Toluene remained the most common solvent and was used in combination with xylenes, ethyl acetate, and methanol. There was an increase in the use of dichloromethane as a degreasing agent.

Design to store gas molecules, such as CO , H , and CH , under low pressure is one of the most important challenges in chemistry and materials science. Herein, we describe the storage of CO in the cavities of a porous coordination polymer (PCP) using molecular rotor dynamics. Owing to the narrow pore windows of PCP, CO was not adsorbed at 195 K. As the temperature increased, the rotors exhibited rotational modes; such rotations dynamically expanded the size of the windows, leading to CO adsorption. The rotational frequencies of the rotors (k≈10 s) and correlation times of adsorbed CO (τ≈10 s) were elucidated via solid-state NMR studies, which suggest that the slow rotation of the rotors sterically restricts CO diffusion in the pores. This restriction results in an unusually slow CO mobility close to solid state (τ≥10 s). Once adsorbed at room temperature, CO is robustly stored in the PCP under vacuum at 195-233 K because of the steric hindrance of the rotors. We also demonstrate that this mechanism can be applied to the storage of CH .

A new semi-empirical equation for the viscosity coefficient of binary mixture of liquids, Eq. (11), has been derived and we have reached the conclusion that the assumption used in order to derive our equation corresponds to the Bethe-Fowler-Takagi approximation for regular assembly qualitatively. The equations for η and ε have been compared with the experimental values and satisfactory results have been obtained.

The main kinetic behavior of the slurry polymerization of propene with a MgC1,-supported TiC14/C,H,COOC,H, catalyst, activated by Al(C,H,), , was studied. Examination of the dependence of the polymerization rate on temperature and concentrations of A1(C2H5), and of propene resulted in a Langmuir-Hinshelwood rate law with the number of polymerization centers dependent on time. The polymerization rate as function of the polymerization temperature shows a maximum, which is compatible with the rate law. The analysis of the phenomenon of an optimum temperature gave 15 kJ . mol-' and 36 kJ . mol-' for the activation energy of the rate determining step and the adsorption energy of Al(C,H,), , respectively. Examination of the rapid decay of the polymerization rate showed that the main part of the decay is represented by a second order decay independent of the amount of polymer produced, which can be understood by a second order decay of surface sites by A1 (C,H5),. The number of active centers of the catalyst in gas phase polymerization was estimated applying the inhibition method with carbon monoxide. The results show a constant value for the propagation rate constant, kp, during the second order rate decay. The observed polymerization kinetics strongly suggest the existence of two kinds of polymerization centers (isotactic and atactic).

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