Hydration Process of Na2- in Small Water Clusters: Photoelectron Spectroscopy and Theoretical Study of Na2-(H2O)n

An infrared spectroscopic and theoretical study on (CH3)3N–H+–(H2O)n, n = 1–22: highly polarized hydrogen bond networks of hydrated clusters

Highly polarized water networks are found in the micro hydaration of protonated trimethylamine.

Microsolvation and protonation effects on geometric and electronic structures of tryptophan and tryptophan-containing dipeptides

Photodissociation spectroscopy of solvated clusters of protonated tryptophan (TrpH(+)) and dipeptides containing tryptophan (Val-TrpH(+), Ala-TrpH(+), and Gly-TrpH(+)) has been carried out at low temperature to investigate the protonation and solvation effects on the electronic spectrum. For the protonated dipeptides, the S(1)-S(0) transition exhibits a substantial red shift due to the stronger interaction between the NH(3)(+) group and the indole pi ring. The S(1)-S(0) spectra of TrpH(+)(CH(3)OH)(n) clusters exhibit a drastic change with the number of methanol molecules. This behavior is interpreted in terms of the decrease in the interaction between the pi pi* and the repulsive pi sigma* states. Ala-TrpH(+) and Gly-TrpH(+) exhibit an extensive spectral change with addition of two methanol molecules. This change is ascribed to a conformational change, which is induced by the insertion of solvent molecule in between the NH(3)(+) group and the indole pi ring.