Probing angular correlations in sequential double ionization.

We study electron correlation in sequential double ionization of noble gas atoms and HCl in intense, femtosecond laser pulses. We measure the photoelectron angular distributions of Ne+ relative to the first electron in a pump-probe experiment with 8 fs, 800 nm, circularly polarized laser pulses at a peak intensity of a few 10(15) W/cm2. Using a linear-linear pump-probe setup, we further study He, Ar, and HCl. We find a clear angular correlation between the two ionization steps in the sequential double ionization intensity regime.

(M)- and (P)-8-[(1S,2R)-2-hydroxy-1-methyl-2-phenylethyl]-8-methyl-8, 9-dihydro-7H-dinaphth[2,1-c:1',2'-e]azepinium bromide solvates.

The title compounds are diastereoisomers with antipodean axial chirality. The M isomer crystallizes as a (1/3) acetone solvate, C(32)H(30)NO(+).Br(-).3C(3)H(6)O, while the P isomer crystallizes as a (1/1) dichloromethane solvate, C(32)H(30)NO(+).Br(-).CH(2)Cl(2). In each structure, O-H.Br hydrogen bonds link the cations and anions to give ion pairs. The seven-membered azepinium ring adopts the usual twisted-boat conformation and its ring strain causes a slight curvature of the plane of each naphthyl ring.