As the development of the work (J. Phys. Chem. B 2019, 123 (10), 2362−2372), we have investigated the translational mobility in the same set of dried imidazoliumbased ionic liquids (ILs) [bmim]A (A = BF 4− , NO 3 − , TfO − , I − , Br − , and Cl − ) in a wide temperature range using the NMR technique. It is shown that for the [bmim] + cation, the temperature dependencies of product Dη do not follow the Stokes−Einstein relation for most systems studied, that is, the so-called "diffusion−viscosity decoupling" was realized. The correlation between local and translational mobility in pure IL of the [bmim][A] type was investigated using the data on NMR relaxation rates and diffusion coefficients. The most recent hypothesis of "water pockets" in mixtures of IL with water is critically discussed. Considering the totality of data in the literature and obtained here, we propose a specific model of the microstructure which may be applied up to water concentrations of 80−90 mol % (the structure of water-rich solutions is out of our current consideration). To confirm the model, molecular dynamics simulations of "IL−water" mixtures were also carried out.

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This paper describes the development and performance of an optical parametric oscillator based on KTP crystal and pumped by a flashlamp-pumped Q-switched Nd:YAG laser at 1.064 .tm. The effect of an optical resonator configuration on OPO performance has been investigated experimentally. A comparison between plane-parallel, stable and unstable resonators in both energy conversion and output beam divergence was also performed and the results are discussed. In summary, we have demonstrated a compact low threshold source for the near JR in a configuration of an intracavity optical parametric oscillator based on the noncntically phase-matched KiT crystal placed inside the resonator of a multi-transverse-mode Nd:YAG laser. The 1.57 tm output energy of 40 mJ was achieved with a stable, short cavity KiT OPO. The overall efficiency (flashlamp input to OPO signal-wave output) of 0.55%was obtained from operating -2 times above oscillation threshold. The dependence of output pulse energy on flashlamp input energy was not changed within the range of 5-50 Hz.