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Two-dimensional materials such as blue phosphorene (BlueP) as a substitute for conventional anode materials in lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) have garnered significant attention recently because of their large surface areas, ultrafast intrinsic carrier mobilities, and shorter ion diffusion paths. In this study, the adsorption and diffusion properties of Li and Na ions on BlueP with defects are investigated through first-principles calculations. The calculations show that the adsorption energy increased from -0.64 to -1.50 eV for Li and from -0.72 to -1.61 eV for Na because of defects. Moreover, the defects resulted in middle bands in the density of states of BlueP, indicating enhanced electron localization. This may contribute to an increase in binding energies. However, it is discovered that Li and Na ion diffusion on the surface of BlueP with defects involves a larger migration energy barrier than Li and Na on pristine BlueP, which is disadvantageous to BlueP as a battery anode. Key words: blue phosphorene, DFT, lithium-ion battery, sodium-ion battery. Les materiaux bidimensionnels, comme le phosphorene bleu (BlueP) ont attire l'attention dernierement comme substituts aux materiaux d'anodes conventionnels dans les batteries lithium-ion (BLI/LIBs) et sodium-ion (BSI/SIBs), a cause de leur grande surface, de la mobilite ultrarapide de leurs porteurs intrinseques et de leur courte distance de diffusion ionique. Sur une base de principes premiers, nous faisons ici une etude numerique des proprietes de diffusion et d'adsorption des ions Li et Na sur BlueP avec defauts. Les calculs montrent qu'a cause des defauts, l'adsorption augmente de -0.64 a -1.50 eV pour le Li et de -0.72 a -1.61 eV pour le Na. De plus, les defauts amenent des bandes intermediaires dans la densite d'etats du BlueP, indiquant une plus grande localisation electronique. Ceci peut contribuer a une augmentation de l'energie de liaison. Cependant, nous observons que la diffusion des ions Li et Na sur la surface de BlueP avec defauts implique une plus grande barriere d'energie que sur le BlueP parfait, ce qui desavantage l'utilisation d'un tel materiau comme anode de batteries electrique. [Traduit par la Redaction] Mots-cles: phosphorene bleu, theorie de la fonctionnelle de densite (TFD), batterie lithium-ion, batterie sodium-ion, defauts (cristallins)., 1. Introduction Lithium-ion batteries (LIBs) have garnered considerable interest owing to their important energy storage application in modern society. However, conventional LIBs based on graphite anodes cannot provide satisfactory performances [...]

