|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Thermodynamic characterization of two novel spin-crossover complexes显示文摘Two novel FeII spin crossover complexes [Fe(L1)3](BF4)25H2O (1) and [Fe(L2)3](BF4)2·2H2O (2) with 4-NHR-1,2,4-triazole (R = isopropyl, L1; cyclohexyl, L2) were synthesized. 1 and 2 remain white at room temperature, whereas they turn purple at liquid temperature. Variable temperature optical detection and magnetic susceptibilities measurement show that the spin-crossover phenomenon for 1 was observed between 120 K and 170 K. The hysteresis loop is about 10 K. The Tc temperature of 2 is 190 K, but no thermal hysteresis loop was found. The molar thermodynamic functions and the microscopic parameters were obtained from the theoretical analysis in terms of the domain model, two level Ising model and regular solution model, respectively. | DING Bin, WANG Hongmei, YI Long, CHENG Peng, LI Licun, ZHAI Yuping, LIAO Daizheng, YAN Shiping & JIANG Zonghui Department of Chemistry, Nankai University, Tianjin 300071, China Correspondence should be addressed to Cheng Peng or Liao Daizheng (e-mail: pcheng@nankai.edu.cn) | 2003 | Chinese Science Bulletin2003，48，22： | 3 |
| 2 | One-dimensional lanthanide complexes bridged by nitronyl nitroxide radical ligands with non-chelating nitrogen donors: Structure and magnetic characterization显示文摘A series of new lanthanide-radical complexes [{Ln(hfac)3}2(NITPhIM)2] (Ln = Nd (1), Eu (2), Tb (3), Er (4); hfac = hexafluoroacetylacetonate; NITPhIM = 2-[4-(1-imidazole)phenyl]-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) have been prepared and characterized. Single crystal X-ray diffraction analyses reveal that these complexes are isostructural with one-dimensional chain structures. These consist in Ln(hfac)3 units bridged by the paramagnetic ligands by the means of coordination of their nitronyl nitroxide groups and imidazole rings. Interestingly, each Ln ion is either bound to two nitronyl nitroxide groups or to two imidazole units, and the different Ln centers alternate along the chain. Magnetic studies show that complex 3 exhibits a single-chain magnet behavior. | LIU RuiNa HU Peng LI LiCun LIAO DaiZheng SUTTER Jean-Pascal | 2012 | Science China Chemistry2012，55，6： | 0 |
| 3 | Effect of mutations on acetohydroxyacid synthase(AHAS)function in Cyperus difformis L.显示文摘Cyperus difformis L.is a troublesome weed in paddy fields and has attracted attention due to its resistance to acetohydroxyacid synthase(AHAS)inhibitors.It was found that the amino acid mutation in AHAS was the primary cause for the resistance of Cyperus difformis.However,the effect of different mutations on AHAS function is not clear in Cyperus difformis.To confirm the effect of mutations on AHAS function,six biotypes were collected,including Pro197Arg,Pro197Ser,Pro197Leu,Asp376Glu,Trp574Leu and wild type,from Hunan,Anhui,Jiangxi and Jiangsu provinces,China and the function of AHAS was characterized.The AHAS in vitro inhibition assay results indicated that the mutations decreased the sensitivity of AHAS to pyrazosulfuron-ethyl,in which the I_(50)(the half maximal inhibitory concentration)of wild type AHAS was 0.04μmol L^(-1)and Asp376Glu,Pro197Leu,Pro197Arg,Pro197Ser and Trp574Leu mutations were 3.98,11.50,40.38,38.19 and 311.43μmol L^(-1),respectively.In the determination of enzyme kinetics parameters,the Km and the maximum reaction velocity(Vmax)of the wild type were 5.18 mmol L^(-1)and 0.12 nmol mg^(-1)min^(-1),respectively,and the Km values of AHAS with Asp376Glu,Trp574Leu,Pro197Leu and Pro197Ser mutations were 0.38-0.93 times of the wild type.The Km value of the Pro197Arg mutation was 1.14times of the wild type,and the Vmax values of the five mutations were 1.17-3.33-fold compared to the wild type.It was found that the mutations increased the affinity of AHAS to the substrate,except for the Pro197Arg mutation.At a concentration of 0.0032-100 mmol L^(-1)branched-chain amino acids(BCAAs),the sensitivity of the other four mutant AHAS biotypes to feedback inhibition decreased,except for the Pro197Arg mutation.This study elucidated the effect of different mutations on AHAS function in Cyperus difformis and provided ideas for further study of resistance development. | Xiaotong Guo Xiangju Li Zheng Li Licun Peng Jingchao Chen Haiyan Yu Hailan Cui | 2024 | Journal of Integrative Agriculture2024，23，1： | 0 |
您所在的机构暂未开通此部分的功能，请联系管理员