Pnictides

So far little work has been performed on the UPD of pnictides N, P, As, Sb. It would appear that UPD of N, or even electrodeposition of N from an aqueous solution, is not a likely event. P has been known to deposit with ferrous metals, such as Ni, to form NiP alloys [257-261], This induced co-deposition of P with Ni suggests that it can be electrodeposited, although it does not appear that bulk P would be stable in an aqueous solution. It may be that P can be induced to form an atomic layer on the right metal, possibly Ga or In. 

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Pnictides. Plutonium nitride, PuN, has been studied as a possible fast-reactor fuel. It can be prepared by reaction of PuH with NH at 600—650°C or N2 above 230°C. The pnictides ate also interesting for their soHd-state magnetic and electrical properties. For the latter reason they also have been prepared as single crystals (165). 

The pyrites structure is exhibited by several pnictides MAs2 and MSb2 (M = Pd, Pt) and PtP2 (Figure 3.10). 

Crystal chemistry of the chalcogenides and pnictides of transition elements. F. Hulliger, Struct. Bonding (Berlin), 1968,4, 83-229 (532). 

Purex process, 6, 946 oxidation state reduction, 6, 947 Pnictide ligands double bonds, 2, 1045 triple bonds, 2, 1046 Podandocoronands classification, 2, 919 Podands... 

Hulliger F (1968) Crystal Chemistry of Chalcogenides and Pnictides of the Transition Elements. 4 83-229... 

It is clear that targeting only the combinations in this table, with no substitution of a trivalent lanthanide for the pnictide, Pn, there are 72 different reactions to monitor, for each sulfur or selenium and arsenic or antimony system, at varying temperatures (our compounds were prepared between 750 and 1200 °C). 

A closer examination of Table 6-3 reveals a rather startling conclusion. It can be seen that most of these compounds are subject to structure-vacancy defects. Certainly all of the pnictides fall into this class. We are even given the defect concentration. Thus in GaP, we have ... 

It is a tribute to Leslie that very little of the new information in the 5th and this edition is old stuff that he missed almost all comes from new publications. The entries on new groups range from acrylates to yeast passing through drums, fumes, mists and pnictides on the way. Familiar accidents continue to occur and new entries have been added on well-known hazards, such as nitric acid and azides. 

These precursors are generally prepared by alkane elimination (Equation (7a)) or—especially useful with bulkier substituents—the coupling of metal chlorides with lithium pnictides or silyl arsines (Equation (7b)) or salt elimination or silyl halide elimination reactions (Equation (7c)) ... 

The preparation of similar precursors suitable for the deposition of metal nitrides is analogous to the preparations of phosphorus and arsenic compounds. The initial reaction of metal trialkyls MR3 (M = A1, Ga, In) with amines (NHR 2) results in the formation of oligomeric amido compounds [R2MNR 2] (n = 2 or 3) which eliminate alkanes on thermolysis. The incorporation of a proton as a substituent on the pnictide bridging ligand has been examined, and many compounds of the type [R2MNHR ]2 have been synthesized. The presence of this proton may facilitate /3-elimination, allowing lower deposition temperatures to be used. 

There were significantly fewer reports on organozinc compounds bearing ligands with heavier group 15 donors than those on organozinc amides. This is mainly due to the weakness of the zinc-pnictide bonds, which rules out the use of... 

At present, the elements used in the formation of compounds by EC-ALE include the chalcogenides S, Se, and Te the pnictides As and Sb the group three metals Ga and In the group II metals Zn, Cd, and Hg as well as Cu, and Co. The range of compounds accessible by EC-ALE is not clear. The majority of work has been performed on II VI compounds (Table 1). The III-V compounds InAs and InSb have recently been formed, and the first deposits of a III-VI compound, InSe, have been made [151], In addition, Shannon et al. have begun studies of CoSb [152] with the intent of forming thermoelectric materials. 

Initially, EC-ALE was developed on the principle that reductive UPD of a metal and oxidative UPD of a main group element were required to form a working cycle. This would then limit compounds that could be formed to those containing a chal-cogenide or a pnictide, as reduced forms of some of these elements were reasonably stable in aqueous solutions. Recently, it has been shown that reductive UPD of both... 

Among binary transition-metal pnictides, only the first-row transition-metal phosphides have been analysed by XPS extensively, whereas arsenides and antimonides have been barely studied [51-61]. Table 2 reveals some general trends in the P 2p3/2 BEs for various first-row transition-metal monophosphides, as well as some metaland phosphorus-rich members forming for a given transition metal. Deviations of as much as a few tenths of an electron volt are seen in the BEs for some compounds measured multiple times by different investigators (e.g., MnP), but these... 

In terms deriving from the Ramsey approach, a review of chemical shifts in chalcogenide and pnictide semiconductors in terms of Harrison s BOM and related approaches has been given [130]. The Ramsey approach has also been used to explain chemical shifts in III-V compounds [131], and specifically 113Cd shifts in Cd chalcogenides [132]. 

Gleizes, A. N. 2000. MOCVD of chalcogenides, pnictides, heterometallic compounds from single-source molecule precursors. Chem. Vap. Deposition 6 155-173. 

B. Electronic Features and Structural Principles of Molecular Main Group Metal Pnictides... 

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