Transition state spectroscopy of the photoinduced Ca + CH(3)F reaction. 1. A cluster isolated chemical reaction study.

The "cluster isolated chemical reactions" technique is used to examine the dynamics of the photoinduced reaction producing electronically excited CaF when 1:1 Ca-CH(3)F complexes are deposited at the surface of large argon clusters. This technique ensures quantitatively that 1:1 complexes are actually at the origin of the observed signals. The reaction is monitored by observing the CaF chemiluminescence while scanning the photoexcitation laser.

Excited state reactions of metals in clusters: pluridimensional harpoon and solvation effects.

Excited state reactions of metals produce electronically excited products efficiently, as revealed by studies performed both in the gas phase and in free Van der Waals complexes. The reaction mechanism is assigned to an excited state charge transfer from the metal to the molecular reactant (i.e.

Prolonged amenorrhea and oral contraceptives.

Of 106 consecutive women referred for secondary amenorrhea of more than 1 year's duration, 65 were diagnosed as having functional amenorrhea. Of these 65, 29 had amenorrhea directly following discontinuation of oral contraceptives (OC group) and 36 had never used oral contraceptives (NOC group). There was no difference in the incidence of prior menstrual irregularity in either group.