Structure rutile related

It may now be observed that the binary system of oxygen with Ti (as those of other metals close to Ti in the Periodic Table such as vanadium) is very complex and contains a high number of compounds. Many of these have rutile-related structures. For the Ti-0 region around the 50 at.% composition, with NaCl-type structure, see Fig. 3.38. 

Murphy, D.W. Disalvo, F.J. Carides, J.N. Waszczak, J.V. Topochemical reactions of rutile related structures with lithium. Mater. Res. Bull. 1978, 13, 1395. 

Al,Sb,V)204 likewise Sbo.9Vo.9O4 has a rutile-related structure and for both phases only the basic rutile-type reflections are observed with powder X-ray diffraction. Selected area electron diffraction, on the other hand, admits the easy distinction between (Al,Sb,V)204 and Sbo.9Vo.9O4 (see Fig. 1). The diffraction pattern in Fig. lb of (Al,Sb,V)204, or (Al,V)Sb04, shows a 3-fold supercell of trirutile-type [18]. 

MUK 78] Murphy D.W., DiSalvo F.J., Caeides J.N., et al, Topochemical reactions of rutile related structures with lithium , Materials Research Bulletin, vol. 13, pp. 1395-1402, 1978. 

Oxyfluoroniobates, M2Nb05F, containing trivalent metals (where M = Ti, V, Cr) have the same type of structure [264], except for Cr2Nb05F, which has a tri-rutile type structure. This exception is related to the ordered, rather than statistical, distribution of chromium and niobium cations in the oxyfluoride octahedrons, which leads to a corresponding increase in cell parameter c. 

Figure 33. Two interpenetrating rutile-related nets in the structure of [Hg C(CN)3 2]. Circles in order of decreasing size represent Hg, N, and C.

Two of the new M Ni" Fg salts (M = Fe and Co) have shown field dependence of their magnetic susceptibility at unexpectedly high temperatures. Moreover, the reduction of the ordered M Ni Fg (M = Cu, Co) to M Ni F4 has given rutile related materials, the magnetic properties of which are also of some interest. This paper reports the solid state aspects of these new materials, and the structural features of f -NiF3. 

Crystallographic Shear (C5) Phases.—The CS phases are the best-known group of materials which appear to be intolerant of point-defect populations. There are three major families those based upon tungsten trioxide, WO3, upon rutile, Ti02, and upon niobium pentoxide, Nb205. These and other less studied systems have been described in some considerable detail in two previous review articles in this series and elsewhere and the fundamental principles underlying their structures will not be repeated here. In this section some of the results found in the tungsten trioxide and rutile-related systems will be outlined. Older results, covered in the earlier reviews, will merely be sketched in where relevant, and emphasis will be upon newer data or else on a re-examination of earlier results from the point of view of this article. 

We shall see later that (i) and (ii) correspond to families of related structures while (iii) and (iv) produce a single structure in each case. In addition to these structures in which octahedra share only vertices, edges, or faces, there are structures in which vertices and edges are shared in which all the octahedra and all the X atoms are equivalent. The rutile structure is a simple example—others are described later. 

Homologous series of oxides structurally related to the rutile structure. Vanadium and titanium form series of oxides M 02n i which have structures related to the rutile structure in the following way. Slabs of rutile-like structure, n octahedra thick but extending indefinitely in two dimensions, are connected across... 

An interesting series of structures based on the rutile net illustrates the relationship between interpenetration and self-penetration. The compounds are constructed using octahedral metal ions and the trigonal ligands tcm [tricyanomethanide, C(CN) ] and dca [dicyanamide, N(CN)2 ]. It is important to note that dca is a smaller ligand than tcm. Thus, while the compounds M(tcm)2 have two interpenetrating rutile-related networks,the... 

Figure 15.21 shows a unit cell of FeSb20g. (a) How is this unit cell related to the rutile-type structure ... 

The additive elements used to enhance the performance of the Fe-Sb-0 catalyst either enter the iron antimonate rutile phase to form a solid solution (49,50) or they form separate rutile phases (44). The promoter elements that produce the best performing iron antimonate-based ammoxidation catalysts are copper, molybdenum, tungsten, vanadium, and tellurium. Copper serves as a structural stabilizer for the antimonate phase by forming a rutile-related solid solution (23). Molybdenum, tungsten, and vanadium promote the redox properties of iron antimonate catalysts (51). They provide redox stability and prevent reductive deactivation of the catalyst, especially under conditions of low oxygen partial pressure (see above). The tellurium additive produces a marked enhancement of the selectivity of iron antimonate catalyst. How the tellurium additive functions to increase selectivity is not clear, but the presumption is that it must directly modify the active site. In fact, it is likely that it can actually serve as the site of selective oxidation because in its two prevalent oxidation states Te + and Te +, tellurium possesses the requirements for the selective (amm)oxidation site, a-hydrogen abstraction, and 0/N insertion (see below). 

Batten, S. R., Hoskins, B. F., and Robson, R., 3D knitting patterns. Two independent, interpenetrating rutile-related infinite frameworks in the. structure of ZnfC(CN)d2. Chem. Commim., 445-447 (1991). 

The relationship between interpenetration and selfpenetration is best illustrated by considering a series of closely related structures. In the compounds, o -M(dca)2, 3,6-connected rutile networks are formed (Figure 18a). " ... 

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