A novel tridentate ligand N-（6-（diphenylphosphoryl）pyridin-2-yl）-2,2,2-trifluoroacetamide （DPPOPFA） was designed and synthesized. Crystal structure of the ligand revealed the ＂keto＂ form of ligand in solid sta...A novel tridentate ligand N-（6-（diphenylphosphoryl）pyridin-2-yl）-2,2,2-trifluoroacetamide （DPPOPFA） was designed and synthesized. Crystal structure of the ligand revealed the ＂keto＂ form of ligand in solid state other than the ＂enor＇ one, and it was also found that two kinds of molecules with different conformations were connected by hydrogen bonding between amide N-H and phos- phoryl P=O. This ionic ligand was used to coordinate a variety of lanthanide ions, forming neutral 3：1 complexes. Absolute overall quantum yields of these complexes in solid states were 36% for Eu（III）, 29% for Tb（III） and 3% for Dy（III） with lifetimes of 1.1, 1.1 and 0.087 ms, respectively. The complexes had excellent thermal stability and did not decompose till 370 ℃. And they could subli- mate in vacuum （1 ×10^-4 Pa） at 330℃ due to the weak molecular interaction.展开更多
Three stable 4-substituted pyridine-based ruthenium（II）complexes[RuCl2（PPh3）L]（L=4-R-2,6-bis （diethylaminomethylene）pyridine,R=Br,H or allyloxy）were synthesized.The catalytic activities of the complexes toward...Three stable 4-substituted pyridine-based ruthenium（II）complexes[RuCl2（PPh3）L]（L=4-R-2,6-bis （diethylaminomethylene）pyridine,R=Br,H or allyloxy）were synthesized.The catalytic activities of the complexes toward transfer hydrogenation from alcohols to ketones were investigated.The electronic effects of the para-substituent in the pyridyl ring were probed and we found that the electron-donating group increased the catalytic activity.The result suggests that an electron-donating group is probably preferential for linking the catalytic ruthenium complex and the chemically inert supporting molecules such as a carbosilane dendrimer.展开更多
A series of half-sandwich group IV metal complexes with tridentate monoanionic phenoxy-imine arylsulfide [O-NS] ligand [2-Bu^t4-Me-6-（（2-（SC6H5）C6H4N = CHC6H2O）]- （La） and dianionic phenoxy-amine arylsulfide [O...A series of half-sandwich group IV metal complexes with tridentate monoanionic phenoxy-imine arylsulfide [O-NS] ligand [2-Bu^t4-Me-6-（（2-（SC6H5）C6H4N = CHC6H2O）]- （La） and dianionic phenoxy-amine arylsulfide [O-N-S] ligand [2-Bu^t4-Me-6-（（2-（SC6H5）C6H4N-CH2C6H2O）]2- （Lb） have been synthesized and characterized. Lb was obtained easily in high yield by reduction of ligand La with excess LiAlH4 in cool diethyl ether. Half-sandwich Group Ⅳ metal complexes CpTi[O-NS]Cl2 （1a）, CpZr[O-NS]Cl2 （1b）, CpTi[O-N-S]Cl （2a）, CpZr[O-N-S]Cl （2b） and CpZr[O-N-S]Cl （2c） were synthesized by the reactions of La and Lb with CpTiCl3, CpZrCl3 and Cp ZrCl3, and characterized by IR, ^1H-NMR, ^13C-NMR and elemental analysis. In addition, an X-ray structure analysis was performed on ligand Lb. The title Group IV half-sandwich bearing tridentate [O,N,S] ligands show good catalytic activities for ethylene polymerization in the presence of methylaluminoxane （MAO） as co-catalyst up to 1.58 × 10^7 g-PE.mol-Zr-1.h-1. The good catalytic activities can be maintained even at high temperatures such as 100 ℃ exhibiting the excellent thermal stability for these half-sandwich metal pre-catalysts.展开更多
