Luminescent rare earth complexes based on interconfigurational 5d-4f transition have characteristics of adjustable emission spectra and short excited state lifetimes,showing potential applications in display,lighting ...Luminescent rare earth complexes based on interconfigurational 5d-4f transition have characteristics of adjustable emission spectra and short excited state lifetimes,showing potential applications in display,lighting and other fields.In this work,nine Ce^(3+),Eu^(2+)and Yb^(2+)complexes with spiro-bis(pyrazolyl)borate ligands,where pyrazolyl stands for pyrazolyl,3-methylpyrazolyl,or 3,5-dimethylpyrazolyl,were designed and synthesized.Ce^(3+)complexes show emission colors of blue,with photoluminescence quantum yields(PLQYs)of 94%-100%;Eu^(2+)complexes show emission colors of yellow-green,with PLQYs of 60%-78%;Yb^(2+)complexes show emission colors of orange or red,with PLQYs of 3%-4%.In addition,the crystal structures and theoretical calculation results show C-H…M interactions between bridge-head H atoms of the spirane and central metal ions in these complexes.It is found that the introduction of spirane with large steric hindrance and the existence of C-H…M interactions can improve the stability of the complexes in air atmosphere.展开更多
Two novel copper complexes (<strong>1,2</strong>) with N,O-donor ligands were synthesized by reaction of copper(II) malonates with 3,3’-bis(pyrazolyl)pentane and 4,4’-trimethylenedipyridine in methanol a...Two novel copper complexes (<strong>1,2</strong>) with N,O-donor ligands were synthesized by reaction of copper(II) malonates with 3,3’-bis(pyrazolyl)pentane and 4,4’-trimethylenedipyridine in methanol at moderate temperature. These compounds were characterized by elemental analysis, UV-VIS, IR spectroscopies and powder X-ray diffraction analyses. Compound (<strong>1</strong>) melts at higher temperature (202°C) than compound (<strong>2</strong>) (100<span style="white-space:normal;">°</span>C). The IR spectra showed typical vibrations related to C=N and C=C, characteristic of pyrazolyl and pyridine ligands.展开更多
Luminescent rare earth Eu(II)complexes with a characteristic 5d–4f transition have shown potential in various applications.However,the exploration and further application of typical Eu(II)complexes are strongly imped...Luminescent rare earth Eu(II)complexes with a characteristic 5d–4f transition have shown potential in various applications.However,the exploration and further application of typical Eu(II)complexes are strongly impeded by their instability arising from the easily oxidation of Eu^(2+)ions.In this work,three new Eu(II)complexes bis(hydro-tris(3-phenyl-5-methylpyrazolyl)borate)europium(II)(Eu(Tp^(Ph,Me))_(2)),bis(hydro-tris(3-phenylpyrazolyl)borate)europium(II)(Eu(Tp^(Ph))_(2)),and bis(hydro-tris(3,5-diphenylpyrazolyl)borate)europium(II)(Eu(Tp^(Ph2))_(2))were designed and synthesized.Their crystal structures,photophysical properties and air stabilities were characterized and discussed.It is found that the introduction of the bulky phenyl group not only increases the air stability by sterically hindering the central Eu^(2+)ions,but also tunes the maximum emission wavelength by influencing the ligand field.This work provides rules for regulating the luminescence properties of Eu(II)complexes as well as design basis for achieving stable and efficient Eu(II)complexes.展开更多
