TY - JOUR
T1 - Six-membered ring chelate complexes of Ru(II)
T2 - Structural and photophysical effects
AU - Abrahamsson, Maria
AU - Becker, Hans Christian
AU - Hammarström, Leif
AU - Bonnefous, Celine
AU - Chamchoumis, Charles
AU - Thummel, Randolph P.
PY - 2007/11/26
Y1 - 2007/11/26
N2 - The structural and photophysical properties of Ru(II)-polypyridyl complexes with five- and six-membered chelate rings were studied for two bis-tridentate and two tris-bidentate complexes. The photophysical effect of introducing a six-membered chelate ring is most pronounced for the tridentate complex, leading to a room-temperature excited-state lifetime of 810 ns, a substantial increase from 180 ns for the five-membered chelate ring model complex. Contrasting this, the effect is the opposite in tris-bidentate complexes, in which the lifetime decreases from 430 ns to around 1 ns in going from a five-membered to six-membered chelate ring. All of the complexes were studied spectroscopically at both 80 K and ambient temperatures, and the temperature dependence of the excited-state lifetime was investigated for both of the bis-tridentate complexes. The main reason for the long excited-state lifetime in the six-membered chelate ring bis-tridentate complex was found to be a strong retardation of the activated decay via metal-centered states, largely due to an increased ligand field splitting due to the complex having a more-octahedral geometry.
AB - The structural and photophysical properties of Ru(II)-polypyridyl complexes with five- and six-membered chelate rings were studied for two bis-tridentate and two tris-bidentate complexes. The photophysical effect of introducing a six-membered chelate ring is most pronounced for the tridentate complex, leading to a room-temperature excited-state lifetime of 810 ns, a substantial increase from 180 ns for the five-membered chelate ring model complex. Contrasting this, the effect is the opposite in tris-bidentate complexes, in which the lifetime decreases from 430 ns to around 1 ns in going from a five-membered to six-membered chelate ring. All of the complexes were studied spectroscopically at both 80 K and ambient temperatures, and the temperature dependence of the excited-state lifetime was investigated for both of the bis-tridentate complexes. The main reason for the long excited-state lifetime in the six-membered chelate ring bis-tridentate complex was found to be a strong retardation of the activated decay via metal-centered states, largely due to an increased ligand field splitting due to the complex having a more-octahedral geometry.
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U2 - 10.1021/ic7011827
DO - 10.1021/ic7011827
M3 - Article
C2 - 17975915
AN - SCOPUS:37249038955
VL - 46
SP - 10354
EP - 10364
JO - Inorganic Chemistry
JF - Inorganic Chemistry
SN - 0020-1669
IS - 24
ER -