Solvent extraction of base metals using bis((1-decylbenzimidazol-2-yl)methyl)amine (BDNNN) showed a lack of pH-metric separation of the metals. The extraction system was described quantitatively using the equilibria i...Solvent extraction of base metals using bis((1-decylbenzimidazol-2-yl)methyl)amine (BDNNN) showed a lack of pH-metric separation of the metals. The extraction system was described quantitatively using the equilibria involved to derive the mathematical explanation for the two linear log D vs pHe plots for each metal ion extraction curve, and coordination numbers could also be extracted from the two slopes. The lack of separation was attributed to the absence of stereochemical “tailor making” since the complexes isolated from the reaction of the ligand, bis((1H-benzimidazol- 2-yl)methyl)amine (NNN), with base metals suggested the formation of similar octahedral complex species from spectral and crystal structure evidence. The bis tridentate coordination observed was in agreement with information extracted from the extraction data. This investigation opens up an opportunity and an approach for the evaluation of amines as extractants but cautions against tridentate ligands.展开更多
Asymmetric direct hydrogenation(ADH)is a straightforward and atom-economic methodology to achieve optically active compounds.The synthesis of chiral compounds bearing stereogenic centers has been well established.In c...Asymmetric direct hydrogenation(ADH)is a straightforward and atom-economic methodology to achieve optically active compounds.The synthesis of chiral compounds bearing stereogenic centers has been well established.In contrast,the construction of atropisomers,especially atropisomers bearing multiple chiral elements,has sporadically been explored.Herein,we report an innovative atroposelective iridium-catalyzed hydrogenation of N-arylindole ketones and heterobiaryl ketones via dynamic kinetic resolution(DKR)based on a Lewis acid-base interaction between the nitrogen atom and the carbonyl group of ketones,providing C-N and C-C atropisomers bearing multiple chiral elements with excellent enantioselectivities,diastereoselectivities and yields.The lynchpin of the DKR-ADH process stands in the newly developed planar-chiral tridentate PNO ligand,which ensures the excellent control of enantioselectivity and diastereoselectivity simultaneously.The synthetic utilization of this protocol is proved through stereospecific transformation to a tridentate PNN ligand bearing axial and central chirality,which shows promising potential in iridium-catalyzed asymmetric hydrogenation of simple ketones.展开更多
The reaction of NiCl2 and 3-hydrazine-4-amino-1,2,4-triazole （Hatr） in the mixed solvent of EtOH and H2O yielded a dimer compound （[Ni2（Hatr）2（H2O）2（EtOH）2Cl2]ClzoEtOH） with water and EtOH molecules coordina...The reaction of NiCl2 and 3-hydrazine-4-amino-1,2,4-triazole （Hatr） in the mixed solvent of EtOH and H2O yielded a dimer compound （[Ni2（Hatr）2（H2O）2（EtOH）2Cl2]ClzoEtOH） with water and EtOH molecules coordinated to nickle ions. It crystallized in trigonal space group R-3, a=b=29.67（1） A, c=8.95（7） A, β= 120（1）°, as determined by single-crystal X-ray diffraction. Then, they were fully characterized by the IR spectroscopy, differential scanning calorimetry （DSC）, thermogravimetry （TG）, and elemental analysis.展开更多
Reaction of a new type of bidentate ligand PhPQu [ PhPQu = 2-diphenylphosphino-4-methylquinoline] with Fe(CO)5 in bu-tanol gave trans-Fe(PhPQu-P)(CO)3 (1).Compound 1,which can act as a neutral tridentate organometalli...Reaction of a new type of bidentate ligand PhPQu [ PhPQu = 2-diphenylphosphino-4-methylquinoline] with Fe(CO)5 in bu-tanol gave trans-Fe(PhPQu-P)(CO)3 (1).Compound 1,which can act as a neutral tridentate organometallic ligand,was reacted with I B,II B metal compounds and a rhodium complex to give six binuclear complexes with Fe-M bonds,Fe(CO)3(u-Ph2PQu)MXn(2-7) [M=Zn(Ⅰ),Cd(Ⅱ),Hg(Ⅱ),Cu(Ⅰ),Ag(Ⅰ),Rh(Ⅰ)],and an ion-pair complex [Fe(CO)3(n-Ph2PQu)2HgI][HgI3]- (8).The structure of 8 was determined by X-ray crystallography.Complex 8 crystallizes in the space group P-1 with a=1.0758(3),b= 1.6210(4),c = 1.7155(4) nm; a = 75.60(2)β=71.81(2),Y = 81.78(2) and Z = 2 and its structure was refined to give agreement factors of R =0.050 and Rw = 0.057.The Fe-Hg bond distance is 0.2536 nm.展开更多