p38α mitogen activated protein kinase(MAPK) inhibitors provide a novel approach for the treatment of inflammatory disorders.A series of fifteen pyrazolyl urea derivatives(3a-o) were synthesized and evaluated for thei...p38α mitogen activated protein kinase(MAPK) inhibitors provide a novel approach for the treatment of inflammatory disorders.A series of fifteen pyrazolyl urea derivatives(3a-o) were synthesized and evaluated for their p38α MAPK inhibition and antioxidant potential.Compounds 3a-e,3g and 3h showed low micromolar range potency(IC_(50) values ranging from 0.037 ±1.56 to 0.069± 0.07μmol/L)compared to the standard inhibitor SB 203580(IC_(50) = 0.043 + 3.62μmol/L) when evaluated for p38αMAPK inhibition by an immunosorbent-based assay.Antioxidant activity was measured by a 2,2'-diphenyl-1-picryl hydrazyl radical(DPPH) free radical scavenging method and one of the compounds,3c,showed better percentage antioxidant activity(75.06%) compared to butylated hydroxy anisole(71.53%)at 1 mmol/L concentration.Compounds 3a-e,3g and 3h showed promising in vivo anti-inflammatory activity(ranging from 62.25%to 80.93%) in comparison to diclofenac sodium(81.62%).The ulcerogenic liability and lipid peroxidation activity of these compounds were observed to be less in comparison to diclofenac sodium.These compounds also potently inhibited the lipopolysaccharide(LPS)-induced TNF-αrelease in mice(ID_(50) of 3a-c = 19.98,11.32 and 9.67 mg/kg,respectively).Among the screened compounds,derivative 3c was found to be the most potent and its binding mode within the p38α MAPK is also reported.展开更多
Two novel oxo-vanadium complexes of VO(HB(pz)3)(pzH)(SCN) (1) and VO(HB(3,5-Me2pz)3) (3,5-Me2pzH)(SCN)(SCNH)2 (2) with tris(pyrazolyl) hydroborate ligands were prepared by the reaction of VOSO4?nH2O, KSCN with Na(HB(p...Two novel oxo-vanadium complexes of VO(HB(pz)3)(pzH)(SCN) (1) and VO(HB(3,5-Me2pz)3) (3,5-Me2pzH)(SCN)(SCNH)2 (2) with tris(pyrazolyl) hydroborate ligands were prepared by the reaction of VOSO4?nH2O, KSCN with Na(HB(pz)3), pyrazole, or Na(HB(3,5-Me2pz)3) and methyl-substituted pyrazole in the solution of MeOH, respectively. The complexes were characterized by element analysis, IR, and UV- vis spectra. In the mean time, the fluorescence spec-trum was studied too, and the result indicates that the luminescence of the complexes is related to the in-teraction between oxovanadium ion and tris(pyra- zolyl) hydroborate ligands. In addition, structures of oxovanadium complexes 1 and 2 were determined by X-ray diffraction. The electronic structures and the bonding characters of the two complexes were ana-lyzed with ab initio calculations.展开更多
基金Project supported by the National Key R&D Program of China(2021YFB3500400,2021YFB3501800,2022YFB3503700,2023YFB3506901)the National Natural Science Foundation of China(22071003,92156016,62104013)。
文摘Luminescent rare earth complexes based on interconfigurational 5d-4f transition have characteristics of adjustable emission spectra and short excited state lifetimes,showing potential applications in display,lighting and other fields.In this work,nine Ce^(3+),Eu^(2+)and Yb^(2+)complexes with spiro-bis(pyrazolyl)borate ligands,where pyrazolyl stands for pyrazolyl,3-methylpyrazolyl,or 3,5-dimethylpyrazolyl,were designed and synthesized.Ce^(3+)complexes show emission colors of blue,with photoluminescence quantum yields(PLQYs)of 94%-100%;Eu^(2+)complexes show emission colors of yellow-green,with PLQYs of 60%-78%;Yb^(2+)complexes show emission colors of orange or red,with PLQYs of 3%-4%.In addition,the crystal structures and theoretical calculation results show C-H…M interactions between bridge-head H atoms of the spirane and central metal ions in these complexes.It is found that the introduction of spirane with large steric hindrance and the existence of C-H…M interactions can improve the stability of the complexes in air atmosphere.
文摘Two novel copper complexes (<strong>1,2</strong>) with N,O-donor ligands were synthesized by reaction of copper(II) malonates with 3,3’-bis(pyrazolyl)pentane and 4,4’-trimethylenedipyridine in methanol at moderate temperature. These compounds were characterized by elemental analysis, UV-VIS, IR spectroscopies and powder X-ray diffraction analyses. Compound (<strong>1</strong>) melts at higher temperature (202°C) than compound (<strong>2</strong>) (100<span style="white-space:normal;">°</span>C). The IR spectra showed typical vibrations related to C=N and C=C, characteristic of pyrazolyl and pyridine ligands.
