bearing pellets, which were mainly composed of Bayanobo complex iron ore and pulverized coal, was investigated by thermogravimetry at the temperature of 1 273-1 673 K. The effects of xC/xO and the atmospheres on the extent of reduction also were investigated. The results indicate that the fractional reaction increased proportionally with temperature increasing and heating temperature is the significant influence factor to the reaction of carbon bearing pellets. The optimum xC/xO is 1.2 and the effect of atmosphere on the reduction of iron oxides is almost negligible. The results can be interpreted that the reaction was initially controlled by a mixed controlled mechanism of carbon gasification and interface chemical reaction, and in the later stage, interface chemical reaction became the rate-controlling step. Apparent activation energy values of reduction at different levels of fractional reaction were calculated. Before F （fraction of reaction）=0.5, the apparent activation energy ranges from 66.39 to 75.64 kJ/mol, while after F=0.5, the apparent activation energy is 80.98 to 85.37 kJ/mol.展开更多
Two types of small iron clusters supported on γ-Al2O3-RT（dehydroxylated at room temperature） and γ-Al2O3-800 （dehydroxylated at 800 ℃） were prepared by solvated metal atom impregnation （SMAI） techniques. The ...Two types of small iron clusters supported on γ-Al2O3-RT（dehydroxylated at room temperature） and γ-Al2O3-800 （dehydroxylated at 800 ℃） were prepared by solvated metal atom impregnation （SMAI） techniques. The iron atom precursor complex, bis（toluene）iron（0） formed in the metal atom reactor, was impregnated into γ-Al2O3 having different concentrations of surface hydroxyl groups to study the effect of surface hydroxylation on the crucial stage of iron cluster formation. Catalysts prepared in this way were characterized by TEM, Mǒssbauer, and chemisorption measurements, and the results show that higher concentration of surface hydroxyl groups of γ-Al2O3-RT favors the formation of more positively charged supported iron cluster Fen/γ-Al2O3-RT, and the lower concentration of surface hydroxyl groups of γ-Al2O3-800 favors the formation of basically neutral supported iron cluster Fen/γ-Al2O3-800. The measured results also indicate that the higher concentration of surface hydroxyl groups causes the rapid decomposition of precursor complex, bis（toluene）iron（0）, and favors the formation of relatively large iron cluster. Consequently, these two types of catalysts show different catalytic properties in Fischer-Tropsch reaction. The catalytic pattern of Fen/γ-Al2O3-RT in F-T reaction is similar to that of the unreduced γ-Fe2O3 and that of Fen/γ-Al2O3-800 is similar to that of the reduced α-Fe2O3.展开更多
A series of pyrazolylimine ligated Co(II) and Fe(II) complexes with general formula of(PhC=N(C_6H_3(R_1)2-2,6)(C_3 HN_2(R_2)2-3,5)MtCl_2(R_1 = Me, R_2 = H, Mt = Co(1 a), Fe(2 a); R_1 = Me, R_2 = Me, Mt = Co(1b), Fe(2b...A series of pyrazolylimine ligated Co(II) and Fe(II) complexes with general formula of(PhC=N(C_6H_3(R_1)2-2,6)(C_3 HN_2(R_2)2-3,5)MtCl_2(R_1 = Me, R_2 = H, Mt = Co(1 a), Fe(2 a); R_1 = Me, R_2 = Me, Mt = Co(1b), Fe(2b); R_1 = iPr, R_2 = H, Mt = Co(1 c), Fe(2 c); R_1 = i Pr, R_2 = Me, Mt = Co(1 d), Fe(2 d); R_1 = i Pr, R_2 = Ph, Mt = Co(1 e), Fe(2 e)) were synthesized and thoroughly characterized.Determined by single crystal X-ray diffraction, complexes 1 b and 2 b revealed dimeric structures, in which distorted trigonal bipyramid geometries were adopted for each metal centers. In the presence of ethylaluminum sesquichloride(EASC), all the cobalt complexes displayed high activities in 1,3-butadiene polymerization, affording polybutadienes with predominant cis-1,4 contents(up to 97.0%).Influences of ligand structure and polymerization parameters on catalytic performance were investigated systematically. For pyrazolylimine iron(II) dichloride complexes, the catalytic activities and microstructures of the resultant polybutadienes were highly dependent on ligand structures and polymerization conditions. For complex 2 a, changing cocatalyst from trialkyl aluminums to methyl aluminoxane(MAO) led to an shift of selectivity from high cis-1,4-to trans-1,4-/1,2-manner. Being activated by MAO, complexes 2 a and 2 b gave trans-1,4-/1,2-binary polybutadienes, while complexes 2 c, 2 d, and 2 e afforded cis-1,4-enriched polymers.展开更多
