Zr(IV) complexes of some heterocyclic ligands: synthesis, characterization, and ethylene polymerization activity
摘要:
Thirty-one complexes of bis-(benzimidazole, benzothiazole, and benzoxazole) compounds with Zr(IV) metal centers were synthesized, characterized, activated with methylaluminoxane (MAO), and then tested for catalytic ethylene polymerization. The activities of the various catalysts were found to be functions of the heteroatoms in the ligand frameworks and the structure around the active metal center. The highest activity was obtained with 38/MAO (424 kg E/mol cat. h). The produced polyethylenes showed high molecular weights (41/MAO, 1.9 x 10(6) g/mol) and broad molecular weight distributions (38/MAO, M-omega = 9.64 x 10(5) g/mol, PD = 23). This could result from different interactions of the MAO counter ion with the heteroatoms of the catalyst ligand generating different active sites.
An efficient and convenient Cu(OAc)2/air mediated oxidative coupling of azoles via C–H activation
作者:Yan Li、Jun Jin、Weixing Qian、Weiliang Bao
DOI:10.1039/b919396k
日期:——
An efficient and convenient approach to construct CâC bonds at the 2-position of azoles via Cu(OAc)2/air mediated oxidative homo- and cross-coupling reaction was reported. The corresponding products were obtained in good to excellent yield.
benzoxazoles with aryl halides. A series of aryl, heteroaryl, and druglike electrophiles relevant to pharmaceutical applications were surveyed. The desired arylated products were obtained in synthetically useful yields using electronically and structurally varied aryl halides. The use of microscale high-throughput experimentation was essential for both the rapid identification of optimal reaction parameters
Ti (IV) Complexes of Some Heterocyclic Ligands Synthesis, Characterization and Ethylene Polymerization Activity
作者:Hamdi Elagab
DOI:10.13005/ojc/320177
日期:2016.3.25
31 complexes of bis - (benzimidazole, benzothiazole and benzoxazole) compounds with Ti (IV) metal centers were synthesized, characterized, activated with methylalumoxane (MAO) and then tested for catalytic ethylene polymerization. The activities of the various catalysts were found to be functions of the hetero atoms in the ligand frameworks. The highest activity was obtained with 39 / MAO (573 kg PE / mol cat. h). The produced polyethylenes showed high molecular weights (up to 1.5 ×106 g/mol) and broad molecular weight distributions (PD = 65). This could result from different interactions of the MAO counterion with the heteroatoms of the catalyst ligand generating different active sites.
合成了31个双-(苯并咪唑、苯并噻唑和苯并恶唑)化合物与钛(IV)金属中心的配合物,进行了表征,并用甲基铝氧烷(MAO)激活,然后测试了其在催化乙烯聚合中的活性。各种催化剂的活性被发现与配体框架中的杂原子有关。39 / MAO获得了最高活性(573 kg PE / mol cat. h)。所产生的聚乙烯具有高分子量(最高可达1.5 × 10^6 g/mol)和宽的分子量分布(PD = 65)。这可能是由于MAO反离子与催化剂配体中的杂原子之间不同的相互作用生成了不同的活性位点。
Zr(IV), Ti(IV), and V(III) complexes of some benzimidazole, benzothiazole, and benzoxazole ligands: characterization and catalyst efficiency in ethylene polymerization
作者:Hamdi Ali ELAGAB、Helmut G. ALT
DOI:10.3906/kim-1507-82
日期:——
Fifteen complexes of 2, 2-bis- (benzimidazole, benzothiazole, and benzoxazole) compounds with Zr(IV), Ti(IV), and V(III) metal centers were synthesized, characterized, activated with methyalumoxane (MAO), and then tested for catalytic ethylene polymerization. The activities of the various catalysts were found to be functions of the hetero atoms in the ligand frameworks. The activity of the catalyst
合成了15种2、2-双-(苯并咪唑,苯并噻唑和苯并恶唑)化合物与Zr(IV),Ti(IV)和V(III)金属中心的配合物,进行了表征,用甲基铝氧烷(MAO)活化,然后测试用于催化乙烯聚合。发现各种催化剂的活性是配体骨架中杂原子的功能。发现催化剂体系\ textbf 6} / MAO的活性为1372kg PE / mol催化剂。H。用催化剂体系6 / MAO生产的聚乙烯显示出高分子量(1.84 $×10 ^^ 6} g / mol)和宽分子量分布(PD = 11)。这可能是由于MAO抗衡离子与催化剂配体的杂原子发生不同的相互作用而产生不同的活性位点所致。