Schiff base metal complexes are of great importance in pharmaceutical science owing to their unique chemical properties, which enable them to exhibit diverse biological activities such as anti-bacterial,anti-oxidant, ...Schiff base metal complexes are of great importance in pharmaceutical science owing to their unique chemical properties, which enable them to exhibit diverse biological activities such as anti-bacterial,anti-oxidant, anti-inflammatory, and anti-tumor properties. Furthermore, Schiff base metal complexes can serve as reagents and catalysts in chemical reactions. This review aims to provide an overview of our recently published studies on Cu(Ⅱ) and Pd(Ⅱ) complexes derived from proline Schiff base ligands. We also discuss the potential applications of these metal complexes in the fields of antibacterial and chiral resolution.展开更多
The mononuclear vanadium（V） complex with 2-hydroxyl-l-naphthaldehyde isonicotinoyl hydrazone was synthesized and characterized by single-crystal X-ray diffraction. The crystal is of monocfinic, space group P2 1/n wi...The mononuclear vanadium（V） complex with 2-hydroxyl-l-naphthaldehyde isonicotinoyl hydrazone was synthesized and characterized by single-crystal X-ray diffraction. The crystal is of monocfinic, space group P2 1/n with α = 10.3153（15）, b = 7.4024（11 ）, c = 24.413（4） A, β = 101.911（2）°, V= 1824.0（5） A^3, Z= 4, Mr = 427.28, Dc = 1.556 g/cm^3, F（000） = 880,μ（MoKα） = 0.591, the final R = 0.0372 and wR = 0.0926. The vanadium（V） atom adopts a distorted square-pyramidal geometry coordinated by the tridentate ligand and two oxygen atoms. The hydrogen bonds and strong π-π stacking interactions link the complex molecules into a 3-D network structure.展开更多
Anthrones are key structural motifs in many natural products, bioactive compounds and pharmaceutical chemicals. Earth-abundant-metal-catalyzed asymmetric functionalization of anthrones has not proved to be viable. Her...Anthrones are key structural motifs in many natural products, bioactive compounds and pharmaceutical chemicals. Earth-abundant-metal-catalyzed asymmetric functionalization of anthrones has not proved to be viable. Herein, we disclosed a highly enantioselective propargylic substitution of anthrones with propargylic esters using copper salts with chiral N, N, P-ligand. This strategy is amenable to a broad range of substrates, uses readily available starting materials, provides excellent yields with remarkable enantioselectivity under mild conditions, and enables attractive products diversification routes.展开更多
The tridentate ligand DPA-Me（2） was readily prepared from DPA（DPA = 2,2-dipicolylamine） in high yield. The mixture of 2 and Cu（ClO4）26H2O in methanol gave a five-coordinated mononuclear complex [（DPA-Me）Cu（Me...The tridentate ligand DPA-Me（2） was readily prepared from DPA（DPA = 2,2-dipicolylamine） in high yield. The mixture of 2 and Cu（ClO4）26H2O in methanol gave a five-coordinated mononuclear complex [（DPA-Me）Cu（Me CN）（ClO4）]（ClO4）（3）. Recrystallization of 3 in CH3NO2 led to an activation of CH3NO2 to CN- by the formation of product as a dinuclear cyanide bridged complex {[Cu（DPA-Me）]2（CN）（ClO4）3CH3NO2}n（4）. Both 3 and 4 were characterized by X-ray crystallography, IR spectroscopy and elemental analysis. The crystal of 4 was grown in space group P21/c with a = 17.74582（15）, b = 13.89877（11）, c = 14.92546（13） A, β = 91.4246（8）°, V = 3680.15（5） 3, Z = 4, Dc = 1.695 g/cm^3, F（000） = 1912, C28H33Cl3Cu2N8O14, Mr = 939.05, μ = 1.602 cm^-1, Cu Kα radiation（λ = 1.54184 ）, R = 0.0485 and w R = 0.1246 for 6414 observed reflections with I 〉 2σ（I）.展开更多
