25 results on '"Bo Wen Hu"'
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2. Metal–organic coordination architectures of tetrazole heterocycle ligands bearing acetate groups: Synthesis, characterization and magnetic properties
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Bo-Wen Hu, Xiang-Yu Zheng, and Cheng Ding
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Stereochemistry ,chemistry.chemical_element ,Crystal structure ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,Inorganic Chemistry ,Metal ,chemistry.chemical_compound ,chemistry ,visual_art ,Polymer chemistry ,Materials Chemistry ,Ceramics and Composites ,visual_art.visual_art_medium ,Tetrazole ,Azide ,Physical and Theoretical Chemistry ,Cobalt ,Single crystal ,Topology (chemistry) ,Group 2 organometallic chemistry - Abstract
Two new coordination complexes with tetrazole heterocycle ligands bearing acetate groups, [Co(L)2]n (1) and [Co3(L)4(N3)2·2MeOH]n (2) (L=tetrazole-1-acetate) have been synthesized and structurally characterized. Single crystal structure analysis shows that the cobalt-complex 1 has the 3D 3,6-connected (42.6)2(44.62.88.10)-ant topology. By introducing azide in this system, complex 2 forms the 2D network containing the [Co3] units. And the magnetic properties of 1 and 2 have been studied.
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- 2015
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3. The Influence of Plant Growth Regulators and Light Quality on Somatic Embryogenesis in China Rose (Rosa chinensis Jacq.)
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Xing-Yao Xiong, Rong Liu, Zi-Niu Deng, Bo-Wen Hu, Xing Yi, Ji-Ren Chen, and Lian Wu
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animal structures ,Somatic embryogenesis ,Embryogenesis ,food and beverages ,Plant physiology ,Embryo ,Plant Science ,Biology ,biology.organism_classification ,chemistry.chemical_compound ,chemistry ,Germination ,embryonic structures ,Botany ,Darkness ,Rosa chinensis ,Agronomy and Crop Science ,Abscisic acid - Abstract
We investigated the effect of red light and plant growth regulators on somatic embryogenesis in China Rose (Rosa chinensis Jacq.). Embryogenic calli that had been induced by combinations of 2,4-dichlorophenoxyacetic acid and thidiazuron in darkness were exposed to dark, red, and white light treatments. Cultures subjected to red light treatment generated the greatest number of embryos, with one (SE1 embryos) or two (SE2 embryos) expanded cotyledons. The largest numbers of shoot-like embryos without cotyledons (SE0 embryos) were produced in cultures subjected to dark treatment. The effects of different concentrations of abscisic acid (ABA) on the proliferation and germination of different types of somatic embryos were also evaluated. A concentration of 9.45 μM was found to be the most effective in promoting the proliferation and germination of SE2 embryos. The higher the concentration of ABA (from 0 to 18.90 μM), the higher the percentage of abnormal polycotyledonary embryos produced. The highest percentage of regenerated plants was obtained from SE2 embryos.
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- 2013
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4. Dzyaloshinski–Moriya (D–M) oriented weak ferromagnets in isomorphic coordination architectures constructed by flexible 1,2,4-triazole-1-acetate ligands with the assistance of halogen or pseudohalogen anions
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Qian Yang, Fu-Chen Liu, Jiong-Peng Zhao, and Bo-Wen Hu
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Binodal ,Stereochemistry ,Metal ions in aqueous solution ,1,2,4-Triazole ,Inorganic Chemistry ,Crystallography ,chemistry.chemical_compound ,chemistry ,Pseudohalogen ,Halogen ,Materials Chemistry ,Antiferromagnetism ,Physical and Theoretical Chemistry ,Single crystal ,Spin canting - Abstract
Three isomorphic coordination complexes constructed by flexible 1,2,4-triazole-1-acetate with the assistance of halogen or pseudohalogen anions, and [Mn( L )Cl] n ( 1 ), [Co( L )(N 3 )] n ( 2 ) and [Ni( L )(N 3 )] n ( 3 ) ( L = 1,2,4-triazole-1-acetate) have been synthesized and structurally characterized. It is interesting that the linkages of the halogen anions in 1 are the same as those of the pseudohalogen anions in 2 and 3 . Single crystal structure analysis indicated a novel 4,6-connected binodal net with Schlafli {3;4 2 ;5 3 }{3 2 ;4 3 ;5 5 ;6 3 ;7 2 } was formed in these complexes. Dominating antiferromagnetic interactions between the metal ions were detected in these complexes, furthermore evident spin canting presented in 1 and 3 for Dzyaloshinski–Moriya (D–M) interactions.