Marine sediment microbial fuel cell(MSMFCs)can be utilized as a long lasting power source to drive small instruments to work for long time on ocean floor and its higher power has a significant meaning for practical ap...Marine sediment microbial fuel cell(MSMFCs)can be utilized as a long lasting power source to drive small instruments to work for long time on ocean floor and its higher power has a significant meaning for practical application.Anode modification can greatly improve the performance of MSMFCs.Herein,humic acid(HA)and humic acid-iron ion complex(HA-Fe)were used to modify the anode for constructing a better MSMFCs.The results indicated that HA-Fe modified anode,better than HA modification,significantly improved the MSMFCs cell power output.The maximum power density of HA-Fe modified MSMFCs is 165.3 mW m−2,which are 6.5-folds of blank MSMFCs.The number of microorganisms on anode,redox activity,and relative kinetic activity were 1.8-,6.1-,and 13.1-folds of blank MSMFCs,respectively.The MSMFCs improvement would be attributed to the electron transfer media of HA and the valence conversion of Fe ions.A synergistic interaction between the naturally occurring HA and Fe ions on the anodic surface in marine sediments would make the modified anodes have‘renewable’characteristics,which is beneficial for the MSMFCs to maintain its long-term higher power.展开更多
Styrene-acrylic acid copolymer (SAAC)-supported iron complex (SAAC·Fe)was characterized and the effect of the characteristic parameters on the catalytic activity of the complex was investigated. IR spectrum sugge...Styrene-acrylic acid copolymer (SAAC)-supported iron complex (SAAC·Fe)was characterized and the effect of the characteristic parameters on the catalytic activity of the complex was investigated. IR spectrum suggested that the complex SAAC·Fe possesses a structure of(C)and the Fe-O bond is higher in covalency.The complex SAAC·Fe with the structure of(C)shoved a higher catalytic activity in butadiene polymerization. When Fe/-COOH molar ratio in SAAC·Fe was about 0.2 the complex gave optimum catalytic activity. The catalytic activity of SAAC·Fe with the higher content of long sequence of acrylic acid units was low. When the content of the short sequence of acrylic acid units was predominant and at the same time the content of the short sequence was approximately equal to that of the long sequence for stryrene, the activity of the complex was high.展开更多
A molybdenum（V） phosphate supported by iron coordination complexes, Fe[Mo6O12（OH）3（H2PO4）（HPO4）2（PO4）]2[Fe（2,2′-bipy）（H2O）2]2[Fe（2,2′-bipy）3]2·6H2O （bipy = 2,2′-bipyridine） 1, has been synthe...A molybdenum（V） phosphate supported by iron coordination complexes, Fe[Mo6O12（OH）3（H2PO4）（HPO4）2（PO4）]2[Fe（2,2′-bipy）（H2O）2]2[Fe（2,2′-bipy）3]2·6H2O （bipy = 2,2′-bipyridine） 1, has been synthesized by hydrothermal synthesis and characterized. The title complex crystallizes in the monoclinic system, space group P21/c with a = 14.0005（8）, b = 25.5229（12）, c = 17.9956（9） A, β = 103.470（2）°, V= 6253.5（6） A^3, Z= 2, Mr = 4114.03, Dc = 2.185 g/cm^3, F（000） = 4040, μ = 1.931 mm^-1, R = 0.0438 and wR = 0. 1168. The structure of the title polyoxometalate anion is based on a centrosymmetrical cluster Fe[Mo6O2（OH）3（H2PO4）（HPO4）2（PO4）]2 supported by two [Fe（2,2′-bipy）（H2O）2] subunits. The 2D network is formed through intermolecular hydrogen bonds.展开更多
The crystal of complex [Li(THF)4][Fe(S2C2B10H10)2(THF)] 3 belongs to monoclinic, space group P21 with a = 11.964(2), b = 16.527(3), c = 12.554(3) ? = 108.70(3)? V = 2351.3(8) 3, Z = 2, Mr = 835.95, Dc = 1.181 g/cm3, ...The crystal of complex [Li(THF)4][Fe(S2C2B10H10)2(THF)] 3 belongs to monoclinic, space group P21 with a = 11.964(2), b = 16.527(3), c = 12.554(3) ? = 108.70(3)? V = 2351.3(8) 3, Z = 2, Mr = 835.95, Dc = 1.181 g/cm3, (MoK? = 5.30 cm1, F(000) = 874, R = 0.0622 and Rw = 0.1538 for 1641 observed reflections with I > 2(I). The ionic complex of 3 contains the square pyramidal anion of [Fe(S2C2B10H10)2(THF)] and the tetrahedral cation of [Li(THF)4]+. The iron is 5-coordinated and located in the square pyramidal configuration. The iron atom and the four sulfur atoms are almost coplanar. The Lithium atom is coordinated with four oxygen atoms of four THF molecules and located in a tetrahedral configuration.展开更多
