Phillips Halides

The Phillips approach involved the reaction of aryl halides with aromatic nuclei in the presence of Friedel-Crafts catalysts. Whilst many variations in the process existed three main cases were distinguishable. 

Figure 1.4 Actual structures of alkali halides compared with the predictions of the ionic model. The figure is divided into three regions by lines corresponding to rjr = 0.414 and 0.732. The regions correspond to four-, six- and eight-coordinated structures. Filled circles denote six-coordinated structures, open circle, six- or eight-coordinated structure and filled squares, eight-coordinated structures. Note that the predictions of the ionic model do not entirely correspond with the actual structures of alkali halides (Following Phillips, 1973f>).

Diazoalkanes decompose under the influence of metal halides and other Lewis acids, e.g., ZnCl2, HgCl2, BFS to produce, among other things, a-haloalkyl derivatives of the metal (see, for example, Wittig and Schwar-zenbach 1959, 1961 Bethell and Brown 1967 Ledwith and Phillips... 

In common with the polymerisation of acyclic olefins (oc-olefins) by Ziegler Natta catalysts, the ring-opening metathesis polymerisation of monocyclic and bicyclic olefins is promoted by alkylmetal-activated transition metal halides, and only a relatively small proportion of the transition metal atoms introduced into the system is converted into the active sites for the polymerisation. Also, as in the polymerisation of ethylene by Phillips catalysts, the metathesis polymer-... 

As demonstrated by Kahn and co-workers, Phillips-Kleinman types of EPs often yield poor results when computing molecular properties (23). This was found to be particularly true for the halide dimers. Figures 2 and 3 show dissociation curves for F2 and Cl2 computed using all-electron and EP two-configuration wave functions. The shape-consistent and all-electron results are in excellent agreement, whereas the curves obtained using Phillips-Kleinman (PK) types of EPs (23) ( Kahn E.P. ), and even those based on a corrected PK EP (24) ( Hay E.P. ), show dramatic deviations, particularly at short bond lengths. It should be noted that the discrepancies between the... 

The solvolysis of poly-O-acetylglycopyranosyl halides in aqueous acetone and in methanol has been studied by Newth, Phillips, and Mattock. - Since, in aqueous acetone, the rate is not increased by added hydroxyl ion, and since there is a fairly rapid increase in rate with increasing water-content of the solvent, it seems highly probable that the reactions proceed... 

The ionic liquid can, for example, be added to the butene effluent from the Dimersol process to obtain octenes by butene dimerization the octene can be carbonylated (Section 4.6) and hydrogenated to wo-nonanol, used to make phthalate plasticizers. In the case of the Phillips trimerization process the use of an ionic liquid allows an easy separation of the trimers and the catalyst for recycling (see also reviews to Section 5.5). However, the industrial use as solvents of ionic liquids, containing halide species (especially anions such as Bp4, PFg, or AlCU ) has the disadvantage that they readily break down to give HX, which can adversely affect the reaction. New types of non-halide containing ionic liquids are being actively researched. 

Among the reaction series studied by Kenyon and Phillips was one that interconverted the two enantiomers of l-phenyl 2-propanol (Figure 11.2, p. 388). Although this particular series of reactions involves nucleophilic substitution of an alkyl toluenesulfonate (called a tosylate) rather than an alkyl halide, exactly the same type of reaction is involved as that studied by Walden. For all practical purposes, the entire tosylate group acts as if it were simply a halogen substituent ... 

Carbenoid reactions of certain organometallic compounds may be classed as a-eliminations. The problems encountered in deducing the reaction mechanism are largely similar to those met with in interpreting the base-induced a-eliminations discussed in the previous section. Reactions which fall in this category are those of the a-haloalkyl derivatives of a number of metals and these can be readily prepared, often by treatment of a diazoalkane with a metal halide (for a review, see Seyferth, 1955). Such derivatives have been reported for mercury (Seyferth and Burlitch, 1964 Seyferth, et al., 1965a, b Ledwith and Phillips 1962,... 

Synthesis of l,4-diacetoxy-2-butene by stoichiometric reaction of a halide complex was considered in an early period [8], and then some catalysts were developed. Although there are a series of Phillips patents, which include the InBrg-LiBr catalyst system, the l,4-diacetoxy-2-butene production rate was low and the 1,4-selectivity did not exceed 80%. The reaction of this system was summarized by Stapp [9] for example, the reaction using Cu(OAc)2-LiX-based catalysts proceeds by a copper-based redox cycle (Scheme 10.1). In addition, 20s-CuBr2-KBr, CuBr2-NaBr, and Ag(OAc)2-LiOAc were known for diacetoxylation, but either 1,4-selectivity or reaction rate was low. Furthermore, l,4-dichloro-2-butene is obtained in the production of chloroprene from 1,3-butadiene. 

Ziegler Catalysts. For his work in the discovery of a new class of highly active catalysts for polymerization of ethylene, propylene, and dienes, Karl Ziegler shared the 1963 Nobel Prize in Chemistry with Guilio Natta whose contributions were predominantly related to polypropylene. Today, these catalysts together with the Phillips catalyst are responsible for the majority of the world s polyethylene production. Loosely defined, Ziegler catalysts are polyethylene catalysts derived from transition-metal halides and main group metal alkyls (46,50-53). In modem... 

Bloomfield LA, Conover CWS, Yang YA, Twu YJ, Phillips NG. Experimental and theoretical studies of the structure of alkali halide clusters. Nucl Instrum Methods Phys Res B. 

Fig. 10.7. High pressure mercury doped metal halide (lead-gallium-iodide additives) UV lamp, type HPM 17, Phillips [2346].

Traditionally, PE has tended to be classed as low, medium, or high density. These sub-divisions have never been precisely defined. High-pressure polymerisation of ethylene takes place by a free radical process, medium-pressure polymerisation occurs in the presence of molybdenum oxide or chromium oxide (Phillips process), while for low- and medium-pressure polymerisation transition metal halide and alkylaluminium compounds (Ziegler process) are used. Some properties of PE obtained from various ethylene processes are presented in Figure 1.2. 

In the 1950s, almost two decades after the launch of LDPE, transition metal catalysts proved capable of producing unbranched linear low density polyethylene (LLDPE) and linear high-density polyethylene (HOPE), both of which had significantly different properties from LDPE. Remarkably, the discovery occuued nearly simultaneously in three different research groups using three different catalyst systems. First was Standard of Indiana s reduced molybdate on alumina catalyst in 1951, followed by Phillips with chromium oxide on silica ( chromox ) catalysts, and Ziegler s titanium chloride/ alkylaluminum halide systems in 1953 (only the latter two were widely commercialized). At about the same time, crystalline polypropylene (PP) was produced in the Phillips labs... 

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