Time-resolved infrared spectroscopy (TRIR) has been used to probe the nature of the lowest excited state of [PtII(dpphen)(CN)2] (dpphen = 4,7-diphenyl-1,10-phenanthroline) both in fluid solution at room temperature and in a glass at 77 K. The positions of the v(CN) bands in [PtII(dpphen)(CN)2] are only slightly (less than 5 cm-1) shifted upon formation of the excited state, thus supporting their assignment as the π-π* intraligand state. At 77 K [PtII(dpphen)(CN)2] has a highly structured luminescence with a lifetime of 170 μs, which is also characteristic of a π-π* excited state. In contrast, the lowest excited state of [Ru(bpy)2(CN)2] has MLCT character in both fluid solution at ambient temperature and at 77 K as shown by a large positive shift of v(CN) relative to the ground state. Also we have monitored the monomer-excimer equilibrium of [PtII(dpphen)(CN)2] in fluid solution using the ns-TRIR technique.
|Number of pages||5|
|Journal||Journal of the Chemical Society. Dalton Transactions|
|Publication status||Published - 2002|
ASJC Scopus subject areas
- Chemistry (all)