Doo Wan Boo

The infrared spectra for the molecular hydrogen-solvated carbonium ions, CH+5(H2)n (n=1–6) in the frequency range of 2700–4200 cm−1 are presented. Spectroscopic evidence was found in support of the scrambling of CH+5 through the large amplitude motions such as the CH3 internal rotation and the in-plane wagging motion of three-center two-electron bond. More importantly, the scrambling motions of CH+5 cores were slowed down considerably by attaching the solvent H2 molecules to the core ion. The co

A femtosecond negative ion−neutral−positive ion charge reversal apparatus has been developed, following the concept of Wöste and Berry, to carry out spectroscopy of transient neutral species along the reaction coordinate. We report studies of the ultrafast dynamics of linear Ag 3 produced by photodetachment of linear Ag 3 - . The background-free time-resolved multiphoton ionization spectra of Ag 3 taken at various wavelengths show a strong probe time and wavelength dependence, indicating importa

Carbohydrates, as components of glycoproteins, glycolipids and proteoglycans, play an important biological role as recognition markers through carbohydrate-protein interactions. For the most part, biophysical and biochemical methods have been used to analyze these biomolecular interactions. In contrast, less attention has been given to the development of high-throughput procedures to elucidate carbohydrate-protein recognition events. Recently, carbohydrate arrays were developed and employed as a

The infrared spectrum for the H–H stretching mode of the siliconium ion SiH+5 in the frequency range of 3650–3740 cm−1 is presented. The observed vibration–rotation transitions were fitted with the A-type rotational transitions of an asymmetric top using the Watson S-type asymmetric top rotational Hamiltonian. The results suggested that the siliconium ion SiH+5 can be described as a complex between SiH+3 and a freely internally rotating H2 groups, with a highly localized three-center two-electro

The surface-enhanced Raman scattering (SERS) intensities for ethanethiol adsorbed on a silver island film have been measured for a variety of annealing conditions over the 15−300 K temperature range. Reversible temperature dependence of the C−S stretching intensities for an unannealed film similar to the case of 1-propanethiol reported previously was found, with the intensity at 15 K being greater than that at 300 K by a factor of ∼2.5. The preferential SERS enhancement at lower surface temperat

[structure: see text] To develop novel consecutive beta- and gamma-turn mimetics, we designed and characterized alpha-aminooxy tripeptides (trimers) consisting of oxanipecotic acid dimer and alpha-aminooxy acid. According to FT-IR and NMR data, as well as ab initio quantum calculations, the trimers adopted unusual folded structures with consecutive beta- and gamma-turnlike conformations.

Structures, interactions, and vibrations of an intramolecular hydrogen bond (IHB)-containing protonated ion−(water) 3 complex, g -enH + (H 2 O) 3 ( g- enH + = gauche -protonated ethylenediamine) and t -enH + (H 2 O) 3 ( t- enH + = trans -protonated ethylenediamine) with no IHB were investigated by combined vibrational predissociation spectroscopy and ab initio calculations. The observed vibrational feature at 3552 cm -1 (signature of cyclic ion−(water) 3 structure), consistent with ab initio res

We report a novel strategy for reversible immobilization of diffusive membrane-associated proteins in a native orientation using a liquid-gel bilayer phase transition, and its application to the single molecule study of Cy3-labeled Annexin V (A5) monomers on supported lipid bilayers containing phosphatidylserine (PS) in a Ca(2+)-rich environment. Total internal reflection fluorescence single molecule trajectory analysis revealed that, at low membrane occupancy, A5 monomers diffuse randomly on li