The reaction of 2-substituted imidazolinium salt with bis-Grignard reagents is reported and a new method for the synthesis of symmetric diketones from carboxylic acids and bis-Grignard reagents is provided.
In this study,the interaction between primary amine and diketones was investigated.Three diketones with a general structure of—(CH2C(O)CH2C(O))-X-R(X is C,O or N and R is H and/or alkyl groups)were selected to react ...In this study,the interaction between primary amine and diketones was investigated.Three diketones with a general structure of—(CH2C(O)CH2C(O))-X-R(X is C,O or N and R is H and/or alkyl groups)were selected to react with primary amine in aqueous solutions.The reaction was in-situ monitored by Raman technique and the reaction products were identified by FTIR,NMR and LC-MS.It is found that the reaction products strongly depend on the structures of diketones.When X is nitrogen,the expected Schiff base or its analog can be obtained.However,Schiff base or its analog is not detected if X is C or O,instead,ion pairs or hydrolysis products are formed accordingly,suggesting critical impacts of acidity of CH2 inβ-diketone on the product formation.This study also shows that in-situ Raman is a powerful technique for reaction monitoring and structure characterization,which is useful for mechanism understanding.展开更多
A new Ce^(3+)modified Dawson-like polyoxometalate cluster(C_(2)H_(8)N)_(12)Na_(2)[H_(10){Ce(H_(2)O)_(5)}_(2)(Te_(2)W_(37)O_(132))]·^(39)H_(2)O was synthesized using pH and temperature-controlled one-pot strategy....A new Ce^(3+)modified Dawson-like polyoxometalate cluster(C_(2)H_(8)N)_(12)Na_(2)[H_(10){Ce(H_(2)O)_(5)}_(2)(Te_(2)W_(37)O_(132))]·^(39)H_(2)O was synthesized using pH and temperature-controlled one-pot strategy.The compound was characterized by single-crystal X-ray structure analysis,IR spectroscopy,thermogravimetric(TG)analysis,X-ray photoelectron spectroscopy(XPS),and electrospray ionization mass spectrometry(ESI-MS).Singlecrystal X-ray structure analysis revealed that there was a new{Te_(2)W_(37)O_(132)}structure and two Ce^(3+)in this compound.Moreover,it is notable that this compound presents excellent Lewis acid-and Lewis base activities in the condensation cyclization of 1,3-diketones with hydrazines/hydrazides or diamines.All the desired products were obtained in moderate to good yields(up to 99%)and with a high turnover number(up to 4347).展开更多
A simple, efficient and eco-friendly route has been developed for the synthesis of fl-mercapto diketones via a multicomponent reaction of an aldehyde, acetylacetone and thiol in water. This methodology affords a numbe...A simple, efficient and eco-friendly route has been developed for the synthesis of fl-mercapto diketones via a multicomponent reaction of an aldehyde, acetylacetone and thiol in water. This methodology affords a number of β-mercapto diketone derivatives in moderate to good yields.展开更多
4-Acyl-β-lactams are important synthetic intermediates in both pharmaceutical and organic chemistry. Cis- and trans-4-acyl-β- lactams were synthesized stereoselectively from vicinal diketones via the formation of bu...4-Acyl-β-lactams are important synthetic intermediates in both pharmaceutical and organic chemistry. Cis- and trans-4-acyl-β- lactams were synthesized stereoselectively from vicinal diketones via the formation of bulky and less bulky diimines as key intermediates, respectively. The diimines reacted with acyl chloride in the presence of triethylamine to give rise to the corre- sponding 4-imino-β-lactams, which were further hydrolyzed to afford 4-acyl-β-lactams. The cis- and trans selectivity is de- pended on the steric hindrance of the imine N-substituents. A series of cis-4-acyl-β-lactams were synthesized from vicinal ketoaldehydes via the formation of their monoimines and diimines as intermediates. Pyruvic aldehyde produced cis-4-acetyl-β- lactams and cis-4-formyl-β-lactams, respectively, through the reactions of its monoimine and diimine with acyl chlorides. Phenylglyoxal generated cis-4-benzoyl-β-lactams via its monoaldimine.展开更多
