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1 INTRODUCTION The coordination chemistry of the nitrogen-contai- ning diphosphine ligand bis(diphenylphosphino)ami- ne (Ph2PNHPPh2) has recently received much atten- tion because the P atoms can bridge metal centers in μ-bonding mode to form bi- or polynuclear complex- es[1~10]. It has been shown that the acidity of N–H proton would promote functionalization on the ligand backbone[4, 5, 11]. Although a few complexes contain- ing deprotonated tridentate Ph2PNPPh2 have been synthesi… 相似文献
33.
Esna Killian Kevin Blann Annette Bollmann John T. Dixon Sven Kuhlmann Munaka C. Maumela Hulisani Maumela David H. Morgan Palesa Nongodlwana Matthew J. Overett Mari Pretorius Karola Hfener Peter Wasserscheid 《Journal of molecular catalysis. A, Chemical》2007,270(1-2):214-218
A systematic study was conducted on the Cr catalysed tri- and tetramerisation of ethylene using bis(diphenylphosphino)amine ligands with N-aryl functionality. This study revealed that the oligomerisation reaction product selectivity is primarily dependent on the structure and size of the N-aryl groups.
Addition of sufficient steric bulk to the N-phenyl group via ortho-alkyl substitution increased the combined 1-hexene and 1-octene selectivity (overall alpha selectivity) to above 82% at an overall 1-octene selectivity of 56%. The introduction of a single carbon spacer between the N-atom and the aryl-moiety, as well as the addition of branching on this carbon, resulted in further selectivity improvements, achieving an overall 1-octene selectivity of 64% and an overall alpha selectivity of 84%. This was obtained at catalyst productivities in excess of 1,000,000 g/g Cr/h. 相似文献
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1 INTRODUCTION Recently, the low-spin square-planar nickel(II) complexes and high-spin octahedral nickel(II) complexes with Schiff base ligands have received much attention in optical materials[1~3]. Some nic- kel(II) complexes are widely used as lubricating oil, rubber industry additives, a fire-resistant additive and fungicide for leather[4~7]. Also, their adducts with nitrogen have attracted broad attention due to their potential applications as organic conductors and magnetic mate… 相似文献
35.
Effect of 1,10-phenanthroline on the extraction and separation of lithium(I), sodium(I) and potassium(I) with thenoyltrifluoroacetone 总被引:1,自引:0,他引:1
The extraction of Li+ with thenoyltrifluoroacetone (Htta) in the presence of 1,10-phenanthroline (phen) has been studied in various organic solvents. The remarkable enhancement of the extraction of Li+, that is a synergistic effect, was observed by the addition of phen, and the high extractability of Li+ was attained in toluene, benzene, chlorobenzene and o-dichlorobenzene. The extraction equilibrium of Li+, Na+ and K+ (denoted as M+) in the presence or absence of phen in chlorobenzene and the adduct formation reaction in the organic phase were studied in detail. The adduct of Li+ was Li(tta)(phen) in the wide concentration range of phen in the organic phase, while in Na+ and K+ M(tta)(phen)2 also exists in the high concentration region. The maximum value of the separation factor between Li+ and Na+ was observed in the present system and was larger than that in the Htta-trioctylphosphine oxide (TOPO)-benzene system reported previously. 相似文献
36.
Ratajczak等研究了S-(1-二茂铁烷基)疏代乙醇酸的合成与反应(?)Ugi等将它们与羟胺反应,合成了一种有用的手性模板试剂。最近,Czech等用键合载体液相色谱对它们进行了光学拆分研究。本文报导了此类化合物与胺的反应,合成了一类新的化合物(?)二茂铁烷基)硫代乙醇酸胺。 相似文献
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本文系统详细地研究了七种贵金属彼此分离以及与贱金属分离的可能条件。此种工作尚未见报道。用三正辛胺作固定相。分别用1mol/L HCl、6mol/LHCl、2mol/L HNO_3—2mol/L HCl、3mol/L HNO_3-2mol/L HCl、4mol/L HNO_3-2mo1/L HCl和5%硫脲-1mol/L HCl为淋洗液,可以将Rh、Ru、Pd、Pt、Ir、Os、Au分步淋洗下来,达到彼此完全分离。为了使Rh(Ⅱ)与贱金属分离,必须将RhC1_6~(3-)转化为RhBrb_6~(3-),然后在另一色层柱上使它与贱金属分离。合成矿样的分析结果符合分析要求。 相似文献
40.