The phosphorus（P） fraction distribution and formation mechanism in the supernatant after P adsorption onto iron oxides and iron oxide-humic acid（HA） complexes were analyzed using the ultrafiltration method in this...The phosphorus（P） fraction distribution and formation mechanism in the supernatant after P adsorption onto iron oxides and iron oxide-humic acid（HA） complexes were analyzed using the ultrafiltration method in this study.With an initial P concentration of 20 mg/L（I =0.01 mol/L and pH = 7）,it was shown that the colloid（1 kDa-0.45 μm） component of P accounted for 10.6%,11.6%,6.5%,and 4.0%of remaining total P concentration in the supernatant after P adsorption onto ferrihydrite（FH）,goethite（GE）,ferrihydrite-humic acid complex（FH-HA）,goethite-humic acid complex（GE-HA）,respectively.The 〈1 kDa component of P was still the predominant fraction in the supernatant,and underestimated colloidal P accounted for 2.2%,55.1%,45.5%,and 38.7%of P adsorption onto the solid surface of FH,FH-HA,GE and GE-HA,respectively.Thus,the colloid P could not be neglected.Notably,it could be interpreted that Fe3＋ hydrolysis from the adsorbents followed by the formation of colloidal hydrous ferric oxide aggregates was the main mechanism for the formation of the colloid P in the supernatant.And colloidal adsorbent particles co-existing in the supernatant were another important reason for it.Additionally,dissolve organic matter dissolved from iron oxide-HA complexes could occupy large adsorption sites of colloidal iron causing less colloid P in the supernatant.Ultimately,we believe that the findings can provide a new way to deeply interpret the geochemical cycling of P,even when considering other contaminants such as organic pollutants,heavy metal ions,and arsenate at the sediment/soil-water interface in the real environment.展开更多
An iron（Ⅱ） coordination polymer, [Fe（Haip）2（H2O）2]n （1, Haip = 5-ammoniumiso- phthalato）, has been hydro/solvothermally synthesized and characterized by single-crystal X-ray diffraction, elemental analysis, i...An iron（Ⅱ） coordination polymer, [Fe（Haip）2（H2O）2]n （1, Haip = 5-ammoniumiso- phthalato）, has been hydro/solvothermally synthesized and characterized by single-crystal X-ray diffraction, elemental analysis, infrared spectrum and magnetic measurement. Compound 1 crystalizes in monoclinic, space group P2/c with a = 6.9874（14）, b = 9.960（2）, c = 12.894（4） A, β = 117.47（2）°, Fe（C8H6NO4）2（H2O）2, Mr = 452.16, V= 796.2（3） A3, Z = 2, Dc = 1.886 g.cm-3, p = 1.017 mm-1, F（000） = 464.0, 2.71〈0〈28.42°, R = 0.0307, wR = 0.0840 and S = 1.005. Single-crystal X-ray diffraction analysis reveals that 1 features an infinite one-dimensional loop-like chain structure and Haip ligand in 1 is of zwitterionic form. Magnetic measurement results show the dominated ferromagnetic interactions among Fe11 atoms.展开更多
A method of size exclusion chromatography coupled with ultraviolet spectrophotometry and off-line graphite furnace atomic absorption spectrometry was developed to assess the complexation properties of iron（Fe） and h...A method of size exclusion chromatography coupled with ultraviolet spectrophotometry and off-line graphite furnace atomic absorption spectrometry was developed to assess the complexation properties of iron（Fe） and humic acid（HA） in a water environment. The factors affecting the complexation of Fe and HA, such as ionic strength, pH, temperature and UV radiation, were investigated. The Fe–HA complex residence time was also studied. Experimental results showed that pH could influence the deprotonation of HA and hydrolysis of Fe, and thus affected the complexation of Fe and HA. The complexation was greatly disrupted by the presence of NaCl. Temperature had some influence on the complexation. The yield of Fe–HA complexes showed a small decrease at high levels of UV radiation, but the effect of UV radiation on Fe–HA complex formation at natural levels could be neglected. It took about 10 hr for the complexation to reach equilibrium, and the Fe–HA complex residence time was about 20 hr.Complexation of Fe and HA reached a maximum level under the conditions of pH 6, very low ionic strength, in the dark and at a water temperature of about 25°C, for 10 hr. It was suggested that the Fe–HA complex could form mainly in freshwater bodies and reach high levels in the warm season with mild sunlight radiation. With changing environmental parameters, such as at lower temperature in winter or higher pH and ionic strength in an estuary, the concentration of the Fe–HA complex would decrease.展开更多