Rate coefficients of the gas-phase reactions of Cl atoms with a series of fluorinated diketones(FDKs):CF_(3)C(O)CH_(2)C(O)CH_(3)(TFP),CF_(3)C(O)CH_(2)C(O)CH_(2)CH_(3)(TFH)and CF_(3)C(O)CH_(2)C(O)CH(CH_(3))2(TFMH),have...Rate coefficients of the gas-phase reactions of Cl atoms with a series of fluorinated diketones(FDKs):CF_(3)C(O)CH_(2)C(O)CH_(3)(TFP),CF_(3)C(O)CH_(2)C(O)CH_(2)CH_(3)(TFH)and CF_(3)C(O)CH_(2)C(O)CH(CH_(3))2(TFMH),have been measured at(298±2)K and under atmospheric pressure.The experiments were performed using the relative-rate method with a GC-FID detection system.From different determinations and references used,the following rate coefficients were obtained(in cm3/(molecule·sec)):k_(4)(TFP+Cl)=(1.75±0.21)×10^(−10),k_(5)(TFH+Cl)=(2.05±0.23)×10^(−10),k_(6)(TFMH+Cl)=(2.71±0.34)×10^(−10).Reactivity trends of FDKs were discussed and Free Energy Relationships analysis was developed.The expression lgkOH=1.68 lgkCl+5.71 was obtained for the reactivity of the studied FDKs together with similar unsaturated VOCs with Cl and OH radicals Additionally,acetic acid(CH_(3)C(O)OH)and trifluoroacetic acid(CF_(3)C(O)OH)were positively identified and quantified as degradation products using in situ FTIR spectroscopy.According to the identified products,atmospheric chemical mechanisms were proposed.The atmospheric implications of the studied reactions were assessed by the estimation of the tropospheric lifetimes of TFP,TFH,and TFMH concerning their reaction with Cl atoms to be 48,41,and 31 hours,respectively.The relatively short residence in the atmosphere of the fluorocarbons studied will have a local/regional impact with restricted transport.Global warming potential(GWP(20 yr))calculated for the studied fluoro diketones were 0.014,0.003 and 0.001 for TFP,TFH and TFMH,respectively with a negligible contribution to the greenhouse effect.展开更多
Two new ternary complexes of 1-（2-thienyl）-3-（p-phenylethynylphenyl）-1,3-propanedione（HTPP） and 1,10-phenanthroline（phen） with Sm^3＋ and Dy^3＋ were synthesized.The composition of the ternary complexes was ch...Two new ternary complexes of 1-（2-thienyl）-3-（p-phenylethynylphenyl）-1,3-propanedione（HTPP） and 1,10-phenanthroline（phen） with Sm^3＋ and Dy^3＋ were synthesized.The composition of the ternary complexes was characterized as Sm（TPP）3phen and Dy（TPP）3phen,respectively,by infrared（IR） spectra,chemical analysis,elemental analysis,and thermodynamic analysis.At room temperature,under UV light excitation,the Sm^3＋ and Dy^3＋ complexes exhibit characteristic emissions of the central ions.It is found that the fluorescence intensity of Sm（TPP）3phen is stronger than that of Dy（TPP）3phen.In order to explain this phenomenon,an accurate quantum chemistry calculation was carried out,and the result is in good agreement with the experiment data.展开更多
The title compound of PhCH_3C_3HN_2 (O )C (O) (CH_2) _3C [N (CH_2 )_4 NH_2]C_3HN_2 (O)CH_3Ph (L), a new Schiff-base containing diketone, has been synthesized. Its crystal structure has been determined by X-ray diffrac...The title compound of PhCH_3C_3HN_2 (O )C (O) (CH_2) _3C [N (CH_2 )_4 NH_2]C_3HN_2 (O)CH_3Ph (L), a new Schiff-base containing diketone, has been synthesized. Its crystal structure has been determined by X-ray diffraction analysis. The crystal, C_(30)H_(41)N_6O_(5.5) (L·0. 5C_2H_5OH·2H_2O) , is triclinic, space group P1 ,a=11.544 (1) , b=11. 723(5) , c=12. 344(2) A , a=80. 61(2) . β=84. 17(1) ,γ=78. 80(2)°.V=1612. 6(9) A￣3, M_r=1147. 40, Z=2, D_x= 1. 18 g/cm￣3 . μ=0. 77 cm-1, F(000) = 614. The final agreement factor R=0. 079 for 1828 independent reflections with I≥ 3σ(I) considered to be observed. L contains three functional groups:β-diketone,β-ketoimine(Schiff-base) and NH_2. The β-diketone group has partially delocalized. The pyrazoline plane is not coplanar with its connected phenyl plane. The big πbond is not extended between these planes. There are one ethanol and four water molecules in the crystal. Intermolecular hydrogen bonds may exist between C=O and H_2O. NH_2 and H_2O, H_2O and EtOH, or H_2O and H_2O.展开更多
Solid state reactions between β diketones (HPMBP, HDBM) and LnAc 3· x H 2O(La,Nd: x =3/2;Tb: x =4) have been investigated at low heating temperature. Pure compounds of Ln(PMBP) 3 and Ln(DBM) 3 are obt...Solid state reactions between β diketones (HPMBP, HDBM) and LnAc 3· x H 2O(La,Nd: x =3/2;Tb: x =4) have been investigated at low heating temperature. Pure compounds of Ln(PMBP) 3 and Ln(DBM) 3 are obtained by solid state reaction, and characterized by elemental analysis, infrared radiation (IR),X ray diffraction (XRD) and photoacoustic spectra. The solid state reaction properties of β diketones and their influences on the structures of products are discussed.展开更多