A series of mono- and bis-ethynyl phosphonium salts have been prepared via reaction of bromoacetylenes, Ph-C[equivalent to]C-Br or Br-C[equivalent to]C-[C.sup.6][H.sup.4]-C[equivalent to]C-Br, with various phosphines. Some of the derivatives reported are previously known, ([Ph-C[equivalent to]C-P[Ph.sub.3]]Br, [Ph-C[equivalent to]C-P[Me.sub.3]]Br, [Ph-C[equivalent to]C-P[Bu.sub.3]]Br, and [[Ph.sub.3]P-C[equivalent to]C-[C.sub.6][H.sub.4]-C[equivalent to]C-P[Ph.sub.3]][[Br.sub.2]]), however typically these are missing complete spectroscopic characterization and many have been prepared using much more complicated methods. The derivative [Ph-C[equivalent to]C-PP[Ph.sub.3]]Br is capable of inhibiting the growth of tumour cells and has been shown crystallographically to have a significant interaction with the heat shock proteins (HSP70 or DnaK). Thus, solid state structures for all seven phosphonium salts prepared have been reported as they may be of interest to others in this field. Sterically encumbered phosphines such as [Mes.sub.3]P did not react with Ph-C[equivalent to]C-Br; however, [(2,4,6-MeO-[C.sub.6][H.sub.2]).sub.3]P was found to slowly react at moderate temperature to give the expected alkynyl phosphonium salt. However, at higher temperatures, the alkynyl phosphonium undergoes an intramolecular cyclization to form a phosphonium analogue of a 1,4-oxazine. Finally, electronic structure calculations reveal the positive charge on the acetylenic [beta]-carbon, a result of a significant contribution of other canonical structures. The flexibility of the P-C[equivalent to]C bond has been investigated showing a low-energy barrier ( Key words: main group chemistry, phosphorus, phosphonium, X-ray crystallography. Nous avons prepare une serie de sels de mono-ethynylphosphonium et de bis-ethynylphosphonium en faisant reagir les bromoacetylenes Ph-C[equivalent to]C-Br ou Br-C[equivalent to]C-[C.sub.6][H.sub.4]-C[equivalent to]C-Br avec diverses phosphines. Certains des derives que nous presentons sont deja connus : ([Ph-C[equivalent to]C-P[Ph.sub.3]]Br, [Ph-C[equivalent to]C-P[Me.sub.3]]Br, [Ph-C[equivalent to]C-P[Bu.sub.3]]Br et [[Ph.sub.3]P-C[equivalent to]C-[C.sub.6][H.sub.4]-C[equivalent to]C-P[Ph.sub.3]][[Br.sub.2]]). Cependant, la plupart de ces derniers n'avaient pas fait l'objet d'une caracterisation spectroscopique complete et bon nombre d'entre eux avaient ete synthetises par des methodes beaucoup plus compliquees. Le derive [Ph-C[equivalent to]C-P[Ph.sub.3]]Br s'est revele capable d'inhiber la croissance des cellules tumorales et a montre par cristallographie une interaction importante avec les proteines de choc thermique (Hsp70 ou DnaK). Par consequent, nous avons publie les structures a l'etat solide des sept sels de phosphonium que nous avons prepares, car ces derniers pourraient presenter un interet pour d'autres chercheurs dans ce domaine. Les phosphines steriquement encombrees comme la [Mes.sub.3]P n'ont pas reagi avec le Ph-C[equivalent to]C-Br, quoique la [(2,4,6-MeO-[C.sub.6][H.sub.2]).sub.3]P a reagi lentement a ttemperaturemodereepourproduireseld'alcynylphosphoniumattendu.Cependant,:adestemperaturespluselevees,l'alcynylphos-phonium subit une cyclisation intramoleculaire pour former un analogue phosphonium de la 1,4-oxazine. Enfin, les calculs de structure electronique revelent que le carbone [beta] acetylenique est charge positivement; ce qui temoigne d'une contribution importante des autres structures canoniques. Nous avons etudie la flexibilite de la liaison P-C[equivalent to]C et nous avons observe que la barriere d'energie de flexion etait faible ( Mots-cles : chimie des elements du groupe principal, phosphore, phosphonium, radiocristallographie., Introduction Since their initial discovery, (1) ethynylphosphonium salts continue to be popular and extremely valuable building blocks in organic synthesis. These compounds have classically been used as electrophiles, allowing for [...]

Temperature and nutrient availability are both hypothesized to affect organisms at the cellular and genomic levels. In this multigenerational study, Daphnia magna (D. magna) and Daphnia pulex (D. pulex) were maintained at high (20°C) and low (10°C) temperatures and nourished with phosphorus (P)-sufficient (50 µmol/L) and P-deficient (2 µmol/L) algae for up to 35 generations to assess the multigenerational impacts on genome size and nucleus size. Analysis by flow cytometry revealed significant increases in nucleus size for both species as well as genome size for D. magna in response to a low temperature. The degree of endoreplication, measured as cycle value, was species specific and responded to temperature and dietary composition. Under dietary P deficiency, D. magna, but not D. pulex, showed an apparent reduction in haploid genome size (C-value). These genomic responses are unlikely to reflect differences in nucleotide numbers, but rather structural changes affecting fluorochrome binding. While the ultimate and proximate causes of these responses are unknown, they suggest an intriguing potential for genomic responses that merits further research. Key words: genome size, nucleus size, Daphnia, flow cytometry, phosphorus. Il a ete postule que la temperature et la disponibilite de nutriments affecteraient tous deux les organismes aux niveaux cellulaire et genomique. Dans cette etude multi-generationelle, Daphnia magna (D. magna) et Daphnia pulex (D. pulex) ont ete maintenues a des temperatures elevees (20°C) ou basses (10°C) et cultivees dans des conditions d'alimentation suffisante (50 µmol/L) ou insuffisante (2 µmol/L) en phosphore (P) jusqu'il un maximum de 35 generations pour mesurer les impacts multi-generationnels sur la taille du genome et du noyau. Une analyse par cytometrie en flux a revele des accroissements significatifs de la taille du noyau chez les deux especes, de meme qu'une augmentation de la taille du genome chez le D. magna en reponse a une temperature basse. Le degre d'endoreplication, mesure en terme de valeur du cycle, etait specifique de chaque espece et changeait en fonction de la temperature et de la diete. En conditions de deficience en P, une apparente reduction dans la taille du genome haploide (valeur C) a ete observee chez le D. magna mais pas chez le D. pulex. Ces reponses genomiques ne refletent vraisemblablement pas des differences quant au nombre de nucleotides mais plutot des changements structuraux affectant la coloration au fluorochrome. Bien que les causes ultimes et directes de ces reponses ne soient pas connues, elles suggerent la possibilite de reponses genomiques qui meritent des etudes plus approfondies. [Traduit par la Redaction] Mots-cles : taille du genome, taille du noyau, Daphnia, cytometrie en flux, phosphore., Introduction Temperature is a major determinant of adult body size in a range of ectotherms (Angilletta et al. 2004; Atkinson et al. 2006), and developmental temperature can also affect cell [...]

