Kinetic studies on the electron transfer(ET) reaction of [Co(NH3)5(ImH)]3+/[Fe(CN)6]4- and trans-[Co(NH3)(en)2(ImH)]3+/[Fe(CN)6]4- have been carried out at various temperatures. The results indicated that these two ET...Kinetic studies on the electron transfer(ET) reaction of [Co(NH3)5(ImH)]3+/[Fe(CN)6]4- and trans-[Co(NH3)(en)2(ImH)]3+/[Fe(CN)6]4- have been carried out at various temperatures. The results indicated that these two ET reactions followed the outersphere mechanism. At 25℃,I=0.50mol’L-1, the ion pair formation constants Qip ofthe prectirsor complexes in the ET reactions are 2.6×102 and 4.9 × 1O2mol’L-1 ,and theelectron transfer rate constants kct are 2.1 ×10-4 and 5.2 ×10-5s-1 respectively. The activation enthalpy and the activation entropy of these two processes are 1.2×1O2,0.8 ×102kJ ’mol -1 and 5. 1×102, 3.6 ×102J·mol-1 ·K-1 respectively.展开更多
Roseiflexus castenholzii is a gram-negativefilamentous phototrophic bacterium that carries out anoxygenic photosynthesis through a cyclic electron transport chain(ETC).The ETC is composed of a reaction center(RC)–lig...Roseiflexus castenholzii is a gram-negativefilamentous phototrophic bacterium that carries out anoxygenic photosynthesis through a cyclic electron transport chain(ETC).The ETC is composed of a reaction center(RC)–light-harvesting(LH)complex(rcRC–LH);an alternative complex III(rcACIII),which functionally re-places the cytochrome bc1/b6f complex;and the periplasmic electron acceptor auracyanin(rcAc).Although compositionally and structurally different from the bc1/b6f complex,rcACIII plays similar essential roles in oxidizing menaquinol and transferring electrons to the rcAc.However,rcACIII-mediated electron transfer(which includes both an intraprotein route and a downstream route)has not been clearly elucidated,nor have the details of cyclic ETC.Here,we identify a previously unknown monoheme cytochrome c(cyt c551)as a novel periplasmic electron acceptor of rcACIII.It reduces the light-excited rcRC–LH to complete a cyclic ETC.We also reveal the molecular mechanisms involved in the ETC using electron paramagnetic resonance(EPR),spectroelectrochemistry,and enzymatic and structural analyses.Wefind that electrons released from rcACIII-oxidized menaquinol are transferred to two alternative periplasmic electron acceptors(rcAc and cyt c551),which eventually reduce the rcRC to form the complete cyclic ETC.This work serves as a foundation for further studies of ACIII-mediated electron transfer in anoxygenic photosynthesis and broadens our under-standing of the diversity and molecular evolution of prokaryotic ETCs.展开更多
High response organic ultraviolet photodetectors（UV-PDs） were demonstrated with 4,4＇,4”- tris[3-methyl-pheny（phenyl）amino]triphenylamine（m-MTDATA） and two Re（Ⅰ） complexes, （bathocuproine）- Re（CO）3CI（Re...High response organic ultraviolet photodetectors（UV-PDs） were demonstrated with 4,4＇,4”- tris[3-methyl-pheny（phenyl）amino]triphenylamine（m-MTDATA） and two Re（Ⅰ） complexes, （bathocuproine）- Re（CO）3CI（Re-BCP） and （bathophenanthroline）Re（CO）3Cl（Re-Bphen） to act as the electron donor and acceptor, re- spectively. UV-PDs have the configuration of indium tin oxide（ITO）/m-MTDATA（25 nm）/m-MTDATA：Re-complex （25-35 nm）/Re-complex（20 nm）/LiF（l nm）/Al（200 nm） with different blend layer thicknesses of 25, 30 and 35 nm. The optimized PD based on Re-Bphen offers a corrected-dark photocurrent up to 760μA/cm^2 at -10 V, corresponding to a response of 310 mA/W which is among the best values reported for organic UV-PDs. Excellent electron transport ability makes for such high photo-to-electron conversion.展开更多
以N-乙基-3-吲哚三氟甲基β-二酮(EIFD)为主配体,分别以乙二醇单甲醚(EM)、乙二醇二甲醚(EDM)、二缩三乙二醇(TEG)为辅助配体,与DyCl3·6H2O反应合成了一系列Dy(Ⅲ)配合物[Dy(EIFD)3(EM)]·CH2Cl2(1)、[Dy(EIFD)3(EDM)]·CH...以N-乙基-3-吲哚三氟甲基β-二酮(EIFD)为主配体,分别以乙二醇单甲醚(EM)、乙二醇二甲醚(EDM)、二缩三乙二醇(TEG)为辅助配体,与DyCl3·6H2O反应合成了一系列Dy(Ⅲ)配合物[Dy(EIFD)3(EM)]·CH2Cl2(1)、[Dy(EIFD)3(EDM)]·CH2Cl2(2)和[Dy(EIFD)3(TEG)](3)。X射线单晶衍射分析表明,3个配合物都是八配位的单核结构,配位构型分别为双帽三棱柱、正十二面体和双帽三棱柱,分别具有C2v、D2d和C2v对称性。磁学性质显示了配合物1~3具有慢弛豫现象,能垒分别为95.1 K (1)、40.5 K (2)、53.8和13.4 K (3),且配合物1和3有明显的蝴蝶状磁滞回线。进一步讨论了配合物中Dy-O键长和含氧辅助配体的电子效应对配合物有效翻转能垒的影响。展开更多
文摘Kinetic studies on the electron transfer(ET) reaction of [Co(NH3)5(ImH)]3+/[Fe(CN)6]4- and trans-[Co(NH3)(en)2(ImH)]3+/[Fe(CN)6]4- have been carried out at various temperatures. The results indicated that these two ET reactions followed the outersphere mechanism. At 25℃,I=0.50mol’L-1, the ion pair formation constants Qip ofthe prectirsor complexes in the ET reactions are 2.6×102 and 4.9 × 1O2mol’L-1 ,and theelectron transfer rate constants kct are 2.1 ×10-4 and 5.2 ×10-5s-1 respectively. The activation enthalpy and the activation entropy of these two processes are 1.2×1O2,0.8 ×102kJ ’mol -1 and 5. 1×102, 3.6 ×102J·mol-1 ·K-1 respectively.
