TY - JOUR
T1 - A Concept for Controlling Singlet Oxygen (1δg) Yields Using Nitroxide Radicals
T2 - Phthalocyaninatosilicon Covalently Linked to Nitroxide Radicals
AU - Ishii, Kazuyuki
AU - Takeuchi, Shoji
AU - Shimizu, Shinsuke
AU - Kobayashi, Nagao
PY - 2004/2/25
Y1 - 2004/2/25
N2 - In this study, we have investigated the singlet oxygen ( 1Δg) generation mechanism using phthalocyaninatosilicon (SiPc) covalently linked to nitroxide radicals (NRs), and we succeeded in increasing the singlet oxygen quantum yield (Ψ Δ) by linking the NRs. This originates from both an increase in the triplet quantum yield and excited-state lifetimes long enough to utilize photochemical reactions. Because the electron exchange interactions with paramagnetic species were known to result only in very fast excited-state relaxation, leading to a decrease in photochemical reaction yields, this increase in ΨΔ is an unusual and precious example for increasing photochemical reaction yields by electron exchange interactions with paramagnetic species, In addition, our experiments and theoretical analyses show that the spin-selective energy transfer rate constant is not influenced by linking the NRs and can be evaluated by the product of spin-statistical factors and matrix elements between the initial and final states.
AB - In this study, we have investigated the singlet oxygen ( 1Δg) generation mechanism using phthalocyaninatosilicon (SiPc) covalently linked to nitroxide radicals (NRs), and we succeeded in increasing the singlet oxygen quantum yield (Ψ Δ) by linking the NRs. This originates from both an increase in the triplet quantum yield and excited-state lifetimes long enough to utilize photochemical reactions. Because the electron exchange interactions with paramagnetic species were known to result only in very fast excited-state relaxation, leading to a decrease in photochemical reaction yields, this increase in ΨΔ is an unusual and precious example for increasing photochemical reaction yields by electron exchange interactions with paramagnetic species, In addition, our experiments and theoretical analyses show that the spin-selective energy transfer rate constant is not influenced by linking the NRs and can be evaluated by the product of spin-statistical factors and matrix elements between the initial and final states.
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U2 - 10.1021/ja035352v
DO - 10.1021/ja035352v
M3 - Article
C2 - 14971943
AN - SCOPUS:1242274594
VL - 126
SP - 2082
EP - 2088
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 7
ER -