A new dinuclear iron（Ill） complex has been synthesized and structurally charac- terized by X-ray crystallography： [Fem2（L）（C6HsCOO）（SO4）（CH3OH）2]·CH3CN＇CH3OH （1, H3L = N,N＇-bis（salicylidene）q,3-di...A new dinuclear iron（Ill） complex has been synthesized and structurally charac- terized by X-ray crystallography： [Fem2（L）（C6HsCOO）（SO4）（CH3OH）2]·CH3CN＇CH3OH （1, H3L = N,N＇-bis（salicylidene）q,3-diamino-2-propanol）. Complex 1 belongs to orthorhombic space group Pna21 with a= 11.4400（8）, b = 22.9705（2）, c = 12.5712（9）A, V= 3303.5（4）A3, Z= 4, F（000） = 1576, Dc= 1.531 g·cm-3, Mr= 761.36,μ = 1.007 mm-1, S = 1.014, the final R= 0.0505 and wR= 0.1018. The crystal packing is stabilized by intermolecular O-H…O hydrogen bonds, forming an extended one-dimensional chain structure. The temperature dependence of magnetic susceptibility measurement shows that antiferromagnetic interaction is propagated between the metal centers. Fit as dinuclear arrangement gave parameters ofJ= 19.7 cm-1, g = 1.89 and R2 = 0.9999.展开更多
Halfsandwich iron dicarbonyl complex [η 5-C5H3（t-Bu）2]Fe（CO）2Cl（1） reacts with 1, 2-dilithium diseleno carborane Li2Se2C2B 10H 10（2） to give a binuclear iron carborane complex [η 5-C5H3（t-Bu）2]2Fe2（CO）3&...Halfsandwich iron dicarbonyl complex [η 5-C5H3（t-Bu）2]Fe（CO）2Cl（1） reacts with 1, 2-dilithium diseleno carborane Li2Se2C2B 10H 10（2） to give a binuclear iron carborane complex [η 5-C5H3（t-Bu）2]2Fe2（CO）3·Se2C2B 10H 10（3）. The X-ray diffraction analysis of complex 3 reveals that one of the iron atoms is chiral.展开更多
基金supported by the National Natural Science Foundation of China(Nos.42207450,42067056,and 21866017)the Yunnan Fundamental Research Projects(No.202101BE070001-013)the Foundation for Distinguished Young Talents of Yunnan Province(No.202101AV070006).
文摘Dissolved black carbon(DBC)plays a crucial role in the migration and bioavailability of iron in water.However,the properties of DBC releasing under diverse pyrolysis conditions and dissolving processes have not been systematically studied.Here,the compositions of DBC released from biochar through redox processes dominated by bacteria and light were thoroughly studied.It was found that the DBC released from straw biochar possess more oxygen-containing functional groups and aromatic substances.The content of phenolic and carboxylic groups in DBC was increased under influence of microorganisms and light,respectively.The concentration of phenolic hydroxyl groups increased from 10.0~57.5 mmol/gC to 6.6~65.2 mmol/gC,and the concentration of carboxyl groups increased from49.7~97.5 mmol/gC to 62.1~113.3 mmol/gC.Then the impacts of DBC on pyrite dissolution andmicroalgae growth were also investigated.The complexing Fe^(3+)was proved to play a predominant role in the dissolution of ferrous mineral in DBC solution.Due to complexing between iron ion and DBC,the amount of dissolved Fe in aquatic water may rise as a result of elevated number of aromatic components with oxygen containing groups and low molecular weight generated under light conditions.Fe-DBC complexations in solution significantly promoted microalga growth,which might be attributed to the stimulating effect of dissolved Fe on the chlorophyll synthesis.The results of study will deepen our understanding of the behavior and ultimate destiny of DBC released into an iron-rich environment under redox conditions.
文摘This paper reports the preparation of three di‑iron complexes containing a thiazole moiety.Esterification of complex[Fe_(2)(CO)_(6)(μ‑SCH_(2)CH(CH_(2)OH)S)](1)with 4‑methylthiazole‑5‑carboxylic acid gave the corresponding ester[Fe_(2)(CO)_(6)(μ‑tedt)](2),where tedt=SCH_(2)CH(CH_(2)OOC(5‑C_(3)HNSCH_(3)))S.Further reactions of complex 2 with tri(ptolyl)phosphine(tp)or tris(4‑fluorophenyl)phosphine(fp)gave the phosphine‑substituted derivatives[Fe_(2)(CO)_(5)(tp)(μ‑tedt)](3)and[Fe_(2)(CO)_(5)(fp)(μ‑tedt)](4).The structures of the newly prepared complexes were elucidated by elemental analysis,NMR,IR,and X‑ray photoelectron spectroscopy.Moreover,single‑crystal X‑ray diffraction analysis confirmed their molecular structures,showing that they contain a di‑iron core ligated by a bridged dithiolate bearing a thiazole moiety and terminal carbonyls.The electrochemical and electrocatalytic proton reduction were probed by cyclic voltammetry,revealing that three complexes can catalyze the reduction of protons to H_(2) under the electrochemical conditions.For comparison,complex 4 possessed the best efficiency with a turnover frequency of 23.5 s^(-1)at 10 mmol·L^(-1)HOAc concentration.In addition,the fungicidal activity of these complexes was also investigated in this study.CCDC:2477511,2;2477512,3;2477513,4.