The thermal and optical characteristics of phosphor converted white light-emitting diodes (LEDs) with different phosphor concentrations ranging from 4 wt % to 13 wt % are investigated. The light output of LEDs with higher phosphor concentration is found to have larger degradation in constant current compared with pulse current than that with lower phosphor concentration. In addition, the junction temperatures of phosphor converted white LEDs raise with increasing phosphor concentration, so that the decreased phosphor conversion efficiency is observed both in pulse and constant current modes. The physical mechanisms for these observations are discussed. This study elucidates the phosphor dependent optical and thermal behavior of phosphor converted white LEDs. [DOI: 10.1115/1.4002298] Keywords: light-emitting diodes, phosphor, current regulation, and junction temperature

Anion exchange membranes are commonly used to measure readily exchangeable and microbial P in soil, yet there is little information on their interactions with organic and condensed inorganic P compounds, which can interfere with interpretation of the results. We addressed this by quantifying the sorption of a range of P compounds to a commonly used anion exchange membrane (551642S, BDH-Prolabo, VWR International, Lutterworth, UK). Sorption and recovery of orthophosphate by the membranes was complete up to 1.17 g P [m.sup.-2]. The membranes also completely recovered sodium pyrophosphate, glucose 6-phosphate, and adenosine 5'-monophosphate, as well as significant levels (Z0-60%) of 2-aminoethylphosphonic acid, sodium hexametaphosphate, and sodium phytate. Only sodium pyrophosphate, sodium hexametaphosphate, and D-glucose 6-phosphate were detected subsequently as molybdatereactive P after elution with 0.25 mol [L.sup.-1] [H.sub.2]S[O.sub.4], however, indicating their hydrolysis in the acid eluant. Solution 31p nuclear magnetic resonance spectroscopy was used to confirm the stability of the tested compounds when exposed to the membrane and the absence of significant concentrations of orthophosphate as trace contaminants ill the compound preparations. Finally, for a series of tropical wetland soils from the Republic of Panama, we found negligible difference in eluted P concentrations determined by molybdate colorimetry and inductively coupled plasma optical emission spectrometry for both unfumigated and hexanol-fumigated samples. We therefore conclude that although organic and condensed inorganic P compounds can be recovered by anion exchange membranes, this is likely to have limited impact on the analysis of soil samples. doi: 10.2136/sssaj2009.0295

The photoluminescence (PL) and the optically stimulated luminescence (OSL) of the SrS:Ce,Sm phosphor are examined by using a time-resolved spectroscopy with excitation laser pulses of 2 ps duration. The measurements are discussed in connection with applications where the speed of the SrS:Ce,Sm luminescence is a very important factor.

A study was conducted to generate enols where Y,Y' were two dialkoxyphosphinyl [(RO).sub.2]P=O groups or a combination of [(RO).sub.2]P=O and [CO.sub.2]R or CN. The O=P[(OR').sub.2] substituent was found to be suitable activator for enolization as no competing enolization was observed on the P=O group.

