Phosphides and arsenides

The dimeric lithium diorganophosphides (LiP(CH2SiMe3)2]2, 110 [96], and [LiP CH(SiMe3)2 2]2, HI [97], have been reported and structurally characterized. The latter compound was the first uncomplexed phosphidolithium to be isolated. It was prepared by the reaction of metallic lithium with PCl[CH(SiMe3)2]2 and isolated as a yellow crystalline solid. Its central Li2N2 ring is essentially planar. 

One of the first structurally characterized lithium organoarsenides, [Li As(Bu )As(Bu )2 (THF)]2, 114, was obtained by reaction of LiAs(Bu )2 with MgBr2 in THF solution [99]. [LiAsPh2(Et20)2]2, 115, can be prepared by metal- 

6 Supmmolecular Self-Assembly Caused by Ionic Interactions 

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FdSe[12137-76-7], PdSe2 [60672-19-7], PdTe [12037-94-4], and PdTe2 [12037-95-5], Borides, sihcides, phosphides, and arsenides are also known (23,24). 

When colloids of metal sulfides, selenides, phosphides and arsenides are illxuninated in the presence of air, decomposition takes place. Metal ions migrate into solution and sulfate, selenite, phosphate or arsenate are formed. The process was first investigated in the case of colloidal CdS... 

A further interesting feature of the gallium phosphides and arsenides is that the former compounds are colorless whereas the latter range from yellow to orange. Color can arise from ir- ir transitions in main group compounds for example, in the disilylenes and digermenes R2E = ER2 (E = Si, Ge) in which the it- tt transitions occur at lower energy than... 

As the solid state structures of heterocyclic group 13 amides, phosphides and arsenides have been reviewed in the past,76 they will not be discussed here. Instead, the solid state structures of group 13 stibides and bismuthides will be described in detail. 

Heterocyclic stibino- and bismuthinoalanes, -gallanes and -indanes adopt structures in the solid state analogous to those observed for the corresponding amides, phosphides and arsenides. Their central structural parameters are summarized in Table XVIII. 

Compounds pertaining to this structural types are phosphides and arsenides of Sr and Eu and Ba3P4. Several R5Sb2X2 compounds (with R = Y or a lanthanide and X = Si or Ge) have the Tm5Sb2Si2-type structure which is an ordered superstructure (of the second kind) of the oS36-Eu5As4 type and corresponds to the following data ... 

The term S] is defined by the authors as an ionicity factor and assumes a value of 0.5 for oxides and silicates, 0.75 for halides, 0.40 for calcogenides, 0.25 for phosphides and arsenides, and 0.2 for nitrides and carbides (Z is the anion charge). Equation 1.94 is based on the thermal expansion data listed in table 1.15. 

Nitrides, Phosphides, and Arsenides. The phase diagram for the Cr-N system between 900 and 1350°C has been constructed and thermodynamic relationships in this system have been calculated. These latter studies indicated the extreme sensitivity of the kinetics of Cr-N reactions to oxygen impurity. ... 

FIGURE 110. Schematic structures of organozinc-phosphides and -arsenides 234-242... 

Colloidal sulfide, selenide, telluride, phosphide, and arsenide semiconductor particles are prepared by the controlled precipitation of appropriate aqueous metal ions by H2S, H2Se, H2Te, PH3, and AsH3, respectively. Colloids are stabilized, typically, by sodium poly-phosphate. A large number of experimental parameters determine the size, size distribution, morphology, and chemical composition of a semiconductor particles in a given preparation. Concentrations, rates, and the order of addition of the reagents the counterions selected ... 

The difference in heat of formation is even more marked between the nitrides and phosphides. By the same reasoning as for the oxides and sulphides, the alkali phosphides (where r+ is large) should have higher heats of formation than nitrides while the nitrides, with the exception of Li3N, cannot be prepared, the phosphides and arsenides of the alkali metals are fairly stable compounds. 

The nitro group does not necessarily have to be in the o- or -position of the benzene ring, nor is the presence of a nitro group a prerequisite for nucleophilic photosubstitution via the S l mechanism to occur. The meta-nitro analogue 35 with a tert-butyl group at Ca displays S l behaviour (with a series of nucleophiles)197 and so do the bridgehead halide 9-bromotriptycene (with phosphide and arsenide ions)32, compound 36 (with nitronate and azide ions)1, compound 37, X = Cl (with nitronate ions)199 and compound 38 (with azide ion)200. For compound 37, X = Br, SN2 substitution is competitive. 

The phosphide IrP2 is isomorphous with RI1P2 fr2P and IrPs adopt the anti-CnF2 and skuttemdite stmctures, respectively. Crystalline IrAss and IrSbs also possess a skuttemdite stmcture. Ternary phosphides and arsenides include Ca2fri2P7 andCa5fri9Pi2. ... 

Some interest in group 12 phosphide and arsenide complexes has come from their possible applications as precursors for IFV semiconductors (see Semiconductors). They can be prepared by two different ways, namely, by metaUa-tion reaction of phosphines and arsines with diorganozinc compounds (equation 32), and by transmetallation reaction between organozinc halides and lithium salt of the corresponding phosphines and arsines (equation 33). 

Uranous Antimonide, UgSb4, is not obtained by the ordinary methods used for the arsenide (see p. 332). By fusing a mixture of sodium uranous chloride, antimony, and aluminium Colani obtained a silvery white mass practically free from aluminium. The product resembled the phosphide and arsenide in properties, and produced vivid sparks when projected into the Bunsen flame. 

The M(14) nitrides, phosphides, and arsenides are materials with industrially useful properties, and while these are fascinating areas and although there is a wealth of literature relating to these compounds they do not fall within the scope of this article. Some materials or methods of preparation that relate to this group of compounds that are new are covered because they are of more general interest. 

The phosphides and arsenides of the elements M—PRR and M—AsRR are well known for main group elements, but transition metal analogues are more unusual. Insertion reactions were not widely explored until recently, but examples are given in reactions (j) and (k) (X = O or S) ° and (l) (n) (X = or As ) and (m) are effectively oxidative insertions of a nitrene, or specifically PhN into an Sn-P or Sn-As bond, and thus represent an extension of the Staudinger reactions whereby a phosphine or arsine is treated with an azide, and thereby converted into a phosphine-imine or the arsine analogue, as follows ... 

When subjected to high pressure certain phosphides and arsenides of metals of Groups IIIB and IVB adopt either the cubic NaCl structure (InP, InAs) or a tetragonal variant of this structure (GeP, GeAs) shown in Fig. 6.1(c) in which there are bonds of three different lengths and effectively 5-coordination. The compounds of Ge and Sn, with a total of nine valence electrons, are metallic conductors. This property is not a characteristic only of the distorted NaCl structure, for SnP forms both the cubic and tetragonal structures, and both polymorphs exhibit metallic conduction. (IC 1970 9 335 JSSC 1970 1 143.)... 

Nitrides, phosphides and arsenides Halides, oxohalides and complex halides Oxides of nitrogen Oxoacids of nitrogen... 

Quantum dots metal chalcogenides, phosphides, and arsenides 12.03.4 Conclusion... 

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