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1.
Reacting [PtCl(PTA)3]Cl(PTA = 1,3,5-triaza-7-phosphatricyclo[3.3.1.13,7]decane) with KSeCN in aqueous or MeOH medium results in the abstraction of the PTA ligands to yield SePTA. The reaction also proceeds quantitatively by direct reaction of PTA and KSeCN in water or methanol. The methylated PTA ligand, [PTA-Me]I (1-methyl-1-azonia-3,5-diaza-7-phosphatricyclo[3.3.1.13,7]decane iodide), reacts accordingly with KSeCN, albeit significantly slower. The crystal structure of SePTA, 1, and [SePTA-Me]I · CH3OH, 2, revealed PSe bond distances of 2.0991(19) and 2.100(2) Å, respectively. The first order phosphorous selenium coupling constants, 1JP-Se (D2O), of 722 and 788 Hz for SePTA and [SePTA-Me]I, respectively, indicates the latter is significantly less electron rich. 相似文献
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Elisabetta Maccaroni 《Journal of organometallic chemistry》2010,695(4):487-8610
Reduction of [NMe4]2[ReBr5(NO)] (1) with zinc in acetonitrile leads to the known trisacetonitrile compound [ReBr2(CH3CN)3(NO)] (2). Attempts to turn 2 into a dihydrogen or a hydride complex applying direct reaction with H2 or with H2 and a base were unsuccessful. Complex 2 could be transformed into [ReBr(BF4)mer-(CH3CN)3(NO)] (2a) with AgBF4 in acetonitrile and was used as a starting material in a ligand exchange reaction with the water soluble phosphine 1,3,5-triaza-7-phosphadamantane (PTA) to obtain the complex [ReBr2(NO)(PTA)3] (3). When the reduction of 1 with zinc was carried out in the presence of PTA in acetonitrile, the disubstituted complex [ReBr2(CH3CN)(NO)(PTA)2] (4) was formed. The olefin-coordinated rhenium complexes [ReBr2(NO)(CH2CH2)(PTA)2] (5a) and [ReBr2(NO)(PhCHCH2)(PTA)2] (5b) were obtained from the reaction of 4 with the corresponding olefins. Complex 4 reacts further with NaHBEt3 in THF to give the dihydride [ReH2(THF)(NO)(PTA)2] (6). In the presence of ethylene 6 is transformed into the ethyl hydride complex [ReH(CH2CH3)(η2-C2H4)(NO)(PTA)2] (7). Complexes 6 showed catalytic activity in the hydrogenation of olefins. 相似文献
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In this study, a novel and eco‐friendly synthesis of benzochromenopyrimidines catalyzed by phosphotugstic acid immobilized on aminated multiwalled carbon nanotubes (MWCNTs@NHBut/PTA) is reported. New solid acid catalyst was prepared through a simple process with good percentage of organo metallic groups and characterized with FTIR, TEM, SEM, EDX and TGA techniques. Reusable catalytic system provides a convenient, safe and green pathway to generate a variety of benzochromenopyrimidines under mild conditions. 相似文献
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为提高304不锈钢的摩擦学性能,将质量分数为30%和60%的球形WC添加到铁基复合粉末,采用等离子堆焊技术在其表面制备了WC增强铁基复合涂层.分析其显微组织结构、物相和显微硬度,在恒定载荷(50 N)和滑动速度(20 mm/s)下进行干摩擦磨损试验,研究其干滑动摩擦学性能.结果表明:富含Cr的固溶强化奥氏体、高硬度的Cr7C3和WC增强相的存在,提高了WC增强铁基堆焊层的硬度,30%WC和60%WC涂层的显微硬度达到HV0.2665和HV0.2724,比铁基涂层提高了21.1%和31.9%,是304基体的3.7和4倍;30%WC和60%WC涂层的摩擦系数和磨损率分别为0.59和2.639×10~(–6) mm~3·N~(–1)·m~(–1),0.42和1.111×10~(–6) mm~3·N~(–1)·m~(–1).30%WC和60%WC涂层均表现出优异的耐磨性能,其磨损机理分别为黏着磨损和二体磨粒磨损的混合机制,和三体磨粒磨损. 相似文献
6.
