Base component in fusion

Rings are cited in increasing order of preference for selection as base components in fusion names, i.e. the ring which comes later in the list takes precedence. 

In Table 4 (drawn from Sections B and D of the lUPAC Blue Book (B-79MH0200)) are listed most of the heteropolycyclic systems having trivial names still in common use. This Table also includes monocycles described in the preceding section, so as to make clear the order of preference for selection as base component in a fusion name (Section 1.02.3.3). 

Transparent fused silica can be formed at a temperature of 1200°C and a pressure of 13.8 MPa (2000 psi) from silica powder consisting of 15 nm ultimate particles (92) or by electric arc fusion of pure silica sand having low iron and alkali metal contents. The cooled product is ground to the desired particle size. Fused sihca is primarily manufactured by C-E Minerals, Minco, and Precision Electro Minerals in the United States by Chuo Denko, Denki Kagaku Kogyo, NKK, Showa Denko, and Toshiba Ceramics in Japan. Based on 1988 data and projected growth, an estimated 135,000 metric tons of fused siUca were used in 1994 as a sacrificial component or investment casting in the manufacture of metals and as a component in refractory materials (62). 

For designating the position of fusion, the peripheral bonds of the base component, starting with the 1,2-bond, are consecutively assigned italic letters in alphabetical order, following the direction of numbering thus in quinoxaline (35) the 1,2-bond is assigned... 

A component fused to the base component (referred to as a primary component) is cited as a prefix terminating usually in o, with the locants of the bond engaged in fusion specified in square brackets in the order corresponding to the direction of lettering of the base component, as in example 13. A (secondary) component fused to a primary component is cited as a further prefix, with the use of primes to indicate the... 

Orf/io-fused and ortho- and pen-fused ring compounds containing hetero atoms are named according to the fusion principle described in Rule A-21 for hydrocarbons. The components are named according to Rules A-21, B-l and B-2. When the name of a component in a fusion name contains locants (numerals or letters) that do not apply also to the numbering of the fused system, these locants are placed in square brackets (as are also the locants for fusion positions required by Rule A-21.5). The base component should be a heterocyclic system. If there is a choice, the base component should be, by order of preference ... 

In a compound name for a fusion prefix when more than one pair of square brackets is required), the points of fusion in the compound prefix are indicated by the use of unprimed and primed numbers, the unprimed numbers being assigned to the ring attached directly to the base component, thus ... 

Skeletal catalysts consist of a metal skeleton remaining after the less noble components of an alloy has been removed by leaching with base or acid. The skeleton metals belong almost exclusively to Groups IB and VIIB of the periodic table (Fe, Co, Ni, Cu, and Ag), whereas Al, Zn, Si, and Mg are the most commonly used alloy components. The alloys are prepared by fusion of the components in the proper proportion, Raney pioneered the development of skeleton catalysts. A widely used Ni and Co catalyst, which is highly active... 

Fe304 is the main component in the magnetite based fused iron catalyst. Its content is about 90 wt % before reduction. The promoters mainly include metal oxides of Al, K, Ca and Mg etc. Magnetite is usually used as the raw material to manufacture the catalyst by fusion method. 

According to the third criterion, quinoxaline is the base component The heterocycle imidazole, which is fused to the base component, is numbered in the usual way the pyridine ring, however, is denoted by 1, 2, and so on, and it is not necessary to mark the double bonds. Pyrido[T,2 l,2]imidazo denotes one ring fusion, imidazo[4,5-b]quinoxaline the... 

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