The reaction of a reactive nickel dimethyl 1 bearing a redox-active,dissymmetric ligand,which is obtained by deprotonation of 2-pyrimidin-2-yl-1H-benzimidazole(Hbimpm)with a divalent lanthanide complex,Cp*_(2)Yb(OEt_(...The reaction of a reactive nickel dimethyl 1 bearing a redox-active,dissymmetric ligand,which is obtained by deprotonation of 2-pyrimidin-2-yl-1H-benzimidazole(Hbimpm)with a divalent lanthanide complex,Cp*_(2)Yb(OEt_(2)),affords an unprecedented,trimeric 2 with C(sp^(3))-C(sp^(3))bond formation between two ligands in an exo position.Meanwhile,the transient,dimeric species 3 can be isolated with the same ligand coupling fashion,however,with a drastic distorsion angle of the bimpm ligand and reactive NiMe2 fragment,revealing the possible mechanism of this rearrangement.A much more stable dimeric conge ner,5,with an exo ligand coupling,is synthesized in the presence of 18-crown-6,which captures the pot assium counter ion.The C-C coupling formation between two bimpm ligands results from the effective electron transfer from divalent lanthanide fragments.Without the divalent lanthanide,the reductive coup ling occurs on a different carbon of the ligand,nicely showing the modulation of the spin density induced by the presence of the lanthanide ion.The electronic structures of these complexes are investigated by magnetic study(SQUID),indicating a 2 F7/2 ground state for each ytterbium in all the heterometallics.This workfirstly reports ligand coupling reactivity in a redox-active,yet dissymmetric system with divalent organolanthanides,and the reactive nickel moiety can impact the intriguing transition towards a stable homoleptic,trinulear lanthanide species.展开更多
通过超高效液相色谱串联四极杆飞行时间质谱技术(UPLC-Q-TOF/MS^(E))对肝豆扶木汤的化学成分进行分析鉴定;采用ZORBAX RRHD Eclipse Plus C_(18)色谱柱(2.1 mm×100 mm,1.8μm),以0.1%甲酸水-乙腈为流动相进行梯度洗脱,流速为0.2 m ...通过超高效液相色谱串联四极杆飞行时间质谱技术(UPLC-Q-TOF/MS^(E))对肝豆扶木汤的化学成分进行分析鉴定;采用ZORBAX RRHD Eclipse Plus C_(18)色谱柱(2.1 mm×100 mm,1.8μm),以0.1%甲酸水-乙腈为流动相进行梯度洗脱,流速为0.2 m L·min^(-1),柱温35℃。质谱分析采用电喷雾电离源(ESI)的方式,在正、负离子模式下,通过UPLC-Q-TOF/MS^(E)分析鉴定肝豆扶木汤的化学成分。共鉴定出102种化合物,其中黄酮类成分26个,萜类成分22个,皂苷类成分19个,苯丙素类成分10个和其他类成分25个。本研究所建立的定性分析方法能快速、高效地对肝豆扶木汤的化学成分进行分析鉴定,为肝豆扶木汤的质量评价和临床应用提供了科学依据。展开更多
以16S r DNA为分子标记,通过构建克隆文库、限制性片段长度多态性(Restriction Fragment Length Polymorphism,RFLP)分析等技术手段,研究大黄鱼(Larimichthys crocea)网箱养殖水体中细菌的群落结构。样品采自福建省宁德市三都湾富发养...以16S r DNA为分子标记,通过构建克隆文库、限制性片段长度多态性(Restriction Fragment Length Polymorphism,RFLP)分析等技术手段,研究大黄鱼(Larimichthys crocea)网箱养殖水体中细菌的群落结构。样品采自福建省宁德市三都湾富发养殖基地。随机选取5个不同养殖网箱水样混合,取3 L混合水样过滤富集细菌后提取总DNA,用细菌通用引物27F和1 492R扩增其16S r RNA基因,构建克隆文库。从文库中随机挑选154个克隆子进行分析,得到137个阳性克隆,92种RFLP带型。对部分代表性克隆子进行测序的结果表明,大黄鱼养殖水体中细菌多样性非常丰富。序列分析结果显示,γ-变形菌纲的假交替单胞菌属(Pseudoalteromonas)细菌为最优势菌(占γ-变形菌纲克隆子数的31.2%),海源菌属(Idiomarina)次之(占γ-变形菌纲克隆子数的15.1%)。此外还存在6.6%的厚壁菌门(Firmicutes)、5.9%的拟杆菌门(Bacteroidetes)、各0.7%的浮霉状菌门(Planctomycetes)、绿屈挠菌门(Chloroflexi)、绿菌门(Chlorobi)细菌和OP11类群。本研究结果阐明了网箱养殖大黄鱼水体细菌的群落结构,为大黄鱼养殖区病害防治、环境监测以及探讨大黄鱼健康养殖与养殖水体细菌间的关系奠定了基础。展开更多
基金the H2020 European Research Council(ERC)under the European Union’Horizon H2020 research program(grant agreement No.716314)CNRS and Ecole Polytechnique are thanked for funding.