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- 2013
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5. Tuning the Subunits and Topologies in Cluster-Based Cobalt–Organic Frameworks by Varying the Reaction Conditions
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Wei-Chao Song, Jiong-Peng Zhao, Bo-Wen Hu, Xian-He Bu, Qian Yang, and Ran Zhao
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Reaction conditions ,Acrylate ,biology ,Chemistry ,Stereochemistry ,chemistry.chemical_element ,General Chemistry ,Condensed Matter Physics ,biology.organism_classification ,Ion ,chemistry.chemical_compound ,Cluster (physics) ,Tetra ,General Materials Science ,Formate ,Carboxylate ,Cobalt - Abstract
Different ways of anions introduction were applied to construct cluster-based frameworks, owning to the versatile coordination ability of the formate anion and its sensitivity to the pH value of the reaction system. Three tetra-, penta-, and hexanuclear cluster-based cobalt-organic frameworks, [Co2(L)3(HCO2)·MeOH]n (1), [Co5(L)6(OH)2(NO3)2·2H2O]n (2), and [CoL(HCO2)]n (3) [L = (E)-3-(pyridin-3-yl)acrylate], have been successfully synthesized. In these complexes, each CoII cluster is linked by twelve L ligands with different connectivities to generate unique topological nets. In 1, two formate anions link four CoII ions forming a tetranuclear cluster, and each of the tetranuclear clusters is connected to eight neighbors by L ligands, giving an 8-connected 36418536 net. In 2, the pentanuclear cluster is formed by five CoII ions linked through two OH– and six carboxylate groups, which are further connected by L ligands to afford a pcu (primitive cubic lattice) net. Different from 1 and 2, complex 3 is a 2-fo...
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- 2013
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6. New Manganese(II) Azido Coordination Polymers with Nicotinic/Isonicotinic Acids as Coligands: Synthesis, Structure, and Magnetic Properties
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Qian Yang, Xiao-Feng Zhang, Xian-He Bu, Bo-Wen Hu, and Jiong-Peng Zhao
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chemistry.chemical_classification ,Phase transition ,Stereochemistry ,chemistry.chemical_element ,Manganese ,Polymer ,Isonicotinic acid ,Magnetic susceptibility ,Ion ,Inorganic Chemistry ,Crystallography ,chemistry.chemical_compound ,chemistry ,Antiferromagnetism ,Physical and Theoretical Chemistry ,Spin canting - Abstract
The reactions of Mn(II) ions with azido ligands in the presence of nicotinic/isonicotinic acids gave two manganese(II) azido coordination polymers, [Mn(3)(L(1))(2)(N(3))(4)](n).nH(2)O (1) and [Mn(2)(L(2))(N(3))(3)](n) (2), where L(1) = nicotinate and L(2) = isonicotinate, with different topological structures. Complex 1 consists of 2D azido-Mn(II) planes, which is further linked by L(1) to form a 3D framework with unprecedented 3,6-connected 4-nodal net topology, and complex 2 presents an unprecedented 3,4,6-connected 6-nodal 3D azido-Mn(II) structure with L(2) as the coligand. Magnetic susceptibility measurements reveal dominant antiferromagnetic coupling existing in 1 and 2. Complex 1 is a spin-competitive system and enters into a weak ferromagnetic-to-magnetic phase transition at the critical temperature of 6 K due to spin canting. Complex 2 is an antiferromagnet and exhibits field-induced spin-flop behavior.
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- 2010
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7. Structure and magnetism of carboxylate/EO-azido-mixed-ligands bridged CuII systems
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Fu-Chen Liu, Qian Yang, Jiong-Peng Zhao, Tong-Liang Hu, Xian-He Bu, and Bo-Wen Hu
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Multidisciplinary ,Stereochemistry ,Magnetism ,Supramolecular chemistry ,chemistry.chemical_element ,Copper ,Benzoates ,chemistry.chemical_compound ,Crystallography ,chemistry ,Ferromagnetism ,Carboxylate ,Magnetic study ,Ternary operation - Abstract
Using two structurally related benzoates bearing different H-bond acceptors as co-ligands, three new azido-CuII compounds, [Cu(L1)(N3)(H2O)]n (1), [Cu(L1)(N3)(MeOH)]n (2), and [CuL2HL2(N3)3(H2O)]n (3) (HL1 = 4-nitrobenzoic acid; HL2 = 2-phenyl-4-quinolinecarboxylic acid), have been synthesized and structurally characterized. 1 is a carboxylate/EO-azido bridged copper chain, forming 3D structure by H-bonds, and 2 has a similar chain structure as 1 but forming a 2D structure by H-bonds, while 3 is a 3D supramolecular network with ternary center H-bonds. Magnetic study indicates that domain ferromagnetic coupling interactions were found to exist in complexes 1 and 3.
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- 2009
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8. Metal–organic coordination architectures of azole heterocycle ligands bearing acetic acid groups: Synthesis, structure and magnetic properties
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Wen-Ping Du, Qian Yang, Bo-Wen Hu, Xian-He Bu, Jiong-Peng Zhao, and Tong-Liang Hu
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chemistry.chemical_classification ,Benzimidazole ,Ligand ,Stereochemistry ,Crystal structure ,Condensed Matter Physics ,Medicinal chemistry ,Electronic, Optical and Magnetic Materials ,Inorganic Chemistry ,Metal ,Acetic acid ,chemistry.chemical_compound ,chemistry ,visual_art ,Materials Chemistry ,Ceramics and Composites ,visual_art.visual_art_medium ,Imidazole ,Azole ,Physical and Theoretical Chemistry ,Group 2 organometallic chemistry - Abstract
Four new coordination complexes with azole heterocycle ligands bearing acetic acid groups, [Co(L1)2]n (1), [CuL1N3]n (2), [Cu(L2)2·0.5C2H5OH·H2O]n (3) and [Co(L2)2]n (4) (here, HL1=1H-imidazole-1-yl-acetic acid, HL2=1H-benzimidazole-1-yl-acetic acid) have been synthesized and structurally characterized. Single-crystal structure analysis shows that 3 and 4 are 2D complexes with 44-sql topologies, while another 2D complex 1 has a (43)2(46)-kgd topology. And 2 is a 3D complex composed dinuclear μ1,1-bridging azido CuII entities with distorted rutile topology. The magnetic properties of 1 and 2 have been studied.