The mechanisms of highly selective ferric ion sorption, as well as the exchange by the crystalline metal phosphonates that are constructed from the tetraphosphonic acids are described. These materials exhibit excellent ferric ion uptake capacities due to the electrostatic attraction between them.

The [pi]-bonding chemistry between phosphinidene and phosphonium ion was studied by computational methods. It was shown that the protonated species behave more like the heavy carbene for their weak [pi]-bonding character.

Phosphorus, a group V element, has always been found so far in minerals, biological systems, and synthetic compounds with an oxygen coordination number of four (i.e., P[O.sub.4] groups). We demonstrate using phosphorus K-edge XANES spectroscopy that this element can also adopt a sixfold oxygen coordination (i.e., P[O.sub.6] groups). This new coordination was achieved in phosphorus-doped (1 wt% [P.sub.2] [O.sub.5] level) Si[O.sub.2]-stishovite synthesized at 18 GPa and 1873 K and quenched to ambient conditions. This change of phosphorus coordination at high pressure within a dense silicate structure is particularly relevant to phosphorus mineralogy (and geochemistry) in the deep Earth. With a mantle abundance below 0.25 wt%, phosphorus has been shown to be mainly hosted by silicates (e.g., olivine) in the Earth's upper-mantle, in the fourfold-coordinated silicon sites. In the lower mantle where all silicon is sixfold coordinated, we show here that phosphorus has the crystal-chemical ability to remain incorporated into silicate structures. Keywords: Phosphorus, coordination, XANES, stishovite, berlinite, lower mantle

Alkylation reactions of diphosphines or phosphinophosphonium cations have provided a versatile approach to hexaalkyl-1,2-diphosphonium dications, which have represented prototypical phosphorus analogues of ethane. The synthetic approaches have provided access to a wide array of derivatives and means to systematic development of phosphorus analogues of hydrocarbon chemistry.

The synthesis, structures and the pseudorotation of the derivatives of Cyclotetraphosphinophosphonium ions are described. The frameworks of the cations in the solid state are found to be the snapshots of different conformational isomers within the solution-phase pseudorotation process.

A study was conducted to examine the necessity of the covalent connection between the phosphodianion and triose sugar portions of the substrate by carving up glyceraldehyde 3-phosphate (GAP) into the minimal neutral two-carbon sugar glycolaldehyde and phosphite dianion pieces. Based on the result it was proposed that the interactions of the closed flexible loops of TIM and OMPDC with the substrate phosphodianion group represent a common strategy that enables efficient recruitment of the intrinsic binding energy of a small remote binding determinant for transition state stabilization.

The first definitive examples of cyclodiphosphinophosphonium and cyclotriphosphinophosphonium cations that represent new prototypical frameworks in the rational and systematic development of catena-phosphorus chemistry are described. Addition of methyl triflate or triflic acid to cyclotetraphosphines predictably gives cyclotriphosphinophosphonium salts.

A kinetic study of the aminolyses of aryl diphenylphosphinates and diphenylphosphinothioates, demonstrating the various effects of the modification of the electrophilic center from the P[double bond]O to P[double bond]S is presented. The results prove that the reaction of the aryl diphenylphosphinothioates proceeds through a tighter transition state, as compared to the other compound, as it is comparatively less reactive in nature.

The first sequential one-pot double dearomatization of bis(N-benzyl-P,P-diphenylphosphinamides) is described via an anionic cyclization. The analysis provides a facile route of accessing the multifunctional systems with the antitumor properties, as the doubly phosphorylated systems prove to be active against a series of cancer line cells.

The binding of the most common metal cations of cytoplasm ([Li.sup.+], [Na.sup.+], [K.sup.+], [Mg.sup.2+] and [Ca.sup.2+] to a model molecule having an intramolecular hydrogen-bonding network, myo-inositol-2-monophosphate was studied. The results revealed a strong coupling between the conformational preference of these components and the interactions with metal ions, the environmental pH, and the dielectric strenght of the surrounding medium.