China's salt lakes hold significant lithium reserves,yet the development of low-concentration lithium resources from the carbonate brines in Xizang is a pressing matter.Alkylβ-diketones extractants are capable of...China's salt lakes hold significant lithium reserves,yet the development of low-concentration lithium resources from the carbonate brines in Xizang is a pressing matter.Alkylβ-diketones extractants are capable of efficiently extracting lithium from alkaline solutions using an extraction method,but its optimized extraction prerequisite is an extreme alkaline solution with higher pH.This research introduces a process for the effective extraction and separation of lithium and sodium from the carbonate brine of Jieze Caka Salt Lake,utilizing trifluorinatedβ-biketone HB TA(4,4,4-trifluoro-1-phenyl-1,3-butanedione)-TBP(tributyl phosphate)/kerosene system.A threestage extraction yielded 98.06%of Li^(+)and 1.69%of Na^(+)from the initial brine with a lower pH of 8.961 and a separation factor(β_(Li/Na))of 2948.The simplified process was then implemented using organic direct recycling without regeneration and scrubbing raffinate reflux for a total of 23 cycles,thereby demonstrating the exceptional effectiveness and stability of this system.The resulting lithium-rich stripping solution,with the Li/Na mass ratio amplified by 747 times,underwent further magnesium removal and precipitation using sodium carbonate to yield a high-purity lithium carbonate product of 99.50%.This study offers a novel approach and technology for the efficient separation of lithium ion directly from a partialneutral carbonate salt lake with a high Na/Li ratio and low lithium concentration.展开更多
A novel complex Cu（PPh3）2（acac） 1 （PPh3 = triphenylphosphine, acac = acetylacetone） was obtained by a solution reaction and structurally characterized by X-ray diffraction. The crystal belongs to monoclinic, spa...A novel complex Cu（PPh3）2（acac） 1 （PPh3 = triphenylphosphine, acac = acetylacetone） was obtained by a solution reaction and structurally characterized by X-ray diffraction. The crystal belongs to monoclinic, space group P21/n with a = 13.7361（8）, b = 12.8204（7）, c = 19.7638（13）A, β = 95.946（2）^o, C41H37CuO2P2, Mr= 687.19, V = 3461.7（4）A3, Z = 4, Dc = 1.319 g/cm^3, S = 1.067,μ（MoKa） = 0.758 mm^-l, F（000） = 1432, R = 0.0403 and wR = 0.0990. Complex 1 is characterized by an isolated structure. X-ray structure analysis of I shows that acac behaves as a chelating ligand and PPh3 coordinates as a monodentate ligand to the Cu（I） atoms. Photoluminescent investigation reveals that the title complex displays a strong green-light emission.展开更多
Poly(arylene ether diketone)s were prepared by the aromatic nucleophilic displacement reaction of 4,4'-difluorobenzil with different bisphenols in the presence of anhydrous potassium carbonate in diphenylsulfone a...Poly(arylene ether diketone)s were prepared by the aromatic nucleophilic displacement reaction of 4,4'-difluorobenzil with different bisphenols in the presence of anhydrous potassium carbonate in diphenylsulfone at elevated temperature. The polymers obtained had inherent viscosity of 0.51 similar to 0.63 dL/g, and exhibited glass transition temperature ranging from 136 similar to 217 degrees C mainly depending on the bisphenols used in the polymer synthesis. Thermogravimetry of these polymers showed excellent thermal stability, indicating that 10% weight losses of the polymers were observed in the range above 428 degrees C and 438 degrees C in air and nitrogen, respectively. The mechanical properties of these polymers were also described and the permeability of five polymers for H-2, O-2 and N-2 was determined at 30 degrees C.展开更多
The symmetrical diketone Ⅱ, which can be synthesized in gram scale using a well established method, was used as a starting material to prepare the 11α-methoxy ketomethylene Ⅵ. This is in continuation of our study a...The symmetrical diketone Ⅱ, which can be synthesized in gram scale using a well established method, was used as a starting material to prepare the 11α-methoxy ketomethylene Ⅵ. This is in continuation of our study aiming at the synthesis of multihydroxylated cephalostatin analogues, as for example cephalostatin 1Ⅰ, a potent anti-tumor natural product. Compound Ⅵ underwent chemo- and regioselective hydroboration reaction at only one of △14.15 double bonds furnishing compound Ⅸ as a major product in a fair yield.展开更多
series of fourβ-diketone mononuclear dysprosium complexes,namely,Dy(DBM)_(3)(bpy)(1),Dy(DBM)_(3)(phen)·Tol(2),Dy(DBM)_(3)(dpq)·Tol(3),and Dy(DBM)_(3)(dppz)(4)(bpy=2,2’-bipyridine,phen=1,10-phenanthroline,d...series of fourβ-diketone mononuclear dysprosium complexes,namely,Dy(DBM)_(3)(bpy)(1),Dy(DBM)_(3)(phen)·Tol(2),Dy(DBM)_(3)(dpq)·Tol(3),and Dy(DBM)_(3)(dppz)(4)(bpy=2,2’-bipyridine,phen=1,10-phenanthroline,dpq=dipyrazine[2,3-f:2’,3’-h]quinoxaline,dppz=dipyrido[3,2-a:2’,3’-c]phenazine,Tol=toluene)have been isolated by the reactions of dibenzoylmethane(DBM),azacyclo-auxiliary ligands and DyCl_(3)·6H_(2)O.X-ray crystallographic analysis reveals that complexes 1–4 are all eight-coordinate mononuclear structures.The azacyclo-auxiliary ligands have a dramatic effect on the structure and magnetic characteristics of complexes 1–4,originating from the different degrees of deviation from the ideal coordination symmetries.Complexes 1 and 2 display a single relaxation mode under 0 Oe and complexes 3 and 4 display two single relaxation modes under 2000 Oe.展开更多
