检索结果-南通市图书馆

Steric hindrance effect of Schiff-base ligands on magnetic relaxation dynamics and emissive behavior of two dinuclear dysprosium complexes

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2023年第7期41卷 1049-1057,I0003页

作者： Youdong Jiang Sourav Dey Hongshan Ke Yongsheng Yang Lin Sun Gang Xie Sanping Chen Gopalan Rajaraman Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education College of Chemistry and Materials ScienceNorthwest UniversityXi'an 710127China Department of Chemistry Indian Institute of Technology BombayPowaiMumbai400076India State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China Henan Key Laboratory of Polyoxometalate Chemistry Institute of Molecular and Crystal EngineeringCollege of Chemistry and Chemical EngineeringHenan UniversityKaifeng 475004China

The self-assembly reactions between mixed-ligand and tetrahydrate dysprosium acetate in the presence of mixed organic solvents lead to two structural similar dinuclear dysprosium complexes with composition formulas of Dy_(2)(L_1)_(2)(L_(2))_(2)(CH_(3)OH)_(2)·CH_(2)Cl_(2)·CH_(3)OH(1) and Dy_(2)(L_1)_(2)(L_(3))_(2)(CH_(3)OH)_(2)·CH_(3)CN(2),where L_1,L_(2) and L_(3) represent the deprotonated form of 4-tert-butyl-2-(7-methoxybenzo[d]oxazol-2-yl)phenol,(E)-1-(((3,5-di-tert-butyI-2-hydroxyphenyI)imino)methyl)naphthalen-2-ol and(E)-2,4-di-tertbutyl-6-((2-hydroxybenzylidene)amino)*** tiny difference of the core structure of 1 and 2 is derived from the steric hindrance of Schiff base ligands L_(2) and L_(3).Dynamic magnetic measurements reveal that 1 and 2 show frequency-dependent out-of-phase alternating-current susceptibility signal peaks at different temperatures under zero dc field,diagnostic of single-molecule magnet *** experimental derived energy barrier to magnetization reversal for 1 and 2 is 108(1),47(2) and 33(3) *** initio CASSCF calculations performed on 1 and 2 suggest that the origin of the difference in magnetic properties originates from the variation in the single-ion anisotropy that arises due to minor structural ***,the equation to calculate the effective energy barrier for Dy_(2) proposed earlier is found to yield an excellent agreement with the experimental *** state fluorescence measurements performed on 1 and 2 demonstrate that both exhibit two ligands centered components of fluorescent emissive,in addition,with different emitting colors and chromaticity *** discrepancy of fluorescence and single molecule magnet behavior showed by 1 and 2 can be attributed to the steric hindrance effect of Schiff base ligands.

关键词： Fluorescent single-molecule magnets Dinuclear dysprosium complexes mixed ligand Steric hindrance Theoretical calculations Rare earths

Hydrothermal Synthesis and Crystal Structure of Manganese(Ⅱ) Coordination Polymer Assembled by 4-Sulfophthalate and 4,4′-Bipyridine

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2007年第1期23卷 105-108页

作者： WANG Qing-wei LI Xiu-mei GAO Guang gang Department of Chemistry Jilin Normal University Siping 136000 P. R. China Department of Chemistry Tonghua Teachers College Tonghua 134002 P.R. China

The rational design and synthesis of metal-directed supramolecular framework compounds have received much attention in coordination chemistry because of their potential applications in catalysis, molecular selection, nonlinear optics, ion exchange, and microelectronics. Many high-dimensional coordination complexes have been designed and prepared through molecular self-assembly processes. The open metal organic framework can be produced via two kinds of interactions, i. e. , coordinate covalent bonds and weaker intermolecular forces. For this reason, the most efficient means to synthesize these compounds is to establish possible connections among different units.

关键词： Hydrothermal synthesis Crystal structure Supramoleeular network mixed ligand

Polynuclear Lanthanoid Complexes Containing Aluminium—The Structure of[HoAl(CF_3COO)_2(CF_3CHOO)(C_2H_5)_2(C_4H_8O)_2]_2 at 233K

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 1991年第3期9卷 165-168页

作者：林永华金松春金鹰泰李振祥 Changchun Institute of Applied Chemistry Academia SinicaChangchun 130022China

[HoAl(CF_3COO)_2(CF_3CHOO)(C_2H_5)_2(C_4H_8O)_2]_2,Mr=1468.7,monoclinic,P 2_1/n,a=1.0084(4), b=1.8453(6),c=1.4501(6)nm,β=102.40(3)°,V=2.6355(1)nm^3,Z=2,D_c=1.81gcm^(-3),F(000)=1511, T=233K,Mo Kα radiation(λ=0.071069nm).R=0.052 for 6176 unique reflections[Ⅰ≥36(Ⅰ)].The structural units consist of dimeric molecules with the mixed ligand and central bimetallic atoms,which are polynuclear lanthanoid complexes containing ***-Ho'distance is 0.3619(1)*** coordination polyhedron of Ho can be described in terms of a distored bicap-prism.

关键词： Crystal structure Bimetallic mixed ligand Dimeric Polynuclear lanthanoid complex

Crystal Structure of 〔PrAl（CF3COO）2（CF3CHOO）(C2H5)2（C4H8O）2〕2

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 1999年第1期 49-52页

作者： TONG Yue Jin a CHENG Yan Xiang b GUAN Huai Min a LIN Yong Hua c JIN Ying Tai c a (Department of Chemistry, Fujian Normal University, Fuzhou, 350007, China) b (Department of Chemistry, Henan University, Kaifeng, 475001, C

１ＩＮＴＲＯＤＵＣＴＩＯＮＩｎｒｅｃｅｎｔｙｅａｒｓ，ａｓｅｒｉｅｓｏｆｌａｎｔｈａｎｉｄｅａｌｕｍｉｎｉｕｍｃｏｍｐｌｅｘｅｓｗｈｉｃｈａｒｅａｃｔｉｖｅｆｏｒｐｏｌｙｍｅｒｉｚａｔｉｏｎｏｆｏｌｆｉｎｓ〔１〕... 详细信息

１ＩＮＴＲＯＤＵＣＴＩＯＮＩｎｒｅｃｅｎｔｙｅａｒｓ，ａｓｅｒｉｅｓｏｆｌａｎｔｈａｎｉｄｅａｌｕｍｉｎｉｕｍｃｏｍｐｌｅｘｅｓｗｈｉｃｈａｒｅａｃｔｉｖｅｆｏｒｐｏｌｙｍｅｒｉｚａｔｉｏｎｏｆｏｌｆｉｎｓ〔１〕ｈａｖｅｂｅｅｎｒｅｐｏｒｔｅｄ．...

关键词： crystal structure mixed ligand lanthanoid complex aluminium