Ab initio calculations are performed to determine the structures and binding energies of open and cyclic complexes formed from the [sp.sup.2] [[H.sub.2]C=PH and HP=PH (cis and trans)] and [sp.sup.3] [P[H.sub.2](C[H.sub.3]) and P[H.sub.3]) hybridized phosphorus bases and their corresponding protonated ions. The experimental measurements of [super 2h][J.sub.p-p] are able to differentiate between open and cyclic complexes.

The binary mixtures containing quaternary phosphonium salt- tetrabutylphosphonium methanesulfonate and alcohols or alkylbenzenes were analyzed for solid-liquid phase and liquid-liquid phase equilibria. The aromatic hydrocarbons were used to detect the immiscibility of solid-liquid equilibria with immiscibility in the liquid phase.

The [C.sub.3] structures at the density functional theory levels-DFT, MP2 and CCSD (T) are found to be less stable than the asymmetric P[(OH).sub.3] isomers. On comparison, the energy differences observed between [C.sub.1] and [C.sub.3] species contribute to the instability.

An efficient and general procedure, which was developed for the direct alkylation of H-phosphinate esters with LHMDS at low temperature, is reported. The simplicity of the reaction allows the use of various H-phosphinate esters and takes place with a wide range of electrophiles which could be employed to access some GABA analogues or precursor to GABA analogues.

9-Formyljulolidine is oxidized by using a microwave-assisted Willgerodt-Kindler reaction to the N-piperidine or N-morpholine julolidine-9-thioamide. The products are converted to chalcogenoxanthones with phosphorus oxychloride and triethylamine (PO[Cl.sub.3]/[Et.sub.3]N).

9-Formyljulolidine is oxidized by using a microwave-assisted Willgerodt-Kindler reaction to the N-piperidine or N-morpholine julolidine-9-thioamide. The products are converted to chalcogenoxanthones with phosphorus oxychloride and triethylamine (PO[Cl.sub.3]/[Et.sub.3]N).

An efficient protocol is described for the synthesis of structurally diverse (diphenylphosphinoylmethyl)benzenes. The transformation and elaboration of 4-bromo-1,3-bis(diphenylphosphinoyl)benzene through the transition-metal-mediated procedures has produced functionalized (diphenylphosphinoylmethyl)benzenes.

The structure, spectra, and rearrangement mechanisms of P[H.sub.2][F.sub.3], the first member of the P[H.sub.n][F.sub.5-n] series and a prototype for molecules that undergo rotational isomerism, are analyzed. The results have identified the spectral fingerprints that could distinguish various rotational isomers that could form a powerful basis for the characterization of various rotational isomers of P[H.sub.2][F.sub.3] when used along with high resolution measurements.

The high-level ab initio electronic structure theory is used to calculate the heats of formation of diphosphene (cis- and trans-[P.sub.2][H.sub.3]), phopshinophosphinidene (singlet and triplet [H.sub.2]PP) and diphosphine ([P.sub.2][H.sub.4]), and those of the [P.sub.2]H and [P.sub.2][H.sub.3] radicals ensuing from PH bond cleavages. The calculated results for the hydrogenation reactions have shown that substitution of an organic substituent for H improves the energetics, suggesting that secondary diphosphines and diphosphenes are potential candidates for use in a chemical hydrogen storage system.

Synthetic, X-ray structural and reactivity studies of Cp*[Ru.sup.IV] complexes containing bidentate dithiocarbonate, xanthate, carbonate, and phosphinate ligands (Cp*=[eta.sup.5]-[C.sub.5][Me.sub.5] was carried out. The observed reversible one step four-electron redox reactions in the [Ru.sup.II] complex [[Ru(DTC)(CO)(PP[h.sub.3])([mu]-SPh)].sub.2] indicates that electron-rich Ru(DTC) complexes are potential candidates as multielectron catalysis.

One-step redox reaction of the appropriate N-alkyl, N-cycloalkyl and N-aryl substituted [alpha]-diimines which afforded N-heterocyclic phosphenium ions was investigated. A redox reaction of this type was found to be involved in the reaction of an N-heterocyclic germylene with P[Cl.sub.3] and As[Cl.sub.3] to form the [[Ge[Cl.sub.5]].sup.-] salts of the corresponding phosphenium and arsenium cations.