文摘Iron deficiency anemia affects approximately 1.62 billion people worldwide,yet traditional iron supplements present bioavailability limitations and gastrointestinal side effects.This randomized,double-blind clinical trial investigated a novel Auricularia auricula polysaccharide-iron complex(AAPIC)compared with heme iron and ferrous glycinate in 180 iron-deficient adults receiving 30 mg elemental iron daily for 12 weeks.AAPIC achieved comparable hemoglobin improvements(from 98.3±8.7 to 126.5±9.2 g/L)to heme iron(from 97.8±9.1 to 128.3±8.6 g/L)and was significantly superior to ferrous glycinate(from 98.6±8.9 to 119.7±10.3 g/L;p<0.001).Iron absorption efficiency showed AAPIC at 23.7±4.2%,heme iron at 25.1±3.8%,and ferrous glycinate at 18.4±5.1%.Toxicological assessments revealed no hepatotoxicity,nephrotoxicity,or mutagenicity.Gastrointestinal adverse events occurred in 8.3%of AAPIC recipients versus 15.0%with ferrous glycinate and 10.0%with heme iron.The polysaccharide component facilitates iron transport through enhanced intestinal uptake mechanisms.AAPIC represents a promising,well-tolerated alternative with clinical efficacy comparable to established iron formulations.
文摘Leveraging the modularity and efficiency of click chemistry,a series of chiral diamine-triazole tetradentate nitrogen donor ligands and their corresponding nonheme iron complexes were synthesized.These iron-based catalysts demonstrated excellent catalytic activity and enantioselectivity in the asymmetric epoxidation of electron-deficient olefins using H_(2)O_(2) as the terminal oxidant.
文摘The methylene-selective oxidation of simple alkanes catalyzed by a nonheme iron(Ⅲ)-monoamidate complex using H_(2)O_(2)as the terminal oxidant is reported.Mechanistic studies suggest that iron(V)-oxo species is the active intermediate,undergoing hydrogen atom abstraction(HAA)as the rate-determining step to initiate C-H bond activation.
基金supported by the National Natural Science Foundation of China(21103121,21276187)Tianjin Municipal Natural Science Foundation(13JCQNJC05800)the Specialized Research Fund for the Doctoral Program of Higher Education(20121317110009)~~
文摘Two mono iron complexes Fe（CO）2PR3（NN） （R = Cy （3）, Ph （4）, NN = o-phenylenediamine dianion ligand, N2H2Ph2-） derived from the ligand substitution of Fe（CO）3hPR3 by the NN ligand were isolated and structurally characterized by single crystal X-ray diffraction. They have a similar first coordination sphere and oxidation state of the iron center as the [Fe]-hydrogenase active site, and can be a model of it IR demonstrated that the effect of the NN ligand on the coordinated CO stretch- ing frequencies was due to its excellent electron donating ability. The reversible protonation/deprotonation of the NN ligand was identified by infrared spectroscopy and density functional theory computation. The NN ligand is an effective proton acceptor as the internal base of the cysteine thiolate ligand in [Fe]-hydrogenase. The electrochemical properties of complexes 3, 4 were investigated by cyclic voltammograms. Complex 3 catalyzed the transfer hydrogenation of benzoquinone to hydroquinone effectively under mild conditions.
基金supported by FAR, Fondo Ateneoper la Ricerca Universitá di Pavia,Italy
文摘A robust voltammetric method has been developed and validated for the determination of Fe（Ⅱ） and Fe（Ⅲ） in pharmaceutical iron polysaccharidic complexes. Undesirable low molecular weight iron complexes, at concentration about 3% in the pharmaceutical formulation, can be easily determined with good accuracy and precision. This methodology can be proposed as a viable, environmentally sustainable substitute for the conventional Normal Pulse Polarographic method in US Pharmacopeia, with better analytical figures of merit, and reduced Hg consumption. A deeper insight in Fe（Ⅱ） and Fe（Ⅲ） composition can be gained by the combined use of a new potentiometric technique after chemical decomposition of the complex.
基金the National Natural Science Foundation of China (50574046)National Natural Science Foundation of Major Research Projects (90610035)+1 种基金Natural Science Foundation of Yunnan Province (2004E0058Q)High School Doctoral Subject Special Science and Research Foundation of Ministry of Education (20040674005)
文摘The cerium iron complex oxides oxygen carrier was prepared by the co-precipitation method. The reactions between methane and lattice oxygen from the complex oxides were investigated in a fixed micro-reactor system. The reduced oxygen carder could be re-oxidized by air and its initial state could be restored. The characterizations of the oxygen carders were studied using XRD, O2-TPD, and H2-TPR. The results showed that the bulk lattice oxygen of CeO2-Fe2O3 was found to be suitable for the partial oxidation of methane to synthesis gas. There were two kinds of oxygen species on the oxygen carrier： the stronger oxygen species that was responsible for the complete oxidation of methane, and the weaker oxygen species （bulk lattice oxygen） that was responsible for the selective oxidation of methane to CO and H2 at a higher temperature. Then, the lost bulk lattice oxygen could be selectively supplemented by air re-oxidation at an appropriate reaction condition. CeFeO3 appeared on the oxygen carrier after 10 successive redox cycles, however, it was not bad for the selectivity of CO and H2.