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- 2009
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9. Synthesis, structure and magnetic properties of two new coordination polymers with carboxylate-substituted benzoimidazole ligands
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Qian Yang, Xiao-Feng Zhang, Bo-Wen Hu, Xian-He Bu, and Jiong-Peng Zhao
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chemistry.chemical_classification ,Crystallography ,chemistry.chemical_compound ,chemistry ,Stereochemistry ,Antiferromagnetism ,Formate ,General Chemistry ,Carboxylate ,Polymer ,Spin (physics) ,Antiferromagnetic coupling ,Topology (chemistry) - Abstract
This paper reports two new coordination polymers formed by carboxylate-substituted benzoimidazole and formate ligands: [Mn(L)·(HCO2)] n (1) and [Co(L)·(HCO2)] n (2) (L = benzoimidazol-1-yl-acetate). Complexes 1 and 2 are isomorphous and adopt a new 3,6-connected three-nodal topology showing interesting magnetic properties: spin canted antiferromagnetism for MnII complex 1, but simple antiferromagnetic coupling for CoII complex 2.
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- 2009
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10. Partial Substitution of Hydroxyl by Azide: An Unprecedented 2D Azido-Copper-Hydroxyl Compound with a [Cu24] Macrocycle in the Presence of [Cu(H2O)6]2+
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E. Carolina Sañudo, Xian-He Bu, Bo-Wen Hu, Fu-Chen Liu, Yong-Fei Zeng, Xin Hu, and Jiong-Peng Zhao
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chemistry.chemical_classification ,Coordination sphere ,Chemistry ,Ligand ,Organic Chemistry ,General Chemistry ,Crystal structure ,Photochemistry ,Catalysis ,Phthalic acid ,chemistry.chemical_compound ,Crystallography ,Magnetochemistry ,Hydroxide ,Azide ,Counterion - Abstract
The investigation of magnetic materials with fascinating structures and unusual magnetic behavior has witnessed flourishing development. Transition-metal hydroxides are of particular significance because of their potential application in magnetic devices (as substitutes for traditional ferrite or nanometric magnetic memory units), and have been extensively explored. Even so, it is still a tremendous challenge for researchers to rationally design, precisely control, artfully modulate, and effectively re-assemble new transition-metal/hydroxide species (hydroxide-bridged clusters, chains, and layers). In the hydroxyl inorganic layers (such as Cu(OH)2, FeO(OH), Mg(OH)2, etc.), the hydroxide groups are present in m2 and m3 modes. To replace some of the hydroxide ligands with other bridging groups in order to alter the magnetic properties is still a challenge to chemists today. As we know, azide is one of the most studied ligands in magnetochemistry, and its complexes display exciting magnetic properties ranging from long-range ordering to SMM (single-molecule magnet) and SCM (single-chain magnet) behavior. Additionally, the magnetic interaction through an azide bridge can be easily predicted based on its bridging mode and the M-N-M angles. The most typical bridging modes are end-to-end (EE, m2-1,3) and end-on (EO, m2-1,1), usually resulting in antiferromagnetic and ferromagnetic coupling, respectively, but this greatly depends on the Cu-N-Cu angle for end-on azides. Azides can also bridge more than two ions in their EO mode; for instance, it can bridge three metal ions in a pyramidal fashion analogous to that of a m3-OH group. In view of azides being able to take both m2-1,1 and m3-1,1,1 bridging modes, it may replace some OH positions in the 2D inorganic layer, which could lead to different magnetic behavior. To avoid the inorganic layer collapsing or aggregating into a 3D solid, a second ligand is usually introduced into the system. Herein, phthalic acid (H2-pta) is our second ligand of choice. A Cu / N3 /OH /pta network could have a high negative charge and counterion will then be needed. Herein we report the synthesis of an unusual 2D N3-Cu -OH complex, [CuACHTUNGTRENNUNG(H2O)6]ACHTUNGTRENNUNG[{Cu2(N3)4/3-(OH) ACHTUNGTRENNUNG(pta)}6] (1). Indeed, our results show that the [Cu ACHTUNGTRENNUNG(H2O)6] 2+ complex ion from the CuACHTUNGTRENNUNG(NO3)2 aqueous solution may serve as a template for the [Cu24] macrocycles. The crystal structure of complex 1 (Figure 1) consists of a new anionic 2D layer network containing two Cu ions, one phthalic anion (in m4-O,O’,O’’,O’’’ bridging mode), one m3 hydroxyl anion, and =3 azide anions, which take m2-1,1 and m3-1,1,1 bridging modes (Figure S1). As can be seen in Figure 1 (top), Cu1 is five-coordinate with a distorted square-based pyramid CuN2O3 geometry formed by the coordination of two nitrogen atoms, from the m2-1,1and m31,1,1-azide anions (apical position) (Cu1 N1=2.000(5), Cu1 N4=2.287(3) ;), and three oxygen atoms, one from the m3 hydroxyl anion and two from phthalic anions (Cu1 O5=1.969(4), Cu1 O1=1.983(4), Cu1 O4=2.018(4) ;). The square-based pyramidal coordination sphere of Cu2 is CuNO4, in which the N atom is from a m2-1,1 azide anion (Cu2 N1A=1.972(5) ;), and the four oxygen atoms are from two m3 hydroxyl anions and two phthalic anions (one occupied the apical position) (Cu2 O5=1.954(4), Cu2 O5A=1.979(4), Cu2 O2=2.646, Cu2 O3=1.934(4) ;). Two hydroxyl anions in the m3 mode (Cu1-O5-Cu2=100.74, Cu1-O5-Cu2A=118.24, Cu2-O5-Cu2A=100.308) bridge [a] Y.-F. Zeng, X. Hu, J.-P. Zhao, B.-W. Hu, Dr. F.-C. Liu, Prof. X.-H. Bu Department of Chemistry Nankai University Tianjin 300071 (China) Fax: (+86)22-2350-2458 E-mail : buxh@nankai.edu.cn [b] Dr. E. C. SaCudo Departament de QuJmica InorgKnica Universitat de Barcelona Diagonal, 647, Barcelona (Spain) Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/chem.200800068.