Extraction of metal ions into perfluorocarbon solvents using fluorinated ligands has shown promise in a number of applications ranging from catalysis to biomedical imaging.However,the speciation of the extracted metal...Extraction of metal ions into perfluorocarbon solvents using fluorinated ligands has shown promise in a number of applications ranging from catalysis to biomedical imaging.However,the speciation of the extracted metal complexes is poorly understood hindering the design and implementation of new fluorous extraction systems.The extraction of s-,p-,d-,and f-block metal ions from the aqueous phase to the fluorous phase(perfluoro-15-crown-5 ether)with a fluorinated acetylacetonate pro-ligand was investigated and the speciation of the extracted metal complexes characterized,including coordinatively saturated mononuclear and polynuclear species and coordinatively unsaturated mononuclear species.The leaching of these species back into aqueous media was studied along with the effects of synergistic extraction using a combination of fluorinated acac and nonfluorinated neutral ligands.Our findings indicate that formation of coordinatively saturated mononuclear metal complexes in the fluorous phase is essential for retaining extracted species and suggest an important role for synergistic extraction for metal ions that do not form these types of metal complexes with acac ligands alone.展开更多
Three Dy_(4)clusters,[Dy_(4)(tmhd)_(8)(L)_(2)(CH_(3)OH)_(2)]·CH_(3)OH(1),[Dy_(4)(hfac)_(8)(L)_(2)(DMF)_(2)]·C_(7)H_(16)(2)and[Dy_(4)(dbm)_(6)(L)_(2)(μ_(3)-OH)_(2)]·CH_(2)Cl_(2)(3)(tmhd=2,2,6,6-tetramet...Three Dy_(4)clusters,[Dy_(4)(tmhd)_(8)(L)_(2)(CH_(3)OH)_(2)]·CH_(3)OH(1),[Dy_(4)(hfac)_(8)(L)_(2)(DMF)_(2)]·C_(7)H_(16)(2)and[Dy_(4)(dbm)_(6)(L)_(2)(μ_(3)-OH)_(2)]·CH_(2)Cl_(2)(3)(tmhd=2,2,6,6-tetramethyl-3,5-heptanedione,hfac=hexafluoroacetylacetonate,dbm=1,3-diphenyl-1,3-propanedione,HL=2-[(2-(hydroxyimino)propanehydrazide)methyl]),have been successfully synthesized by using three differentβ-diketonate salts(Dy(tmhd)_(3)·2H_(2)O,Dy(hfac)_(3)·2H_(2)O,and Dy(dbm)_(3)·2H_(2)O)to react with HL and by changing the solvent.The X-ray structural analysis shows that four Dy^(Ⅲ)ions in clusters 1 and 2 are linearly arranged;however,cluster 3 contains one Dy_(4)center with a rhombus-shaped arrangement.The different structures of three Dy_(4)clusters were profoundly affected by these minor changes inβ-diketonate or a change in the solvent.Magnetic studies reveal that Dy_(4)clusters 1-3 exhibit different single-molecule magnet(SMM)behaviors under a zero dc field.1 and 2 display slow magnetic relaxation behaviors with effective energy barriersΔE/k_(B)=1.44 K for 1 andΔE/k_(B)=50.96 K for 2,while for 3,two distinct slow magnetic relaxation processes are observed,with effective energy barriersΔE/k_(B)=40.45 K for the fast relaxation process andΔE/k_(B)=113.63 K for the slow relaxation process.This study shows that theβ-diketonate coligands play an important role in modulating molecular structures and further affecting the magnetic dynamics of the lanthanide clusters towards multiple magnetic relaxation processes.展开更多
The synthesis of novel dinuclear lanthanide complexes with formulas[(LnL_(3))(LiL)(MeOH)](1-3)and[(LnL_(3))(LiL)(H_(2)O)](4-6)(Ln=Eu(III),Tb(III),Dy(III))based on functionalized lithiumβ-diketonate(LiL)is reported.Th...The synthesis of novel dinuclear lanthanide complexes with formulas[(LnL_(3))(LiL)(MeOH)](1-3)and[(LnL_(3))(LiL)(H_(2)O)](4-6)(Ln=Eu(III),Tb(III),Dy(III))based on functionalized lithiumβ-diketonate(LiL)is reported.The coordination environment of the Ln(III)ion is formed by oxygen atoms of both the 1,3-dicarbonyl moiety and the acetal group.Depending on the solvent used for the crystallization,methanol or water molecules participate in the coordination with Li(I)ions affecting the crystal structure of complexes.In contrast to[(LnL_(3))(LiL)(H_(2)O)]4-6,a series of complexes[(LnL_(3))(LiL)(MeOH)]1-3 showed mechanoluminescence properties,thereby demonstrating the relationship between the observed optical properties and crystal packing architecture.The magnetic measurements of[(LnL_(3))(LiL)(MeOH)]1-3 revealed SMM behavior of[(DyL_(3))(LiL)(MeOH)]_(3)at low temperatures(Ueff is 37.7 cm^(−1)).展开更多
