Quaternary phosphides

Comparatively few quaternary metal phosphides have been reported. A P-rich example is crystalline cubic AgjSnCuPio which is built from AgjSn clusters and P,o cages [51]. Recent metal-rich examples are Ca2CuZn2P3, Ca3Cu2Zn2P4 and Ca4Cu3Zn2P5 [52,53]. 

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Figure 20 Crystal structures of various ternary and quaternary phosphide oxides of the alkaline earth, rare earth, and actinoid metals. Alkaline earth (rare earth, actinoid), transition metal, phosphorus, and oxygen atoms are drawn as large light grey, medium grey, filled, and open circles, respectively. Some relevant coordination polyhedra around the oxygen atoms and the transition metal-phosphorus bonds are emphasized...

The thermal properties of the huge number of ternary or even quaternary phosphides have only scarcely been investigated. However, these data are important for planning the syntheses of new compounds. For example, the ternary skutterudite type phosphides do not melt congruently. 

Bullett, D. W., and W. G. Dawson (1986). Bonding relationships in some ternary and quaternary phosphide and tetrahedrite structures, ... 

The first part of this section is concerned with the crystal structures of ternary and quaternary phosphides and the isothermal sections of ternary systems. Systems R-M-P are considered in order of increasing atomic number of rare earth and then transition metal. The crystallographic characteristics of the phosphides are listed in tables. For phosphide structures which have been refined by single-crystal methods, atomic parameters and if-values are given. Compounds in each system are considered in order of increasing phosphorus and then rare-earth content. A separate column in the table indicates the method used for preparing the phosphide. 

The structure types of the ternary and quaternary phosphides are presented in order of increasing phosphorus content and at the same P content in order of increasing rare-earth content. Some closely related STs are also discussed. Information about the structure types of ternary phosphides is reported similarly as for binary phosphides above. 

Classification of structure types of ternary and quaternary phosphides... 

U.S. Bureau of Mines Bull. 672, 674, and 677. Bulletins 672 and 674 cover the elements, binary oxides and binary halides in a very complete fashion. Bulletin 677, summarizes the values from Bulletins 672 and 674, and adds a modest selection of tables for arsenides, antimonides, borides, carbides, carbonates, hydrides, nitrides, phosphides, selenides, silicates, silicides, sulfates, sulfides and tellurides. The coverage of these added compound types, however, is far from complete for example, there are no tables for PbS04, SnS04, GaS and Li2S. The only ternary compounds included are the carbonates, sulfates and silicates, and no quaternary compounds are listed except for a limited number of hydrated compounds. Only brief references are given to the data sources, without attempt to explain the choice between conflicting values. 

Kuz ma and Chykhrij present a systematic and encyclopedic discussion of the phosphides of the binary, ternary and quaternary rare earths. Their coverage includes preparation, phase diagrams, structure, as well as chemical and physical properties. The crystallochemical regularities, the nature of the interaction between components in ternary systems, and structural relationships also constitute important aspects of this review. 

P-0-, P-Hal-, and P-S-compounds, as well as quaternary phosphonium salts can be reduced with finely divided Na to Na-phosphides, which give phosphines or, with alkyl halides, phosphonium salts.— E ... 

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