文摘The reaction of a reactive nickel dimethyl 1 bearing a redox-active,dissymmetric ligand,which is obtained by deprotonation of 2-pyrimidin-2-yl-1H-benzimidazole(Hbimpm)with a divalent lanthanide complex,Cp*_(2)Yb(OEt_(2)),affords an unprecedented,trimeric 2 with C(sp^(3))-C(sp^(3))bond formation between two ligands in an exo position.Meanwhile,the transient,dimeric species 3 can be isolated with the same ligand coupling fashion,however,with a drastic distorsion angle of the bimpm ligand and reactive NiMe2 fragment,revealing the possible mechanism of this rearrangement.A much more stable dimeric conge ner,5,with an exo ligand coupling,is synthesized in the presence of 18-crown-6,which captures the pot assium counter ion.The C-C coupling formation between two bimpm ligands results from the effective electron transfer from divalent lanthanide fragments.Without the divalent lanthanide,the reductive coup ling occurs on a different carbon of the ligand,nicely showing the modulation of the spin density induced by the presence of the lanthanide ion.The electronic structures of these complexes are investigated by magnetic study(SQUID),indicating a 2 F7/2 ground state for each ytterbium in all the heterometallics.This workfirstly reports ligand coupling reactivity in a redox-active,yet dissymmetric system with divalent organolanthanides,and the reactive nickel moiety can impact the intriguing transition towards a stable homoleptic,trinulear lanthanide species.
文摘通过超高效液相色谱串联四极杆飞行时间质谱技术(UPLC-Q-TOF/MS^(E))对肝豆扶木汤的化学成分进行分析鉴定;采用ZORBAX RRHD Eclipse Plus C_(18)色谱柱(2.1 mm×100 mm,1.8μm),以0.1%甲酸水-乙腈为流动相进行梯度洗脱,流速为0.2 m L·min^(-1),柱温35℃。质谱分析采用电喷雾电离源(ESI)的方式,在正、负离子模式下,通过UPLC-Q-TOF/MS^(E)分析鉴定肝豆扶木汤的化学成分。共鉴定出102种化合物,其中黄酮类成分26个,萜类成分22个,皂苷类成分19个,苯丙素类成分10个和其他类成分25个。本研究所建立的定性分析方法能快速、高效地对肝豆扶木汤的化学成分进行分析鉴定,为肝豆扶木汤的质量评价和临床应用提供了科学依据。
文摘以16S r DNA为分子标记,通过构建克隆文库、限制性片段长度多态性(Restriction Fragment Length Polymorphism,RFLP)分析等技术手段,研究大黄鱼(Larimichthys crocea)网箱养殖水体中细菌的群落结构。样品采自福建省宁德市三都湾富发养殖基地。随机选取5个不同养殖网箱水样混合,取3 L混合水样过滤富集细菌后提取总DNA,用细菌通用引物27F和1 492R扩增其16S r RNA基因,构建克隆文库。从文库中随机挑选154个克隆子进行分析,得到137个阳性克隆,92种RFLP带型。对部分代表性克隆子进行测序的结果表明,大黄鱼养殖水体中细菌多样性非常丰富。序列分析结果显示,γ-变形菌纲的假交替单胞菌属(Pseudoalteromonas)细菌为最优势菌(占γ-变形菌纲克隆子数的31.2%),海源菌属(Idiomarina)次之(占γ-变形菌纲克隆子数的15.1%)。此外还存在6.6%的厚壁菌门(Firmicutes)、5.9%的拟杆菌门(Bacteroidetes)、各0.7%的浮霉状菌门(Planctomycetes)、绿屈挠菌门(Chloroflexi)、绿菌门(Chlorobi)细菌和OP11类群。本研究结果阐明了网箱养殖大黄鱼水体细菌的群落结构,为大黄鱼养殖区病害防治、环境监测以及探讨大黄鱼健康养殖与养殖水体细菌间的关系奠定了基础。