Three new iridium complexes containing 3-(pyridine-2-yl)coumarin as the cyclometalated ligand(L)and 1-(3,5-bis(trifluoromethyl)phenyl)-3-(4-methoxyphenyl)propane-1,3-dione(^(1)L),1-(furan-2-yl)-4,4-dimethylpentane-1,3...Three new iridium complexes containing 3-(pyridine-2-yl)coumarin as the cyclometalated ligand(L)and 1-(3,5-bis(trifluoromethyl)phenyl)-3-(4-methoxyphenyl)propane-1,3-dione(^(1)L),1-(furan-2-yl)-4,4-dimethylpentane-1,3-dione(^(2)L)and 1-(3,4-dimethoxyphenyl)-4,4-dimethylpentane-1,3-dione(^(3)L)as the ancillary ligands,respectively,were synthesized as emissive materials for organic light-emitting devices.展开更多
基金This work was supported by the National NatUral Science Foundation of China the Provincial Natural Science Foundation of Sha
文摘The reaction of 2-substituted imidazolinium salt with bis-Grignard reagents is reported and a new method for the synthesis of symmetric diketones from carboxylic acids and bis-Grignard reagents is provided.
文摘In this study,the interaction between primary amine and diketones was investigated.Three diketones with a general structure of—(CH2C(O)CH2C(O))-X-R(X is C,O or N and R is H and/or alkyl groups)were selected to react with primary amine in aqueous solutions.The reaction was in-situ monitored by Raman technique and the reaction products were identified by FTIR,NMR and LC-MS.It is found that the reaction products strongly depend on the structures of diketones.When X is nitrogen,the expected Schiff base or its analog can be obtained.However,Schiff base or its analog is not detected if X is C or O,instead,ion pairs or hydrolysis products are formed accordingly,suggesting critical impacts of acidity of CH2 inβ-diketone on the product formation.This study also shows that in-situ Raman is a powerful technique for reaction monitoring and structure characterization,which is useful for mechanism understanding.
基金Natural Science Foundation of China(21501010,21231002,21671019)the 111 Project(B07012)for financial support.
文摘A new Ce^(3+)modified Dawson-like polyoxometalate cluster(C_(2)H_(8)N)_(12)Na_(2)[H_(10){Ce(H_(2)O)_(5)}_(2)(Te_(2)W_(37)O_(132))]·^(39)H_(2)O was synthesized using pH and temperature-controlled one-pot strategy.The compound was characterized by single-crystal X-ray structure analysis,IR spectroscopy,thermogravimetric(TG)analysis,X-ray photoelectron spectroscopy(XPS),and electrospray ionization mass spectrometry(ESI-MS).Singlecrystal X-ray structure analysis revealed that there was a new{Te_(2)W_(37)O_(132)}structure and two Ce^(3+)in this compound.Moreover,it is notable that this compound presents excellent Lewis acid-and Lewis base activities in the condensation cyclization of 1,3-diketones with hydrazines/hydrazides or diamines.All the desired products were obtained in moderate to good yields(up to 99%)and with a high turnover number(up to 4347).
基金Project supported by the National Natural Science Foun-dation of China （Nos. 20704037, 20872130 and 20874086） and the Zhejiang Provincial Natural Science Foundation （Nos. 2008-Y407086, 2009-Y4080198 and 2010-Z4090225）.
文摘A simple, efficient and eco-friendly route has been developed for the synthesis of fl-mercapto diketones via a multicomponent reaction of an aldehyde, acetylacetone and thiol in water. This methodology affords a number of β-mercapto diketone derivatives in moderate to good yields.
基金the support from the National Natural Science Foundation of China (20972013 and 20772005)Beijing Natural Science Foundation (2092022)+1 种基金the Fundamental Research Funds for the Central Universities (ZZ1020)the Doctoral Fund of Ministry of Edu-cation of China (200800100010)
文摘4-Acyl-β-lactams are important synthetic intermediates in both pharmaceutical and organic chemistry. Cis- and trans-4-acyl-β- lactams were synthesized stereoselectively from vicinal diketones via the formation of bulky and less bulky diimines as key intermediates, respectively. The diimines reacted with acyl chloride in the presence of triethylamine to give rise to the corre- sponding 4-imino-β-lactams, which were further hydrolyzed to afford 4-acyl-β-lactams. The cis- and trans selectivity is de- pended on the steric hindrance of the imine N-substituents. A series of cis-4-acyl-β-lactams were synthesized from vicinal ketoaldehydes via the formation of their monoimines and diimines as intermediates. Pyruvic aldehyde produced cis-4-acetyl-β- lactams and cis-4-formyl-β-lactams, respectively, through the reactions of its monoimine and diimine with acyl chlorides. Phenylglyoxal generated cis-4-benzoyl-β-lactams via its monoaldimine.
