Nickel(Ⅱ)complexes with pyrazole-based ligands are widely employed in catalysis of ethylene oligomerization and subsequent Friedel-Crafts alkylation of toluene.We have prepared ten new nickel(Ⅱ)dibromide complexes w...Nickel(Ⅱ)complexes with pyrazole-based ligands are widely employed in catalysis of ethylene oligomerization and subsequent Friedel-Crafts alkylation of toluene.We have prepared ten new nickel(Ⅱ)dibromide complexes with various substituted bis(azolyl)methanes.They have been characterized using^(1)H NMR,IR,high resolution mass spectrometry and elemental analysis.The structures of three complexes have been unambiguously established using X-ray diffraction.It was found that these complexes in the presence of Et2AlCl or Et_(3)Al_(2)Cl_(3)are active both in ethylene oligomerization and Friedel-Crafts alkylation processes(activity up to 3720 kgoligomer·mol[Ni]^(−1)·h^(−1)).The use of Et_(3)Al_(2)Cl_(3)results in a higher share of alkylated products(up to 60%).Moreover,catalytic systems activated with Et_(3)Al_(2)Cl_(3)produced small amounts of odd carbon number olefins(up to 0.8%).The Friedel-Crafts alkylation was used as a trap for previously undetected short-chain odd carbon number olefins(C_(3)and C_(5)).展开更多
Carbon nanotube （CNT） arrays were fabricated on Ct-Me-N-（O） alloys with content of Ct in the range of 6-40 at.% by chemical vapour deposition. The Ct was a catalytic metal from the group of the following elements...Carbon nanotube （CNT） arrays were fabricated on Ct-Me-N-（O） alloys with content of Ct in the range of 6-40 at.% by chemical vapour deposition. The Ct was a catalytic metal from the group of the following elements： Ni, Co, Fe, Pd, while Me was a transition metal from the group of IV-VII of the periodic table （where Me=Ti, V, Cr, Zr, Nb, Mo, Ta, W, Re）. Carbon nanotubes were found to grow efficiently on the alloy surface with its composition containing Ti, V, Cr, Zr, Hf, Nb or Ta. The growth of CNTs was not observed when the alloy contained W or Re. Additions of oxygen and nitrogen in the alloy facilitated the formation of oxynitrides and catalyst extrusion on the alloy surface. Replacement of the metals in alloy composition affected the diameter of the resulting CNTs. The obtained results showed that the alloy films of varying thickness （10-500 nm） may be used for the CNTs growth. The resulting CNT material was highly homogenous and its synthesis reproducible.展开更多
基金This work was financially supported by the Russian Science Foundation-Russia(Project No.22-23-00578)NMR measurement was performed according to the Development Program of the Interdisciplinary Scientific and Educational School of Lomonosov Moscow State University"The future of the planet and global environmental change"'X-Ray analysis was supported by the RUDN University Strategic Academic Leadership Program.Elemental and GC analyses were performed with the financial support from the Ministry of Science and Higher Education of the Russian Federation using the equipment of the Centre for molecularcomposition studies of INEOS RAS.
文摘Nickel(Ⅱ)complexes with pyrazole-based ligands are widely employed in catalysis of ethylene oligomerization and subsequent Friedel-Crafts alkylation of toluene.We have prepared ten new nickel(Ⅱ)dibromide complexes with various substituted bis(azolyl)methanes.They have been characterized using^(1)H NMR,IR,high resolution mass spectrometry and elemental analysis.The structures of three complexes have been unambiguously established using X-ray diffraction.It was found that these complexes in the presence of Et2AlCl or Et_(3)Al_(2)Cl_(3)are active both in ethylene oligomerization and Friedel-Crafts alkylation processes(activity up to 3720 kgoligomer·mol[Ni]^(−1)·h^(−1)).The use of Et_(3)Al_(2)Cl_(3)results in a higher share of alkylated products(up to 60%).Moreover,catalytic systems activated with Et_(3)Al_(2)Cl_(3)produced small amounts of odd carbon number olefins(up to 0.8%).The Friedel-Crafts alkylation was used as a trap for previously undetected short-chain odd carbon number olefins(C_(3)and C_(5)).
基金financially supported by the Russian Science Foundation(No.16-19-10625)
文摘Carbon nanotube （CNT） arrays were fabricated on Ct-Me-N-（O） alloys with content of Ct in the range of 6-40 at.% by chemical vapour deposition. The Ct was a catalytic metal from the group of the following elements： Ni, Co, Fe, Pd, while Me was a transition metal from the group of IV-VII of the periodic table （where Me=Ti, V, Cr, Zr, Nb, Mo, Ta, W, Re）. Carbon nanotubes were found to grow efficiently on the alloy surface with its composition containing Ti, V, Cr, Zr, Hf, Nb or Ta. The growth of CNTs was not observed when the alloy contained W or Re. Additions of oxygen and nitrogen in the alloy facilitated the formation of oxynitrides and catalyst extrusion on the alloy surface. Replacement of the metals in alloy composition affected the diameter of the resulting CNTs. The obtained results showed that the alloy films of varying thickness （10-500 nm） may be used for the CNTs growth. The resulting CNT material was highly homogenous and its synthesis reproducible.