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- 2008
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11. Structures with Tunable Strong Ferromagnetic Coupling: from Unordered (1D) to Ordered (Discrete)
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Jordi Ribas-Arino, Jiong-Peng Zhao, Fu-Chen Liu, Xian-He Bu, Joan Ribas, Yong-Fei Zeng, Bo-Wen Hu, and Xin Hu
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Coupling ,Condensed matter physics ,Magnetism ,Organic Chemistry ,chemistry.chemical_element ,General Chemistry ,Crystal structure ,Copper ,Catalysis ,chemistry.chemical_compound ,Ferromagnetism ,chemistry ,Atomic orbital ,Computational chemistry ,Carboxylate ,Spin (physics) - Abstract
The X-ray crystal structures, magnetic susceptibilities from 2 to 300 K, and theoretical analyses of the magnetism for 1D and trinuclear azido Cu(II) carboxylate complexes [Cu(1.5)(hnta)(N(3))(2)(H(2)O)](n) (1) and [Cu(3)(hnta)(4)(N(3))(2)(H(2)O)(3)] (2), respectively, where hnta is 6-hydroxynicotinate, are described. Although both exhibit strong ferromagnetic coupling, discrete complex 2 exhibits long-range ferromagnetic ordering, while the very similar 1D system 1 does not. Density functional calculations provided accurate J values and allowed rationalization of the ferromagnetic coupling in terms of the magnetic orbitals and spin densities.
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- 2007
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12. An unusual 3-D asymmetric mixed valence copper-azido complex with pyrazinecarboxylate as co-ligand showing rare net topology: Hydrothermal synthesis, structure and magnetic properties
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Bo-Wen Hu, Joan Ribas, Fu-Chen Liu, Yong-Fei Zeng, Jiong-Peng Zhao, Xian-He Bu, and Stuart Robert Batten
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Valence (chemistry) ,Coordination polymer ,Ligand ,chemistry.chemical_element ,Crystal structure ,Topology ,Copper ,Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,Hydrothermal synthesis ,Azide ,Point of zero charge ,Physical and Theoretical Chemistry - Abstract
A new 3-D mixed valence copper-azido coordination polymer, [Cu I · Cu II (N 3 )(pzc) 2 (H 2 O)] n 1 , has been synthesized and characterized, and its magnetic properties studied. In this compound, the azide acts as rare asymmetric μ 1,1,3 bridging mode. The azide ligands and the Cu(2) ions act as 3-connecting nodes, and the Cu(1) ions act as 4-connecting nodes. The overall net takes rare topology with the Schlafli symbol of (6.8 2 )(6.8 2 )(6.8 5 ).
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- 2007
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13. 3D MnIIcoordination polymer with alternating azide/azide/formate/formate bridged chains: synthesis, structure and magnetic properties
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Xian-He Bu, Qian Yang, Tong-Liang Hu, Bo-Wen Hu, Xiao-Feng Zhang, and Jiong-Peng Zhao
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Inorganic Chemistry ,chemistry.chemical_compound ,chemistry ,Ligand ,Coordination polymer ,Polymer chemistry ,Antiferromagnetism ,Formate ,Azide ,Carboxylate ,Photochemistry ,Solvothermal reaction - Abstract
A new 3D Mn(II) coordination polymer, [Mn(2)(HCO(2))(L)(2)(N(3)) x MeOH](infinity) (1) (L = nicotinate N-oxide), was synthesized by a solvothermal reaction and characterized magnetically. Complex 1 is a typical antiferromagnet with alternating azide/azide/formate/formate bridges, exhibiting a new -J(1)J(1)J(2)J(2)- coupling sequence. This is the first complex to contain an azide, formate and another type of carboxylate ligand.
