Polymers
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2018
·Vol. 10
·期 9
·934
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IF 2.935
Guangqian Zhu,Xianhui Zhang,Mengmeng Zhao,Liang Wang,Chuyang Jing,Peng Wang,Xiaowu Wang,Qinggang Wang
A series of iminopyridine complexes of Fe(II) and Co(II) complexes bearing fluorinated aryl substituents were synthesized for the polymerization of isoprene. The structures of complexes3a,2band3bwere determined by X-ray diffraction analysis. Complex3acontained two iminopyridine ligands coordinated to the iron metal center forming an octahedral geometry, whereas2badopted a chloro-bridged dimer, and3bfeatured with two patterns of cobalt centers bridged via chlorine atoms. Complexes2band3brepresented rare examples of chlorine bridged bimetallic Co(II) complexes. The fluorine substituents effects, particularly on catalytic activity and polymer properties such as molecular weight and regio-/stereo-selectivity were investigated when these complexes were employed for isoprene polymerization. Among the Fe(II)/methylaluminoxane (MAO) systems, the 4-CF3substituted iminopyridine Fe(II) complex1awas found as a highly active isoprene polymerization catalyst exhibiting the highest activity of 106g·(mol of Fe)−1·h−1. The resultant polymer displayed lower molecular weight (Mn= 3.5 × 104g/mol) and moderate polydispersity index (PDI = 2.1). Furthermore, the ratio ofcis-1,4-/3,4 was not affected by the F substituents. In the series of Co(II)/AlEt2Cl binary systems, complexes containing electron-withdrawing N-aryl substituents (R = 4-CF3, 2,6-2F) afforded higher molecular weights polyisoprene than that was obtained by the complex containing electron-donating N-alkyl substituents (R = octyl). However, ternary components system, complex/MAO/[Ph3C][B(C6F5)4] resulted in low molecular weight polyisoprene (Mn< 2000) with hightrans-1,4-unit (>95%).Keywords:iminopyridine ligands;Fe(II);Co(II) complexes;isoprene polymerization;fluorinated aryl substituents
研究领域:
有机金属化学
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高分子科学
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催化
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DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
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2019
·
IF 2.12
Yun Li,Yueqin Li,Xiaohui Liu,Yong Yang,Dong Lin,Qinwei Gao
Two Co(II) complexes, Co(BBH)phenMeCN (1) and Co(BSH)phenMeCN (2) (HBBH = benzophenone benzoyl hydrazone, HBSH = benzophenone salicylylhydrazone ligand and phen = 1,10-phenanthroline) were prepared and characterized by single X-ray crystallography. The investigation of the complexes binding with herring sperm DNA (HS-DNA) revealed that stronger binding interaction exists between the complexes and HS-DNA compared to the corresponding free ligands. And both complexes can bind to DNA through intercalation of the phenyl rings between adjacent base pairs in the double helix. Meanwhile, bovine serum albumin (BSA) binding studies reveal the complexes can effectively interact with BSA and change the secondary structure of BSA. Superoxide dismutase (SOD) mimic activity of the complexes was investigated and the results showed that complex 2 showed a stronger radical scavenging potency against O 2 .- radical with an IC 50 value of 16.10 μM. The catecholase-like activity of both complexes has been investigated with 3,5-di- tert -butylcatechol (3,5-DTBC) as the substrate in methanol solution under completely aerobic conditions. The catalytic reaction follows Michaelis-Menten enzymatic reaction kinetics with turnover numbers ( k cat ) of 34.14 h −1 and 30.36 h −1 for complex 1 and complex 2, respectively.
研究领域:
配位化学
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生物无机化学
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药物化学
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DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
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2013
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IF 3.41
Zhiguo Sun,Gang Li,Hai-ou Liu,Liping Liu
A series of MOF-based catalysts, metal-salen complexes incorporated into amino-functionalized MIL-101 matrices by salicylaldehyde condensing to amino group and coordinating metal ion through one pot method, have been prepared and characterized. The successful preparation of catalysts demonstrates that postsynthetic modification (PSM) is a practical and powerful route to generate MOF-based catalyst with multiple active sites. The catalytic performances of prepared catalysts were investigated via selective oxidation of cyclohexane to cyclohexanone and cyclohexanol (KA-oil) by molecular oxygen in the absence of solvent. It was found that NH 2 -MIL-101(Cr)-Sal-Co, as a typical case, behaves as cooperative catalyst for cyclohexane selective oxidation. That is, salen-Co(II) attached to framework of MOF is able to assist in the generation of new radicals from peroxides via a Haber–Weiss catalytic cycle to promote conversion of cyclohexane while framework Cr ion is able to catalyze the dehydration of intermediate product cyclohexyl hydroperoxide (CHHP) to improve KA-oil selectivity. Furthermore, this catalyst exhibits good recyclability and behaves as truely heterogeneous catalyst.
研究领域:
材料化学
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催化化学
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DOI
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2022
·Vol. 36
·期 4
·e6587
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IF 4.072
Dan Mo,Xun Song,Jiri Wu,Yogini Jaiswal,Yifu Guan,Yuzhen Zhang,Yunjun Shen,Hedong Bian
Metal complexes have been reported to possess excellent free radical scavenging and antimicrobial properties. In the present study, seven linear trinuclear complexes were synthesized based on bis Schiff base ligand and complexes 1 , 3 – 7 are reported for the first time. Their structure was characterized by IR spectroscopy and single crystal diffraction. BSA was used as carrier to hybridize the synthesized complexes to construct hybrid proteins. The interaction between metal complex and BSA was studied by UV–Vis spectrophotometry and fluorescence spectroscopy. Static quenching was the main mechanism identified for the interaction between metal complex and BSA. In the superoxide dismutase (SOD) activity test, IC 50 values of complexes and hybrid proteins range between 2.89 and 26.53 μM, with hybrid proteins demonstrating a stronger activity than the complexes. Among all the complexes studied, complex 5 exhibited the strongest inhibition against Candida albicans (MIC 12.5 μg ml −1 ) and Cryptococcus neoformans (MIC 6.5 μg ml −1 ).
研究领域:
无机化学
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生物化学
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药学
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微生物学
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DOI
高影响因子
危险品化学品经营许可证（带存储）