Catenanes ruthenium -containing

Artifical photosynthetic reaction centers have continued to peak the interest of scientists over the years and this year is no exception. One such catenane-type example contains a ruthenium /m(2,2 -bipyridine) center, as the sensitizer, which is linked with cycloW.v(paraquat-p-phcnylenc), as the acceptor, and covalently linked with a protoheme or Zn-protoporphyrin, as the donor, located in the myoglobin pocket <00JA241>. A related assembly and on a Au-particle has appeared which possesses a Ru(II)-rm(2,2 -bipyridine)-... 

It is, thus, important that the ruthenium(II) complexes that are to be used as building blocks of the future machines contain sterically hindering chelates so as to force the coordination sphere of the metal to be distorted from the perfect octahedral geometry. We will discuss the photochemical reactivity of rotaxanes and catenanes of this family as well as non-interlocking systems like scorpionates since the lability of bulky monodentate ligands could also lead to useful photosubstitution reactions. 

Photoinduced Decoordination and Thermal Recoordination of a Ring in a Ruthenium(ll)-Containing [2]Catenane... 

The photoproducts, [2]catenanes 37 and 38, contain two disconnected rings since the photochemical reaction leads to decomplexation of the bpy chelate from the ruthenium(II) centre. In a typical reaction, a degassed CH2CI2 solution of 382+ and NEt4+.Cl was irradiated with visible light, at... 

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