基金Sponsored by National Key Technology Research and Development Program of China(2008BAB32B05)Postdoctoral Science Foundation of China(2012m510320)
文摘The kinetics of isothermal reduction of the carbon bearing pellets, which were mainly composed of Bayanobo complex iron ore and pulverized coal, was investigated by thermogravimetry at the temperature of 1 273-1 673 K. The effects of xC/xO and the atmospheres on the extent of reduction also were investigated. The results indicate that the fractional reaction increased proportionally with temperature increasing and heating temperature is the significant influence factor to the reaction of carbon bearing pellets. The optimum xC/xO is 1.2 and the effect of atmosphere on the reduction of iron oxides is almost negligible. The results can be interpreted that the reaction was initially controlled by a mixed controlled mechanism of carbon gasification and interface chemical reaction, and in the later stage, interface chemical reaction became the rate-controlling step. Apparent activation energy values of reduction at different levels of fractional reaction were calculated. Before F （fraction of reaction）=0.5, the apparent activation energy ranges from 66.39 to 75.64 kJ/mol, while after F=0.5, the apparent activation energy is 80.98 to 85.37 kJ/mol.
文摘Two types of small iron clusters supported on γ-Al2O3-RT（dehydroxylated at room temperature） and γ-Al2O3-800 （dehydroxylated at 800 ℃） were prepared by solvated metal atom impregnation （SMAI） techniques. The iron atom precursor complex, bis（toluene）iron（0） formed in the metal atom reactor, was impregnated into γ-Al2O3 having different concentrations of surface hydroxyl groups to study the effect of surface hydroxylation on the crucial stage of iron cluster formation. Catalysts prepared in this way were characterized by TEM, Mǒssbauer, and chemisorption measurements, and the results show that higher concentration of surface hydroxyl groups of γ-Al2O3-RT favors the formation of more positively charged supported iron cluster Fen/γ-Al2O3-RT, and the lower concentration of surface hydroxyl groups of γ-Al2O3-800 favors the formation of basically neutral supported iron cluster Fen/γ-Al2O3-800. The measured results also indicate that the higher concentration of surface hydroxyl groups causes the rapid decomposition of precursor complex, bis（toluene）iron（0）, and favors the formation of relatively large iron cluster. Consequently, these two types of catalysts show different catalytic properties in Fischer-Tropsch reaction. The catalytic pattern of Fen/γ-Al2O3-RT in F-T reaction is similar to that of the unreduced γ-Fe2O3 and that of Fen/γ-Al2O3-800 is similar to that of the reduced α-Fe2O3.
基金financially supported by the National Basic Research Program of China(No.2015CB654700(2015CB654702))the National Natural Science Foundation of China(No.21801236)
文摘A series of pyrazolylimine ligated Co(II) and Fe(II) complexes with general formula of(PhC=N(C_6H_3(R_1)2-2,6)(C_3 HN_2(R_2)2-3,5)MtCl_2(R_1 = Me, R_2 = H, Mt = Co(1 a), Fe(2 a); R_1 = Me, R_2 = Me, Mt = Co(1b), Fe(2b); R_1 = iPr, R_2 = H, Mt = Co(1 c), Fe(2 c); R_1 = i Pr, R_2 = Me, Mt = Co(1 d), Fe(2 d); R_1 = i Pr, R_2 = Ph, Mt = Co(1 e), Fe(2 e)) were synthesized and thoroughly characterized.Determined by single crystal X-ray diffraction, complexes 1 b and 2 b revealed dimeric structures, in which distorted trigonal bipyramid geometries were adopted for each metal centers. In the presence of ethylaluminum sesquichloride(EASC), all the cobalt complexes displayed high activities in 1,3-butadiene polymerization, affording polybutadienes with predominant cis-1,4 contents(up to 97.0%).Influences of ligand structure and polymerization parameters on catalytic performance were investigated systematically. For pyrazolylimine iron(II) dichloride complexes, the catalytic activities and microstructures of the resultant polybutadienes were highly dependent on ligand structures and polymerization conditions. For complex 2 a, changing cocatalyst from trialkyl aluminums to methyl aluminoxane(MAO) led to an shift of selectivity from high cis-1,4-to trans-1,4-/1,2-manner. Being activated by MAO, complexes 2 a and 2 b gave trans-1,4-/1,2-binary polybutadienes, while complexes 2 c, 2 d, and 2 e afforded cis-1,4-enriched polymers.
基金supported by the National Natural Science Foundation of China(No.22075262).
