TY - JOUR
T1 - Zn(II)porphyrin helical arrays
T2 - A strategy to overcome conformational heterogeneity by host-guest chemistry
AU - Zin, Seok Yoon
AU - Easwaramoorthi, Shanmugam
AU - Kim, Dongho
PY - 2008/1/20
Y1 - 2008/1/20
N2 - Conformational heterogeneity of directly linked multiporphyrin arrays with larger molecular length retards their utilities in practical applications such as two-photon absorption and molecular photonic wire. In this regard, here we adopted a way to overcome the conformational heterogeneity through hydrogen bonding by selective binding of meso aryl substituents of porphyrins (host) with urea (guest) to form helical structure. Using steady-state and time-resolved spectroscopy, we observed the enhanced fluorescence quantum yield by ~1.8 to 2.4 times, enhanced anisotropy values and the disappearance of fast fluorescence decay component in the host-guest helical forms. In addition, the enhanced nonlinear optical responses of helical arrays infer the extended inter-porphyrin electronic coupling due to a significant change in dihedral angle between the neighboring porphyrin moieties. The current host-guest strategy will provide a guideline to improve the structural homogeneity of the photonic wire.
AB - Conformational heterogeneity of directly linked multiporphyrin arrays with larger molecular length retards their utilities in practical applications such as two-photon absorption and molecular photonic wire. In this regard, here we adopted a way to overcome the conformational heterogeneity through hydrogen bonding by selective binding of meso aryl substituents of porphyrins (host) with urea (guest) to form helical structure. Using steady-state and time-resolved spectroscopy, we observed the enhanced fluorescence quantum yield by ~1.8 to 2.4 times, enhanced anisotropy values and the disappearance of fast fluorescence decay component in the host-guest helical forms. In addition, the enhanced nonlinear optical responses of helical arrays infer the extended inter-porphyrin electronic coupling due to a significant change in dihedral angle between the neighboring porphyrin moieties. The current host-guest strategy will provide a guideline to improve the structural homogeneity of the photonic wire.
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U2 - 10.5012/bkcs.2008.29.1.197
DO - 10.5012/bkcs.2008.29.1.197
M3 - Article
AN - SCOPUS:38949175010
SN - 0253-2964
VL - 29
SP - 197
EP - 201
JO - Bulletin of the Korean Chemical Society
JF - Bulletin of the Korean Chemical Society
IS - 1
ER -