Preparation of, III

A number of methods for the preparation of III were examined. Best results were obtained using a modification of the procedure of Surmatls, et al. (10) A mixture of 1.00 mole of mesityl oxide,... 

As described above, the precursors traditionally employed for preparation of III-V films have been group 13 metal alkyls (Me3Ga, Me3Al, Me3In) in combination with the group 15 hydride gases (Table 2). These are available on a commercial scale and have appropriate vapor pressures for both atmospheric pressure and low-pressure applications. 

An alternative route from (11) to (V) involves adding (II) and diethylmethylmalonate to prepare dimethyl-3,5-dimethoxyhydro-cinnamic acid as described for the preparation of (III). Then dehydrate and hydrolyze to dimethyl-3,5-dimethoxycinnamic acid which is hydrogenated to the alcohol and converted in several steps to (V). 

Preparation of III-V magnetic semiconductors by molecular beam epitaxy... 

Our main discussion of the MOCVD preparation of III-V semiconductors is in Section III.A. Single-source precursors for III-V semiconductors have shown advantages and [Bu2 s.AlEt2]2 has been proposed by Cowley and coworkers as such a source. Other possibilities are available such as Et2A1 AsCHMe CHMe CHMe dHMe . Aluminium containing III-V semiconductors are often ternary phases. Cowley and coworkers have synthesized a potential ternary precursor containing an aluminium/arsenic moiety. 

The silylstibines, Sb(SiR3)3, provide the onW series of examples of Si—Sb bonds and are normally treated with other organostibines. Such compounds have found use in the preparation of (III)-(V) materials via pyrolysis of their group 13 adducts.There are also examples of Sb(YR3)3 (Y = Ge, Sn, or Pb) types. ... 

Preparation of polv(4.4 diphenvldiol phosphate). (III). The procedure employed for the preparation of III was analogous to the one for aliphatic polyphosphates. 

Glycosyl acceptors III.3 and III.4, used in the preparation of the )8( 1,3)-disac-charides, were obtained from methyl 2-azido-2-deoxy-)8-D-galactopyranoside [67]. Selective 3,6-di-O-silylation followed by treatment with benzyl bromide led to the installation of the benzyl ether at C4. Desilylation occurred in situ under the ben-zylation reaction conditions to produce III.15 and subsequent 6-O-acetylation of III.15 with 1-acetylimidazole produced III.3 in 78% yield (Scheme 25). The preparation of III.4, carried out as reported earlier by Jacquinet and Sinay [67], was obtained from III.16 by regioselective ring opening of the isopropylidene to unmask the 3-OH. 

The Waters procedure (see page 151) has proved its value also for preparation of iii-bromonitrobenzene 374... 

Organometallic precursors were also used for the preparation of III-V semiconductors. Buhro reported the use of a single-source precursor Bu 2ln[/t-P(SiMe3)2] 2, which upon methanolysis in toluene leads to a mixture of InP and In nanoparticles, which promote the growth of InP fibers through a solution-liquid-solid mechanism. " ... 

Metallorganic chemical vapor deposition (MOCVD) is now widely used in the preparation of III-V and II-VI devices. In addition to the hydride gases used as source materials in other CVD systems (e g., arsine and phosphine), less toxic liquid alternatives (e.g., tertiary butyl arsine and tertiary butyl phosphine) are also used in MOCVD systems along with other toxics such as cadmium alkyls and mercuiy.[42][43]... 

R. K. Willardson, H.L. Goering, 1962, Compound Semiconductors, Vol. 1 Preparation of III-V Compounds, Reinhold Publishing Corporation, New York. 

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