Article
Physics, Condensed Matter
A. A. Guda, M. Chegerev, A. G. Starikov, V. G. Vlasenko, A. A. Zolotukhin, M. P. Bubnov, V. K. Cherkasov, V. V. Shapovalov, Yu Rusalev, A. A. Tereshchenko, A. L. Trigub, A. Chernyshev, A. Soldatov
Summary: Valence tautomer transition primarily occurs in 3d metalorganic complexes with redox-active ligands, making them potential candidates for single-molecular switches. In this study, bis(o-semiquinonato) cobalt complex with TEMPO-functionalized iminopyridine ancillary ligand was investigated using ligand-sensitive FTIR and metal-sensitive Co K-edge XAS techniques. The results showed a temperature hysteresis of magnetization larger than 40 K in the solid state, with XAS being advantageous for liquid phase analysis and FTIR having larger sensitivity to ligand related interactions in solid.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2021)
Article
Chemistry, Multidisciplinary
K. C. Khadanand, Toby Woods, Lisa Olshansky
Summary: In mononuclear monodioxolene cobalt complexes, the transition from low spin to high spin state has been achieved by modifying the ligand structure, and the magnetic switching in the intermediate state has been observed for the first time, which may provide a new criterion for the design of stimulus-responsive multi-state molecular switches.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Minoru Mitsumi, Yuuki Komatsu, Masahiro Hashimoto, Koshiro Toriumi, Yasutaka Kitagawa, Yuji Miyazaki, Hiroki Akutsu, Haruo Akashi
Summary: This study reports a one-dimensional rhodium-dioxolene complex that exhibits drastic changes in properties during phase transition. The room-temperature phase is in a mixed-valence state, leading to the appearance of the mixed-valence state and increased displacements of rhodium atoms along the 1D chain. These results suggest a possible mechanism for the appearance of mixed-valence state based on thermal electron transfer and large-amplitude vibration of the Rh-Rh bonds.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Inorganic & Nuclear
Xiao-Peng Sun, Zheng Tang, Jiajia Li, Pengtao Ma, Zi-Shuo Yao, Jingping Wang, Jingyang Niu, Jun Tao
Summary: This study fully investigated two isostructural valence tautomeric complexes with different critical temperatures using a series of magnetic, structural, spectral, and differential scanning calorimetry evidence. The kinetic effect in the valence tautomeric complex was observed for the first time through scan-rate-dependent studies and further validated by annealing tests.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Inorganic & Nuclear
Sriram Sundaresan, Marcel Diehl, Luca M. Carrella, Eva Rentschler
Summary: This study reports the synthesis of a new octadentate ligand and its combination with a known compound to prepare di-nuclear cobalt complexes. The obtained complexes were characterized and their structure and magnetic properties were studied. The results indicate the occurrence of valence tautomerism in some of the complexes.
Article
Chemistry, Inorganic & Nuclear
Michael P. Bubnov, Alexey Zolotukhin, Konstantin A. Kozhanov, Evgeny V. Baranov, Artem S. Bogomyakov, Maxim V. Arsenyev, Sergey Yu. Ketkov, Vladimir K. Cherkasov
Summary: Three novel five-coordinated bisdioxolene cobalt complexes with triphenylphosphine were synthesized. These complexes have similar geometry and magnetic properties, but different dioxolene ligands. DFT calculations correctly predict the structures and spectroscopic properties of the complexes.
