By using a "complex as ligand approach," the metal-ion-templated self-assembly of heterometallic tetranuclear metallomacrocycles containing kinetically locked Ru(II) centers is described. Depending on the metal-ion template employed in the self-assembly process, the final macrocycle can be kinetically labile or inert. Electrochemical studies reveal that the kinetically inert macrocycles display reversible Ru(III/II) oxidation couples. The crystal structure of a kinetically inert Ru2Re2 macrocycles reveals a structurally complex palmate anion-binding pocket. Host-guest studies carried out with the same macrocyle in organic solvents reveals that the complex functions as a luminescent sensor for anions and that binding affinity and luminescent modulation is dependent on the structural nature and charge of the guest anion. Computational density functional theory (DFT) studies support the hypothesis that the luminescence of the macrocycle is from a 3MLCT state and further suggests that the observed guest-induced luminescence changes are most likely due to modulation of nonradiative decay processes.

In the reaction between ethylene and chlorine Stewart and Smith1 postulated a chain mechanism of the typein which the starred formulas represent an intermediate compound, presumably an activated ethylene dichloride.The experiments described here were first designed to determine whether this intermediate would induce a reaction in other reacting systems, or itself undergo a reaction with other substances (than chlorine). For instance, in the presence of benzene, a Friedel-Crafts reaction is possible between the intermediate and benzene, or in the presence of both benzene and benzoyl chloride, benzophenone might be formed. Thorough search for these reactions has shown no indication of them. Oxidations of the reaction products by alkaline permanganate or chromic acid have yielded only traces of materials which could be considered aromatic carboxylic acids. Similarly, when the reaction between ethylene and chlorine was carried out in the presence of a mixture of benzoyl chloride and benzene, no trace of benzophenone could be found.2However, when benzene is used as a solvent for the chlorine-ethylene reaction, considerable benzene hexachloride is always formed, usually a mixture of the stereoisomeric forms, with the -form (m. p. 157°) predominating.CgHe + 3Cla-> CeHsCI, This reaction has long been known as one susceptible of induction by light,3

A luminescent sensor for anions is described by J. A. Thomas, S. L. Heath, A. J. H. M. Meijer et al. on page 2188 ff. The sensor is composed of a heterometallic self‐assembled macrocycle that has a palmate anion‐binding pocket. Host–guest studies carried out in organic solvents reveal that the macrocycle functions as a luminescent sensor for anions, and the binding affinity and luminescent modulation are dependent on the structural nature and charge of the guest anion.