KEIO RESEARCHERS INFORMATION SYSTEM

Books 【 Display / hide 】

Books 【 Display / hide 】

• Magneto-Structural Correlation in Organic Radical Crystals Containing Nitroxyl and Triazinyl Spin Centers

  Yoshioka N., Takii M., Miura Y., Advances in Organic Crystal Chemistry Comprehensive Reviews 2025 on Crystal Functions, 2025.01

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  Stable organic radicals have drawn attention as promising building blocks for multifunctional materials. In order to realize the tailored magnets based on molecular materials, it is necessary to investigate magneto-structural correlation of open-shell molecules. In the present chapter, we describe the magnetic property of dihydroquinoline N-oxyl-based radicals and benztriazynyl-based radicals to discuss the substituent effect on molecular packing and intermolecular magnetic interaction. Relatively large magnetic interactions were observed through π-π stacking for dihydroquinoline N-oxyl-based radicals. Spin transition behavior was demonstrated in benztriazynyl-based radical.

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Papers 【 Display / hide 】

Papers 【 Display / hide 】

• Ferromagnetic interaction observed in the crystal of 5-methoxy-2,2-diphenyl-1,2-dihydroquinoline N-oxyl

  Takii M., Miura Y., Yoshioka N.

  Chemical Physics Letters 889 2026.04

  ISSN  00092614

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  A novel purely organic radical, 5-methoxy-2,2-diphenyl-1,2-dihydroquinoline N -oxyl ( 2 ), has been synthesized and structurally characterized in order to examine the substituent effect on the known derivative, 2,2-diphenyl-1,2-dihydroquinoline N -oxyl ( 1 ). Based on SQUID measurement, 2 exhibited a ferromagnetic interaction obeying the Bleaney–Bowers equation with 2 J = +17 cm⁻¹. X-ray analysis revealed that the 5-methoxy substitution induces an offset π-stacking, resulting in ferromagnetic interactions.

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• Synthesis and magnetic properties of 2,2-diphenyl-1,2-dihydroquinoline N-oxyl carrying an ethynyl group at the 5-position

  Takii M., Nishiura F., Yao M., Inoue H., Miura Y., Yoshioka N.

  New Journal of Chemistry 50 ( 3 ) 1377 - 1384 2026.01

  ISSN  11440546

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  Two aromatic nitroxyl radical derivatives of 2,2-diphenyl-1,2-dihydroquinoline N-oxyl (1), namely, 5-[2-(trimethylsilyl)ethynyl]-2,2-diphenyl-1,2-dihydroquinoline N-oxyl (2) and 5-ethynyl-2,2-diphenyl-1,2-dihydroquinoline N-oxyl (3), were synthesized, and their magneto-structural correlation was described in connection with their assembled structures. Single-crystal XRD analysis of 3 revealed a hydrogen bond between the oxygen atom in the nitroxyl group and the terminal hydrogen atom of the ethynyl group with d<inf>O⋯(H)C</inf> = 3.099(5) Å. SQUID measurements revealed that 3 follows a 1D antiferromagnetic chain model with J = −10.4 cm⁻¹. In contrast, a slight increase in the χ<inf>M</inf>T value to 0.44 emu K mol⁻¹ was observed in 2, with a decreasing temperature indicating the presence of a weak intermolecular ferromagnetic interaction. These magnetic behaviors differ from that of the unsubstituted radical 1.

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Courses Taught 【 Display / hide 】

Courses Taught 【 Display / hide 】

• LABORATORIES IN APPLIED CHEMISTRY C

  2026

• LABORATORIES IN SCIENCE AND TECHNOLOGY

  2026