蒙特卡罗方法在径迹显微技术中的应用 总被引:1,自引:1,他引:0
径迹显微技术(PTA)是研究硼的晶界偏聚的行之有效的方法.本文运用蒙特卡罗方法建立了径迹固体探测器上蚀坑带宽度与晶界区域硼富集带实际宽度之间的对应关系.模拟计算结果表明,蚀坑带宽度受实际富集带宽度和晶界平面与磨面夹角2个因素影响.蚀坑带宽度随晶界硼富集带宽度的增加与晶界面与探测器平面夹角的减小而增加,利用本文程序计算结果,可根据蚀坑带宽度和晶界平面与磨面夹角更准确的获得实际富集带宽度. 相似文献
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Sizwe J. Zamisa 《Journal of Coordination Chemistry》2016,69(20):3043-3052
Reactions of silver(I) salts of acetate and trifluoroacetate with 1,3,5-triaza-7-phosphaadamantane (PTA) afforded 1-D coordination polymers [Ag(μ2-PTA-κ2P?-:N)(μ2-O2CCH3-κ2O:O′)]n·2nH2O (1) and [Ag(μ2-PTA-κ2P:N)(μ2-O2CCF3-κO)]n·nH2O (2), while a reaction of silver(I)trifluoroacetate with N-methyl-1,3,5-triaza-7-phosphaadamantane (PTAMe) afforded the coordination polymer [Ag(PTAMe)(μ3-O2CCF3-κ3O:O:O’)(μ2-O2CCF3-κ2O:O′)]n (3). The coordination polymers were characterized using single-crystal X-ray diffraction. Nuclear magnetic resonance, infrared, and electron spray ionization mass spectrometries were used to initially establish complexation of Ag(I) to the PTA or PTAMe before recrystallization. In the crystal structures of 1 and 2, coordination of the PTA moieties to Ag(I) is via P and N forming chains that are linked through bridging carboxylates. The resulting structural motif can be described as ladder-like in which –[PTA–Ag–PTA]– chains are the strands while the bridging carboxylates comprising of –[Ag–O–C–O]2– or –[Ag–O]2– metallacycle rungs of the ladder. Compound 3 forms single-stranded coil-like coordination polymers with two non-equivalent Ag(I) centers, both tetrahedrally coordinated by four oxygens from four trifluoroacetates in one and by three oxygens from the trifluoroacetates and in each by the P of the PTAMe with alternating Ag?Ag interactions. The crystal structures of all three coordination polymers have a variety of fairly strong hydrogen bonds and intermolecular interactions which contribute stabilization of the crystal lattices. 相似文献
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Jamal Lasri María José Fernández Rodríguez M. Fátima C. Guedes da Silva Piotr Smoleński Maximilian N. Kopylovich Armando J.L. Pombeiro 《Journal of organometallic chemistry》2011,696(22):3513-3520
[2 + 3] Cycloaddition reactions of the di(azido)-PdII complex trans-[Pd(N3)2(PPh3)2] (1) with an organonitrile RCN (2), under heating for 12 h, give the bis(tetrazolato) complexes trans-[Pd(N4CR)2(PPh3)2] (3) [R = Me (3a), Ph (3b), 4-ClC6H4 (3c), 4-FC6H4 (3d), 2-NC5H4 (3e), 3-NC5H4 (3f), 4-NC5H4 (3g)]. The reaction of trans-[Pd(N3)2(PPh3)2] (1) with propionitrile (2h) also affords, apart from trans-[Pd(N4CEt)2(PPh3)2] (3h), the unexpected mixed cyano-tetrazolato complex trans-[Pd(CN)(N4CEt)(PPh3)2] (3h′) which is derived from the reaction of the bis(tetrazolato) 3h with propionitrile, with concomitant formation of 5-ethyl-1H-tetrazole, via a suggested unusual oxidative addition of the nitrile to PdII. The [2 + 3] cycloadditions of [Pd(N3)2(PTA)2] (4) (PTA = 1,3,5-triaza-7-phosphaadamantane) with RCN (2), under heating for 12 h, give the bis(tetrazolato) complexes trans-[Pd(N4CR)2(PTA)2] (5) [R = Ph (5a), 2-NC5H4 (5b), 3-NC5H4 (5c), 4-NC5H4 (5d)]. All these reactions are greatly accelerated by microwave irradiation (1 h, 125 °C, 300 W). Taking advantage of the hydro-solubility of PTA, a simple liberation of 5-phenyl-1H-tetrazole from the coordination sphere of trans-[Pd(N4CPh)2(PTA)2] (5a) was achieved. The complexes were characterized by IR, 1H, 13C{1H} and 31P{1H} NMR spectroscopies, ESI+-MS, elemental analyses and, for 3b, also by X-ray structure analysis. Weak agostic interactions between the CH groups of the triphenylphosphines and the palladium(II) centre were found. 相似文献
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Abstract The homogeneous hydrogenation of carbon dioxide into formate anion has been investigated in aqueous solution, using water soluble ruthenium(1I)-phosphine (meta-monosulphonated triphenylphosphine, TPPMS; and 1,3,5-triaza-7-phosphaadamantane, PTA) complexes as catalysts. These reactions take place in amine free medium under mild conditions, bicarbonate anion is more active than carbon dioxide in the reduction. The initial turnover frequenc of the reduction increases with increasing H2 pressure, as it was observed in situ by C and 'H NMR spectroscopy. High pressure FT-IR were used to find evidence for the formation of the catalytically active ruthenium hydride species. 相似文献