GNO Solar Neutrino Observations: Results for GNOI

We report the first GNO solar neutrino results for the measuring period GNOI, solar exposure time May 20, 1998 till January 12, 2000. In the present analysis, counting results for solar runs SR1 - SR19 were used till April 4, 2000. With counting completed for all but the last 3 runs (SR17 - SR19), the GNO I result is [65.8 +10.2 -9.6 (stat.) +3.4 -3.6 (syst.)]SNU (1sigma) or [65.8 + 10.7 -10.2 (incl. syst.)]SNU (1sigma) with errors combined. This may be compared to the result for Gallex(I-IV), which is [77.5 +7.6 -7.8 (incl. syst.)] SNU (1sigma). A combined result from both GNOI and Gallex(I-IV) together is [74.1 + 6.7 -6.8 (incl. syst.)] SNU (1sigma).Comment: submitted to Physics Letters B, June 2000. PACS: 26.65. +t ; 14.60 Pq. Corresponding author: [email protected] ; [email protected]

Ferrocenyl carbocations. The ionization of ferrocenyl alcohols in aqueous sulfuric acid

A detailed study of the ionization equilibrium between ferrocenyl alcohols and α-ferrocenyl carbocations in aqueous sulfuric acid has been performed by spectral methods. The spectral characterization of the carbocations, the extent of their formation as a function of the proton-donor ability of the solvent, and the determination of the equilibrium constants are reported. The behavior of ferrocenyl alcohols as indicators compared to that of triarylmethanols is discussed. The transmission of the polar effects of the heteroannular substituents, the heteroannular bridging of an α-hydroxytrimethylene chain, and the high charge delocalization power of the carbocation are also examined

Stereochemical consequences of the intramolecular hydrogen bond in 1′-acetyl-1-α-hydroxyethyl- and 1,1′-bis(α-hydroxyethyl)ferrocenes

1′-Acetyl-1-α-hydroxyethyl- and 1,1′-bis(α-hydroxyethyl)ferrocenes and the carbocations derived from them have been characterized by electronic, infrared and NMR spectroscopy. The existence of intramolecular hydrogen bonds between the interannular substituents in the various species examined has been established. The restricted rotation caused by such interaction leads to preferential formation of pairs of enantiomers

Ferrocenyl carbocations. The ionization of ferrocenyl alcohols in aqueous sulfuric acid

A detailed study of the ionization equilibrium between ferrocenyl alcohols and α-ferrocenyl carbocations in aqueous sulfuric acid has been performed by spectral methods. The spectral characterization of the carbocations, the extent of their formation as a function of the proton-donor ability of the solvent, and the determination of the equilibrium constants are reported. The behavior of ferrocenyl alcohols as indicators compared to that of triarylmethanols is discussed. The transmission of the polar effects of the heteroannular substituents, the heteroannular bridging of an α-hydroxytrimethylene chain, and the high charge delocalization power of the carbocation are also examined