TY - JOUR
T1 - Phenylene-bridged core-modified planar aromatic octaphyrin
T2 - Aromaticity, photophysical and anion receptor properties
AU - Karthik, Ganesan
AU - Cha, Won Young
AU - Ghosh, Arindam
AU - Kim, Taeyeon
AU - Srinivasan, A.
AU - Kim, Dongho
AU - Chandrashekar, Tavarekere K.
N1 - Publisher Copyright:
© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
PY - 2016/5/6
Y1 - 2016/5/6
N2 - The synthesis of a planar expanded meso porphyrin with an intramolecular para-phenylene-bridged core is reported. The planarity of the octaphyrin macrocycle was confirmed by single-crystal X-ray structural analysis, in which the bridged para-phenylene unit deviated by 27° from the mean macrocyclic plane. Spectroscopic analyses and theoretical calculations suggested that the macrocycle was Hückel aromatic and followed a major [34 π] single-conjugation pathway, which indicated that the bridging para-phenylene unit was not involved in the macrocyclic conjugation. Analysis of the photophysical properties of this system by steady-state absorption/fluorescence spectroscopy and transient absorption spectroscopy revealed moderate enhancement in the parameters of the octaphyrin as compared to its non-bridged octaphyrin congeners, which was attributed to the planarity and rigidity of the macrocycle as imposed by the bridging para-phenylene unit. Preliminary anion-binding studies revealed that the protonated macrocycle bound selectively with chloride ions through N-H Cl hydrogen-bonding interactions. Crazy eights: A "figure-eight" nonaromatic octaphyrin became a planar aromatic molecule upon the introduction of a phenylene bridge between two opposing meso-carbon atoms. This structural change not only made the molecule planar, but also rigid, as revealed by its enhanced photophysical parameters.
AB - The synthesis of a planar expanded meso porphyrin with an intramolecular para-phenylene-bridged core is reported. The planarity of the octaphyrin macrocycle was confirmed by single-crystal X-ray structural analysis, in which the bridged para-phenylene unit deviated by 27° from the mean macrocyclic plane. Spectroscopic analyses and theoretical calculations suggested that the macrocycle was Hückel aromatic and followed a major [34 π] single-conjugation pathway, which indicated that the bridging para-phenylene unit was not involved in the macrocyclic conjugation. Analysis of the photophysical properties of this system by steady-state absorption/fluorescence spectroscopy and transient absorption spectroscopy revealed moderate enhancement in the parameters of the octaphyrin as compared to its non-bridged octaphyrin congeners, which was attributed to the planarity and rigidity of the macrocycle as imposed by the bridging para-phenylene unit. Preliminary anion-binding studies revealed that the protonated macrocycle bound selectively with chloride ions through N-H Cl hydrogen-bonding interactions. Crazy eights: A "figure-eight" nonaromatic octaphyrin became a planar aromatic molecule upon the introduction of a phenylene bridge between two opposing meso-carbon atoms. This structural change not only made the molecule planar, but also rigid, as revealed by its enhanced photophysical parameters.
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U2 - 10.1002/asia.201600177
DO - 10.1002/asia.201600177
M3 - Article
C2 - 26957207
AN - SCOPUS:84981234399
VL - 11
SP - 1447
EP - 1453
JO - Chemistry - An Asian Journal
JF - Chemistry - An Asian Journal
SN - 1861-4728
IS - 9
ER -