文摘Rate coefficients of the gas-phase reactions of Cl atoms with a series of fluorinated diketones(FDKs):CF_(3)C(O)CH_(2)C(O)CH_(3)(TFP),CF_(3)C(O)CH_(2)C(O)CH_(2)CH_(3)(TFH)and CF_(3)C(O)CH_(2)C(O)CH(CH_(3))2(TFMH),have been measured at(298±2)K and under atmospheric pressure.The experiments were performed using the relative-rate method with a GC-FID detection system.From different determinations and references used,the following rate coefficients were obtained(in cm3/(molecule·sec)):k_(4)(TFP+Cl)=(1.75±0.21)×10^(−10),k_(5)(TFH+Cl)=(2.05±0.23)×10^(−10),k_(6)(TFMH+Cl)=(2.71±0.34)×10^(−10).Reactivity trends of FDKs were discussed and Free Energy Relationships analysis was developed.The expression lgkOH=1.68 lgkCl+5.71 was obtained for the reactivity of the studied FDKs together with similar unsaturated VOCs with Cl and OH radicals Additionally,acetic acid(CH_(3)C(O)OH)and trifluoroacetic acid(CF_(3)C(O)OH)were positively identified and quantified as degradation products using in situ FTIR spectroscopy.According to the identified products,atmospheric chemical mechanisms were proposed.The atmospheric implications of the studied reactions were assessed by the estimation of the tropospheric lifetimes of TFP,TFH,and TFMH concerning their reaction with Cl atoms to be 48,41,and 31 hours,respectively.The relatively short residence in the atmosphere of the fluorocarbons studied will have a local/regional impact with restricted transport.Global warming potential(GWP(20 yr))calculated for the studied fluoro diketones were 0.014,0.003 and 0.001 for TFP,TFH and TFMH,respectively with a negligible contribution to the greenhouse effect.
基金supported by the Natural Science Foundation of Inner Mongolia,China (No.2009MS0205)the Education Department of Inner Mongolia,China (No.NJcxy08124)
文摘Two new ternary complexes of 1-（2-thienyl）-3-（p-phenylethynylphenyl）-1,3-propanedione（HTPP） and 1,10-phenanthroline（phen） with Sm^3＋ and Dy^3＋ were synthesized.The composition of the ternary complexes was characterized as Sm（TPP）3phen and Dy（TPP）3phen,respectively,by infrared（IR） spectra,chemical analysis,elemental analysis,and thermodynamic analysis.At room temperature,under UV light excitation,the Sm^3＋ and Dy^3＋ complexes exhibit characteristic emissions of the central ions.It is found that the fluorescence intensity of Sm（TPP）3phen is stronger than that of Dy（TPP）3phen.In order to explain this phenomenon,an accurate quantum chemistry calculation was carried out,and the result is in good agreement with the experiment data.
文摘The title compound of PhCH_3C_3HN_2 (O )C (O) (CH_2) _3C [N (CH_2 )_4 NH_2]C_3HN_2 (O)CH_3Ph (L), a new Schiff-base containing diketone, has been synthesized. Its crystal structure has been determined by X-ray diffraction analysis. The crystal, C_(30)H_(41)N_6O_(5.5) (L·0. 5C_2H_5OH·2H_2O) , is triclinic, space group P1 ,a=11.544 (1) , b=11. 723(5) , c=12. 344(2) A , a=80. 61(2) . β=84. 17(1) ,γ=78. 80(2)°.V=1612. 6(9) A￣3, M_r=1147. 40, Z=2, D_x= 1. 18 g/cm￣3 . μ=0. 77 cm-1, F(000) = 614. The final agreement factor R=0. 079 for 1828 independent reflections with I≥ 3σ(I) considered to be observed. L contains three functional groups:β-diketone,β-ketoimine(Schiff-base) and NH_2. The β-diketone group has partially delocalized. The pyrazoline plane is not coplanar with its connected phenyl plane. The big πbond is not extended between these planes. There are one ethanol and four water molecules in the crystal. Intermolecular hydrogen bonds may exist between C=O and H_2O. NH_2 and H_2O, H_2O and EtOH, or H_2O and H_2O.
文摘Solid state reactions between β diketones (HPMBP, HDBM) and LnAc 3· x H 2O(La,Nd: x =3/2;Tb: x =4) have been investigated at low heating temperature. Pure compounds of Ln(PMBP) 3 and Ln(DBM) 3 are obtained by solid state reaction, and characterized by elemental analysis, infrared radiation (IR),X ray diffraction (XRD) and photoacoustic spectra. The solid state reaction properties of β diketones and their influences on the structures of products are discussed.