A new dinuclear copper（Ⅱ） complex, [Cu（L）（py）]2 1 （H2L = N-（2-hydroxybenzyl）- salicylaldimine, py = pyridine）, has been synthesized and characterized by elemental analysis, IR and UV spectra. 1 crystallizes...A new dinuclear copper（Ⅱ） complex, [Cu（L）（py）]2 1 （H2L = N-（2-hydroxybenzyl）- salicylaldimine, py = pyridine）, has been synthesized and characterized by elemental analysis, IR and UV spectra. 1 crystallizes in space group P2 1/n with a = 8.2106, b = 10.715, c = 17.864A, β = 99.365°, V = 1550.7A3, Z = 4, C19H16CuN2O2, Mr = 367.88, Dc = 1.576 g/cm3,μ（MoKα） = 1.422 mm-1, F（000） = 756, the final R = 0.0280 and wR = 0.0746. Complex 1 is a centrosymmetric dimer with two copper（H） centers, two py ligands and two L2- ligands. Each L2- ligand donates its azomethine nitrogen and one of the phenolate groups to one copper（Ⅱ） ion and shares the other phenolate group between the two copper（H） ions, affording a Cu2O2 plane. Each copper（Ⅱ） center has a slightly distorted square pyramidal geometry with a bridging phenolate group at the apex. Magnetic studies suggest the presence of a weak ferromagnetic interaction Via two phenoxo bridges. The magnetic susceptibility data （2-300 K） of complex 1 were analyzed by means of H = -2JS1S2 -DSz. The least-squares fitting of the data to the theoretical equation leads to J = 10.3 cm-1, g = 2.03, D = 0.67 cm-1 and R = ∑（Xobsd -Xcalcd）2/∑Xobsd2= 2.76 × 10^-3.展开更多
The title complex, 2 benzoyl pyridine thiosemicarbazato palladium(II) chloride [C 13 H 11 N 4SPdCl, M r =379.17], crystallizes in monoclinic, space group C2/c with a=12.1061(5), b=21.877(3), c=11.4...The title complex, 2 benzoyl pyridine thiosemicarbazato palladium(II) chloride [C 13 H 11 N 4SPdCl, M r =379.17], crystallizes in monoclinic, space group C2/c with a=12.1061(5), b=21.877(3), c=11.4832(6), β=108.29(9)°, V=2887.7(4) 3, Z = 8, D c =1.827g/cm 3; μ= 1.608cm -1 and F(000)=1568. R =0.0281 and wR =0.0684 for 1446 reflections with I>2σ(I) . X ray crystal structure analysis revealed that the coordination geometry of Pd atom is a distorted square plane with two Pd-N bonds, one Pd-S bond and one Pd-Cl bond. The Schiff base ligand loses a proton from its tautomeric thiol form and coordinates to the Pd atom via the mercapto sulfur and the β nitrogen atoms.展开更多
The title compound, [N-(2-pyridylmethyl)-(L)-alanine]Co(III) thiocyanate (1) was obtained from the reaction of Co(OOCH3)2·H2O with the tridentate reduced Schiff base ligand, N-(2-pyridylmethyl)-(L)-alanine (L) an...The title compound, [N-(2-pyridylmethyl)-(L)-alanine]Co(III) thiocyanate (1) was obtained from the reaction of Co(OOCH3)2·H2O with the tridentate reduced Schiff base ligand, N-(2-pyridylmethyl)-(L)-alanine (L) and NH4SCN and characterized by elemental analysis, IR, UV-visible, TGA and single- crystal X-ray diffraction. Structural and spectroscopic analyses reveal [Co(L)2)]SCN to be monomeric with Cobalt(III) adopting a pseudo-octahedral geometry, coordinating to two reduce Schiff base ligands. In the crystal lattice, the thiocyanate anion forms an intermolecular SCN···HNamine hydrogen bond, while adjacent monomers are linked by intermolecular Ocarboxyl···HNamine···H-bonds to form a supramolecular network. This work is therefore undertaken in an attempt to construct coordination framework structures of varying properties using the mixed-ligand strategy involving reduced Schiff bases and the thiocyanate ion.展开更多
