P , anionic

The alkah metal phosphides of formula M P and the alkaline-earth phosphides of formula M2P2 contain the P anion. Calcium diphosphide [81103-86-8] CaP2, contains P reaction with water Hberates diphosphine and maintains the P—P linkage. 

J. P., Anionic pol3nnerization of lactones initiated by alkali graphitides. 1 Polymerization of e-caprolactone initiated by KC24, J. Polym. Sci.. Part A Polym. Chem.. 21. 923-936, 1983. 

Hsieh, H. L. Quirk, R. P. Anionic Polymerization Principles and Practical Applications. Marcel Dekker New York, 1996. 

Quirk, R. P, Anionic Polymerization, in Kirk-Othmer Encyclopedia of Chemical Technology, 4th ed., Vol. 14, pp. 461-476, Wiley, New York, 1995 Applications of Anionic Polymerization Research, Am. Chem. Soc. Symp. Ser., Vol. 686, American Chemical Society, Washington, DC, 1998 Anionic Polymerization, in Encyclopedia of Polymer Science and Technology (online version), Wiley-VCH, New York, 2002. 

Quirk, R. P., Anionic Polymerization, in Encyclopedia of Polymer Science and Technology (online version), Wiley, New York, 2002. 

Shifts of the anodic current peak potential of the ferrocene/ferrocenium couple produced by the presence of anions (2 equiv.) added as their tetrabutylammonium salts (Af = (fp,(free) - p (anion)l). 

Detailed studies - band structure calculations, de Haas-van Alphen effect and polarized neutron diffraction - have evidenced the strong hybridization of 5 f bands either with p anions bands (USi3, UGes, USns) or 4d bands (URhs, UIts). 

Fig. 19. The structure of humite, 3Mg2Si04 Mg(OH, F)2, projected on (001) (Pnma). Atoms represented by circles as in Figs. 16-18. Left, SiMg trigonal prisms only right, bottom, conventional depiction as Si04 tetrahedra and MgX octahedra top, Si04 tetrahedra and Mgt trigonal prisms and (OH, F) atoms. Again note the distortion of the MgX octahedra, and h.c.p. anion array...

Anion-stuffed, twinned c.c.p. 1 (CrB) cation arrays were considered in Sect. 2.4 those of twinned c.c.p. 2 (Nijin) in Sect. 2.6. But an additional example of the latter is depicted in Fig. 25 cadmium chondrodite, 2Cd2Si04 Cd(OH)2, in which the anion array is extremely distorted (from h.c.p.) although the cation array remains regular, emphasising even more strongly the point made earlier that the h.c.p. anion array description is not entirely satisfactory for this family of structures. 

Fig. 16.45 (.0 Molecular structure ol the [ Bi3H j. p" anion, lb). Id front and back of I be [BiaHiJ— framework showing one of many canonical forms cnninhwmg to the resonance hybrid. a> From Mueuertics. E L- The Chemistry of Bvrrm ami Us Campoymlf. Wiley-New York. IW7- ih) from Jolly. W L. The Chemistry f the Ntm-Meioh. Prentice-Hall Englewood Cliffs. NJ. 1966. Reproduced with permission. ...

S t Davis, A. P., Anion binding and transport by steroid-based receptors , Coord. Chem. Rev. 2006, 250, 2939-2951. 

R = alkyl, aryl)], commonly used for the synthesis of bis (p-anion)dirhodium(i) tetracarbonyls, has revealed the presence of [Rh2(CO)4XY] type intermediates containing two different bridging ligands.129... 

Jerome, R. and Teyssie, P., Anionic Ring-opening Polymerization Lactones, in Comprehensive Polymer Science, Pergamon Press, Oxford, 1989, Vol. 3, pp. 501-510. 

Cyclopropanols in general, can well serve as homoenolate anion precursors, i.e., the P-anion of ethyl propionate 99), however, to avoid the easy base or acid induced ring opening the hydroxyl function of 42 must be protected when necessary. On simple addition of one equivalent of 3,4-dihydro-2H-pyran to a CH2C12 solution of the a-hydroxy acid 42, the tetrahydropyranyl ether 163 was obtained exclusively,... 