The 1,5-dilithiation of o-TMS locked (dimethylamino)phenylmethylferrocene has occurred unexpectedly, even though one equimolar amount of t-BuLi is used. The methoxy 1,5-diphosphane is obtained by the inversive substitution of the dimethylamino group of 1,5-diiodoferrocene by NaOMe and subsequent dilithiation and trapping with [Ph.sub.2]PCl.

A novel method is described for the synthesis of phosphocitrate (PC) starting from triethyl ester of citric acid and MeOP[Cl.sub.2]. This novel method is based on selective stepwise hydrolysis of ester moieties from the intermediate Me-O-P(O)(Cl)(Z) (Z = triethylcitrate), which has allowed to prepare partially esterified derivatives of PC with good yield and purity without using chromatographic purifications.

The specific ion (Hofmeister) effect on the cloud point of dioctanoylphosphatidylcholine (di[C.sub.8]PC)/water dispersions is investigated as a function of the lipid mole fraction, in the presence of different anions at the same concentration and with the same cation. Nonelectrostatic (NES) quantum mechanical fluctuation forces have shown to regulate lyotropic Hofmeister effects, both explicitly and implicitly.

A new pyrrole-based tetraphosphorus ligand, capable of forming multiple chelating modes, is prepared and applied in the regioselective isomerization-hydroformylation of internal olefins. Results of the experiment clearly indicate that tetraphosphorus ligand has an enhanced ability to coordinate to metal and thus afforded better regioselectivity in isomerization-hydroformylation compared with the corresponding bisphosphorus ligand.

Fluorescence measurements and {(31 super)]P NMR} are used to investigate physicochemical properties of mixed membranes of 1-palmitoyl-2-oleoylphosphatidylcholine (POPC) and a nonlamellar-forming lipid, 1-monoolein (MO) and the effects of an amphipathic [alpha]-helical peptide, 18A (DWLKAFYDK VAEKLKEAF), on the membranes. It is suggested that 18A induces a positive curvature strain and lowers the lateral pressure and water penetration.

A study was conducted to investigate the preparation and characterization of rhodium(I) complexes with the anion of 4-mercatobenzoic acid as a ligand and determine the influence of the phosphane coligands on the tendency of the products [Rh[(S[C.sub.6][H.sub.4]COOH)[(P[R.sub.3]).sub.3]] to dimerize. An equilibrium between the monomeric and dimeric form is observed for the electron-richer triethylphosphane [L=[(P[Et.sub.3]).sub.3]] which is shifted to the monomer by excess free P[Et.sub.3] in solution.

The reaction of Ru[Cl.sub.2][(PPh3).sub.3] with lithium iminopyrrolide is examined to clarify the isomerization tendencies of the iminopyrrolato ligand within an unequivocally labile environment by direct comparison with the behavior of pyrrolide. [super 31]P dipolar-chemical shift spectroscopy is applied to determine benchmark phosphorous chemical shift tensors for phosphine ligands in hexacoordinate ruthenium complexes.

A new experimental study was carried out to determine the accurate rate constant and activation parameters for the isomerization process of the [[Cp*Fe(dppe)[H.sub.2]].sup.+] system when the counterion is either B[F.sub.4.sup.-] or C[F.sub.3]CO[O.sup.-]. The isomerization rate constant is found to be essentially independent of the nature and quantity of strong acid.

The preparation of two new heptanuclear Mn clusters, [[Mn.sub.7][O.sub.5][(OMe).sub.2][(O2CPh).sub.9](terpy)] and [[Mn.sub.7][O.sub.5][(OCH2Ph).sub.2][(O2CPh).sub.9](terpy)] from the partial alcoholysis of the trinuclear complex [[Mn.sub.3]O[(O2CPh).sub.6][(py).sub.2]([H.sub.2]O)] in the presence of terpy (terpy = 2,2'; 6',2'-terpyridine) is illustrated. The obtained complexes possess S = 6 ground states and could be rationalized by qualitative considerations of the expected [Mn.sub.2] pairwise coupling.

