Phosphides lanthanide

A mechanism that involves ytterbium phosphide species has been proposed, similarly to the foregoing intramolecular hydrophosphination. Generation of the phosphide species is supported by the formation of Ph2CDNHPh (after aqueous quench) upon treatment of the imine complex with Ph2PD (Scheme 15). Lanthanide phosphide is known to react with THF, forming a 4-diphenylphosphino-l-butoxyl species [21], which was indeed found as a side product in the catalytic hydrophosphination of disubstituted aliphatic alkynes run in THF, supporting further the ytterbium-phosphide intermediate (Scheme 16). 

In the review by Kanatzidis et al. (2005), the preparation by the tin-flux method is mentioned also for several ternary phosphides and polyphosphides of rare-earth and transition metals. Typically the components (R metal, T metal, P and Sn in an atomic ratio of about 1 4 20 50) in sealed silica tubes were slowly heated, to avoid violent reactions, up to 800°C, annealed at that temperature for 1 week and slowly (2 K/h) cooled to ambient temperature. The tin-rich matrix was dissolved in diluted hydrochloric acid. The authors described the preparation of compounds corresponding for instance to the formula MeT4P12 (Me = heavy rare-earth metals and Th and U, T = Fe, Ru, etc.) and to the series of phases MeT2P2 (Me is a lanthanide or an actinide and T a late transition metal) having a structure related to the BaAl4 or ThCr2Si2 types. 

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 ... 

No, the editor didn t know what this name meant either.) It means salts of the triva-lent anions of Group V, restricted in [1] to arsenides, antimonides and bismuthides and prepared by reaction of sodium pnictides with anhydrous halides of transition and lanthanide metals. This violently exothermic reaction may initiate as low as 25°C. Avoidance of hydrated halides is cautioned since these are likely to react uncontrollably on mixing. Another paper includes a similar reaction of phosphides, initiated by grinding [2], Nitrides are reported made from the thermally initiated reaction of sodium azide with metal halides, a very large sealed ampoule is counselled to contain the nitrogen [3],... 

When lanthanide metals (M = La - Lu) were heated directly with phosphorus, or M203 with PH3 in air, the binary phosphides MP were produced.55 These decomposed in water and, in air at 700°C, were oxidized to phosphates on heating PrP at 2850 °C, a refractory material, deficient in P but containing free Pr and adsorbed oxygen, was formed. EuP2, obtained by reaction of Eu203 with Pn, contains euro-pium(n).56... 

Although the first filled skutterudites were aheady synthesized in the late 1970s by Jeitschko and coworkers, this class of phosphides has found renewed interest in recent years with respect to the outstanding thermoelectric properties. However, the thermoelectric properties of the filled skutterudites with the higher homologues arsenic and antimony are superior to the phosphides. Most of the research on filled lanthanide skutterudites has recently... 

Lithium di-tert-butyl phosphide and Uthium tert-butyl phenylphosphide react with some dicyclopentadienyl lanthanide chlorides with elimination of lithium chloride and formation of the corresponding dicyclopentadienyl (organophosphide) lanthanide derivatives. Molecular-weight determinations indicate an oligomeric structure in solution (Schumann and Jarosch, 1976 Schumann and Frisch, 1981) ... 

Fig. 21. Logarithm of upstroke-transition pressure versus cation/anion radius ratio for the B1 to B2 transition in lanthanide and actinide compounds. Trivalent ionic radii are used for all cations. Some transitions to other high-pressure structures are included for comparison and have been marked as such in the graphs, (a) Mono-pnictides with As, Sb, and Bi. The isolated data for the phosphides CeP and ThP are not included. No mononitrides have been observed to transform to the B2 type under pressure, (b) Mono-chalcogenides with S, Se, and Te. The EuO transition is outside the graph.

Mixed Ln-An phosphides and sulfides. The mixed compounds US-PrS, US-NdS, UP-PrP and UP-NdP have also been investigated. A summary of results obtained on these systems is given by Troc (1980) and Troc et al. (1980b), where the corresponding references may be found. The ferromagnetism of US converts into a spin-glass system on addition of the lanthanide. The antiferromagnetism of UP, on the other hand, is not affected. As can be expected, the behaviour of these mixtures is very complicated, and a satisfactory explanation cannot be offered. 

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