H. Wincel
May 4, 2007
Citations
0
Influential Citations
25
Citations
Journal
Chemical Physics Letters
Abstract
Abstract Sequential hydration thermochemical data for the protonated amino acids, AAH + (AA = Gly, Ala, Phe and Pro), were obtained using a pulsed ion-beam high-pressure mass spectrometer. The hydration bond energies for AAH + (H 2 O) n decrease with n . For the complexes, GlyH + (H 2 O) n , AlaH + (H 2 O) n and PheH + (H 2 O) n with n ⩽ 4, the measured enthalpy and entropy changes show that the first three H 2 O molecules bind to the hydrogen atoms of the – NH 3 + group, while the fourth H 2 O forms the second hydration shell. In the case of ProH + (H 2 O) n with n ⩽ 3, two H 2 O molecules bind to the – NH 2 + group, and the third one is in a second shell.