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- 2010
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14. A unique substituted Co(II)-formate coordination framework exhibits weak ferromagnetic single-chain-magnet like behavior
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Bo-Wen Hu, Miao Du, Zhong-Yi Liu, Jiong-Peng Zhao, Qian Yang, Xian-He Bu, Ran Zhao, and Ze Chang
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Stereochemistry ,Metals and Alloys ,General Chemistry ,Single chain ,equipment and supplies ,Block (periodic table) ,Catalysis ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Ion ,Condensed Matter::Materials Science ,chemistry.chemical_compound ,Crystallography ,chemistry ,Chain (algebraic topology) ,Ferromagnetism ,Magnet ,Materials Chemistry ,Ceramics and Composites ,Antiferromagnetism ,Condensed Matter::Strongly Correlated Electrons ,Formate ,human activities - Abstract
A magnetic isolated chain-based substituted cobalt-formate framework was obtained with isonicotine as a spacer. In the chain, canted antiferromagnetic interactions exist in between the Co(II) ions, and slow magnetic relaxation is detected at low temperature. For the block effects of the isonicotine ligands, the complex could be considered as a peculiar example of a weak ferromagnetic single-chain-magnet.
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- 2012
15. Construction of tandem repeats of DNA fragments by a polymerase chain reaction-based method
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Ji-Ren Chen, Jing-Jing Lü, Yue-Lin Long, Zi-Niu Deng, Bo-Wen Hu, Yan-Bin Chen, and Xing-Yao Xiong
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Sequence analysis ,Biology ,urologic and male genital diseases ,Polymerase Chain Reaction ,DNA sequencing ,law.invention ,chemistry.chemical_compound ,Tandem repeat ,law ,Primer dimer ,Two-Hybrid System Techniques ,Genetics ,Cloning, Molecular ,Molecular Biology ,Polymerase chain reaction ,DNA Primers ,Tandem ,Arabidopsis Proteins ,Cell Biology ,General Medicine ,DNA ,Sequence Analysis, DNA ,chemistry ,Tandem Repeat Sequences ,Primer (molecular biology) - Abstract
We describe a new application of megaprimer polymerase chain reaction (PCR) for constructing a tandemly repeated DNA sequence using the drought responsive element (DRE) from Arabidopsis thaliana as an example. The key feature in the procedure was PCR primers with partial complementarity but differing melting temperatures (T(m)). The reverse primer had a higher T(m), a 3' end complementary to the DRE sequence and a 5' region complementary to the forward primer. The initial cycles of the PCR were conducted at a lower primer annealing temperature to generate products that served as megaprimers in the later cycles conducted at a higher temperature to prevent annealing of the forward primer. The region of overlap between the megaprimers was extended for generating products with a variable copy number (one to four copies) of tandem DRE sequence repeats (71 bp). The PCR product with four tandem repeats (4× DRE) was used as a template to generate tandem repeats with higher copies (copy number large than four) or demonstrated to bind DRE-binding protein in an yeast one-hybrid assay using promotorless reporter genes (HIS and lacZ). This PCR protocol has numerous applications for generating DNA fragments of repeated sequences.
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- 2011
16. One pot synthesis of heterometallic 3d-3d azide coordination architectures: effect of the single-ion anisotropy
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Qian Yang, M. S. El Fallah, Xiao-Feng Zhang, Xian-He Bu, Joan Ribas, Bo-Wen Hu, and Jiong-Peng Zhao
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Magnetism ,Inorganic chemistry ,One-pot synthesis ,Hydrothermal circulation ,Ion ,Inorganic Chemistry ,chemistry.chemical_compound ,Crystallography ,chemistry ,Ferromagnetism ,Azide ,Carboxylate ,Physical and Theoretical Chemistry ,Anisotropy - Abstract
Five new isomorphic three-dimensional (3D) heterometallic 3d-3d azide complexes, [CuNi(1-x)Co(x)(N(3))(2)(isonic)(2)](∞) (x = 0 for 1, x = 0.3 for 2, x = 0.5 for 3, x = 0.6 for 4, and x = 1 for 5), were obtained by assembling Cu(II), M(II) (Ni(II) and Co(II)), azide, and pyridyl carboxylate in hydrothermal condition. The 3D structure can be described as end on (EO) azide and syn,syn carboxylates mixed bridged alternate Cu-M chains linked by the pyridyl groups. Dominant ferromagnetic interactions were observed between the Cu(II) and M(II) ions in the chains. At low temperature diverse magnetic phenomena were presented in those complexes. As the Ni(II) ions were replaced by Co(II) ions with large anisotropy, the magnetism of the complexes change gradually from metamagnet to single-chain magnet (SCM)-like behaviors.
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- 2010
17. Synthesis, structure and magnetic properties of two new azido-Co(II) coordination architectures: from ferromagnetic coupling to single-chain-magnets
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Xian-He Bu, Qian Yang, M. Evangelisti, E. C. Sañudo, Xiao-Feng Zhang, Jiong-Peng Zhao, and Bo-Wen Hu
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Inorganic Chemistry ,Coupling ,chemistry.chemical_compound ,Crystallography ,Pyrazine ,chemistry ,Ferromagnetism ,Stereochemistry ,Magnet ,Structure (category theory) ,Single chain - Abstract
Two new azido-Co(II) complexes with pyrazine carboxylato ligands, [Co(N(3))(L)·H(2)O](n) (L = pyrazine-2-carboxylato) (1) and [CoNa(N(3))(2)(L)](n) (2), have been obtained by carefully tuning the Co(II):N(3)(-) ratio. Here we present the structural and magnetic characterization of these new species. Modulation of the coordination environment of Co(II) leads to a variation of the magnetic properties of the obtained compounds. Complex 1 exhibits ferromagnetically coupled [Co(2)] units that form the rungs of the ladder with a nearly negligible coupling between these units, while complex 2 is a 2D arrangement of 1D Co(II) single-chain magnets.
