The behavior of benzene molecules in ZSM-5 has been studied in detail with the use of diffuse reflectance FT-IR spectroscopy. The infrared difference spectra indicate that benzene molecules have a high selectivity for adsorption first on the most energetic (Brönsted acid) ZSM-5 sites. The existence of at least two adsorbed benzene species has also been confirmed by infrared spectroscopy. Deuterated benzene (C6D6) species located at the ZSM-5 channels and channel intersections are characterized by the C-D stretching vibrations at 2284 and 2276 cm−1, respectively. Since the high symmetry ( D6h) of the adsorbed benzene molecules is preserved, the framework of ZSM-5 may have been distorted. The distortion of the framework of ZSM-5 is also indicated by the red shift of the Si-O (or Al-O) asymmetric stretching vibrations (at ∼1215 cm−1) when adsorbed benzene molecules are present.

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Ultrasonic absorption relaxation spectra are reported covering the frequency range -1-500 MHz for the complexation of LiC104 by the open-chain polyethers triethylene glycol (EG3) and tetraethylene glycol (EG4) in acetonitrile at 25 OC and at a molar ratio R = [EG3]/[LiC104J or R = [EG4]/[LiCI04] = 1. The ultrasonic spectra can be described by the sum of two Debye relaxation processes which were interpreted according to the Eigen-Winkler mechanism Li+ + EG Li' ... EG Li+EG (LPEG) k-1 k-i(where EG denotes either EG3 or EG4), giving the rate constants k , , k~, k2, and k2. The first step is taken to be a preequilibration step for which KO is calculated from classical statistical theory. The rate constants are compared with those of the corresponding process involving triglyme and poly(ethy1ene oxide) (PEO) previously reported. Infrared data for the 3800-3200-~m-~ region show a shift of 70 cm-' to lower energy, indicating a strong interaction between the ethanolic oxygen of EG3 and the Lit ion.

An easily constructed alkali-metal-ion gun with a large metal-zeolite reservoir is described. The gun provides ion-beam currents from 100 eV to 5 keV in excess of 10 μA with a wide range of focal lengths. The ion trajectories of the extraction, acceleration, and focusing have been computed using the program simion. A versatile three-electrode extraction geometry that provides ion trajectories which emulate the planar diode is described.

Abstract