Zirconium compounds preparation

Separation. - The zirconium compounds prepared from the oresalmnst invariably contain iron, which is difficult to remove completely. Several met hods are available for separating iron... 

Zirconium compounds prepared by reactive sputtering under Ar -t O2 + N2 atmosphere also had some catalytic activity for the ORR in acid electrolyte [49,78]. We investigated the effect of the gaseous atmosphere during the sputtering on the ORR activity [78]. The thin film XRD and Rutherford backscattering... 

Alkoxides. Zirconium alkoxides are part of a family of alcohol-derived compounds (219). The binary zirconium compounds have the general formula ZRX — (OR). They are easily hydrolyzed and must be prepared under anhydrous conditions. They are prepared by the reaction of zirconium tetrahahdes and alcohols ... 

Zirkonium-Btahl, m. zirconium steel. ver bindung, /, zirconium compound, Zirkon-lampe, /. zirconium lamp, -licht, n. zircon hght, -oxyd, n. zirconium oxide, prUparat, n. zirconium preparation, -saure, /. zirconic acid, stahl, m, zirconium steel. Zirkulonte,/. (Math.) circulant. 

The oxidation-resistant SiC fiber was prepared from polycarbosilane containing Zr(OC4H9)4 by the same process as that used for the aforementioned tita-nia/silica fiber, except that the calcination was performed in Ar atmosphere at 1400 °C. In this case, the polycarbosilane and Zr(OC4H9)4 were effectively converted into SiC-based bulk ceramic and zirconium oxide (cubic zirconia). Before the conversion, bleed-out of the zirconium compound proceeded effectively. AES depth analysis of the fiber surface showed an increase in the concentration of zirconium towards the surface. This construction was confirmed by the TEM image of the cross-section near the fiber surface. This indicates the direct production of a SiC-based fiber covered with a Zr02 surface layer, which... 

Zirconyl chloride is used to make pigment toners and improve properties of color lakes of acid and basic dyes. Also, it is used to prepare body deodorants and antiperspirant, water repellant, dye precipitant, catalysts, and many zirconium compounds. 

Hafnium had lain hidden for untold centuries, not because of its rarity but because of its dose similarity to zirconium (16), and when Professor von Hevesy examined some historic museum specimens of zirconium compounds which had been prepared by Julius Thomsen, C. F. Rammelsberg, A. E. Nordenskjold, J.-C. G. de Marignac, and other experts on the chemistry of zirconium, he found that they contained from 1 to 5 per cent of the new element (26, 27). The latter is far more abundant than silver or gold. Since the earlier chemists were unable to prepare zirconium compounds free from hafnium, the discovery of the new element necessitated a revision of the atomic weight of zirconium (24, 28). Some of the minerals were of nepheline syenitic and some of granitic origin (20). Hafnium and zirconium are so closely related chemically and so closely associated in the mineral realm that their separation is even more difficult than that of niobium (columbium) and tantalum (29). The ratio of hafnium to zirconium is not the same in all minerals. 

Preparation of CH -CHabridged zirconium compounds W. Kaminsky and H. Sinn, Liebigs Ann. Chem. p. 424 (1975). 

Mono(cyclooctatetraenyl) lanthanide(III) compounds, synthesis and characteristics, 4, 124 Mono(cyclooctatetraenyl) zirconium(III) compounds, preparation and reactions, 4, 743 Mono(cyclopentadienyl) amido complexes alkane elimination, 4, 446 amine elimination, 4, 442 HCL elimination, 4, 446 metathesis reactions, 4, 438 miscellaneous reactions, 4, 448 properties, 4, 437... 

A different approach for the in situ preparation of 2-zirconated 1,3-dienes 68 was reported by Szymoniak and Bertus et al.,by treatment of 2-silyloxy-l,3-di-enes 81 with dialkylzirconocene 21 (Scheme 28) [61]. The zirconocene induced the C-0 bond cleavage of 81 and led to the dienyl zirconium compound 68,... 

Dicarbonyl complexes of mixed cyclopentadienyl bis(phosphine)amide zirconium compounds have also been prepared by ligand-induced disproportionation of (775-C5H5)ZrBH4[N(SiMe2CH2PPr12)2] 47, yielding the bis(tetra-hydroborate) complex (775-C5H5)Zr(BH4)2[N(SiMe2CH2PPr12)2] 48 and the dicarbonyl derivative... 

Analogous dienyl zirconium compounds can be prepared by addition of unconjugated dienes that contain enol ethers to 105 (Scheme 19).56-58 These reactions are believed to proceed by initial coordination of the terminal olefin followed by isomerization via zirconocene allyl hydride intermediates to eventually yield zirconacyclopentanes that... 

Several analogous tripodal (amido)zirconium compounds 202170 and 203171 were prepared earlier using salt metathesis. Only when X in compound 202 is small, such as Me, the spectroscopic data and structural considerations indicate all three F-donors at ortho-positions of the aryl rings are bonded to Zr, demonstrating the coordinative flexibility of the ancillary donor functions in the tripodal amido complexes. 

During the last ten years, the chemistry of 1,1-boriozirconocene complexes has been studied. Both hydrozirconation and hydroboration reactions are well established, and are widely applicable to a wide variety of vinyl and acetylene derivatives [1], Alkenylboranes and alkenyl zirconium compounds can also be readily prepared. Therefore, hydrometalla-tion of the corresponding alkenyl metals should offer a convenient method for preparing gem-boriozirconocenes [24]. 

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