N o~i o NISH~MURA, TOHRU TANAKA, and TAKUSH~ MOTOYAMA. Can. J. Chem. 65, 2248Chem. 65, (1987. A critical test of additivity for partial molar volume has been made at 25' C in CCI4 with polyethylene glycol dimethyl ethers, crown ethers, cycloalkanes, n-alkanes, and others. Plots of partial molar volume at infinite dilution (v O ) against the properly chosen number of repeating unit ( n ) are linear except for small cyclic molecules, and the slopes of homologous straight chain and ring compounds are the same. The values of v O extrapolated to 11 = 0 for cycloalkanes and crown ethers support the validity of the contribution due to the translational kinetic energy that has been predicted recently on a theoretical basis. The importance of packing efficiencies around the solute molecules has been examined by means of simple models.NORIO NISHIMURA, TOHRU TANAKA et TAKUSH~ MOTOYAMA. Can. J. Chem. 65,2248Chem. 65, (1987. OpCrant i 25"C, dans des solutions de CC14, on a effectuC une Cvaluation critique de I'additivitC des volumes molaires partiels pour des Cthers dimtthyliques du polyCthylkne glycol, des Cthers couronnes, des cycloalcanes, des n-alcanes et d'autres composCs. A l'exception des molCcules contenant des petits cycles, on a trouvC qu'il existe une relation linCaire entre les volumes molaires partiels i dilution infinie (a O) et le nombre choisi appropriC d'unitts periodiques (n); de plus, les pentes des courbes pour les composCs homologues aliphatiques sont les mkmes que celles pour les composts cycliques. Pour les cycloalcanes et pour les Cthers couronnes, les valeurs de (v O ) extrapolCes i n = 0 sont en accord avec la prCdiction qui a rCcemment CtC faite sur une base thCorique et selon laquelle on pr6voit une contribution de la part de 1'Cnergie cinCtique de translation. Utilisant des moddes simples, on a CtudiC I'importance des efficacitCs d'empilement autour des moltcules de solutCs.[Traduit par la revue]

The rates of reaction of Leucocrystal Violet (LCV) with chloranil (CA) and tetracyanoethylene (TCNE) were measured, and the kinetic isotope and pressure effects were examined. In the LCV–CA system, a very large isotope effect (kH⁄kD≈11) was observed, while in the LCV–TCNE system, it was not so large (kH⁄kD=5–6) suggesting the tunnel effect is not substantial. For both systems, the formation of a CT complex in equilibrium with the reactants was observed at low temperatures (<−50 °C). From the rate law, the isotope effect, the electronic and ESR spectra observed during the reaction, and their time dependence, possible reaction processes are proposed.

The proton/deuteron transfer reaction of Leucocrystal Violet(LCV) with tetracyanoethylene(TCNE) and chloranil(CA) in various solvents has been followed spectrophotometrically. It was found that the reaction proceeds slower in polar solvents such as acetonitrile and acetone than in less polar solvents such as chloroform and 1,2-dichloroethane. The rate is remarkably accelerated by pressure indicating probably a substantial polarity increase in the rate processes. The formation of CT complexes was observed at low temperatures. Their nature is presumed to be similar to that of a complex formed by the reaction of CA with N,N-dimethyl-p-toluidine(DMT), and the latter is discussed in connection with the reaction rate of the LCV–TCNE and LCV–CA systems. A possible reaction path is proposed.

The reaction of Leucomalachite Green with chloranil to produce Malachite Green cations has been carried out in acetonitrile. Prior to the formation of the cations, a 1:1 CT complex is formed between the reactants. The equilibrium and the rate constants were estimated.