- Published
- 2010
18. One-dimensional metal-azido complex constructed by a double EO azido bridged trinuclear nickel(II) unit: synthesis, structure and magnetic properties
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Xian-He Bu, Bo-Wen Hu, Joan Ribas, Fu-Chen Liu, Yong-Fei Zeng, and Jiong-Peng Zhao
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Inorganic Chemistry ,Metal ,chemistry.chemical_compound ,Nickel ,Crystallography ,chemistry ,Stereochemistry ,visual_art ,Hydrothermal reaction ,Phenanthroline ,visual_art.visual_art_medium ,chemistry.chemical_element ,Azide - Abstract
The hydrothermal reaction of Ni(NO(3))(2).6H(2)O, NaN(3) phenanthroline and nicotinic acid yielded a one-dimensional (1D) complex, [Ni(1.5)(N(3))(2)(phen)(nic)](n) (1) (phen = phenanthroline, nic = nicotinate), which is a new example of the named orbital countercomplementarity-like complex. In 1, the nicotinate shows mu(3)-nic-N,O,O coordination mode, and the azide groups adopt mu(1,1) bridging mode linking Ni(II) ions to form a rare trinuclear Ni(II) unit bridged by a double mu(1,1) azido.
- Published
- 2010
19. Tuning the structure and magnetism of azido-mediated Cu(II) systems by coligand modifications
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E. C. Sañudo, Yong-Fei Zeng, Jiong-Peng Zhao, Xian-He Bu, Bo-Wen Hu, and Qian Yang
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chemistry.chemical_classification ,Phase transition ,Chemistry ,Stereochemistry ,Magnetism ,chemistry.chemical_element ,Polymer ,Copper ,Benzoates ,Inorganic Chemistry ,Crystallography ,chemistry.chemical_compound ,Ferromagnetism ,Carboxylate ,Physical and Theoretical Chemistry ,Spontaneous magnetization - Abstract
Through the use of a series of structurally related benzoates bearing different substituents as coligands, three new azido-copper compounds, [Cu(benzoate)(N(3))](n) (1), [Cu(2-methyl-benzoate)(N(3))](n) (2), and [Cu(1-naphthoate)(N(3))](n) (3), have been successfully obtained and structurally and magnetically characterized. Single-crystal structure analyses indicated that the uncoordinating substituents in the benzoates greatly affect the structure of the complexes. Complex 1 displays isolated ferromagnetic chains with the largest Cu-N-Cu angle in known carboxylate/end-on-azido mixed-bridged copper systems, while complexes 2 and 3 were 2D coordination polymers, containing mu-(1,1,3,3) and mu-(1,1,3) bridging azides and exhibiting new azido-copper networks with (4(4)) and (4.8(2)) topologies, respectively. Furthermore, 2 was a chiral complex obtained through spontaneous resolution. In the low-temperature range, both 2 and 3 showed spontaneous magnetization with characteristics of soft ferromagnetic magnetism with phase transition temperatures of 13 and 10 K, respectively.
- Published
- 2009
20. ChemInform Abstract: Partial Substitution of Hydroxyl by Azide: An Unprecedented 2D Azido-Copper-Hydroxyl Compound with a [Cu24] Macrocycle in the Presence of [Cu(H2O)6]2+
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Bo-Wen Hu, E. Carolina Sañudo, Xin Hu, Yong-Fei Zeng, Fu-Chen Liu, Jiong-Peng Zhao, and Xian-He Bu
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chemistry.chemical_classification ,Crystallography ,chemistry.chemical_compound ,Phthalic acid ,Coordination sphere ,chemistry ,Ligand ,Magnetochemistry ,Hydroxide ,General Medicine ,Crystal structure ,Azide ,Counterion - Abstract
The investigation of magnetic materials with fascinating structures and unusual magnetic behavior has witnessed flourishing development. Transition-metal hydroxides are of particular significance because of their potential application in magnetic devices (as substitutes for traditional ferrite or nanometric magnetic memory units), and have been extensively explored. Even so, it is still a tremendous challenge for researchers to rationally design, precisely control, artfully modulate, and effectively re-assemble new transition-metal/hydroxide species (hydroxide-bridged clusters, chains, and layers). In the hydroxyl inorganic layers (such as Cu(OH)2, FeO(OH), Mg(OH)2, etc.), the hydroxide groups are present in m2 and m3 modes. To replace some of the hydroxide ligands with other bridging groups in order to alter the magnetic properties is still a challenge to chemists today. As we know, azide is one of the most studied ligands in magnetochemistry, and its complexes display exciting magnetic properties ranging from long-range ordering to SMM (single-molecule magnet) and SCM (single-chain magnet) behavior. Additionally, the magnetic interaction through an azide bridge can be easily predicted based on its bridging mode and the M-N-M angles. The most typical bridging modes are end-to-end (EE, m2-1,3) and end-on (EO, m2-1,1), usually resulting in antiferromagnetic and ferromagnetic coupling, respectively, but this greatly depends on the Cu-N-Cu angle for end-on azides. Azides can also