PHOTOPHYSICAL PROPERTIES OF A DINUCLEAR RACK-TYPE RU(II) COMPLEX AND OF ITS COMPONENTS

The luminescence spectra and lifetimes (at room temperature and 77 K) and triplet-triplet transient absorption spectrum (at room temperature ) of a rack-type complex (4) made of two Ru(II) ions, a bridging ligan d (3) containing a bis-(bipyridyl)pyrimidine subunit (2) covalently li nked to an anthracene moiety (1) and two 2,2':6',2/'-terpyridine ligan ds have been investigated. Comparison with the luminescence properties and transient absorption spectra of the 1, 2, and 3 subunits shows th at in the supramolecular species 4 excitation energy flows with unitar y efficiency to the lowest excited state, which is a triplet Ru --> 3 CT level, regardless of which chromophoric subunit is excited.