Phospholide anions can undergo coupling reactions with sp -C-centers bearing halogens in the presence of metals. This method has been exploited with the 3,4-dimethylphospholide anion, which can be converted into l-(8-quinolyl)-phosphole 223 (52% yield) upon reaction with 8-chloroquinoline at 80 C in presence of Cul (Scheme 71) <1997JOM17>. In the presence of Ni in THF at reflux, the same P-anion reacts with 1,2-dibromobenzene to give the phosphole derivative 224 in 55% yield (Scheme 71) <19980M2996>. 

Surprisingly, the reaction of diethyl carbonate and 0,0 -diethyl thiocarbonate with lithium bis(trimethylsilyl)phosphanide has been found to give ethoxy trimethylsilane and the phosphaalkynes (dme)2Li-0-CsP and [(dme)3Li] [S-CsP] respectively. As known so far, lithoxymethylidynephosphane shows a great tendency to undergo [2+2] cycloaddition and reduction reactions. The NMR parameters of the [S-C=P] -anion resemble much more the values of diorganylamino-phosphaalkynes than those of its oxygen homologue. 

A. .. A etc. contacts between the layers (see later). The reason for the great importance of the most closely packed structures is that in many halides, oxides, and sulphides the anions are appreciably larger than the metal atoms (ions) and are arranged in one of the types of closest packing. The smaller metal ions occupy the interstices between the c.p. anions. In another large group of compounds, the interstitial borides, carbides, and nitrides, the non-metal atoms occupy Interstices between c.p. metal atoms. 

In Chapter 5 we show how certain structures may be constructed from octahedral coordination groups sharing vertices, edges, or faces (or combinations of these), and it is instructive to make models relating this way of describing structures to the description in terms of c.p. anions. For this reason we show in Fig. 4,26 both these types of representation of the anatase structure which should be compared... 

Another method of examining ion-solvent interactions is to study the chemical shifts of the solute ions. This type of investigation has been carried out for the Li +, 2 Na+, and TP cations and for the CP, Br , and P anions. 

Inorganic anions, mostly SO are co-pertracted during the studied ELM pertraction process. The authors proposed this to be solved by the addition of a second ELM pertraction module, leading to practically complete rejection of the SO p anions from the resulting effluent [72]. The combined two-module system allowed for the removal of up to 99.5% of Cr (VI), and the concentration in the stripping phase, after phase separation of the ELM, was equal to 20 mol m The optimum setup and the number of modules could be optimized by the nonlinear dynamic programming as demonstrated by Fresnedo San Roman et al. [88]. 

Fig. 16.62 Rhenium(l l) dusters (a) The structural unit present in a Refill) trinuclcar cluster. The positions marked O are empty in the trihalidcs in the gas phase but have coordinating groups in other situations. (From Penfold, B. R. In Perspectives in Structural Chemistry Dunitz, J. D. Ibers. J. A.. Eds. Wiley New York, 1968 Vol. 2, p 71. Reproduced with permission.) (b) The structure of solid (ReCI ). (From Cotton. F. A. Mague. J. T. Inorp. Chem. 1964. J. 1402. Reproduced with permission. (c) The JRcjCI P-anion. [From Bertrand, J. A. Cotton. F. A. Dollase, W. A. inarp. Chem. 1963. 2. 1166. Reproduced with permission.)...

A silyl substituent also stabilizes adjacent N" and P anions as shown by the increased calculated acidities of H3SiNH2, (H3Si)2NH2, H3SiPH2 and (H3Si)2PH relative to the corresponding parent and methyl substituted amines and phosphines356. 

Figure 6. Structure of the [MofiO] 8(N2C(Me)C6H40Me)p anion 6. Adapted with permission from Angew. Chem. Int. Ed. 1999, jS, 1145. WILEY-VCH Verlag GmbH, D-69451 Weinheim, 1999.

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