Synthesis and Characterization of Group 2 Compounds

We have tried to identify and quantify trends in precursor properties, especially those required for CVD precursors. However, it is very difficult 

The paucity of vapor pressure data is not surprising because these compounds generally have low volatility compared to other species that have been used as precursors for CVD (e. g., WF6 exhibits a vapor pressure of 1000 torr at room temperature )50 and are frequently plagued with problems such as lack of long-term thermal stability (ligand dissociation). Unfortunately, it is not possible to make an unambiguous direct comparison of the volatility of different species from comparison of their sublimation temperature, because no information is provided on the rate of sublimation. In this review, we report the sublimation temperatures and use this as an approximate guide to make qualitative comparisons of apparent volatility between precursors where we feel it is reasonable to do so. 

The only well-characterized amides and phosphides of the Group 2 metals, with the exception of the carbazoles, are those containing the bis(trimethylsilyl)amido(phosphido) ligand. This ligand has been successfully used to produce soluble, low-nuclearity, and low-coordination-num- 

Yields range from 40% for Mg[N(SiMe3)2]2(DME)2 up to 80-90% for Sr[N(SiMe3)2]2(DME)2 and [Ca(N(SiMe3)2)2]2.The advantage of this reaction over that of the mercury reaction is in the ability to isolate the 

and Ba Amide and Phosphide Compounds and Their Physical Properties 

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The synthesis and characterization of the monomeric amidinato-indium(I) and thallium(I) complexes [Bu C(NAr)2]M[But(NAr(NHAr)] (M = In, Tl Ar = 2,6-Pr2CgH3) have been reported. Both compounds were isolated as pale yellow crystals in 72-74% yield. These complexes, in which the metal center is chelated by the amidinate ligand in an N, j -arene-fashion (Scheme 33), can be considered as isomers of four-membered Group 13 metal(I) carbene analogs. Theoretical studies have compared the relative energies of both isomeric forms of a model compound, In[HC(NPh)2]. ... 

In this chapter, two general synthetic methods of poly (aryl ether ketone) copolymers were introduced, that is, (1) nucleophilic substitution step copolycondensation of at least two different monomers of bisphenol and at least one dihalobenzoid compound or at least one monomer of bisphenol and at least two different dihalobenzoid compounds (2) electrophilic Friedel-Crafts copolycondensation of at least two different monomer of diphenyl ether and terephthaloyl chloride or at least one monomer of diphenyl ether and terephthaloyl chloride as well as isophthaloyl chloride. Some representative monomers were included. By the method (1), the synthesis and characterization of structural poly (aryl ether ketone) copolymers—poly (ether ether ketone)-poly (ether ether ketone ketone) (PEEK-PEEKK), poly (ether ether ketone)-poly (ether biphenyl ether ketone) (PEEK-PEDEK), poly (ether ether ketone ketone)-poly (ether biphenyl ether ketone ketone) (PEEKK-PEDEKK), poly (ether ether ketone)-poly (ether ether ketone biphenyl ketone) (PEEK-PEEKDK) and poly (ether biphenyl ether ketone)-poly (ether biphenyl ether ketone biphenyl ketone) (PEDEK-PEDEKDK) were discussed. The s5mthesis and characterization of the functional PAEK copolymers, such as liquid crystal poly (aryl ether ketone) copol5oners, poly (aryl ether ketone) copolymers with pendent group of low dielectric constant and poly (aryl ether ketone) copolymers with crosslinking moieties were also discussed in details. These PAEK copolymers showed a lot of special performance and can maybe be applied in optical waveguides, microelectronics, display devices, membrane materials and so on. 

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