基金Project supported by the National Key Basic Research Program of China(2014CB643802)the National Natural Science Foundation of China(21371012,21321001)
文摘A novel tridentate ligand N-（6-（diphenylphosphoryl）pyridin-2-yl）-2,2,2-trifluoroacetamide （DPPOPFA） was designed and synthesized. Crystal structure of the ligand revealed the ＂keto＂ form of ligand in solid state other than the ＂enor＇ one, and it was also found that two kinds of molecules with different conformations were connected by hydrogen bonding between amide N-H and phos- phoryl P=O. This ionic ligand was used to coordinate a variety of lanthanide ions, forming neutral 3：1 complexes. Absolute overall quantum yields of these complexes in solid states were 36% for Eu（III）, 29% for Tb（III） and 3% for Dy（III） with lifetimes of 1.1, 1.1 and 0.087 ms, respectively. The complexes had excellent thermal stability and did not decompose till 370 ℃. And they could subli- mate in vacuum （1 ×10^-4 Pa） at 330℃ due to the weak molecular interaction.
基金Supported by the National Natural Science Foundation of China（20576052） the Joint Innovation Fund of Jiangsu Province（BY2009107） the National Basic Research Program of China（2003CB615707）
文摘Three stable 4-substituted pyridine-based ruthenium（II）complexes[RuCl2（PPh3）L]（L=4-R-2,6-bis （diethylaminomethylene）pyridine,R=Br,H or allyloxy）were synthesized.The catalytic activities of the complexes toward transfer hydrogenation from alcohols to ketones were investigated.The electronic effects of the para-substituent in the pyridyl ring were probed and we found that the electron-donating group increased the catalytic activity.The result suggests that an electron-donating group is probably preferential for linking the catalytic ruthenium complex and the chemically inert supporting molecules such as a carbosilane dendrimer.
基金financially supported by the Shanghai Science and Technology Committee(08DZ2270500,08DJ1400103)Shanghai Leading Academic Discipline Project(B108)the National Basic Research Program of China(2009CB825300,2010DFA41160)
文摘A series of half-sandwich group IV metal complexes with tridentate monoanionic phenoxy-imine arylsulfide [O-NS] ligand [2-Bu^t4-Me-6-（（2-（SC6H5）C6H4N = CHC6H2O）]- （La） and dianionic phenoxy-amine arylsulfide [O-N-S] ligand [2-Bu^t4-Me-6-（（2-（SC6H5）C6H4N-CH2C6H2O）]2- （Lb） have been synthesized and characterized. Lb was obtained easily in high yield by reduction of ligand La with excess LiAlH4 in cool diethyl ether. Half-sandwich Group Ⅳ metal complexes CpTi[O-NS]Cl2 （1a）, CpZr[O-NS]Cl2 （1b）, CpTi[O-N-S]Cl （2a）, CpZr[O-N-S]Cl （2b） and CpZr[O-N-S]Cl （2c） were synthesized by the reactions of La and Lb with CpTiCl3, CpZrCl3 and Cp ZrCl3, and characterized by IR, ^1H-NMR, ^13C-NMR and elemental analysis. In addition, an X-ray structure analysis was performed on ligand Lb. The title Group IV half-sandwich bearing tridentate [O,N,S] ligands show good catalytic activities for ethylene polymerization in the presence of methylaluminoxane （MAO） as co-catalyst up to 1.58 × 10^7 g-PE.mol-Zr-1.h-1. The good catalytic activities can be maintained even at high temperatures such as 100 ℃ exhibiting the excellent thermal stability for these half-sandwich metal pre-catalysts.
