Widely tunable cavity-enhanced ultrafast spectroscopy

Generation of widely tunable frequency combs in the UV, visible, and infrared is discussed for use in cavity-enhanced transient absorption spectroscopy on gas-phase clusters. Progress towards cavity-enhanced two-dimensional spectroscopy is also presented.

Is Lewis Acidity in Metal Dications Triggered by Solvent Shell Fluctuations?

Using experimental data collected on the stabilities of gas phase clusters consisting of metal dications in association with water molecules, a model is proposed to account for Lewis acidity. It is suggested that acidity is driven be fluctuations in the numbers of water molecules surrounding a metal ion, and that these fluctuations reduce numbers in the coordination shells to below those need to stabilise a +2 charge on the metal. The timescale on which these fluctuations are calculated to occur is approximately 6 orders of magnitude longer than any of the measure mean residence times of water molecules surrounding a central metal ion. This time difference reflects both the rarity of the event require to drive acidity and the extreme nature of some of the fluctuations.

Is Lewis Acidity in Metal Dications Triggered by Solvent Shell Fluctuations?

Using experimental data collected on the stabilities of gas phase clusters consisting of metal dications in association with water molecules, a model is proposed to account for Lewis acidity. It is suggested that acidity is driven be fluctuations in the numbers of water molecules surrounding a metal ion, and that these fluctuations reduce numbers in the coordination shells to below those need to stabilise a +2 charge on the metal. The timescale on which these fluctuations are calculated to occur is approximately 6 orders of magnitude longer than any of the measure mean residence times of water molecules surrounding a central metal ion. This time difference reflects both the rarity of the event require to drive acidity and the extreme nature of some of the fluctuations.