基金financially supported by the National Natural Science Foundation of China(No.U21A20305)Qinghai Provincial Department of Science and Technology(No.2022-ZJ-728)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.2021430)。
文摘China's salt lakes hold significant lithium reserves,yet the development of low-concentration lithium resources from the carbonate brines in Xizang is a pressing matter.Alkylβ-diketones extractants are capable of efficiently extracting lithium from alkaline solutions using an extraction method,but its optimized extraction prerequisite is an extreme alkaline solution with higher pH.This research introduces a process for the effective extraction and separation of lithium and sodium from the carbonate brine of Jieze Caka Salt Lake,utilizing trifluorinatedβ-biketone HB TA(4,4,4-trifluoro-1-phenyl-1,3-butanedione)-TBP(tributyl phosphate)/kerosene system.A threestage extraction yielded 98.06%of Li^(+)and 1.69%of Na^(+)from the initial brine with a lower pH of 8.961 and a separation factor(β_(Li/Na))of 2948.The simplified process was then implemented using organic direct recycling without regeneration and scrubbing raffinate reflux for a total of 23 cycles,thereby demonstrating the exceptional effectiveness and stability of this system.The resulting lithium-rich stripping solution,with the Li/Na mass ratio amplified by 747 times,underwent further magnesium removal and precipitation using sodium carbonate to yield a high-purity lithium carbonate product of 99.50%.This study offers a novel approach and technology for the efficient separation of lithium ion directly from a partialneutral carbonate salt lake with a high Na/Li ratio and low lithium concentration.
基金Supported by the National Natural Science Foundation of China (50572030)the NSF of Fujian Province (2004HZ01-3)
文摘A novel complex Cu（PPh3）2（acac） 1 （PPh3 = triphenylphosphine, acac = acetylacetone） was obtained by a solution reaction and structurally characterized by X-ray diffraction. The crystal belongs to monoclinic, space group P21/n with a = 13.7361（8）, b = 12.8204（7）, c = 19.7638（13）A, β = 95.946（2）^o, C41H37CuO2P2, Mr= 687.19, V = 3461.7（4）A3, Z = 4, Dc = 1.319 g/cm^3, S = 1.067,μ（MoKa） = 0.758 mm^-l, F（000） = 1432, R = 0.0403 and wR = 0.0990. Complex 1 is characterized by an isolated structure. X-ray structure analysis of I shows that acac behaves as a chelating ligand and PPh3 coordinates as a monodentate ligand to the Cu（I） atoms. Photoluminescent investigation reveals that the title complex displays a strong green-light emission.
文摘Poly(arylene ether diketone)s were prepared by the aromatic nucleophilic displacement reaction of 4,4'-difluorobenzil with different bisphenols in the presence of anhydrous potassium carbonate in diphenylsulfone at elevated temperature. The polymers obtained had inherent viscosity of 0.51 similar to 0.63 dL/g, and exhibited glass transition temperature ranging from 136 similar to 217 degrees C mainly depending on the bisphenols used in the polymer synthesis. Thermogravimetry of these polymers showed excellent thermal stability, indicating that 10% weight losses of the polymers were observed in the range above 428 degrees C and 438 degrees C in air and nitrogen, respectively. The mechanical properties of these polymers were also described and the permeability of five polymers for H-2, O-2 and N-2 was determined at 30 degrees C.
文摘The symmetrical diketone Ⅱ, which can be synthesized in gram scale using a well established method, was used as a starting material to prepare the 11α-methoxy ketomethylene Ⅵ. This is in continuation of our study aiming at the synthesis of multihydroxylated cephalostatin analogues, as for example cephalostatin 1Ⅰ, a potent anti-tumor natural product. Compound Ⅵ underwent chemo- and regioselective hydroboration reaction at only one of △14.15 double bonds furnishing compound Ⅸ as a major product in a fair yield.
基金supported by the National Natural Science Foundation of China(no.21471051 and 51402092).
文摘series of fourβ-diketone mononuclear dysprosium complexes,namely,Dy(DBM)_(3)(bpy)(1),Dy(DBM)_(3)(phen)·Tol(2),Dy(DBM)_(3)(dpq)·Tol(3),and Dy(DBM)_(3)(dppz)(4)(bpy=2,2’-bipyridine,phen=1,10-phenanthroline,dpq=dipyrazine[2,3-f:2’,3’-h]quinoxaline,dppz=dipyrido[3,2-a:2’,3’-c]phenazine,Tol=toluene)have been isolated by the reactions of dibenzoylmethane(DBM),azacyclo-auxiliary ligands and DyCl_(3)·6H_(2)O.X-ray crystallographic analysis reveals that complexes 1–4 are all eight-coordinate mononuclear structures.The azacyclo-auxiliary ligands have a dramatic effect on the structure and magnetic characteristics of complexes 1–4,originating from the different degrees of deviation from the ideal coordination symmetries.Complexes 1 and 2 display a single relaxation mode under 0 Oe and complexes 3 and 4 display two single relaxation modes under 2000 Oe.
基金funding from the Welch Foundation(EQ:F-1883,RJ:F-816)the Cancer Prevention Research Institute of Texas(EQ:RP200223)the support of a fellowship from the“la Caixa”Banking Foundation(ID 100010434,Fellowship code:LCF/BQ/AA17/11610005).
