Food Chemistry Volume 266, 15 November 2018, Pages 24-30 http://doi.org/10.1016/j.foodchem.2018.05.092 Fe-transferrins/their homologues in ex-vivo mushrooms were identified by ESR spectroscopy at liquid helium temperature, 4 K. The ESR fine-structure signals from Grifola frondosa were analyzed by spectral simulation with a full spin-Hamiltonian approach, determining the spin Hamiltonian parameters of the ferric iron species bound in the biological environment: S = 5/2, g = (2.045, 2.01, 2.235), |D| = 0.28 cm−1, |E/D| = 0.05. The zero-field splitting (ZFS) parameters, D– and E-values, are very close to the reported values, |D| = 0.25 cm−1 and |E/D| = 0.06, for an Fe-transferrin with oxalate anion, and to |D| = 0.25 cm−1 and |E/D| = 0.04 for one with malonate anion in human sera, suggesting that the Fe3+ species are from Fe-transferrins or their […]
J. Magn. Reson., 291, pp.14-22 (2018). DOI:10.1016/j.jmr.2018.03.005 A method is proposed for optimizing the performance of the APSOC (Adiabatic-Passage Spin Order Conversion) technique, which can be exploited in NMR experiments with singlet spin states. In this technique magnetization-to-singlet conversion (and singlet-to-magnetization conversion) is performed by using adiabatically ramped RF-fields. Optimization utilizes the GRAPE (Gradient Ascent Pulse Engineering) approach, in which for a fixed search area we assume monotonicity to the envelope of the RF-field. Such an approach allows one to achieve much better performance for APSOC; consequently, the efficiency of magnetization-to-singlet conversion is greatly improved as compared to simple model RF-ramps, e.g., linear ramps. We also demonstrate that the optimization […]
The Third Joint Conference of the Asia-Pacific EPR/ESR Society and The International EPR (ESR) Society (IES) Symposium will be held at The University of Queensland’s St. Lucia campus on the 24 – 28 September 2018.
Phys. Chem. Chem. Phys., 19, pp.30128-30138 (2017). DOI: 10.1039/C7CP05533a Spin–orbit contributions to the zero-field splitting (ZFS) tensor (DSO tensor) of MIII(acac)3 complexes (M = V, Cr, Mn, Fe and Mo; acac = acetylacetonate anion) are evaluated by means of ab initio (a hybrid CASSCF/MRMP2) and DFT (Pederson–Khanna (PK) and natural orbital-based Pederson–Khanna (NOB-PK)) methods, focusing on the behaviour of DFT-based approaches to the DSO tensors against the valence d-electron configurations of the transition metal ions in octahedral coordination. Both the DFT-based approaches reproduce trends in the D tensors. Significantly, the differences between the theoretical and experimental D (D = DZZ – (DXX + DYY)/2) values are smaller in NOB-PK than in PK, emphasising the usefulness of […]
Prof. Takeji Takui received the Zavoisky Award 2017 for his contributions to the development of organic high-spin and open-shell molecules and their EPR-based quantum spin technology.
Phys. Chem. Chem. Phys., 19, pp.24769-24791 (2017). DOI: 10.1039/C7CP03850J The fictitious spin-1/2 Hamiltonian approach is the putative method to analyze the fine-structure/hyperfine ESR spectra of high spin metallocomplexes having sizable zerofield splitting (ZFS), thus giving salient principal g-values far from around g = 2 without explicitly providing their ZFS parameters in most cases. Indeed, the significant departure of the g-values from g = 2 is indicative of the occurrence of their high spin states, but naturally they never agree with true g-values acquired by quantum chemical calculations such as sophisticated DFT or ab initio MO calculations. In this work, we propose facile approaches to determine the magnetic tensors of high spin metallocomplexes having sizable ZFS, instead of performing advanced high-field/high-frequency […]
Chem, Eur. J., accepted (2017). DOI: 10.1002/chem.201703220 Three structural isomers of trioxytriphenylamine (TOT) dimers, 4,4”’-bis(2,2′:6′,2″:6″,6-trioxytriphenylamine) (4), 3,3”’-bis(2,2′:6′,2″:6″,6-trioxytriphenylamine) (5), and 3,4”’-bis(2,2′:6′,2″:6″,6-trioxytriphenylamine) (6) were prepared and their electronic and magnetic properties in the di(radical cationic) states were investigated. The X-ray crystal structure analysis demonstrated that the TOT moieties of all the di(radical cation)s have planar structures similar to that of the structure of the parent TOT radical cation 3+. The UV-vis spectrum of the di(radical cation) showed characteristic absorptions depending on the connecting pattern. Thus, in the long wavelength region (600-900 nm), 4-2+ exhibited strong and broad characteristic absorptions, while compounds 5-2+ and 62+ exhibited weak absorptions. Notably, in the 450-600 […]
The 5th Awaji International Workshop on “Electron Spin Science & Technology: Biological and Materials Science Oriented Applications” (AWEST 2017) will be held at Awaji Yumebutai International Conference Center, Hyogo on June 18-21, 2017.
J. Phys. Chem. A 120, pp.6459-6466 (2016). DOI: 10.1021/acs.jpca.6b04932 Quantum computers are capable to efficiently perform full configuration interaction (FCI) calculations of atoms and molecules by using the quantum phase estimation (QPE) algorithm. Because the success probability of the QPE depends on the overlap between approximate and exact wave functions, efficient methods to prepare accurate initial guess wave functions enough to have sufficiently large overlap with the exact ones are highly desired. Here, we propose a quantum algorithm to construct the wave function consisting of one configuration state function, which is suitable for the initial guess wave function in QPE-based FCI calculations of openshell molecules, based on the addition theorem of […]
Dr. Satoru Yamamoto received the JEOL prize at the 49th Annual International Meeting of the ESR Spectroscopy Group of the Royal Society of Chemistry, University of Essex, Colchester, 3rd April – 7th April 2016.