稀散金属室温离子液体研究I.InCl_3/BPC体系

利用差示扫描量热曲线（DSC）方法构筑了InCl_3/BPC二元体系相图，并指出 该体系可形成含稀散金属的室温离子液体，有一定宽度的室温离子液体窗口和较小 的室温离子液体深度。从头算和Raman光谱都指出，在InCl_3/BPC体系室温离子液 体中InCl_4~-是主要负离子。     

新型电荷转移多金属氧酸盐的合成和红外光谱研究

以4种道森结构的杂多酸和3种芳香杂环化合物为原料合成了11种新型电荷转移多金属氧酸盐，研究了它们的红外光谱。结果表明：杂多酸形成电荷转移盐后，杂多阴离子的结构略有畸变但仍保持道森结构；有机给体和杂多阴离子之间存在电荷转移相互作用。     

Spectroscopic signatures of halogens in clathrate hydrate cages. 2. Iodine

UV-vis and Raman spectroscopy were used to study iodine molecules trapped in sII clathrate hydrate structures stabilized by THF, CH(2)Cl(2), or CHCl(3). The spectra show that the environment for iodine inside the water cage is significantly less perturbed than either in aqueous solution or in amorphous water-ice. The resonance Raman progression of I(2) in THF clathrate hydrate can be observed up to v = 6 when excited at 532 nm. The extracted vibrational frequency omega e = 214 +/- 1 cm(-1) is the same as that of the free molecule to within experimental error. At the same time, the UV-vis absorption spectrum of I(2) in the sII hydrate exhibits a relatively large, 1440 cm(-1), blue-shift. This is mainly ascribed to the differential solvation of the I(2) electronic states. We conclude that iodine in sII hydrate resides in a 5(12)6(4) cavity, in which the ground-state I(2) potential is not significantly perturbed by the hydrate lattice. In contrast, in water and in ice, the valence absorption band of I(2) is dramatically broadened and blue-shifted by 3000 cm(-1), and the resonance Raman scattering is effectively quenched. These observations are shown to be consistent with a strong interaction between water molecule and iodine through the lone pair of electrons on water as in the case of bromine in the same media. The results presented here, and the stability of other halogen hydrates, were used to test the predictions of simple models and force-field calculations of the host cage-guest association energy.     

Quenched by ice: transient grating measurements of vibronic dynamics in bromine-doped ice

In both water and in ice, the absorption spectra of bromine are dramatically broadened and blueshifted, and all fluorescence is quenched. Time resolved, electronically resonant transient grating measurements are carried out to characterize the vibronic dynamics of the trapped molecule in its electronic B(3Pi0u) state in ice. Independent of the initial excitation energy, after the first half-period of motion, a vibrational packet is observed to oscillate near the bottom of the potential, near nu=1. The oscillations undergo a chirped decay to a terminal frequency of 169 cm(-1) on a time scale of taunu=1240 fs, to form the stationary nu=0 level. The electronic population in the B state decays in taue=1500 fs. Adiabatic following to the cage-compression coordinate is a plausible origin of the chirp. Analysis of the absorption spectrum is provided to recognize that solvent coordinates are directly excited in the process. The observed blueshift of the absorption is modeled by considering the Br2-OH2 complex. Two-dimensional simulations, that explicitly include the solvent coordinate, reproduce both the time data and the absorption spectrum. The observed sharp vibrational recursions can be explained by overdamped motion along the solvent coordinate, and wave packet focusing by fast dissipation during the first half-period of motion of the molecular coordinate.