Article
Chemistry, Physical
Manishkumar R. Shimpi, Patrick Rohlmann, Faiz Ullah Shah, Sergei Glavatskih, Oleg N. Antzutkin
Summary: It was found that Li[BOB]·nH(2)O salts were not suitable for the synthesis of high-purity orthoborate-based tetraalkylphosphonium ionic liquids, while Na[BOB] was found to be more suitable. Therefore, a preparation protocol for ultra-pure Na[BOB] was developed, resulting in boron-impurity-free ionic liquids with significantly different physico-chemical properties compared to those containing transition anionic complexes. This work highlights the implications of boron-containing transition anionic complexes in tetraalkylphosphonium-orthoborate ILs used in various applications.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Inorganic & Nuclear
Andrey G. Starikov, Alyona A. Starikova, Maxim G. Chegerev, Sergey M. Aldoshin, Anatoly Metelitsa, Vladimir Minkin
Summary: Density functional theory calculations were used to study the electronic structure, energy characteristics, and magnetic properties of a series of heterometallic CrCo complexes. The compounds prone to spin-state switching involving cobalt center were identified, opening prospects for the purposeful search of new magnetically bistable heterometallic dinuclear paramagnetic species with potential applications in smart dynamic materials design.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Christoph Metzger, Ramapada Dolai, Sabine Reh, Harald Kelm, Markus Schmitz, Benjamin Oelkers, Mathias Sawall, Klaus Neymeyr, Hans-Joerg Krueger
Summary: The synthesis and characterization of a monocationic cobalt(III) catecholate complex [Co(L-(N4Bu2)-Bu-t)(Cl(2)cat)](+) (L-(N4Bu2)-Bu-t=N,N'-Di-tert.-butyl-2,11-diaza[3.3](2,6)pyridinophane, Cl(2)cat(2-)=4,5-dichlorocatecholate) are reported. The complex displays valence tautomeric properties, with a unique conversion from a cobalt(III) catecholate to a low-spin cobalt(II) semiquinonate state upon increasing temperature. This new type of valence tautomerism in a cobalt dioxolene complex has been confirmed through detailed spectroscopic investigations.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Electrochemistry
Hsing-Wen Yeh, Nobuyuki Serizawa, Yasushi Katayama
Summary: In this study, attempts were made to recover metallic Co from CoO using BMPTFSA solution, and the electrochemical reduction of [CoCl4](2-) was successfully achieved in the ionic liquid. Co nanowires composed of crystalline Co nanoparticles were successfully deposited under an external magnetic field.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2021)
Article
Engineering, Chemical
Stephanie Boudesocque, Lydie Viau, Habiba Nouali, Laurent Dupont
Summary: In this study, a strategy was developed to use ionogels as materials for metal extraction. The researchers first confined a commercial salt [THN]Br in silica-based ionogels and then carried out anionic metathesis to enhance their extracting efficiency or selectivity. The results showed that the ionogels could fully extract Au(III), Pt(IV), and Cr(VI), but the extraction of Co(II) was minimal. Treatment with NaDca or LiTFSI improved the extraction capabilities and allowed for separation of specific metals. Overall, the study demonstrated that ionogels can be modulated for desired extraction properties through simple anion exchange.
SEPARATION AND PURIFICATION TECHNOLOGY
(2023)
Article
Chemistry, Physical
Michael Benjamin, Devaraj Manoj, K. Theyagarajan, Kathavarayan Thenmozhi, Duraisamy Saravanakumar, Sellappan Senthilkumar
Summary: Electrocatalytic hydrogen production in a neutral aqueous medium is a promising technology to obtain clean and carbon-free fuel. The use of cobalt terpyridine complexes as catalysts showed superior electrocatalytic activity and high faradaic efficiency in generating hydrogen.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Biochemistry & Molecular Biology
Feng Wu, Fengshuo Jiang, Jiahao Yang, Weiyan Dai, Donghui Lan, Jing Shen, Zhengjun Fang
Summary: This study examines the electrochemical reduction in CO2 using room temperature ionic liquids as solvents or electrolytes, aiming to minimize the environmental impact of CO2 emissions. Through in-situ surface-enhanced Raman spectroscopy and electrochemical techniques, the researchers investigate the CO2 reduction using a cobalt porphyrin molecular immobilized electrode in 1-n-butyl-3-methyl imidazolium tetrafluoroborate ionic liquids. The results show a high efficiency of producing CO, while H-2 is produced as a competitive product.