文摘Marine sediment microbial fuel cell(MSMFCs)can be utilized as a long lasting power source to drive small instruments to work for long time on ocean floor and its higher power has a significant meaning for practical application.Anode modification can greatly improve the performance of MSMFCs.Herein,humic acid(HA)and humic acid-iron ion complex(HA-Fe)were used to modify the anode for constructing a better MSMFCs.The results indicated that HA-Fe modified anode,better than HA modification,significantly improved the MSMFCs cell power output.The maximum power density of HA-Fe modified MSMFCs is 165.3 mW m−2,which are 6.5-folds of blank MSMFCs.The number of microorganisms on anode,redox activity,and relative kinetic activity were 1.8-,6.1-,and 13.1-folds of blank MSMFCs,respectively.The MSMFCs improvement would be attributed to the electron transfer media of HA and the valence conversion of Fe ions.A synergistic interaction between the naturally occurring HA and Fe ions on the anodic surface in marine sediments would make the modified anodes have‘renewable’characteristics,which is beneficial for the MSMFCs to maintain its long-term higher power.
文摘Styrene-acrylic acid copolymer (SAAC)-supported iron complex (SAAC·Fe)was characterized and the effect of the characteristic parameters on the catalytic activity of the complex was investigated. IR spectrum suggested that the complex SAAC·Fe possesses a structure of(C)and the Fe-O bond is higher in covalency.The complex SAAC·Fe with the structure of(C)shoved a higher catalytic activity in butadiene polymerization. When Fe/-COOH molar ratio in SAAC·Fe was about 0.2 the complex gave optimum catalytic activity. The catalytic activity of SAAC·Fe with the higher content of long sequence of acrylic acid units was low. When the content of the short sequence of acrylic acid units was predominant and at the same time the content of the short sequence was approximately equal to that of the long sequence for stryrene, the activity of the complex was high.
基金This work was supported by the National Natural Science Foundation of China (20431010, 20171012) and Natural Science Foundation of Fujian Province (E0110010)
文摘A molybdenum（V） phosphate supported by iron coordination complexes, Fe[Mo6O12（OH）3（H2PO4）（HPO4）2（PO4）]2[Fe（2,2′-bipy）（H2O）2]2[Fe（2,2′-bipy）3]2·6H2O （bipy = 2,2′-bipyridine） 1, has been synthesized by hydrothermal synthesis and characterized. The title complex crystallizes in the monoclinic system, space group P21/c with a = 14.0005（8）, b = 25.5229（12）, c = 17.9956（9） A, β = 103.470（2）°, V= 6253.5（6） A^3, Z= 2, Mr = 4114.03, Dc = 2.185 g/cm^3, F（000） = 4040, μ = 1.931 mm^-1, R = 0.0438 and wR = 0. 1168. The structure of the title polyoxometalate anion is based on a centrosymmetrical cluster Fe[Mo6O2（OH）3（H2PO4）（HPO4）2（PO4）]2 supported by two [Fe（2,2′-bipy）（H2O）2] subunits. The 2D network is formed through intermolecular hydrogen bonds.
基金Financially Supported by the National Natural Science Foundation of China (29974029, 29925101) and Special Funds for Major State Basic Research Projects of China (G1999064800)
文摘The crystal of complex [Li(THF)4][Fe(S2C2B10H10)2(THF)] 3 belongs to monoclinic, space group P21 with a = 11.964(2), b = 16.527(3), c = 12.554(3) ? = 108.70(3)? V = 2351.3(8) 3, Z = 2, Mr = 835.95, Dc = 1.181 g/cm3, (MoK? = 5.30 cm1, F(000) = 874, R = 0.0622 and Rw = 0.1538 for 1641 observed reflections with I > 2(I). The ionic complex of 3 contains the square pyramidal anion of [Fe(S2C2B10H10)2(THF)] and the tetrahedral cation of [Li(THF)4]+. The iron is 5-coordinated and located in the square pyramidal configuration. The iron atom and the four sulfur atoms are almost coplanar. The Lithium atom is coordinated with four oxygen atoms of four THF molecules and located in a tetrahedral configuration.
基金supported by the National Natural Science Foundation of China(nos.41171198,41403079)the Chongqing Research Program of Basic Research and Frontier Technology(no.cstc2015jcyj A20021)the Fundamental Research Funds for the Central Universities of Ministry of Education of China(no.XDJK2015B035)
文摘The phosphorus（P） fraction distribution and formation mechanism in the supernatant after P adsorption onto iron oxides and iron oxide-humic acid（HA） complexes were analyzed using the ultrafiltration method in this study.With an initial P concentration of 20 mg/L（I =0.01 mol/L and pH = 7）,it was shown that the colloid（1 kDa-0.45 μm） component of P accounted for 10.6%,11.6%,6.5%,and 4.0%of remaining total P concentration in the supernatant after P adsorption onto ferrihydrite（FH）,goethite（GE）,ferrihydrite-humic acid complex（FH-HA）,goethite-humic acid complex（GE-HA）,respectively.The 〈1 kDa component of P was still the predominant fraction in the supernatant,and underestimated colloidal P accounted for 2.2%,55.1%,45.5%,and 38.7%of P adsorption onto the solid surface of FH,FH-HA,GE and GE-HA,respectively.Thus,the colloid P could not be neglected.Notably,it could be interpreted that Fe3＋ hydrolysis from the adsorbents followed by the formation of colloidal hydrous ferric oxide aggregates was the main mechanism for the formation of the colloid P in the supernatant.And colloidal adsorbent particles co-existing in the supernatant were another important reason for it.Additionally,dissolve organic matter dissolved from iron oxide-HA complexes could occupy large adsorption sites of colloidal iron causing less colloid P in the supernatant.Ultimately,we believe that the findings can provide a new way to deeply interpret the geochemical cycling of P,even when considering other contaminants such as organic pollutants,heavy metal ions,and arsenate at the sediment/soil-water interface in the real environment.