文摘Solvent extraction of base metals using bis((1-decylbenzimidazol-2-yl)methyl)amine (BDNNN) showed a lack of pH-metric separation of the metals. The extraction system was described quantitatively using the equilibria involved to derive the mathematical explanation for the two linear log D vs pHe plots for each metal ion extraction curve, and coordination numbers could also be extracted from the two slopes. The lack of separation was attributed to the absence of stereochemical “tailor making” since the complexes isolated from the reaction of the ligand, bis((1H-benzimidazol- 2-yl)methyl)amine (NNN), with base metals suggested the formation of similar octahedral complex species from spectral and crystal structure evidence. The bis tridentate coordination observed was in agreement with information extracted from the extraction data. This investigation opens up an opportunity and an approach for the evaluation of amines as extractants but cautions against tridentate ligands.
基金supported by the National Key Research and Development Program of China(2023YFA1507500)the National Natural Science Foundation of China(22171260,92356302)+1 种基金the Natural Science Foundation of Liaoning Province(2023-MS-009)the Dalian Institute of Chemical Physics(DICP I202442)。
文摘Asymmetric direct hydrogenation(ADH)is a straightforward and atom-economic methodology to achieve optically active compounds.The synthesis of chiral compounds bearing stereogenic centers has been well established.In contrast,the construction of atropisomers,especially atropisomers bearing multiple chiral elements,has sporadically been explored.Herein,we report an innovative atroposelective iridium-catalyzed hydrogenation of N-arylindole ketones and heterobiaryl ketones via dynamic kinetic resolution(DKR)based on a Lewis acid-base interaction between the nitrogen atom and the carbonyl group of ketones,providing C-N and C-C atropisomers bearing multiple chiral elements with excellent enantioselectivities,diastereoselectivities and yields.The lynchpin of the DKR-ADH process stands in the newly developed planar-chiral tridentate PNO ligand,which ensures the excellent control of enantioselectivity and diastereoselectivity simultaneously.The synthetic utilization of this protocol is proved through stereospecific transformation to a tridentate PNN ligand bearing axial and central chirality,which shows promising potential in iridium-catalyzed asymmetric hydrogenation of simple ketones.
文摘The reaction of NiCl2 and 3-hydrazine-4-amino-1,2,4-triazole （Hatr） in the mixed solvent of EtOH and H2O yielded a dimer compound （[Ni2（Hatr）2（H2O）2（EtOH）2Cl2]ClzoEtOH） with water and EtOH molecules coordinated to nickle ions. It crystallized in trigonal space group R-3, a=b=29.67（1） A, c=8.95（7） A, β= 120（1）°, as determined by single-crystal X-ray diffraction. Then, they were fully characterized by the IR spectroscopy, differential scanning calorimetry （DSC）, thermogravimetry （TG）, and elemental analysis.
基金Project supported by the National Natural Science Foundation of China (No. 29672078)
文摘Reaction of a new type of bidentate ligand PhPQu [ PhPQu = 2-diphenylphosphino-4-methylquinoline] with Fe(CO)5 in bu-tanol gave trans-Fe(PhPQu-P)(CO)3 (1).Compound 1,which can act as a neutral tridentate organometallic ligand,was reacted with I B,II B metal compounds and a rhodium complex to give six binuclear complexes with Fe-M bonds,Fe(CO)3(u-Ph2PQu)MXn(2-7) [M=Zn(Ⅰ),Cd(Ⅱ),Hg(Ⅱ),Cu(Ⅰ),Ag(Ⅰ),Rh(Ⅰ)],and an ion-pair complex [Fe(CO)3(n-Ph2PQu)2HgI][HgI3]- (8).The structure of 8 was determined by X-ray crystallography.Complex 8 crystallizes in the space group P-1 with a=1.0758(3),b= 1.6210(4),c = 1.7155(4) nm; a = 75.60(2)β=71.81(2),Y = 81.78(2) and Z = 2 and its structure was refined to give agreement factors of R =0.050 and Rw = 0.057.The Fe-Hg bond distance is 0.2536 nm.