Article
Chemistry, Multidisciplinary
S. O. Shapovalova, A. A. Guda, M. P. Bubnov, G. Smolentsev, Yu Rusalev, V. V. Shapovalov, A. A. Zolotukhin, V. K. Cherkasov, A. G. Starikov, V. G. Vlasenko, A. Soldatov
Summary: The transition from high-spin Co-II to low-spin Co-III state was observed in both solid and liquid forms of the complex. A low-temperature nanosecond pump-probe XANES experiment was conducted for the first time to reveal the valence tautomeric transition in a solution of Co complex. The reversible transition was induced by both temperature and laser radiation stimuli.
Article
Chemistry, Multidisciplinary
Jun Zhang, Zhanying Chen, Yan Zhang, Shengyi Dong, Yufang Chen, Shiguo Zhang
Summary: By introducing alkoxy moieties into poly(ionic liquid)s, highly efficient adhesives with strong hydrogen bonding interactions can be designed, exhibiting excellent adhesive properties on various substrates. Furthermore, photosensitive or electronically conductive composite adhesives can be fabricated by utilizing the compatibility between ionic liquids and carbon nanotubes or silver nanofibers.
ADVANCED MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Mihiro Kubo, Hiroyuki Yoshida
Summary: The electron affinity (A) of an organic semiconductor is a crucial parameter that can be estimated through inverse photoelectron spectroscopy (IPES) or cyclic voltammetry (CV). However, previous IPES data may have inaccuracies, while low-energy inverse photoelectron spectroscopy (LEIPS) allows for more precise determination of A values.
ORGANIC ELECTRONICS
(2022)
Article
Chemistry, Physical
Haruki Sato, Syed A. Abd Rahman, Yota Yamada, Hiroyuki Ishii, Hiroyuki Yoshida
Summary: The authors employed angle-resolved low-energy inverse photoelectron spectroscopy to reveal the LUMO band structure of pentacene and proposed an improved polaron model to explain the phenomenon of bandwidth reduction. The results demonstrate that electron mobility in high-mobility organic semiconductors is limited by polaron formation.
Article
Chemistry, Multidisciplinary
Luca Muenzfeld, Milena Dahlen, Adrian Hauser, Nolwenn Mahieu, Senthil Kumar Kuppusamy, Jules Moutet, Maxime Tricoire, Ralf Koeppe, Leo La Droitte, Olivier Cador, Boris Le Guennic, Gregory Nocton, Eufemio Moreno-Pineda, Mario Ruben, Peter W. Roesky
Summary: The solvation of [(CNT)Ln(eta(8)-COT)] complexes with tetrahydrofuran (THF) can lead to neutral and ionic species in a solid-to-solid transformation. These species exhibit switchable luminophores and single-molecule magnet properties due to the distortion caused by solvation. The desolvation of the coordinated solvents can be achieved through a dynamic vacuum or temperature gradient stimulus. Raman spectroscopic investigations confirm the fast and reversible solvation and desolvation processes, and a Nd:YAG laser is found to induce a spatially resolved self-sufficient switching process for the Ce(III) analogue.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Kais Dhbaibi, Maxime Grasser, Haiet Douib, Vincent Dorcet, Olivier Cador, Nicolas Vanthuyne, Francois Riobe, Olivier Maury, Stephan Guy, Amina Bensalah-Ledoux, Bruno Baguenard, Geert L. J. A. Rikken, Cyrille Train, Boris Le Guennic, Matteo Atzori, Fabrice Pointillart, Jeanne Crassous
Summary: The combination of physical properties sensitive to molecular chirality in a single system allows the observation of interesting phenomena such as magneto-chiral dichroism (MChD) and circularly polarized luminescence (CPL), which have potential applications in optical data readout and display technology. By coordinating a chiral organic chromophore to Yb(hfac)(3) units, homochiral one-dimensional coordination polymers of Yb-III were designed, which exhibit strong magnetic anisotropy and show single-molecule magnet behavior and room temperature magneto-chiral dichroism (MChD). Computational investigations support the correlation between MChD and the structure.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Moritz Bernhardt, Maciej D. D. Korzynski, Zachariah J. J. Berkson, Fabrice Pointillart, Boris Le Guennic, Olivier Cador, Christophe Coperet