The preparation and reactions of the salts [H-DBU][Mo2Cp2([mu]-PR2)(CO)4] and [H-DBU][Mo2Cp2([mu]-PHR)(CO)4] with p-benzoquinone (R= Cy, Ph) is reported. The oxidation reactions reported result in either O-coordination of the hemiquinone radical to the metal center or, if a P-H bond is present in the phosphide bridge, its incorporation at the phosphorus site.

A study of Langmuir isotherms and 2D bulk moduli of binary lipid mixtures is presented, where changes in monolayer collapse pressure are followed while varying the relative amounts of the two components. A distinctly non-monotonic change in collapse pressure is observed with varying composition in the case of monolayers containing dipalmitoylphosphocholine with either hexadecanol or palmitic acid.

The representative of P,P,P-trichloroylides-5-methyl-2-phenyl-4-(trichlorophosphoranylidene)2,4-dihydro-3H-pyrazol-3-one was synthesized and characterized. Some chemical properties were studied and compared with one of P,P,P-trichloroylides-5-methyl-2-phenyl-4-(trichlorophosphoranylidene)2,4-dihydro-3H-pyrazol-3-one.

A study describes the synthesis of the novel phospha-(III)guanidines [Cy.sub.2]PC{NR'}{NHR'} (R' = [super i]Pr, Cy). In the phosphorus (III) systems, the P-diphenyl substituted compounds in the phosphorus(III) systems are observed as only one isomer, shown by nuclear magnetic resonance (NMR) spectroscopy to be the [E.sub.syn]-(alpha) configuration. In contrast, the corresponding P-dicyclohexyl derivatives exist as a mixture of [E.sub.syn]-alpha and [Z.sub.anti] in solution.

The synthesis of the neutral and zwitterionic titanium(IV) phosphinidene complexes as well as catalytic studies surrounding the Ti=P bond for the latent low-coordinate zwitterion is reported. Solid-state structural studies reveal all these titanium phosphinidenes to possess the shortest Ti=P bonds ever reported.

The nature of valency and bonding in the highly unusual [O.sub.2]P[R.sub.3] 'phosphadioxirane' species isolated as an intermediate in the reaction of [super 1][O.sub.2] with organic phosphines P[R.sub.3] is investigated. The ramifications and limits of the cyclic hyperbonding phenomenon in analogous carbon compounds are examined and some broader implications of its structural representation and nomenclature are discussed.

A study was conducted to elucidate the structures and chemistry that occur on a dry silica gel surface when it is treated with P[Cl.sub.5] and moisture. The occurrence of phosphorous bridging between two adjacent silanols sites is seen and bridging structures based on Si-O-P-O-P-O-Si linkages are also seen.

Aminophosphinites or simple phosphites containing an amine arm upon treatment with elemental sulfur or selenium undergo 1,3-sigmatropic rearrangement to give chalcogenophosphates. The analogous ether- and thioether-functionalized aminophosphinites or phosphites afford the simple chalcogenides.

The 50 weak intramolecular interactions ranging from C-H...O hydrogen bonds to H-H bonds for three molecular crystals are considered and a correlation is obtained using properties of electron density at bond critical point. The correlations of the three types of interactions helped better understanding of the differences and similarities between them and allow H-H bonds to be distinguished from other types of weak interactions such as hydrogen bonds.

A new class of [pi]-conjugated macromolecule, poly(p-phenylenephosphaalkene) (PPP) is reported. The colored PPPs and their model compounds are studied by UV/vis spectroscopy, and the results are consistent with extended [pi]-conjugation.

[Au(NH=C[Me.sub.2])P[Ph.sub.3]]Cl[O.sub.4] and [Ag(NH=C[Me.sub.2])[sub.2]]Cl[O.sub.4] can be used to prepare acetimino complexes of platinum. The species include the first cationic mono- and bis- (acetimino) complexes of Pt(II), the first Pt(IV) complexes with NH=C[R.sub.2] ligands, and the first heteronuclear mu-acetimido complexes of any metals.

Synthesis of three regioisomers of aromatic-substituted phosphinyl-oxazolinyl-[2,2]paracyclophanes, pseudo-geminal, pseudo-ortho and ortho is conducted. It is demonstrated that all aromatic-substituted isomers relevant for use as chelating ligands for asymmetric catalysis are accessible.