基金support from the National Key R&D Program of China(2017YFA0205100,2016YFB0401001)the Beijing Natural Science Foundation(2202015).
文摘Luminescent rare earth Eu(II)complexes with a characteristic 5d–4f transition have shown potential in various applications.However,the exploration and further application of typical Eu(II)complexes are strongly impeded by their instability arising from the easily oxidation of Eu^(2+)ions.In this work,three new Eu(II)complexes bis(hydro-tris(3-phenyl-5-methylpyrazolyl)borate)europium(II)(Eu(Tp^(Ph,Me))_(2)),bis(hydro-tris(3-phenylpyrazolyl)borate)europium(II)(Eu(Tp^(Ph))_(2)),and bis(hydro-tris(3,5-diphenylpyrazolyl)borate)europium(II)(Eu(Tp^(Ph2))_(2))were designed and synthesized.Their crystal structures,photophysical properties and air stabilities were characterized and discussed.It is found that the introduction of the bulky phenyl group not only increases the air stability by sterically hindering the central Eu^(2+)ions,but also tunes the maximum emission wavelength by influencing the ligand field.This work provides rules for regulating the luminescence properties of Eu(II)complexes as well as design basis for achieving stable and efficient Eu(II)complexes.
基金Department of Science and Technology,Women Scientists Scheme-A(File No.SR/WOS-A/CS-84/2013),New Delhi,for providing financial assistance
文摘p38α mitogen activated protein kinase(MAPK) inhibitors provide a novel approach for the treatment of inflammatory disorders.A series of fifteen pyrazolyl urea derivatives(3a-o) were synthesized and evaluated for their p38α MAPK inhibition and antioxidant potential.Compounds 3a-e,3g and 3h showed low micromolar range potency(IC_(50) values ranging from 0.037 ±1.56 to 0.069± 0.07μmol/L)compared to the standard inhibitor SB 203580(IC_(50) = 0.043 + 3.62μmol/L) when evaluated for p38αMAPK inhibition by an immunosorbent-based assay.Antioxidant activity was measured by a 2,2'-diphenyl-1-picryl hydrazyl radical(DPPH) free radical scavenging method and one of the compounds,3c,showed better percentage antioxidant activity(75.06%) compared to butylated hydroxy anisole(71.53%)at 1 mmol/L concentration.Compounds 3a-e,3g and 3h showed promising in vivo anti-inflammatory activity(ranging from 62.25%to 80.93%) in comparison to diclofenac sodium(81.62%).The ulcerogenic liability and lipid peroxidation activity of these compounds were observed to be less in comparison to diclofenac sodium.These compounds also potently inhibited the lipopolysaccharide(LPS)-induced TNF-αrelease in mice(ID_(50) of 3a-c = 19.98,11.32 and 9.67 mg/kg,respectively).Among the screened compounds,derivative 3c was found to be the most potent and its binding mode within the p38α MAPK is also reported.
文摘Two novel oxo-vanadium complexes of VO(HB(pz)3)(pzH)(SCN) (1) and VO(HB(3,5-Me2pz)3) (3,5-Me2pzH)(SCN)(SCNH)2 (2) with tris(pyrazolyl) hydroborate ligands were prepared by the reaction of VOSO4?nH2O, KSCN with Na(HB(pz)3), pyrazole, or Na(HB(3,5-Me2pz)3) and methyl-substituted pyrazole in the solution of MeOH, respectively. The complexes were characterized by element analysis, IR, and UV- vis spectra. In the mean time, the fluorescence spec-trum was studied too, and the result indicates that the luminescence of the complexes is related to the in-teraction between oxovanadium ion and tris(pyra- zolyl) hydroborate ligands. In addition, structures of oxovanadium complexes 1 and 2 were determined by X-ray diffraction. The electronic structures and the bonding characters of the two complexes were ana-lyzed with ab initio calculations.
