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The adsorption behaviors of tris(1,10-phenanthroline)metal(II) ([M(phen)3]2) by saponite clay have been simulated by the Monte Carlo method. A two-dimensional sheet of linked [SiO4]4- and [AlO4]5- tetrahedra is used for the model tetrahedral sheet of a saponite clay. The thermal distributions of the configurations are obtained using the Metropolis algorithm at 300 K for the systems which have racemic or enantiomeric metal complex molecules intercalated between two sheets. For adsorption within the cation exchange capacity (CEC), the interlayer distance at the thermal equilibrium is obtained to be 10.5 A for both the racemic and enantiomeric chelates. For adsorption over the CEC, the interlayer distance is 18.5 and 20.7 A for the racemic and enantiomeric chelates in the presence of SO42- anions, respectively. The racemic mixture with SO42- has a mean binding energy 31.1 kJ/mol lower than that of the pure enantiomer. In both cases, the adsorbed molecules form a bimolecular layer with the anions at the middl...

Stereochemical effects on monolayer formations have been studied at an air−water interface for the racemic mixture and enantiomer of [Ru(dpp)3](ClO4)2 (dpp = 4.7-diphenyl-1,10-phenanthroline). Stearic acid (SA) was added to reduce the cohesive interaction of the Ru(II) complexes. The ratio of SA to Ru(II) complex, [SA]/[Ru], was varied from 0 to 4. At [SA]/[Ru] = 0 and 1, the “lift-off” area per molecule at which the surface pressure increased from zero was smaller for the racemic mixture than for the enantiomer. The results indicated that the racemic mixture of the Ru(II) complex formed a more compact monolayer than the enantiomer. There was no difference observed in the surface pressure−molecular area (π−A) curves at [SA]/[Ru] larger than 3. The monolayer was transferred onto a hydrophobic glass or silicon wafer substrate as a Langmuir−Blodgett (LB) film of Y-type. At [SA]/[Ru(II)] = 1, the d(001) spacing of the film was determined by X-ray diffraction measurements, leading to d(001) = 50.4 and 37.8 A f...

Monte Carlo simulations are used to investigate the intercalation structures of a metal complex within a smectite clay. The investigated model system [M(phen) 3 ] 2+ (phen=1,10-phenanthroline) intercalated between two linked [SiO 4 ] 4- and [AlO 4 ] 5- tetrahedra sheets

The adsorption of tris(1,10-phenanthroline)metal(II) ([M(phen) 3 ] 2+ ) by a clay is studied with Monte Carlo simulations. A two-dimensional sheet of linked [SiO 4 ] 4- and [AlO 4 ] 5- tetrahedra is used for the model tetrahedral sheet of a clay. The thermal distributions of the configurations are obtained using a Metropolis algorithm at 300 K

An apparatus for measuring stopped-flow electric dichroism is constructed. The instrument enables one to measure electric dichroism as a function of time after two solutions are mixed within 6 ms. The adsorption of enantiomeric or racemic [Ru(phen) 3 ] 2+ (phen=1,10-phenanthroline) by colloidally dispersed montmorillonite is studied with this instrument. As a result, it is confirmed that the adsorption of racemic [Ru(phen) 3 ] 2+ occurs by way of two successive paths: first the chelate binds with a clay rapidly within the cation-exchange capacity (CEC) and then it is adsorbed slowly in excess over the CEC

The adsorption of N-alkylated acridine orange derivatives (AO-C{sub n}; n = the number of carbon atoms in an alkyl group) by colloidally dispersed zirconium phosphate (ZrP) was studied by spectrophotometry and electric dichroism. An AO-C{sub n} cation was bound to ZrP by releasing a proton in the phosphate group of ZrP. The electronic spectrum of bound AO-C{sub n} showed that the dye cations formed an aggregate on the polymer. The reduced linear dichroism of a bound dye molecule, {rho}, was determined as a function of n: {rho} = 1.3-1.0 for n = 0-2, while {rho} = {minus}0.3 to {minus}0.4 for n = 3-9.

The oxidations by Ce(IV) ion of the cations of acridine orange (AOH/sup +/) and its n-alkyl derivatives (AO/sup +/-(CH/sub 2/)NH) have been studied in water and in the reversed micellar system of cetylpyridinium chloride (CYPCL)/water/chloroform. The length of a substituting alkyl chain (N) is varied from methyl to octadecyl groups. In both media, the oxidation is found to proceed via a 2-step mechanism. In water, the bimolecular rate constants, k1 and k2, do not vary very much with the change of N. In the reversed micellar system, the first-order rate constant of step 1, k1, has a sharp maximum at N = 1. In contrast to this, the first-order rate constant of step 2, k2, is little dependent on N. The remarkably high rate of the initial step for AO/sup +/-CH/sub 3/ is rationalized in terms of its favorable orientation at the boundary between the micellar water phase and the surfactant layer. 21 references.

Etude de la liaison entre le poly(styrenesulfonate) de potassium et le chlorure de bis((pyridyl-2 azo)-1 naphtolato) cobalt(III) optiquement actif ou racemique