基金supported by grants from the National Natural Science Foundation of China (32171227,31870740,and 31570738 to X.X.,21825703 and 21927814 to C.T.)the National Key Research and Development Project of China (2019YFA0405600 and 2019YFA0706900 to C.T.)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB37040000)to C.T.,the Youth Innovation Promotion Association CAS (2022455)to L.Y.,the Zhejiang Provincial Natural Science Foundation of China under grant LR22C020002 to X.X.
文摘Roseiflexus castenholzii is a gram-negativefilamentous phototrophic bacterium that carries out anoxygenic photosynthesis through a cyclic electron transport chain(ETC).The ETC is composed of a reaction center(RC)–light-harvesting(LH)complex(rcRC–LH);an alternative complex III(rcACIII),which functionally re-places the cytochrome bc1/b6f complex;and the periplasmic electron acceptor auracyanin(rcAc).Although compositionally and structurally different from the bc1/b6f complex,rcACIII plays similar essential roles in oxidizing menaquinol and transferring electrons to the rcAc.However,rcACIII-mediated electron transfer(which includes both an intraprotein route and a downstream route)has not been clearly elucidated,nor have the details of cyclic ETC.Here,we identify a previously unknown monoheme cytochrome c(cyt c551)as a novel periplasmic electron acceptor of rcACIII.It reduces the light-excited rcRC–LH to complete a cyclic ETC.We also reveal the molecular mechanisms involved in the ETC using electron paramagnetic resonance(EPR),spectroelectrochemistry,and enzymatic and structural analyses.Wefind that electrons released from rcACIII-oxidized menaquinol are transferred to two alternative periplasmic electron acceptors(rcAc and cyt c551),which eventually reduce the rcRC to form the complete cyclic ETC.This work serves as a foundation for further studies of ACIII-mediated electron transfer in anoxygenic photosynthesis and broadens our under-standing of the diversity and molecular evolution of prokaryotic ETCs.
基金Supported by the National Natural Science Foundation of China(No.60978059)the Program for New Century Excellent Talents in Universities of China(No.NCET-10-0176)+1 种基金the Key Project of Ministry of Education of China(No.210053)the Natural Science Foundation of Jilin Province,China(Nos.20101543 and 20100549)
文摘High response organic ultraviolet photodetectors（UV-PDs） were demonstrated with 4,4＇,4”- tris[3-methyl-pheny（phenyl）amino]triphenylamine（m-MTDATA） and two Re（Ⅰ） complexes, （bathocuproine）- Re（CO）3CI（Re-BCP） and （bathophenanthroline）Re（CO）3Cl（Re-Bphen） to act as the electron donor and acceptor, re- spectively. UV-PDs have the configuration of indium tin oxide（ITO）/m-MTDATA（25 nm）/m-MTDATA：Re-complex （25-35 nm）/Re-complex（20 nm）/LiF（l nm）/Al（200 nm） with different blend layer thicknesses of 25, 30 and 35 nm. The optimized PD based on Re-Bphen offers a corrected-dark photocurrent up to 760μA/cm^2 at -10 V, corresponding to a response of 310 mA/W which is among the best values reported for organic UV-PDs. Excellent electron transport ability makes for such high photo-to-electron conversion.
文摘以N-乙基-3-吲哚三氟甲基β-二酮(EIFD)为主配体,分别以乙二醇单甲醚(EM)、乙二醇二甲醚(EDM)、二缩三乙二醇(TEG)为辅助配体,与DyCl3·6H2O反应合成了一系列Dy(Ⅲ)配合物[Dy(EIFD)3(EM)]·CH2Cl2(1)、[Dy(EIFD)3(EDM)]·CH2Cl2(2)和[Dy(EIFD)3(TEG)](3)。X射线单晶衍射分析表明,3个配合物都是八配位的单核结构,配位构型分别为双帽三棱柱、正十二面体和双帽三棱柱,分别具有C2v、D2d和C2v对称性。磁学性质显示了配合物1~3具有慢弛豫现象,能垒分别为95.1 K (1)、40.5 K (2)、53.8和13.4 K (3),且配合物1和3有明显的蝴蝶状磁滞回线。进一步讨论了配合物中Dy-O键长和含氧辅助配体的电子效应对配合物有效翻转能垒的影响。
