Clusters phosphide

Douglas T and Theopold K H 1991 Molecular precursors for indium phosphide and synthesis of small lll-V semiconductor clusters in solution inorg. Chem. 30 594... 

In addition to the heteronuclear clusters considered in the preceding paragraphs. As, Sb and Bi also form homonuclear clusters. We have already seen that alkaline earth phosphides M3P14 contain the [Pv] cluster isoelectronic and isostructural with P4S3, and the analogous clusters [Asy] " and [Sbv] have also been synthesized. Thus, when As was heated with metallic Ba at 800° C, black lustrous prisms of BasAs were obtained, isotypic with Ba3Pi4 these contained the [Asv] anion with dimensions as shown in Fig. 13.25(a).Again,... 

Wright et al. have reported two cases where LiPHCy acts as a precursor to main group phosphinidine complexes. Reaction of the primary lithium phosphide with [AlMe N(mes) ]4 gives the heterometallic cage complex Li(THF) 4[ (AlMe)(ja-PCy) 2(ju.-PCy)]2 C6H5Me (95) (Fig. 12a). Reaction of [SnNBut]4 with 6 equiv of LiPHCy yields the complex cluster [ Sn2(PCy)3 2 Li(THF) 4], 2THF (96) (Fig. 12b). 

Fhst, the number of valence functions (or frontier orbitals) and valence elechons (frontier orbital occupancy) determines the tendency toward cluster bonding. It is instructive to recall that the structural motif in elemental boron is the icosahedron with six-connected boron atoms see Borides Solid-state Chemistry), it is the tetrahedral carbon atom in the diamond form of elemental carbon with four-coimected carbon atoms and it is three-connected phosphorus atoms in the sheets of elemental black phosphorus (see Phosphides Solid-state Chemistry). Boron has more valence orbitals than valence elechons, naturally leading to orbitally rich cluster formation for example, BH has three orbitals and two elechons and forms... 

The second example comes from solid-state chemistry, and the coimection with cluster chemistry is less obvious. Despite this, it is an excellent example of how E/M variation can lead to systematic variation in structure and, consequently, to properties. Although the example is taken from solid-state metal borides, the silicides see Silicon Inorganic Chemistry) and phosphides (see Phosphides Solid-state Chemistry) could have been used. 

Asymmetric Synthesis by Homogeneous Catalysis Carbonyl Complexes of the Transition Metals Carbonylation Processes by Homogeneous Catalysis Heterogeneous Catalysis by Metals Phosphides Solid-state Chemistry Polynuclear OrganometaUic Cluster Complexes Zeolites. 

Various compounds have been prepared by solvothermal reactions metals, metal oxides, chalcogenides, - ° nitrides, - -" phosphides, open-framework structures, - oxometalate clusters, - organic-inorganic hybrid materials, - - and even carbon nanotnbes. - Most of the solvothermal products are nano- or microparticles with well-defined morphologies. The distribution of the particle size of the prodnct is nsnally qnite narrow, and formation of monodispersed particles is freqnently reported. - When the solvent molecules or additives are preferentially adsorbed on (or have a specific interaction with) a certain surface of the products, growth of the surface is prohibited and therefore products with unique morphologies may be formed by the solvothermal reaction. - - Thus nanorods, wires, tnbes, and sheets of various types of products have been obtained solvothermally. 

Abstract Transition metal carbides and phosphides have shown tremendons potential as highly active catalysts. At a microscopic level, it is not well understood how these new catalysts work. Their high activity is usually attributed to ligand or/and ensemble effects. Here, we review recent studies that examine the chemical activity of metal carbides and phosphides as a function of size, from clusters to extended surfaces, and metal/carbon or metal/phosphorous ratio. These studies reveal that the C and P sites in these compounds cannot be considered as simple spectators. They moderate the reactivity of the metal centers and provide bonding sites for adsorbates. 

Fig. 13.24. The copper phosphide cluster core in [Cu96P3o P(SiMe3)2 6(PEt3)i8] 28 [99].

Rinnen K D, Kolenbramder K D, DeSantolo A M and Mandich M L 1992 Direct infrared and visible absorption spectroscopy of stoichiometric and nonstoichiometric clusters of indium phosphide J. Chem. Phys. 96 4088... 

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