Photochemistry of tris(2,2'-bipyridyl)(ruthenium(II) in colloidal clay suspensions

Abstract

complexes the indole chromophore was found to be the protondonating substituent. The spectral shifts of these complexes, and thus the relative strength of the hydrogen bond, are shown to give a reasonable linear correlation with the basicities of the partners as measured by the respective proton affinities. This correlation was also found to hold in general for substituted indoles. The use of the gas-phase proton affinity, which has previously been found to be sensitive to the polarizability of the attached alkyl groups, has made it possible to compare the important interaction components in terms of Morokuma's energy decomposition analysis. We have interpreted the ordering of indole hydrogen-bonded spectral shifts in terms of the interplay of both electrostatic interaction and polarization interaction components. It appears that for weakly bonded systems such as those containing indole as the proton donor, polarization forces can become important in determining electronic spectral shifts.We have also shown that indole and species such as halocarbons that are important in anesthetic activity can participate in hy-drogen bonds where the indole moiety is the proton acceptor. This observation provides a unique opportunity to investigate the dynamics of such biological processes in an isolated environment. Further investigations on these hydrogen-bonded indoles are currently in progress in our laboratory.Acknowledgment. The financial support of the Natural Sciences and Engineering Research Council of Canada and the Petroleum Research Fund, administered by the American Chemical Society, is gratefully acknowledged. We wish to thank Dr. R. Houriet for providing us with unpublished values of proton affinities and Prof. A. G. Harrison for helpful discussions.

X-Ray Diffraction Patterns of Montmorillonite Oriented Films Exchanged with Enantiomeric and Racemic Tris(2,2′-Bipyridyl)Ruthenium(II)

“…Segregation is a phenomenon in which cations are selectively adsorbed in some interlayer spaces, rather than being uniformly distributed in all interlayer spaces. It is known to occur for Ru(bpy)32+ in smectites (Ghosh and Bard, 1984). In fact, it has been invoked to help explain the spectral differences found between clay-adsorbed enantiomeric and racemic Ru(bpy)31+ at low loading levels (Joshi and Ghosh, 1989).…”

Permselective and Preconcentration Properties of a Surfactant‐Intercalated Clay Modified Electrode

“…New sorptive and hopefully interesting ion exchange properties are thus expected for such a hybrid material. This capability will be tested in the next sections for the electrochemical uptake of [Ru(NH 3 The electrochemical behavior of redox species at claymodified electrodes is expected to be affected by three main parameters: the concentration of the analyte, the accessible area of the working electrode and the speed of mass transfer for the probe within the film [7]. It will be first examined how the presence of Na-Sa and HDTMA-Sa films onto the electrode surface would influence its response to redox probes either positively or negatively charged.…”

Interlayer Modification of a Layered Titanate with Two Kinds of Organic Functional Units for Molecule‐Specific Adsorption

“…It should be noted here that two different functionalities resulted in "segregation", as observed for the adsorption of two cationic species in a smectite. [10] In PTMS-C 18 TMS-TLO, the X-ray diffraction pattern of one crystalline compound reveals that the two functionalities (phenyl and octadecyl groups) are located in the same interlayer space and distributed homogeneously as schematically shown in the structures in Figure 1 A. The density of the two silyl groups in the interlayer space is controllable by changing the added amount of PTMS and C 18 TMS.…”