Summary: Generating or retaining slow magnetic relaxation in surface-immobilized single-molecule magnets (SMMs) from molecular precursors is a challenging task. However, a material with SMM characteristics has been successfully generated by chemisorption of (Cp-ttt)(2)DyCl on a silica surface containing tailored Lewis acidic Al-(III) sites. Detailed studies reveal slow magnetic relaxation up to 51 K, hysteresis up to 8 K, and an effective energy barrier (U (eff)) of 449 cm(-1), the highest reported for a supported SMM.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Minh Anh Truong, Tsukasa Funasaki, Lucas Ueberricke, Wataru Nojo, Richard Murdey, Takumi Yamada, Shuaifeng Hu, Aruto Akatsuka, Naomu Sekiguchi, Shota Hira, Lingling Xie, Tomoya Nakamura, Nobutaka Shioya, Daisuke Kan, Yuta Tsuji, Satoshi Iikubo, Hiroyuki Yoshida, Yuichi Shimakawa, Takeshi Hasegawa, Yoshihiko Kanemitsu, Takanori Suzuki, Atsushi Wakamiya
Summary: Hole-collecting monolayers in perovskite solar cell research have gained attention for their easy processing, high performance, and good durability. This study utilized multiple phosphonic acid anchoring groups to control the molecular orientation, resulting in improved efficiency and stability of inverted perovskite solar cells.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Instruments & Instrumentation
Harald Ibach, Haruki Sato, Mihiro Kubo, F. Stefan Tautz, Hiroyuki Yoshida, Francois C. Bocquet
Summary: A high-current electron source for inverse photoemission spectroscopy is developed, which achieves significantly higher electron current and better energy resolution than previously described sources. The improved performance is attributed to a mechanism of velocity selection in forward electron-electron collisions. The findings challenge the existing theoretical predictions and provide new insights into electron-electron interactions.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Article
Instruments & Instrumentation
Yuki Kashimoto, Satoshi Ideta, Haruki Sato, Hibiki Orio, Keita Kawamura, Hiroyuki Yoshida
Summary: This paper describes an angle-resolved low-energy inverse photoelectron spectroscopy (AR-LEIPS) apparatus that examines the conduction band structures of materials sensitive to the electron beam. The apparatus is based on AR inverse photoelectron spectroscopy and employs a previous approach used in LEIPS to minimize radiation damage and improve energy resolution. The achieved overall energy resolution is 0.23 eV with a momentum resolution of 0.9 nm(-1) at electron kinetic energies of 2 eV or higher.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Article
Materials Science, Multidisciplinary
Carlo Andrea Mattei, Vincent Montigaud, Bertrand Lefeuvre, Vincent Dorcet, Gilles Argouarch, Olivier Cador, Boris Le Guennic, Olivier Maury, Claudia Lalli, Yannick Guyot, Stephan Guy, Cyprien Gindre, Amina Bensalah-Ledoux, Francois Riobe, Bruno Baguenard, Fabrice Pointillart
Summary: Lanthanide ions have attracted significant interest due to their optical and magnetic properties. The combination of single-molecule magnet (SMM) behavior and circularly polarized luminescence (CPL) in a single molecular system is rare and deserves attention for the design of multifunctional materials. Chiral one-dimensional coordination compounds involving Yb(iii) center and BINOL-derived bisphosphate ligands exhibited field-induced SMM behavior and near infrared CPL in the solid state, as characterized by X-ray diffraction.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Review
Chemistry, Multidisciplinary
Fabrice Pointillart, Kevin Bernot, Boris Le Guennic, Olivier Cador
Summary: This review article provides a comprehensive description of the influence of nuclear spin, namely the hyperfine interaction, on the magnetic properties of lanthanide single-molecule magnets (SMMs) and on quantum information processing of qudit. The article analyzes this influence for non-Kramers and Kramers lanthanide SMMs, as well as for the electronic distribution of the electron in 4f orbitals, i.e. oblate and prolate ions. Additionally, the role of magnetic interactions in isotopically enriched polynuclear Dy(iii) SMMs is discussed, along with the possible effect of superhyperfine interaction due to the nuclear spin of elements surrounding the lanthanide centre. The effect of nuclear spin on the dynamics of lanthanide SMMs is demonstrated using various techniques such as magnetometry, muon spectroscopy, and Mossbauer and Resonance Vibrational Spectroscopies.
