TY - JOUR
T1 - Bis-palladium(II) complex of doubly N-confused octaphyrin(1.1.1.1.1.1.1.1)
T2 - Möbius aromaticity and chiroptical properties
AU - Basumatary, Biju
AU - Mitsuno, Koki
AU - Ishida, Masatoshi
AU - Furuta, Hiroyuki
N1 - Funding Information:
This work was supported by GrantinAids for Scientific Research (JP19K05439 and JP19H04586) from the Japan Society for the Promotion of Science (JSPS). B.B. thanks for JSPS research fellowship (JP18F18331). We also acknowledge the Tokuyama Science Foundation for generous financial assistance.
Publisher Copyright:
© 2020 World Scientific Publishing Company.
PY - 2020/1/1
Y1 - 2020/1/1
N2 - A novel bis-palladium(II) complex of doubly N-confused octaphyrin (Pd2-2) adopting a Möbius-twisted topological structure was synthesized and characterized. Due to the effective 36π-electronic delocalization over the Möbius-twisted octaphyrin scaffold, characteristic Soret and Q-like absorption features were observed in the near-infrared (NIR) region. However, the complex Pd2-2 exhibited weak aromatic character attributed to the distinct cross-conjugated resonance contribution as inferred from the 1H NMR chemical shifts as well as theoretical assessments (e.g. nucleus-independent chemical shift (NICS)). Since the bis-palladium(II) complexation of doubly N-confused octaphyrin 2 imparted significant conformational stability, topologically chiral enantiomers of Pd2-2 were successfully separated as (P)- and (M)-twisted forms. The resulting isomers revealed relatively large circular dichroism (CD) responses with an absorption anisotropy factor of gabs = 0.009 in the NIR region (λ = 823 nm). In addition, the cyclic voltammogram of Pd2-2 revealed redox-rich properties due to its large π-conjugated system.
AB - A novel bis-palladium(II) complex of doubly N-confused octaphyrin (Pd2-2) adopting a Möbius-twisted topological structure was synthesized and characterized. Due to the effective 36π-electronic delocalization over the Möbius-twisted octaphyrin scaffold, characteristic Soret and Q-like absorption features were observed in the near-infrared (NIR) region. However, the complex Pd2-2 exhibited weak aromatic character attributed to the distinct cross-conjugated resonance contribution as inferred from the 1H NMR chemical shifts as well as theoretical assessments (e.g. nucleus-independent chemical shift (NICS)). Since the bis-palladium(II) complexation of doubly N-confused octaphyrin 2 imparted significant conformational stability, topologically chiral enantiomers of Pd2-2 were successfully separated as (P)- and (M)-twisted forms. The resulting isomers revealed relatively large circular dichroism (CD) responses with an absorption anisotropy factor of gabs = 0.009 in the NIR region (λ = 823 nm). In addition, the cyclic voltammogram of Pd2-2 revealed redox-rich properties due to its large π-conjugated system.
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U2 - 10.1142/S1088424619501116
DO - 10.1142/S1088424619501116
M3 - Article
AN - SCOPUS:85072245695
VL - 24
SP - 416
EP - 423
JO - Journal of Porphyrins and Phthalocyanines
JF - Journal of Porphyrins and Phthalocyanines
SN - 1088-4246
IS - 1-3
ER -