基金the National Key R&D Program of China(No.2022YFA1302900)the National Natural Science Foundation of China (Nos.82130105, 92253305, 82121005, and 22177124)supported by the Lingang Laboratory (Nos.LG-GG-202204–02 and LG202103–04–01)。
文摘Schiff base metal complexes are of great importance in pharmaceutical science owing to their unique chemical properties, which enable them to exhibit diverse biological activities such as anti-bacterial,anti-oxidant, anti-inflammatory, and anti-tumor properties. Furthermore, Schiff base metal complexes can serve as reagents and catalysts in chemical reactions. This review aims to provide an overview of our recently published studies on Cu(Ⅱ) and Pd(Ⅱ) complexes derived from proline Schiff base ligands. We also discuss the potential applications of these metal complexes in the fields of antibacterial and chiral resolution.
基金Supported by the Science Foundation of Guangxi Province (No. 0342025), the Youth Science Foundation of Guangxi Province (No. 0542020) and the Teaching and Research Award Programme for Outstanding Young Teachers in Higher Education Institutions of MOE, China
文摘The mononuclear vanadium（V） complex with 2-hydroxyl-l-naphthaldehyde isonicotinoyl hydrazone was synthesized and characterized by single-crystal X-ray diffraction. The crystal is of monocfinic, space group P2 1/n with α = 10.3153（15）, b = 7.4024（11 ）, c = 24.413（4） A, β = 101.911（2）°, V= 1824.0（5） A^3, Z= 4, Mr = 427.28, Dc = 1.556 g/cm^3, F（000） = 880,μ（MoKα） = 0.591, the final R = 0.0372 and wR = 0.0926. The vanadium（V） atom adopts a distorted square-pyramidal geometry coordinated by the tridentate ligand and two oxygen atoms. The hydrogen bonds and strong π-π stacking interactions link the complex molecules into a 3-D network structure.
基金financial support from the National Natural Science Foundation of China (No.21801087)Fundamental Research Funds for the Central Universities CCNU (No.CCNU19QN064)+2 种基金the Ministry of Science and Technology of China (No.2016YFE0132600)Henan Center for Outstanding Overseas Scientists (No.GZS2020001)the Key Scientific and Technological Project of Henan Province (No.212102311068)。
文摘Anthrones are key structural motifs in many natural products, bioactive compounds and pharmaceutical chemicals. Earth-abundant-metal-catalyzed asymmetric functionalization of anthrones has not proved to be viable. Herein, we disclosed a highly enantioselective propargylic substitution of anthrones with propargylic esters using copper salts with chiral N, N, P-ligand. This strategy is amenable to a broad range of substrates, uses readily available starting materials, provides excellent yields with remarkable enantioselectivity under mild conditions, and enables attractive products diversification routes.
基金granted by the National Natural Science Foundation of China(No.21371171)
文摘The tridentate ligand DPA-Me（2） was readily prepared from DPA（DPA = 2,2-dipicolylamine） in high yield. The mixture of 2 and Cu（ClO4）26H2O in methanol gave a five-coordinated mononuclear complex [（DPA-Me）Cu（Me CN）（ClO4）]（ClO4）（3）. Recrystallization of 3 in CH3NO2 led to an activation of CH3NO2 to CN- by the formation of product as a dinuclear cyanide bridged complex {[Cu（DPA-Me）]2（CN）（ClO4）3CH3NO2}n（4）. Both 3 and 4 were characterized by X-ray crystallography, IR spectroscopy and elemental analysis. The crystal of 4 was grown in space group P21/c with a = 17.74582（15）, b = 13.89877（11）, c = 14.92546（13） A, β = 91.4246（8）°, V = 3680.15（5） 3, Z = 4, Dc = 1.695 g/cm^3, F（000） = 1912, C28H33Cl3Cu2N8O14, Mr = 939.05, μ = 1.602 cm^-1, Cu Kα radiation（λ = 1.54184 ）, R = 0.0485 and w R = 0.1246 for 6414 observed reflections with I 〉 2σ（I）.
