In:
Laser Chemistry, Hindawi Limited, Vol. 19, No. 1-4 ( 1999-01-01), p. 271-274
Abstract:
Time-resolved resonance Raman (TR 3 ) and absorbance difference studies of the excited
states of Cu(TPP) (TPP=5,10,15,20-tetraphenylporphyrin) have been carried out with 〈 10 ps times resolution in THF and pyridine solvents. In THF the distinctive transient
Raman bands in the ν 2 and ν 4 regions, previously observed with ns laser pulses, grow in
the first 55 ps before decaying in 100's of ps. The ∆A spectra also show biphasic decay. This behaviour is associated with attack by solvent on the 4-coordinate excited state to
form the longer lived species observed in TR 3 experiments. In pyridine two component decay is also observed but it is the shorter-lived species
which gives the transient Raman bands seen previously with ns laser excitation. This state is different from that seen in THF. At 5 ps delay ν 4 is broader than in the ground
state and, more importantly, there is a significant shift in the two pyridine bands at ca. 1000 cm -1 . This implies a significant involvement of the pyridine-based orbitals in the
excited state.
Type of Medium:
Online Resource
ISSN:
0278-6273
,
1476-3516
Language:
English
Publisher:
Hindawi Limited
Publication Date:
1999
detail.hit.zdb_id:
2035640-7
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