Phosphorus complexes

NMR spectroscopy of these phosphorus complexes has been used for structure elucidation. Depending on the bulkiness of the thiourea substituents, a single isomer (bulky) or two isomers (small size, example in Scheme 11 with two possibihties for the relative position of the cyano group)... 

The tetrahedral phosphorus complex 2010 is, likewise, readily oxidized by BTSP 1949 to give the complex 2011, with two PO groups as complex ligands, and HMDSO 7 [181] (Scheme 12.52). A similar oxidation of tetraphosphocubane is described elsewhere [182]. 

Nazarov, A. A. Dyson, P. J. Metal phosphorus complexes as antitumor agents. In Phosphorus Chemistry Catalysis and Material Science Applications, Vol. 37 (eds. Gonsalvi, L. Peruzzini, M.) 445-461 (Springer 2011). 

One explanation for the adverse effects of excessive phosphorus intakes on bone health of rodents is that of secondary hyperthyroidism (4,j>,6). Under these circumstances, PTH activities and cAMP urinary excretions would be expected to increase and blood serum phosphorus would be expected to increase. This in turn would be expected to result in formation of calcium-phosphorus complexes, decrease in serum ionized calcium, parathyroid stimulation and bone resorption. 

Metalloporphyrins containing low valent main group elements show hyper-type UV-visible spectra and the corresponding higher valent complexes show normal spectra. Despite this, the phosphorus complexes [P(OEP)R2] show spectra with distinctly hyper character, with two extra Soret bands apparent. The extra Soret band in hyper complexes has been assigned to charge transfer from the low... 

There is a recent review of two-coordinate phosphorus complexes.306 Malisch et a/.307 observed the reversible reaction (86), in which a metal-arsenic(III) double bond is formed, i.e. the M—As a bond is augmented by the arsenic lone pair to form a n bond system (since the cyclopentadienyl coligand is not coplanar with the M=As, the arsenic double bond is isolated). Complex (58) undergoes reactions typical of double bond molecules (Scheme 14). Phosphorus analogues have also been prepared (Scheme 15) the crystal structure of product (c) in Scheme 15 has been solved (59a). The d(W—P) of 2.181 A is shorter than the predicted rf(W=P) of 2.26 A, and the trigonal planar coordination of phosphorus indicates sp2 hybridization.308... 

One of the most common applications of VCD is the AC determinations of chiral compounds. Two recent studies on anthracycline analogs and on pentacoordinate phosphorus complexes from our group are included below as examples. 

Although electrophilic character is expected for cationic phosphenium complexes, only a few examples have been reported. Mer-10 readily reacts with Nu- (Me-, OEt-) to generate 29 [Eq. (20)].20 This shows that mer-10 is susceptible to nucleophilic attack at the phosphenium phosphorus. Complex 29 is not obtained in the reaction of the corresponding phosphite complex (30) with Me- or OEt-. 

Phosphorus complexes are rather rare. The 8-coordinate complex U[P(CH2CH2PMe2)2]433 is isostructural with its thorium analogue. 

The title reagent, studied as an oxidizing agent for furans,104 converts tetraphenylpyrrole into a phosphorus complex, which is hydrolyzed by water to the hydrochloride of 2-hydroxypyrrolenine (32).63 The methyl ether (91) is obtained when the crude complex is treated with sodium methoxide. 

Some defect spectroscopy measurements in n-type a-Si H have been interpreted in terms of close P D pairs (Kocka 1987) and there is also evidence of boron-phosphorus complexes in compensated a-Si H (Boyce et al. 1987). The driving force for pairing is the Coulomb interaction between oppositely charged states. Such a paired state must be treated as a distinct species in the defect reaction, which takes the form,... 

G. L. Simon and Lawrence F. Dahl First naked phosphorus complex... 

These elements, with five valence electrons, form bonds which are almost exclusively covalent in character. For this reason, it is not generally profitable to invoke an ionic description, however formal, and the definition of an ionic radius is usually of Httle value. An exception might be made in certain phosphorus complexes where an empirical radius may be defined and used in the usual way. 

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