Molecular isomerism induced Fe(ii) spin state difference based on the tautomerization of the 4(5)-methylimidazole group

2017 ◽  
Vol 46 (13) ◽  
pp. 4218-4224 ◽  
Author(s):  
Wang-Kang Han ◽  
Zhi-Hua Li ◽  
Wei Zhu ◽  
Tao Li ◽  
Zaijun Li ◽  
...  

Two iron(ii) structural isomers with only one methyl position difference in their ligands exhibit different spin states due to the competition of the electronic effect and steric crowding.

2020 ◽  
Vol 49 (44) ◽  
pp. 15560-15567 ◽  
Author(s):  
Malcolm A. Halcrow

The relationship between ligand design and spin state in base metal compounds is surveyed. Implications and applications of these principles for light-harvesting dyes, catalysis and materials chemistry are summarised.


2017 ◽  
Vol 53 (99) ◽  
pp. 13268-13271 ◽  
Author(s):  
Rafal Kulmaczewski ◽  
Elzbieta Trzop ◽  
Laurence J. Kershaw Cook ◽  
Eric Collet ◽  
Guillaume Chastanet ◽  
...  

Six isostructural compounds show differing agreement with the correlation T(LIESST) = T0 − 0.3T1/2 (red line; LIESST = Light-Induced Excited Spin-State Trapping). This reflects crystallographic symmetry breaking under LIESST conditions, exhibited by one of the compounds but not by two others.


2019 ◽  
Author(s):  
Yan-Cong Chen ◽  
Yan Meng ◽  
Jiří Tuček ◽  
Yan-Jie Dong ◽  
Xiao-Wei Song ◽  
...  

Among the responsive multistable materials, spin crossover (SCO) systems are of particular interest for stabilizing multiple spin states with various stimulus inputs and physical outputs. Here in a 2D Hofmann-type coordination polymer [Fe(isoq)<sub>2</sub>{Au(CN)<sub>2</sub>}<sub>2</sub>] (isoq = isoquinoline), hidden multistability of the spin state is accessed by introducing an medium-temperature annealing after a light/temperature stimulation. With the combined effort of magnetic, crystallographic and Mössbauer spectral investigation, these distinct spin states are identified and the light- and temperature-assisted transition pathways are clarified. Such excitation-relaxation and trapping-relaxation joint mechanisms, as ingenious interplays between the kinetic and thermodynamic effects, uncover hidden possibilities for the discovery of multistable materials and the development of multistate intelligent devices.


2019 ◽  
Vol 127 (11) ◽  
pp. 752
Author(s):  
А.В. Крисилов ◽  
И.В. Нечаев ◽  
В.Е. Чернов ◽  
Б.А. Зон

We perform quantum chemical calculations of structures and IR spectra for endofullerene Gd@C60 in different spin states. It was found that the IR spectrum of endofullerenes Gd@C60 contains many lines in the range of 10-1540 cm−1. The frequencies and intensities of the IR lines of Gd@C60 depend on the spin state and molecular symmetry of the endofullerene. The frequencies of the coupled “metal-cage’’ vibrations lie in the range of 10¬–160 cm−1 and change significantly when the spin state changes. The spin dependence of the vibrational spectra opens up opportunities for monitoring the spin state of endofullerene by measuring the IR line frequencies, which is important for nanoelectronics and quantum Informatics


The Analyst ◽  
2015 ◽  
Vol 140 (17) ◽  
pp. 6147-6148 ◽  
Author(s):  
Yasutaka Kitahama ◽  
Masatoshi Egashira ◽  
Toshiaki Suzuki ◽  
Ichiro Tanabe ◽  
Yukihiro Ozaki

In our SERRS spectra, the peaks at 1510 cm−1, which are assigned not to the non-native 5-coordinated heme in the high spin state, but to the native 6-coordinated heme in the low spin state (6cLS), were observed.


2017 ◽  
Vol 15 (37) ◽  
pp. 7860-7868 ◽  
Author(s):  
S. Stepanović ◽  
D. Angelone ◽  
M. Gruden ◽  
M. Swart

Intradiol vs. extradiol selectivity of Fe(iii)-complexes explained by spin-state consistent density functionals.


2020 ◽  
Vol 224 ◽  
pp. 56-78
Author(s):  
Julia Brüggemann ◽  
Christoph R. Jacob

The exchange–correlation holes of different spin-states are analyzed, as a step towards explicitly spin-state dependent density-functional approximations.


RSC Advances ◽  
2016 ◽  
Vol 6 (2) ◽  
pp. 1403-1407 ◽  
Author(s):  
Aswin V ◽  
Anjana Dogra ◽  
Anurag Gupta ◽  
J. J. Pulikkotil

The thermally mediated low-spin and high spin states observed in LaCoO3 appears to be retained with Al substitutions, revealing a strong interplay between bonding and disorder in the system.


Author(s):  
Raphael Johann Friedrich Berger ◽  
Georgiy V. Girichev ◽  
Angelika A. Petrova ◽  
Valery V. Sliznev ◽  
Nataliya V. Tverdova ◽  
...  

Quantum chemical calculations of the geometric structure, force fields and harmonic vibration frequencies of the molecule Mn(acac)3 for electronic states with multiplicities M = 1, 3 and 5 were performed using the GAUSSIAN 09 program in the framework of density functional theory (DFT/UB3LYP) with correlation-consistent valence three-exponential basis functions cc-pVTZ. The structure with high-spin state S=2 (symmetry of electronic state 5B) possesses the lowest energy and it is characterized by C2 symmetry. The coordination polyhedron MnO6 possesses the shape of “elongated octahedron”. The high-spin state 5A is characterized by structure of compressed octahedron. The distortion of octahedral structure of coordination polyhedron in the states 5A and 5B is significant, and this fact testifies to the strong Jahn-Teller effect, or vibronic effect, in 5E electronic state. The calculations for low-spin state S=0 are notable for some specifics. The optimization resulted in C2 symmetry of molecule having the symmetry of electronic state 1B. The bond distances Mn-O within 0.001 Å were equal to values obtained for structure with D3 symmetry with S=1. This result corresponds to the situation if two electrons occupy different 1e orbitals possessing opposite spins. The spin states 3A2 and 1B lie higher than the high-spin state by 5.2 and 17.3 kcal/mol, respectively. The structural features are explained well in a framework of simple crystal field theory indicating that d-orbitals of Mn3+ ion undergo the significant influence of ligand field.Forcitation:Berger R.J.F., Girichev G.V., Giricheva N.I., Petrova A.A., Sliznev V.V., Tverdova N.V. Molecular structure of manganese tris-acetylacetonate in different spin states. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 4. P. 47-53.


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