文摘Extraction of metal ions into perfluorocarbon solvents using fluorinated ligands has shown promise in a number of applications ranging from catalysis to biomedical imaging.However,the speciation of the extracted metal complexes is poorly understood hindering the design and implementation of new fluorous extraction systems.The extraction of s-,p-,d-,and f-block metal ions from the aqueous phase to the fluorous phase(perfluoro-15-crown-5 ether)with a fluorinated acetylacetonate pro-ligand was investigated and the speciation of the extracted metal complexes characterized,including coordinatively saturated mononuclear and polynuclear species and coordinatively unsaturated mononuclear species.The leaching of these species back into aqueous media was studied along with the effects of synergistic extraction using a combination of fluorinated acac and nonfluorinated neutral ligands.Our findings indicate that formation of coordinatively saturated mononuclear metal complexes in the fluorous phase is essential for retaining extracted species and suggest an important role for synergistic extraction for metal ions that do not form these types of metal complexes with acac ligands alone.
基金supported financially by the National Natural Science Foundation of China(No.21473121,21571138 and 21701039)111 project,B12015.
文摘Three Dy_(4)clusters,[Dy_(4)(tmhd)_(8)(L)_(2)(CH_(3)OH)_(2)]·CH_(3)OH(1),[Dy_(4)(hfac)_(8)(L)_(2)(DMF)_(2)]·C_(7)H_(16)(2)and[Dy_(4)(dbm)_(6)(L)_(2)(μ_(3)-OH)_(2)]·CH_(2)Cl_(2)(3)(tmhd=2,2,6,6-tetramethyl-3,5-heptanedione,hfac=hexafluoroacetylacetonate,dbm=1,3-diphenyl-1,3-propanedione,HL=2-[(2-(hydroxyimino)propanehydrazide)methyl]),have been successfully synthesized by using three differentβ-diketonate salts(Dy(tmhd)_(3)·2H_(2)O,Dy(hfac)_(3)·2H_(2)O,and Dy(dbm)_(3)·2H_(2)O)to react with HL and by changing the solvent.The X-ray structural analysis shows that four Dy^(Ⅲ)ions in clusters 1 and 2 are linearly arranged;however,cluster 3 contains one Dy_(4)center with a rhombus-shaped arrangement.The different structures of three Dy_(4)clusters were profoundly affected by these minor changes inβ-diketonate or a change in the solvent.Magnetic studies reveal that Dy_(4)clusters 1-3 exhibit different single-molecule magnet(SMM)behaviors under a zero dc field.1 and 2 display slow magnetic relaxation behaviors with effective energy barriersΔE/k_(B)=1.44 K for 1 andΔE/k_(B)=50.96 K for 2,while for 3,two distinct slow magnetic relaxation processes are observed,with effective energy barriersΔE/k_(B)=40.45 K for the fast relaxation process andΔE/k_(B)=113.63 K for the slow relaxation process.This study shows that theβ-diketonate coligands play an important role in modulating molecular structures and further affecting the magnetic dynamics of the lanthanide clusters towards multiple magnetic relaxation processes.
基金Financial support of this work(the synthesis part and structure characterization)by the Russian Foundation for Basic Research(grant no.mol_a_dk 16-33-60048)is gratefully acknowledgedASB is thankful to the FASO(0033-2017-0001)VIS is thankful to the Ural Branch of the Russian Academy of Sciences(AAAA-A18-118020290158-5).
文摘The synthesis of novel dinuclear lanthanide complexes with formulas[(LnL_(3))(LiL)(MeOH)](1-3)and[(LnL_(3))(LiL)(H_(2)O)](4-6)(Ln=Eu(III),Tb(III),Dy(III))based on functionalized lithiumβ-diketonate(LiL)is reported.The coordination environment of the Ln(III)ion is formed by oxygen atoms of both the 1,3-dicarbonyl moiety and the acetal group.Depending on the solvent used for the crystallization,methanol or water molecules participate in the coordination with Li(I)ions affecting the crystal structure of complexes.In contrast to[(LnL_(3))(LiL)(H_(2)O)]4-6,a series of complexes[(LnL_(3))(LiL)(MeOH)]1-3 showed mechanoluminescence properties,thereby demonstrating the relationship between the observed optical properties and crystal packing architecture.The magnetic measurements of[(LnL_(3))(LiL)(MeOH)]1-3 revealed SMM behavior of[(DyL_(3))(LiL)(MeOH)]_(3)at low temperatures(Ueff is 37.7 cm^(−1)).
基金supported by the National Natural Science Foundation of China(Grant 51563014).
文摘Three new iridium complexes containing 3-(pyridine-2-yl)coumarin as the cyclometalated ligand(L)and 1-(3,5-bis(trifluoromethyl)phenyl)-3-(4-methoxyphenyl)propane-1,3-dione(^(1)L),1-(furan-2-yl)-4,4-dimethylpentane-1,3-dione(^(2)L)and 1-(3,4-dimethoxyphenyl)-4,4-dimethylpentane-1,3-dione(^(3)L)as the ancillary ligands,respectively,were synthesized as emissive materials for organic light-emitting devices.
