Spirophosphoranylation d'α-aminoacides—I : Preparation et tautomerie

New spirophosphoranes have been prepared by reaction of &alpha-aminoacids with tricoordinate phosphorus substrates. In one case, 1i, an equilibrium chain-cycle P^IIIP^v has been observed.     

Kinetic-fluorimetric determination of microamounts of cerium(IV) by means of sodium 4,8-diamino-1,5-dihydroxyanthraquinone-2,6-disulphonate

Summary A kinetic method for determination of traces of Ce(IV), based on the oxidation of sodium 4,8-diamino-1,5-dihydroxyanthraquinone-2, 6-disulphonate is described. The reaction is monitored by means of the fluorescence of the oxidation product ( _ex=525nm, _em=585 nm), and allows determination of 0.02–0.37 ppm Ce(IV). The proposed method has few interferences.

---

Kinetisch-fluorimetrische Bestimmung von Mikromengen Cer(IV) mit Natnum-4,8-diamino-1,5-dihydroxyanthrachinon-2,6-disulfonat

Zusammenfassung Eine kinetische Methode zur Bestimmung von Spuren Cer(IV) mit Hilfe von Natrium-4,8-diamino-1,5-dihydroxyanthrachinon-2,6-disulfonat wurde beschrieben. Dabei wird ein fluoreszierendes Oxydationsprodukt gebildet, das bei 525 nm angeregt mit einer maximalen Emission bei 585 nm fluoresziert. Die Reaktion ermöglicht die Bestimmung von 0,02–0,37 ppm Cer(IV). Die vorgeschlagene Methode wird nur durch wenige Störungen eingeschränkt.

     

Phosphazene spirannique a partir de derives du phophore dicoordine

The reaction of azidoalcohol $\text{2}$ on triazaphosphole $\text{1}$ takes place according to pathway $\text{a}$ and not $\text{b}$, as shown by the isolation of spirannic phosphazene $\text{3}$. The diazadiphosphetidines $\text{4}$, dimers of $\text{3}$ are also caracterized.     

Resolution of Eigen fuzzy sets equations

When R is a fuzzy relation between the elements of a finite set X, the fuzzy subsets A of X such that R·A = A (max-min composition) are called eigen fuzzy sets. In this paper we describe algorithms for the determination of the greatest eigen fuzzy set associated with a given fuzzy relation, thinking of medical diagnosis applications.     

Synthesis of selenolates from stannyl and silyl alkylselenides

Stannyl and silyl alkylselenides have been efficiently transformed to the corresponding alkylselenolates on reaction with butyllithiums. Other conditions proved to be limited.     

Observation of B(+)-->phiphiK(+) and evidence for B(0)-->phiphiK(0) below eta(c) threshold

We report measurements of the decays B(+)-->phiphiK(+) and B(0)-->phiphiK(0) using a sample of 231 x 10(6) BB pairs collected with the BABAR detector at the PEP-II asymmetric-energy B factory at the Stanford Linear Accelerator Center. The branching fractions are measured to be B(B(+)-->phiphiK(+))=(7.5+/-1.0(stat)+/-0.7(syst)) x 10(-6) and B(B(0)-->phiphiK(0))=(4.1(-1.4)(+1.7)(stat)+/-0.4(syst)) x 10(-6) for a phiphi invariant mass below 2.85 GeV/c(2).     

Observation of an excited charm baryon Omega c* decaying to Omega c0gamma

We report the first observation of an excited singly charmed baryon Omega c* (css) in the radiative decay Omega c0gamma, where the Omega c0 baryon is reconstructed in the decays to the final states Omega(-)pi+, Omega(-)pi+pi0, Omega(-)pi+pi(-)pi+, and Xi(-)K(-)pi+pi+. This analysis is performed using a data set of 230.7 fb(-1) collected by the BABAR detector at the PEP-II asymmetric-energy B factory at the Stanford Linear Accelerator Center. The mass difference between the Omega c* and the Omega c0 baryons is measured to be 70.8+/-1.0(stat)+/-1.1(syst) MeV/c2. We also measure the ratio of inclusive production cross sections of Omega c* and Omega c0 in e+e(-) annihilation.     

Measurement of the B-->pi l nu branching fraction and determination of absolute value of V(ub) with tagged B mesons

We report a measurement of the B-->pi l nu branching fraction based on 211 fb(-1) of data collected with the BABAR detector. We use samples of B0 and B+ mesons tagged by a second B meson reconstructed in a semileptonic or hadronic decay and combine the results assuming isospin symmetry to obtain B(B(0)-->pi- l+ nu) = (1.33+/-0.17stat+/-0.11syst) x 10(-4). We determine the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element absolute value V(ub) by combining the partial branching fractions measured in ranges of the momentum transfer squared and theoretical calculations of the form factor. Using a recent lattice QCD calculation, we find absolute value V(ub) = (4.5+/-0.5stat+/-0.3syst(+0.7) -0.5FF x 10(-3), where the last error is due to the normalization of the form factor.     

Measurement of the branching fraction and photon energy moments of B-->Xs gamma and A(CP)(B --> X(s+d gamma))

The photon spectrum in B-->Xs gamma decay, where Xs is any strange hadronic state, is studied using a data sample of 88.5 x 10(6) e+ e- --> Upsilon(4S) --> BB decays collected by the BABAR experiment at the Stanford Linear Accelerator Center. The partial branching fraction, DeltaB(B --> Xs gamma) = (3.67+/-0.29(stat)+/-0.34(syst)+/-0.29(model)) x 10(-4), the first moment = 2.288+/-0.025+/-0.017+/-0.015 GeV, and the second moment E2(gamma) = 0.0328+/-0.0040+/-0.0023+/-0.0036 GeV2 are measured for the photon energy range 1.9 GeV < E gamma < 2.7 GeV. They are also measured for narrower E gamma ranges. The moments are then fit to recent theoretical calculations to extract the heavy quark expansion parameters m(b) and mu2(pi) and to extrapolate the partial branching fraction to E gamma > 1.6 GeV. In addition, the direct CP asymmetry A(CP)(B-->X(s+d gamma) is measured to be -0.110+/-0.115(stat)+/-0.017(syst).