CHEMICAL COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Hao Wang, Zhenhua Zhu, Leo La Droitte, Wuping Liao, Olivier Cador, Boris Le Guennic, Jinkui Tang
Summary: Two luminescent Tb(iii)-calixarene aggregates with architectures of 1D chain (1) and 3D network (2) have been synthesized, and their single-molecule toroidal (SMT) characteristics have been experimentally investigated with the support of ab initio calculations. Aggregate 2 with a 3D structure is the first covalently bonded 3D SMT polymer that has been successfully synthesized.
Article
Chemistry, Multidisciplinary
Florian Benner, Leo La Droitte, Olivier Cador, Boris Le Guennic, Selvan Demir
Summary: A judicious combination of radical ligands with paramagnetic metal ions elicits strong magnetic exchange coupling, which leads to important properties for future technologies. The metal-radical approach aids in effective magnetic communication, especially for lanthanide ions. The presented complexes of bisbenzimidazole-based dilanthanide exhibit strong antiferromagnetic coupling and single-molecule magnetism, showing potential for applications in organic radical bridge materials.
Article
Materials Science, Multidisciplinary
Syed A. Abd-Rahman, Takuma Yamaguchi, Satoshi Kera, Hiroyuki Yoshida
Summary: The energy levels in organic semiconductors are determined by the molecular orbital energies, but recent studies have shown that the molecular orientation or mixing ratio in films can alter the energy levels due to intermolecular electrostatic interaction. This study investigates the coverage-dependent energy levels of zinc phthalocyanine and per-fluorinated zinc phthalocyanine using ultraviolet photoelectron spectroscopy and low-energy inverse photoelectron spectroscopy. The electrostatic energy was found to contribute significantly to the coverage-dependent energy shift.
Article
Chemistry, Multidisciplinary
Maciej Damian Korzynski, Moritz Bernhardt, Vladyslav Romankov, Jan Dreiser, Guy Matmon, Fabrice Pointillart, Boris Le Guennic, Olivier Cador, Christophe Coperet
Summary: In this study, a family of organometallic rare-earth complexes with different magnetic behaviors was reported by introducing different ligands. Compared to previous research, the complexes in this study exhibited a simplified magnetic relaxation behavior, and a mononuclear derivative of early-lanthanide complex was successfully prepared.
Article
Chemistry, Inorganic & Nuclear
Pawan Kumar, Jessica Flores Gonzalez, Prem Prakash Sahu, Naushad Ahmed, Joydev Acharya, Vierandra Kumar, Olivier Cador, Fabrice Pointillart, Saurabh Kumar Singh, Vadapalli Chandrasekhar
Summary: The synthesis, structure, and magnetism of four tetranuclear complexes have been reported, with two peroxide ligands assisting in their formation. Weak intramolecular antiferromagnetic interactions were found in three of the complexes, while a structural change in the fourth complex led to a ferromagnetic interaction. The magnetothermal behavior of one complex displayed a magnetocaloric effect with a maximum entropy change close to the calculated value.
INORGANIC CHEMISTRY FRONTIERS
(2022)
