Group III halides

At present, primarily the binary compounds have been studied, and considerations of product volatility are the most significant driving force behind much of this research. The group III—V compounds are particularly difficult, because the group V elements form volatile halides, whereas group III halides, particularly the fluorides, tend to be involatile. As a result, F source plasmas, which have been the mainstay of silicon technology, are... 

Values Ip and Q for group III halides all show the same sequence... 

Coordination Numbers of Metal Atoms in Group III Halides"... 

Nucleophilic attack at other atoms. The chemistry of phosphine-borane adducts has continued to generate interest. Simple borane adducts of primary vinyl-, ethynyl- and allenyl-phosphines have been prepared and studied by a range of spectroscopic and theoretical techniques. The same group has also shown that attachment of the BH3 unit to a variety of primary phosphines results in a substantial increase in the intrinsic acidity of the system in the gas-phase. Group III halide adducts of the type Bu 2PH EX3 (E = B, Al, Ga or In X = Cl or Br) are accessible from the reactions of the secondary phosphine with the trihalides at room temperature. The solid state structure and reactivity of these adducts was also reported. Treatment of l,8-bis(diphenylphosphino)naphthalene with the borane-dimethylsulfide complex in ether solvents affords a simple monoborane adduct of the diphosphine irrespective of the molar ratio of the... 

D. F. Shriver et al. - Adduct Formation and Carbonyl Rearrangement of Polynuclear Carbonyls in the Presence of Group III Halides, Inorg. Chem. 13, 499, 1974 ... 

Two areas of passivity are located in Fig. 2-2 where Fe has a very low corrosion rate. In contrast to cathodically protected metals in groups I and II, the corrosion rate of anodically passivated metals in groups III and IV cannot in principle be zero. In most cases the systems belong to group IV where intensified weight loss corrosion or local corrosion occurs when U > U" There are only a few metals belonging to group III e.g., Ti, Zr [44] and A1 in neutral waters free of halides. 

Aryl Halides from Diazonium Ion Intermediates. Replacement of diazonium groups by halides is a valuable alternative to direct halogenation for the preparation of aryl halides. Aryl bromides and chlorides are usually prepared by a reaction using the appropriate Cu(I) salt, which is known as the Sandmeyer reaction. Under the classic conditions, the diazonium salt is added to a hot acidic solution of the cuprous halide.99 The Sandmeyer reaction occurs by an oxidative addition reaction of the diazonium ion with Cu(I) and halide transfer from a Cu(III) intermediate. 

The Structures of the Group 15 Element(III) Halides and Halogenoanions George A. Fisher and Nicholas C. Norman... 

The aprotonic acid catalysts are made up of the halides of the metal of Group III and IV of the periodic table. Catalytic activity is also shown by halides of As, Sb, S, Se and many other metals. 

Treatment of difluoroallylic alcohols with sulfur(II) or phosphorus(III) halides resulted in [2,3]-rearrangement (Eq. 135) under mild conditions [349]. This method constitutes a potential alternative route to difluorophosphonates, and to difluorosulfoxides and sulfones. The Jussieu group showed that thionyl chloride or bromide converted difluoroallylic alcohols to the corresponding halodi-fluoromethyl allylic compounds (Eq. 136) [350]. Exposure to DAST afforded the trifluoromethyl congeners [351, 352] and Kumadaki showed that /i-chloro-y,y-difluoroallylic alcohols afforded the trifluoromethyl alkene products upon treatment with HF. 

Several other synthetic approaches, for example (i) transamination, (ii) the direct reaction between a primary or a secondary amine with a metal(III) halide, or (iii) the direct reaction of a metal (e.g. aluminium) and an amine in the presence or absence of hydrogen, as well as a number of other approaches (outlined in Chapter 4 of Ref. 1) have been known for many years and are occasionally employed. The procedure (iii), in particular, has been used for matrix isolation smdies of the simplest group 13 metal amides (see below). However, it is the three general approaches of Equations (8.1-8.3) that are by far the most commonly used. 

This catalyst class consists mainly of the oxides and halides of the lower elements of Groups III, IV, and V of the periodic table, distin-... 

Arsenic(III) halides are not salt-like compounds but typically non-metallic halides comparable to, for example, GeCl4 and SC12 besides their predecessors in Group 5, PX3. However AsC13 is not as reactive to nucleophilic attack as is PC13. 

Group III and IV halides enhance the activity of chloroplatinic acid in hydrosi-lylation of phenylacetylene 455 whereas aluminum halides alone promote the addition of hydrosilanes to terminal acetylenes 456... 

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