Catenates fluorescence

In detail, the luminescence bands of the Li+, Cd ", Zn +, H+ catenates M.5 are of LC nn ) character (fluorescence and phosphorescence) for Ag.S" " only the 77 K LC phosphorescence is observed due to the rapid singlet-triplet intersystem crossing induced by the heavy metal ion the luminescence band shown (only) at 77 K by Pd.5+ is difficult to attribute (see above), but a substantial MLCT character is indicated by the spectral red-shift and shorter lifetime compared to, for instance, Ag.S" finally, the Cu.5 shows the typical MLCT band (see above). No luminescence is observed for Ni.S" and Co.5 owing to the presence of low-lying non-... 

A similar behavior is found for CuZn.lO, where the Cu-based moiety shows luminescence properties quite similar to those of CuAg-lO " " and CuCu.lO + instead, the Zn-based moiety is quenched, with /tq = 1.1 x 10 s at 298 K. Quite peculiarly, for this [3]catenate a broad emission band with maximum at 560 nm is detected, that can hardly be assigned to an impurity of some sort [64], Tentatively, it was attributed to an intercomponent CT interaction which could play a role in the quenching of the LC fluorescence in CuZn.l0 +. 

Hungerford, G., M. van der Auweraer, and D.B. Amabilino (2001). Intramolecular fluorescence quenching in porphyrin-bearing (2)catenates. J. Porph. Phthalocyan. 5, 633-644. 

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