Ken-ichi Yamashita
ken1yama.bsky.social
Ken-ichi Yamashita
@ken1yama.bsky.social
Associate Professor
Dept. of Chemistry, Grad. School of Science, The University of Osaka
Organic Chemistry, Coordination Chemistry, Supramolecular Chemistry, Porphyrinoid
https://orcid.org/0000-0001-7270-1234
Thrilled to announce our trichalcogenophene research is the Cover Feature of #ChemEurJ! The beautiful cover by Rio's cousin uses a chamber ensemble metaphor to illustrate the harmonious S···S chalcogen interactions that stabilize our ZZ-trithiophene.
doi.org/10.1002/chem...
Cover Feature: Effect of Chalcogen Interaction on the Structure of Methine‐Bridged Trichalcogenophenes
The Cover Feature illustrates the stabilizing chalcogen interactions between sulfur atoms in ZZ-methine-bridged trithiophene by using the metaphor of a chamber ensemble. The intramolecular S···S chal...
doi.org
July 18, 2025 at 11:32 AM
We've already discovered fascinating photoluminescence behaviors and unique isomerization dynamics, plus synthesized larger molecular architectures. These insights enable designing materials with controlled stereochemistry and enhanced properties. Excited to share more soon!
June 5, 2025 at 11:21 AM
Personally, I'm most excited about successfully reproducing the solution-phase geometric isomer ratios using GOAT conformer search (recently introduced in ORCA 6.0) combined with CENSO. This problem had puzzled us for a long time, and solving it significantly expanded our computational toolkit.
June 5, 2025 at 10:45 AM
Trichalcogenophenes have three geometric isomers, but trithiophene and trifuran show dramatically different stability patterns. We discovered this stems from intramolecular S···S interactions between adjacent thiophene rings using interaction analysis (NCI, AIM, etc.) mastered for this study.
June 5, 2025 at 10:31 AM
Honored this work appears in AsianJOC's Special Collection for Prof. Masahiko Iyoda. We shared Tokyo Metropolitan University - I was an assistant prof. while he was a professor in a different lab in the same department. We're also alumni of the same high school, though from different generations! 🎓✨
May 28, 2025 at 1:45 AM
We found that steric bulk of meso-substituents determines their tilt angle relative to the isophlorin macrocycle, critically controlling antiaromaticity strength. Bulkier substituents preserve stronger antiaromaticity!
Computational evaluation was achieved with Haruna's collaboration 👥
May 23, 2025 at 3:40 AM
The package claims "Japanese home style noodles" but interestingly, this cheese yakisoba isn't sold in Japan. While Maruchan is indeed a major instant noodle brand, cheese-topped yakisoba isn't something you'd typically find in Japan. I'm quite curious about how it actually tastes!
February 25, 2025 at 11:30 AM
2/2 The free base that led to our latest complex. The work made the Cover: hand-drawn using traditional Japanese calligraphy! The side texts in archaic Hiragana are so old-style that even most Japanese readers find them challenging to read!

See paper link in cover page: doi.org/10.1002/ejoc...
Front Cover: 20π Antiaromatic Isophlorins without Metallation or Core Modification (Eur. J. Org. Chem. 46/2022)
The Front Cover shows a calligraphy drawing of the structure of the antiaromatic isophlorin synthesized for the first time with this study. Peripheral substituents and negative charge are omitted for....
doi.org
January 15, 2025 at 12:53 PM
1/2 The origin story! This was my first paper on antiaromatic compounds, where we designed and synthesized the original antiaromatic system. A key milestone that led to our recent discoveries.

doi.org/10.1002/chem...
Facile Redox‐Induced Aromatic–Antiaromatic Interconversion of a β‐Tetracyano‐21,23‐Dithiaporphyrin under Ambient Conditions
Facile redox-induced aromatic–antiaromatic interconversion was accomplished with β-tetracyano-21,23-dithiaporphyrin. The introduced cyano groups not only increased the reduction potentials of the por....
doi.org
January 15, 2025 at 11:36 AM
This unusual guest binding stems from the host's rigidity. We discussed the synthesis and structure in our earlier paper (doi.org/10.1002/cplu...) - where we also put special emphasis on developing the synthetic methodology.
Efficient Synthesis of Arylenedioxy‐Bridged Porphyrin Dimers through Catalyst‐Free Nucleophilic Aromatic Substitution
Rigid bridges: A series of porphyrin dimers bridged by one or two arylenedioxy linkers was successfully synthesized in high yields by catalyst-free nucleophilic aromatic substitution. The orientation...
doi.org
January 8, 2025 at 11:42 AM
Thrilled to share that our recent paper on antiaromatic triphyrin synthesis was selected as the Front Cover of Chemistry - A European Journal! Check out our art featuring the key 16π electrocyclization.
chemistry-europe.onlinelibrary.wiley.com/doi/full/10....
Front Cover: Stable Antiaromatic [16]Triphyrin(2.1.1) with Core Modification: Synthesis Using a 16π Electrocyclic Reaction (Chem. Eur. J. 69/2024)
The Front Cover shows trioxa[16]triphyrin(2.1.1), a novel 16π antiaromatic contracted porphyrinoid that has been synthesized and characterized. The synthesis involves the oxidation of dihydrotrioxatr...
chemistry-europe.onlinelibrary.wiley.com
December 11, 2024 at 10:40 AM