Phosphorus—con

The reaction is again most successful with phenol and indole derivatives. Reaction con-litions are also quite mild. Phosphorus oxychloride may be used in refluxing chloroform or ligher boiling hydrocarbons. Duration of the reaction is usually less than 6 hours (T. Kameta-li, 1977 A E.E. van Tamelen, 1969). 

Derivatives of oxazolofS -eNl ltriazines 620 were prepared (87AJC977) by cyclodehydration of the respective 6-acylaminotriazin-5-ones 619, obtained by acylating 618, with phosphorus oxychloride or phosphorus pentoxide. 6-Phenyloxazolotriazines 620 (R1 = Ph) were also obtained directly when aminotriazinones 618 were heated with benzoic acid anhydride. By a different route, 6-aminotriazin-5-one 618 was con-... 

Abstract Many similarities between the chemistry of carbon and phosphorus in low coordination numbers (i.e.,CN=l or 2) have been established. In particular, the parallel between the molecular chemistry of the P=C bond in phosphaalkenes and the C=C bond in olefins has attracted considerable attention. An emerging area in this field involves expanding the analogy between P=C and C=C bonds to polymer science. This review provides a background to this new area by describing the relevant synthetic methods for P=C bond formation and known phosphorus-carbon analogies in molecular chemistry. Recent advances in the addition polymerization of phosphaalkenes and the synthesis and properties of Tx-con-jugated poly(p-phenylenephosphaalkene)s will be described. 

Conceptually and synthetically more straightforward molecules can be prepared through incorporation of chromophores onto simple phosphine moieties. The phosphorus fragment can be used either to influence or to organise the n-con-jugated systems. This section will focus only on derivatives tailored in order to exhibit specific properties related to applications in NLO,opto-electronics or as sensors. 

Unlike 1,3,5-dioxaphosphorinanes the relative population of the con-former with the axial phenyl group at phosphorus decreases in 1,3,5-diazaphosphorinanes both for P(III) and for P(IV) compounds. Conformational analysis of 5-phenyl-1,3,5-diazaphosphorinanes and their oxides, sulfides, and selenides showed that the conformational equilibrium shifted toward the conformer with the axial phenyl group on changing from P(III) to P(1V) derivatives. The same conclusion made for 5-phenyl-l, 3,5-dioxaphosphorinanes, but it is contrary to that made for 1-phenyl-phosphorinane-4-ones and their derivatives (83MI1). 

The two related complexes [Li4 2-As(SiMe3)2 2 3-As(SiMe3)2 2 (THF)2] (37) and [Li As(SiMe3)2 (THF)2]2 have been isolated and structurally characterized (103). The former complex was isolated in very low yield from the reaction of LiAs(SiMe3)2 with InCl3 after recrystallization from pentane, whereas the latter complex was isolated by recrystallization of LiAs(SiMe3)2 from a pentane/THF mix. Complex 37 is isostructural with its phosphorus analogue 7 (vide supra) and con-... 

Galvez et al. (1999) demonstrated that phosphorus up to a P/Fe mol ratio of 0.03 mol mol , can be incorporated into the hematite structure by heating P-con-taining 2-line ferrihydrite. Support for structural incorporation comes from a higher unit cell c (1.3776 => 1.3824 nm), IR-stretching bands of P-OH, a lowered intensity ratio of the XRD 104/113 lines and congruent release of Fe and P upon dissolution. 

Curl, H., Standing crops of carbon, nitrogen, phosphorus and transfer between trophic levels in continental shelf waters south of New York, Rapp. Proc.-Verb. Cons. Int. Explor. Men, 153, 183, 1962. 

Six hundred milliliters of carbon tetrachloride and 200 g. of freshly distilled phosphorus (III) chloride (1.46 mols) are placed in a 1.5-1., three-necked flask which is equipped with a 125-ml. dropping funnel, a mechanical stirrer, and a con-... 

Atomic refractivities of phosphorus in its compounds are calculated as the difference between the molar refractivities and the sums of the refractivities of the other atoms. They vary according to the structure assigned, namely, whether oxygen is to be considered as singly- or doubly-linked. Molar refractivities appear to be affected by con-... 

The first artificial radionuclide (phosphorus-30) was pnv duced by the French radiochemists Frederic Joliet and Irene Curie. Nuclear medicine became a specialty in 1946 when radionuclides became available from cyclotrons and nuclear reactors. In many medical centers, nuclear medicine is con-... 

Furan-2,5-dione, or maleic anhydride, can quite reasonably be regarded as furanoquinone, the reduced form being furan-2,5-diol. The carbonyl groups do have some ketonic activity, and in Scheme 23 the key step of a second route to freelingyne (86 in Vol. 30) makes use of this capacity in a reaction with another phosphorus ylide reagent.96 (cf. Scheme 16). Even ordinary (carbonyl stabilized) carbanions will undergo such aldol con-... 

It was obvious from the outset, however, that the remarkable car-banionic reactivity of these new organometallic compounds made them valuable intermediates in organic and organometallic syntheses. Langer (6, 7) found, for example, that when the BuLi-TMEDA complex was prepared in benzene at 50 °C and phosphorus trichloride was added after one hour, triphenylphosphine could be isolated in 92% yield. By con-... 

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