Catenates photophysical properties

The first report on the photophysical properties of metal catenates dates back to 1989 [54h], when a comparison between a 27- (Cu.4 Figure 2) and 30-membered (Cu.5 Figure 14) ring catenates was reported. 

Photophysical Properties of Catenate. and Knots 617 Table 13. Luminescence data for the CuIVI.14" knots in CH2Cl2 ... 

As in the past two years, fullerenes continue to be a source of considerable photochemical interest and photoinduced electron transfer is a central theme of numerous studies. The field of molecular-scale electronic devices continues to promote interest in the photophysical properties of novel molecular architectures and such aspects of photoactive rotaxanes and catenates have been reviewed (Benniston and Chambron et ai), while Harriman and Ziessel have outlined the design principles associated with the construction of photo-activated molecular wires. 

The photophysical properties of [2]catenane 50", of the copper(I) catenate 49 " and of the models 51", 44 and 38" have been investigated in acetonitrile solutions [83]. Compared to the [2]rotaxanes addressed in the previous section, 40 " and 41", the center-to-center distance between donor and acceptor has increased from ca. 1.9 nm to ca. 2.6 nm and the zinc porphyrin is differ-... 

The luminescence properties of a 3-catenand (20) and related 3-catenates containing a copper(I) center [Cu 20]+ were reported in 1991 [96]. The photophysical data are summarized in Table 5. It is interesting to note that while the mononuclear [Cu 20]+ shows ligand-centered tctc, and MLCT emission, the dinuclear complex [Cu2 20] + only reveals a single MLCT phosphorescence band at 700 nm in CH2CI2. The mixed-metal complex [CuCo 20] + is not lumi-... 

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