基金supported by the Scientific Research Start-up Funds of Shangrao Normal Universitythe Fourth Characteristic Specialty Foundation of University from Ministry of Education(TS11524)the Natural Science Foundation of Jiangxi Province(No.20122BAB203002)
文摘An iron（Ⅱ） coordination polymer, [Fe（Haip）2（H2O）2]n （1, Haip = 5-ammoniumiso- phthalato）, has been hydro/solvothermally synthesized and characterized by single-crystal X-ray diffraction, elemental analysis, infrared spectrum and magnetic measurement. Compound 1 crystalizes in monoclinic, space group P2/c with a = 6.9874（14）, b = 9.960（2）, c = 12.894（4） A, β = 117.47（2）°, Fe（C8H6NO4）2（H2O）2, Mr = 452.16, V= 796.2（3） A3, Z = 2, Dc = 1.886 g.cm-3, p = 1.017 mm-1, F（000） = 464.0, 2.71〈0〈28.42°, R = 0.0307, wR = 0.0840 and S = 1.005. Single-crystal X-ray diffraction analysis reveals that 1 features an infinite one-dimensional loop-like chain structure and Haip ligand in 1 is of zwitterionic form. Magnetic measurement results show the dominated ferromagnetic interactions among Fe11 atoms.
基金supported by the National Natural Science Foundation of China (No. 41176075)
文摘A method of size exclusion chromatography coupled with ultraviolet spectrophotometry and off-line graphite furnace atomic absorption spectrometry was developed to assess the complexation properties of iron（Fe） and humic acid（HA） in a water environment. The factors affecting the complexation of Fe and HA, such as ionic strength, pH, temperature and UV radiation, were investigated. The Fe–HA complex residence time was also studied. Experimental results showed that pH could influence the deprotonation of HA and hydrolysis of Fe, and thus affected the complexation of Fe and HA. The complexation was greatly disrupted by the presence of NaCl. Temperature had some influence on the complexation. The yield of Fe–HA complexes showed a small decrease at high levels of UV radiation, but the effect of UV radiation on Fe–HA complex formation at natural levels could be neglected. It took about 10 hr for the complexation to reach equilibrium, and the Fe–HA complex residence time was about 20 hr.Complexation of Fe and HA reached a maximum level under the conditions of pH 6, very low ionic strength, in the dark and at a water temperature of about 25°C, for 10 hr. It was suggested that the Fe–HA complex could form mainly in freshwater bodies and reach high levels in the warm season with mild sunlight radiation. With changing environmental parameters, such as at lower temperature in winter or higher pH and ionic strength in an estuary, the concentration of the Fe–HA complex would decrease.
基金Supported by the Natural Science Foundation of Mongolian Autonomous Region,China(No.2014MS0215)
文摘A new dinuclear iron（Ill） complex has been synthesized and structurally charac- terized by X-ray crystallography： [Fem2（L）（C6HsCOO）（SO4）（CH3OH）2]·CH3CN＇CH3OH （1, H3L = N,N＇-bis（salicylidene）q,3-diamino-2-propanol）. Complex 1 belongs to orthorhombic space group Pna21 with a= 11.4400（8）, b = 22.9705（2）, c = 12.5712（9）A, V= 3303.5（4）A3, Z= 4, F（000） = 1576, Dc= 1.531 g·cm-3, Mr= 761.36,μ = 1.007 mm-1, S = 1.014, the final R= 0.0505 and wR= 0.1018. The crystal packing is stabilized by intermolecular O-H…O hydrogen bonds, forming an extended one-dimensional chain structure. The temperature dependence of magnetic susceptibility measurement shows that antiferromagnetic interaction is propagated between the metal centers. Fit as dinuclear arrangement gave parameters ofJ= 19.7 cm-1, g = 1.89 and R2 = 0.9999.
基金Supported by the National Natural Science Foundation of China( No.2 99740 2 9,2 992 5 10 1) and Special Funds forMajor State Basic Research Projects of China( G19990 64 80 0)
文摘Halfsandwich iron dicarbonyl complex [η 5-C5H3（t-Bu）2]Fe（CO）2Cl（1） reacts with 1, 2-dilithium diseleno carborane Li2Se2C2B 10H 10（2） to give a binuclear iron carborane complex [η 5-C5H3（t-Bu）2]2Fe2（CO）3·Se2C2B 10H 10（3）. The X-ray diffraction analysis of complex 3 reveals that one of the iron atoms is chiral.