基金supported by the Natural Science Research Program of the Education Department of Hebei Province (No. Z2008107)the National Natural Science Foundation of China (No. 20601014)the National Basic Research Program of China (973 Program, 2007CB815305)
文摘A new dinuclear copper（Ⅱ） complex, [Cu（L）（py）]2 1 （H2L = N-（2-hydroxybenzyl）- salicylaldimine, py = pyridine）, has been synthesized and characterized by elemental analysis, IR and UV spectra. 1 crystallizes in space group P2 1/n with a = 8.2106, b = 10.715, c = 17.864A, β = 99.365°, V = 1550.7A3, Z = 4, C19H16CuN2O2, Mr = 367.88, Dc = 1.576 g/cm3,μ（MoKα） = 1.422 mm-1, F（000） = 756, the final R = 0.0280 and wR = 0.0746. Complex 1 is a centrosymmetric dimer with two copper（H） centers, two py ligands and two L2- ligands. Each L2- ligand donates its azomethine nitrogen and one of the phenolate groups to one copper（Ⅱ） ion and shares the other phenolate group between the two copper（H） ions, affording a Cu2O2 plane. Each copper（Ⅱ） center has a slightly distorted square pyramidal geometry with a bridging phenolate group at the apex. Magnetic studies suggest the presence of a weak ferromagnetic interaction Via two phenoxo bridges. The magnetic susceptibility data （2-300 K） of complex 1 were analyzed by means of H = -2JS1S2 -DSz. The least-squares fitting of the data to the theoretical equation leads to J = 10.3 cm-1, g = 2.03, D = 0.67 cm-1 and R = ∑（Xobsd -Xcalcd）2/∑Xobsd2= 2.76 × 10^-3.
基金supported by the National Natural Science Foundation
文摘The title complex, 2 benzoyl pyridine thiosemicarbazato palladium(II) chloride [C 13 H 11 N 4SPdCl, M r =379.17], crystallizes in monoclinic, space group C2/c with a=12.1061(5), b=21.877(3), c=11.4832(6), β=108.29(9)°, V=2887.7(4) 3, Z = 8, D c =1.827g/cm 3; μ= 1.608cm -1 and F(000)=1568. R =0.0281 and wR =0.0684 for 1446 reflections with I>2σ(I) . X ray crystal structure analysis revealed that the coordination geometry of Pd atom is a distorted square plane with two Pd-N bonds, one Pd-S bond and one Pd-Cl bond. The Schiff base ligand loses a proton from its tautomeric thiol form and coordinates to the Pd atom via the mercapto sulfur and the β nitrogen atoms.
文摘The title compound, [N-(2-pyridylmethyl)-(L)-alanine]Co(III) thiocyanate (1) was obtained from the reaction of Co(OOCH3)2·H2O with the tridentate reduced Schiff base ligand, N-(2-pyridylmethyl)-(L)-alanine (L) and NH4SCN and characterized by elemental analysis, IR, UV-visible, TGA and single- crystal X-ray diffraction. Structural and spectroscopic analyses reveal [Co(L)2)]SCN to be monomeric with Cobalt(III) adopting a pseudo-octahedral geometry, coordinating to two reduce Schiff base ligands. In the crystal lattice, the thiocyanate anion forms an intermolecular SCN···HNamine hydrogen bond, while adjacent monomers are linked by intermolecular Ocarboxyl···HNamine···H-bonds to form a supramolecular network. This work is therefore undertaken in an attempt to construct coordination framework structures of varying properties using the mixed-ligand strategy involving reduced Schiff bases and the thiocyanate ion.