bridge more than two ions in their EO mode; for instance, it can bridge three metal ions in a pyramidal fashion analogous to that of a m3-OH group. In view of azides being able to take both m2-1,1 and m3-1,1,1 bridging modes, it may replace some OH positions in the 2D inorganic layer, which could lead to different magnetic behavior. To avoid the inorganic layer collapsing or aggregating into a 3D solid, a second ligand is usually introduced into the system. Herein, phthalic acid (H2-pta) is our second ligand of choice. A Cu / N3 /OH /pta network could have a high negative charge and counterion will then be needed. Herein we report the synthesis of an unusual 2D N3-Cu -OH complex, [CuACHTUNGTRENNUNG(H2O)6]ACHTUNGTRENNUNG[{Cu2(N3)4/3-(OH) ACHTUNGTRENNUNG(pta)}6] (1). Indeed, our results show that the [Cu ACHTUNGTRENNUNG(H2O)6] 2+ complex ion from the CuACHTUNGTRENNUNG(NO3)2 aqueous solution may serve as a template for the [Cu24] macrocycles. The crystal structure of complex 1 (Figure 1) consists of a new anionic 2D layer network containing two Cu ions, one phthalic anion (in m4-O,O’,O’’,O’’’ bridging mode), one m3 hydroxyl anion, and =3 azide anions, which take m2-1,1 and m3-1,1,1 bridging modes (Figure S1). As can be seen in Figure 1 (top), Cu1 is five-coordinate with a distorted square-based pyramid CuN2O3 geometry formed by the coordination of two nitrogen atoms, from the m2-1,1and m31,1,1-azide anions (apical position) (Cu1 N1=2.000(5), Cu1 N4=2.287(3) ;), and three oxygen atoms, one from the m3 hydroxyl anion and two from phthalic anions (Cu1 O5=1.969(4), Cu1 O1=1.983(4), Cu1 O4=2.018(4) ;). The square-based pyramidal coordination sphere of Cu2 is CuNO4, in which the N atom is from a m2-1,1 azide anion (Cu2 N1A=1.972(5) ;), and the four oxygen atoms are from two m3 hydroxyl anions and two phthalic anions (one occupied the apical position) (Cu2 O5=1.954(4), Cu2 O5A=1.979(4), Cu2 O2=2.646, Cu2 O3=1.934(4) ;). Two hydroxyl anions in the m3 mode (Cu1-O5-Cu2=100.74, Cu1-O5-Cu2A=118.24, Cu2-O5-Cu2A=100.308) bridge [a] Y.-F. Zeng, X. Hu, J.-P. Zhao, B.-W. Hu, Dr. F.-C. Liu, Prof. X.-H. Bu Department of Chemistry Nankai University Tianjin 300071 (China) Fax: (+86)22-2350-2458 E-mail : buxh@nankai.edu.cn [b] Dr. E. C. SaCudo Departament de QuJmica InorgKnica Universitat de Barcelona Diagonal, 647, Barcelona (Spain) Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/chem.200800068.
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- 2008
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21. Diastereoisomer-selective inclusion complexation of Cinchona alkaloids with a modified beta-cyclodextrin: fluorescent behavior enhanced by chiral-tether binding. Short communication
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Bo-Wen Hu, Fei Ding, Chunju Li, Ying-Wei Yang, Heng-Yi Zhang, and Yu Liu
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Quinidine ,Models, Molecular ,Stereochemistry ,Cinchona Alkaloids ,Bioengineering ,Biochemistry ,chemistry.chemical_compound ,medicine ,Hydroxymethyl ,Molecular Biology ,chemistry.chemical_classification ,Aqueous solution ,Binding Sites ,Cyclodextrin ,beta-Cyclodextrins ,Diastereomer ,Stereoisomerism ,General Chemistry ,General Medicine ,Fluorescence ,Spectrometry, Fluorescence ,chemistry ,Molecular Medicine ,Titration ,medicine.drug - Abstract
The molecular 1:1 complexation of cinchona alkaloids by mono(6-deoxy-6-{[(R)-1-(hydroxymethyl)propyl]amino})-beta-cyclodextrin (1) in aqueous solution has been investigated by 2D-NMR, fluorescence titration, and fluorescence-lifetime experiments. Generally, with 1 as the host, in contrast to beta-cyclodextrin proper, strong binding of quinine (2; Ka = 84,200 M(-1)) and quinidine (3; Ka = 27,300 M(-1)) at pH 6.8 was observed, as monitored by an increase in fluorescence intensity, with a fair degree of diastereoisomer discrimination (ca. 3:1). To rationalize these results, two possible cooperative complexation modes, including specific H-bonding interactions to the chiral tether of the cyclodextrin portion, are proposed.
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- 2006
22. A chiral 2p–3d heterometallic azido complex with 2,6-pyridinedicarboxylate as the co-ligand showing magnetic order
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Jie Han, Bo-Wen Hu, Xian-He Bu, Qian Yang, Ran Zhao, Song-De Han, and Jiong-Peng Zhao
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Inorganic Chemistry ,Crystallography ,chemistry.chemical_compound ,Magnetic order ,Chemistry ,Ligand ,Stereochemistry ,Coordination polymer ,Antiferromagnetism ,Magnetic phase transition - Abstract
A new chiral 3D heterometallic coordination polymer [NaCo2(L)2(N3)·(MeOH)]∞ (1) (L = 2,6-pyridinedicarboxylate) was synthesized and characterized magnetically. Ferro- and antiferromagnetic interactions co-exist in 1, which results in a magnetic phase transition at the high temperature of 29 K.
