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排序方式: 共有2364条查询结果,搜索用时 46 毫秒
41.
Shi‐Dong Qin Miao‐Li Zhu Li‐Ping Lu Si‐Si Feng Hong‐Mei Zhang Pin Yang 《无机化学与普通化学杂志》2005,631(10):1761-1762
The novel dinuclear Ni2+ complex [Ni2(μ‐Cl)(μ‐OAc) (EGTB)]·Cl·ClO4·2CH3OH, where EGTB is N, N, N′, N′‐tetrakis (2‐benzimidazolyl methyl‐1, 4‐di‐ethylene amino)glycol ether, crystallizes in the orthorhombic space group Pnma with a = 15.272(2), b = 14.768(2), c = 22.486(3) Å, V = 5071.4(12) Å3, Z = 4, Dcalc = 1.414 g cm?3, and is bridged by triply bridging agents of a chloride ion, an acetate and an intra‐ligand (‐OCH2CH2O‐) group. The nickel coordination geometry is that of a slightly distorted octahedron with a NiN3O2Cl arrangement of the ligand donor atoms. The Ni–Cl distance is 2.361(2) Å, and two Ni–O distances are 1.996(5) and 2.279(6) Å. The three Ni–N distances are 2.033(7), 2.060(6), and 2.166(6) Å with the Ni–N bond trans to an ether oxygen the shortest, the Ni–N bond trans to an acetate oxygen the middle and the Ni–N bond trans to Cl the longest. 相似文献
42.
Synthesis of new tetrazene(N-N=N-N)-linked bi(1,2,4-triazole) 总被引:2,自引:0,他引:2
Sheng Hua Li Si Ping Pang Xiao Tong Li Yong Zhong Yu Xin Qi Zhao 《中国化学快报》2007,18(10):1176-1178
The reaction of 4-amino-1,2,4-triazole with sodium dichloroisocyanurate (SDCI) afforded new tetrazene(N-N=N-N)-linked bi(1.2,4-triazole) 2a in excellent yield.Increasing the molar ratio of SDCI to 4-amino-1,2,4-triazole,the chlorinated product 1,5,5′- trichloro-4,4′-azo-1,2,4-triazole (2b) was formed.These new compounds have been characterized by MS,~1H NMR,~(13)C NMR,and elemental analysis. 相似文献
43.
The complexes of the rare earth metals with 2-phenyltrifluoroacetone in the presence of TX-100 are reported. The characteristic absorbances of neodymium, holmium and erbium complexes can be increased by factors of 8.5, 31 and 15 respectively, compared to those of the cholrides. The third-derivative spectra have been used to eliminate the interference of cerium, and the sensitivities are increased again by factors of 7.4, 5.5 and 6.5. A method for the direct determination of neodymium, erbium and holmium in rare earth mixtures is proposed. 相似文献
44.
Hongyang Su Lanlan Chen Yizhen Chen Prof. Rui Si Yuting Wu Xiaonan Wu Dr. Zhigang Geng Prof. Wenhua Zhang Prof. Jie Zeng 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(46):20591-20596
Efforts have been devoted to achieving a highly efficient artificial synthesis of ammonia (NH3). Reported herein is a novel Fe-MoS2 catalyst with Fe atomically dispersed onto MoS2 nanosheets, imitating natural nitrogenase, to boost N2 electroreduction into NH3 at room temperature. The Fe-MoS2 nanosheets exhibited a faradic efficiency of 18.8 % with a yield rate of 8.63 μg mgcat.−1 h−1 for NH3 at −0.3 V versus the reversible hydrogen electrode. The mechanism study revealed that the electroreduction of N2 was promoted and the competing hydrogen evolution reaction was suppressed by decorating the edge sites of S in MoS2 with the atomically dispersed Fe, resulting in high catalytic performance for the electroreduction of N2 into NH3. This work provides new ideas for the design of catalysts for N2 electroreduction and strengthens the understanding about N2 activation over Mo-based catalysts. 相似文献
45.
Cyrański MK Howard ST Chodkiewicz ML 《Chemical communications (Cambridge, England)》2004,(21):2458-2459
Various models applied to DFT structures and energies of 2-D and 3-D aromatic molecules shed new light on the effects of strain and aromaticity in these systems. The cyclic pi electron delocalisation does not stabilize the fullerene C60 formation; and 5-6 and 6-6 CC bonds have near-identical bond stretch potentials. 相似文献
46.
47.
研究了1-和2-苯基萘, 1, 1'-和2, 2'-联萘, 2, 2-二羟基-, 2, 2'-二甲氧基和-2, 2'-甲基磺酰氧基-1, 1'-联萘等七种萘衍生物和三氧化硫的磺化反应。1-苯基萘和1, 1'-联萘的磺化先发生在4位上, 第二取代位置为6和7位。2-苯基萘和2, 2'-联萘均首先得到8位磺酸取代物, 进一步磺化得到8, 4'-和8, 8'-二磺酸取代物。2, 2'-二甲氧基-1, 1'-联萘以13:87的比例得到3位和6位磺酸取代物。2, 2'-二甲磺酰氧基-1, 1'-联萘以58:42的比例得到5位和6位磺酸取代物。2, 2'-二羟基-1, 1'-联萘的等摩尔磺化得到比例为35:65的5位和6位磺酸取代物, 和大于6摩尔的SO~3反应则以62:38的比例得到5位和6位磺酸取代物。 相似文献
48.
Le Ngoc Xuyen Hoang Dang Lanh Ho Si Thoang J. V?lter 《Reaction Kinetics and Catalysis Letters》1989,39(2):293-298
Pt–Ni/-Al2O3 catalysts have been prepared and studied in n-hexane dehydrocyclization. The selectivity for benzene and toluene, a chain lengthening product formation was improved by Ni and correlated with its content.
Pt–Ni/-Al2O3 -. Ni . Ni , .相似文献
49.
Hoang Dang Lanh G. Lietz Ho Si Thoang J. Völter 《Reaction Kinetics and Catalysis Letters》1982,21(4):429-432
The conversion of n-hexane was studied on a Pt-Sn/Al2O3 catalyst, a PtSn alloy and on the corresponding Pt catalysts. The results indicate the same catalytic effect of tin in supported and unsupported catalysts. It is concluded that the role of tin is connected with alloy formation.
- Pt-Sn/Al2O3, PtSn Pt-. . , .相似文献
50.