Phosphorus clusters

The rather complicated indium-phosphorus cluster framework 24 was obtained by the reaction of indium(III) chloride with PhP(SiMe3)2 in the presence of triethyl-phosphane [Eq. (12)] [29]. Apparently, a complex redox process occurred, in the course of which phosphorus atoms were oxidized by the formation of three P-P bonds, while six indium atoms were reduced from +3 to +2 accompanied by the formation of three In-In bonds. The In-In (average 274 pm) and P-P bond lengths (average 222 pm) represent localized single bonds. Other strategies for the... 

R.O. Jones, D. Hohl, Structure of phosphorus clusters using simulated annealing P2 to Pg, Journal of Chemical Physics, 92 (1990) 6710. 

Figure 2.71 shows the structures of phosphorus clusters for which vibrational assignments are available. 

The PACIS has been used to generate phosphorus cluster anions P,T up to n = 9. Photoelectron spectra recorded at photon energies hv = 2.33 eV, 3.49 eV, and 4.66 eV are shown in Figs. 8, 9a, and 9b, respectively. The spectra of PJ show four electronic transitions (Fig. 9b, A-D), and feature A is assigned to the ground state transition (VDE 0.68 + 0.05 eV). Vibrational fine structure is... 

SANS and APFIM examinations [62,67] showed that phosphorus formed several types of clusters depending on the chemical composition of the steel. This result was found in pressure vessel steels and model alloys, as mentioned above. Phosphorus clusters were often enriched in Ni and occasionally in C. In general commercial RPV steels, these features were present at a much lower number density than the Cu clusters. In cases where the Cu level was very low, or if the P content was increased, the number density of these P clusters became significant. Beaven et al. [67] detected P clusters in irradiated A533B steel, which has 0.002 wt% Cu. The number density of these clusters increased with increasing P content, while its average radius remained nearly constant at 0.5-1 nm. In contrast, when the Cu content was... 

H. Hoffmann and M. Becke-Goehring, Topics in Phosphorus Chemistry 8, 193-271 (1976) J. G. Riess in A. H. Cowley (ed.), Rings, Clusters and Polymers of the Main Group Elements, ACS Symposium Series No. 232, 17-47 (1983). 

Reaction of diphenyl-2-thienylphosphine with Ru3(CO)l2 gives the tiVp) ti Ti C) coordinated species, 144, along with cluster 145 where two ligand molecules participate in coordination, one via the phosphorus atom and the C=C bond of the heteroring, and the other via the phosphorus atom only. P-Coordination in the products of such an interaction is known [95JOM(488)85]. Complex 144, the main product, interacts with carbon monoxide to yield the P-coordinated cluster, 146,... 

Fig 28. Vanadium borophosphates with the composition [(VO)2BP20io] n form cage-like cluster anions, which may be empty (107, n = 4) or centered by a cation (109, n = 6). For clarity only half of the vanadium and phosphorus atoms of the cluster anions are shown... 

A cluster with five Au atoms exists in Au5(dppm)3[(Ph2P)2CH]KN03)2. This cluster has a AU4 core, with an additional Au incorporated in the phosphine ligand, linearly coordinated between a phosphorus and a carbon from the methanido bridge (IV) ... 

Metcalf WW, BL Wanner (1991) Involvement of the Escherichia coli phn (psiD) gene cluster in assimilation of phosphorus in the form of phosphonates, phosphite, Pj esters, and Pj. J Bacterial 173 587-600. 

Figure 5 Model of phosphorus (P) deficiency-induced physiological changes associated with the release of P-mobilizing root exudates in cluster roots of white lupin. Solid lines indicate stimulation and dotted lines inhibition of biochemical reaction sequences or mclaholic pathways in response to P deliciency. For a detailed description see Sec. 4.1. Abbreviations SS = sucrose synthase FK = fructokinase PGM = phosphoglueomutase PEP = phosphoenol pyruvate PE PC = PEP-carboxylase MDH = malate dehydrogenase ME = malic enzyme CS = citrate synthase PDC = pyruvate decarboxylase ALDH — alcohol dehydrogenase E-4-P = erythrosc-4-phosphate DAMP = dihydraxyaceConephos-phate APase = acid phosphatase.

A new, exciton-like mechanism has been proposed by Demidenko et al. [34] to describe the formation of amorphous NiP films. According to these authors, the electroless process is initiated by the reduction of Ni2 + by adsorbed hydrogen to produce clusters of pure Ni. Vacancy sites on these clusters capture a proton (presumably from the H2POJ anion) to form an exciton-like state, which subsequently captures more Ni atoms, and so on. Phosphorus can be captured and fixed at a vacancy site. 

Reviews covering the chemistry of group 2 metal complexes with phosphorus-stabilized carbanions,279 and of molecular clusters of magnesium dimetallated primary phosphanes, are available.2 u Magnesium phosphanes remain rare compounds.281 Lithiation of bromide 98 with BuLi in the presence of tmeda in pentane produces a lithium phosphine dimer subsequent treatment with MgCl2 in EtzO gives the phosphane 99 in 69% overall yield (Equation (19)). The centrosymmetric 99 has Mg-C = 2.217 A Mg-P = 2.77 A (av.).282... 

Although the products in these equations are written as if they were simple ionic binary compounds, this is not always the case. For example, some nonmetals form clusters containing several atoms arranged in polyhedral structures. One such species is the P73- cluster, which has six phosphorus atoms at the vertices of a trigonal prism with the seventh occupying a position above a triangular face... 

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