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- 2013
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23. One pot synthesis of heterometallic 3d–3d azido architectures: assembling strategy and magnetic properties
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Wei-Chao Song, Bo-Wen Hu, Xiao-Feng Zhang, Qian Yang, Ran Zhao, Jiong-Peng Zhao, and Xian-He Bu
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Phase transition ,Chemistry ,Stereochemistry ,One-pot synthesis ,Hydrothermal circulation ,Ion ,Inorganic Chemistry ,Metal ,Crystallography ,chemistry.chemical_compound ,Ferromagnetism ,visual_art ,visual_art.visual_art_medium ,Antiferromagnetism ,Carboxylate - Abstract
The Cu(II) ions usually have different coordinated geometry to other 3d ions, especially Ni(II) and Co(II) ions, in azido-carboxylate mixed ligand systems. That provides a potential way to synthesize rare heterometallic 3d-3d azido complexes with peculiar magnetic properties. Assembling Cu(II), M(II) (M = Ni and Co), azido and nicotinic acid in hydrothermal condition, two novel isomorphic 3D heterometallic 3d-3d azido complexes, [CuM(N(3))(2)(nicotinate)(2)](∞) (M = Ni(II) for 1 and Co(II) for 2) were obtained. The structure of the complexes can be described as EO azido and syn,syn carboxylate mixed bridged spin sequence chains (-1/2-J(1)-1-J(2)-1/2- for 1 and -1/2-J(1)-3/2-J(2)-1/2- for 2) linked by the pyridyl groups. Dominant ferromagnetic interactions were observed between the Cu(II) and M(II) ions in the chains despite the largest M-N-M angle of about 129° in the 3d metal azido-carboxylate mixed coordinated systems and weak antiferromagnetic interactions between the chains. At low temperature, a spin-flop phase transition was present in the Co(II) involved complex 2.
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- 2012
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24. Novel Ag(I) complexes with azole heterocycle ligands bearing acetic acid group: synthesis, characterization and crystal structures
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Bo-Wen Hu, Jian-Rong Li, Rong Cao, Xian-He Bu, Tong-Liang Hu, and Wen-Ping Du
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chemistry.chemical_classification ,Stereochemistry ,General Chemistry ,Crystal structure ,Conductivity ,Condensed Matter Physics ,Characterization (materials science) ,Crystallography ,Acetic acid ,chemistry.chemical_compound ,chemistry ,Group (periodic table) ,Spin crossover ,Azole ,General Materials Science ,Metal-organic framework - Abstract
Four novel AgI coordination complexes with azole heterocycle ligands bearing acetic acid group, [AgL1]n (1), [Ag(L2HL2)]n (2), [AgL3]n (3) and [Ag(L4)]n (4) (here, HL1 = 1H-imidazole-1-acetic acid, HL2 =1H-benzimidazole-1-acetic acid, HL3 =1H-1,2,4-triazole-1-acetic acid, HL4 =1H-benzotriazole-1-acetic acid), have been synthesized and structurally characterized by elemental analysis, IR and X-ray diffraction. Structural analyses show that complex 1 possesses a two-dimensional structure, which contains silver chains formed by weak Ag–Ag interactions, and 2 consists of neutral chains connected by weak bonds (O⋯H⋯O), while 3 and 4 have a three-dimensional network and a one-dimensional chain structure, respectively. It is interesting that in 1 there exist Ag–Ag interactions with a separation of 3.156 A, which play an important role in the formation of the complex. Furthermore, the conductivity of 1 was studied in the powder state.
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- 2008
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25. Arenedisulfonate–lanthanide supramolecular architectures with phenanthroline as a co-ligand: syntheses and structures
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Xin Hu, Yong-Fei Zeng, Fu-Chen Liu, Bo-Wen Hu, Jiong-Peng Zhao, and Xian-He Bu
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Lanthanide ,chemistry.chemical_compound ,Chemistry ,Ligand ,Stereochemistry ,Phenanthroline ,Supramolecular chemistry ,General Materials Science ,Chelation ,General Chemistry ,Condensed Matter Physics ,Medicinal chemistry - Abstract
The reaction of LnIII salts with 1,5-naphthalenedisulfonate (1,5-NDS) or 2,7-naphthalenedisulfonate (2,7-NDS), and phenanthroline (phen) under hydrothermal conditions gave a series of new 2-D complexes {[Ln(1,5-NDS)1.5(phen)2(H2O)2]·3H2O}n [Ln = EuIII (1), GdIII (2), NdIII (3), TbIII (4)] and dinuclear compounds [Ln2(2,7-NDS)2(μ2-OH)2(phen)4(H2O)2]·4H2O [Ln = EuIII (5), GdIII (6), TbIII (7)], respectively. 1–4 are puckered (6,3) networks with 1,5-NDS as a bridge and phen chelating to LnIII ions. 5–7 are hydroxyl bridged dinuclear entities, which extend to 2-D networks by H-bonds.
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- 2007
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