Field Induced Single Ion Magnetic Behaviour in Square-Pyramidal Cobalt(II) Complexes with Easy-Plane Magnetic Anisotropy

Two penta-coordinate CoII complexes with formulae [Co(14-TMC)Cl](BF4) (1, 14-TMC = 1,4,8,11-Tetramethyl-1,4,8,11-tetraazacyclotetradecane) and [Co(12-TBC)Cl](ClO4)·(MeCN) (2, 12-TBC = 1,4,7,10-Tetrabenzyl-1,4,7,10-tetraazacyclododecane) were synthesized and characterized. Structural analysis revealed that ligand coordinates to the CoII centre in a tetradentate fashion and the fifth position is occupied by chloride ion and the geometries around CoII centres are best described as distorted square pyramidal. Detailed magnetic measurements disclose the presence of significant easy-plane magnetic anisotropy and field induced slow magnetic relaxation behaviours of the studied complexes. More insight into the magnetic anisotropy has been given using ab initio theory calculations, which agree well with the experimental values and further confirmed the easy-plane magnetic anisotropy.

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Slow magnetic relaxation in a {CoIICoIII2} complex containing a high magnetic anisotropy trigonal bipyramidal CoII centre

Dalton Transactions ◽

10.1039/c8dt01997e ◽

2018 ◽

Vol 47 (28) ◽

pp. 9237-9240 ◽

Cited By ~ 5

Author(s):

Alexandra Collet ◽

Gavin A. Craig ◽

María José Heras Ojea ◽

Lakshmi Bhaskaran ◽

Claire Wilson ◽

...

Keyword(s):

Magnetic Anisotropy ◽

Magnetic Relaxation ◽

Easy Plane ◽

Trigonal Bipyramidal ◽

Slow Magnetic Relaxation

Incorporation of a trigonal bipyramidal CoII centre in {CoIICoIII2} leads to a large, easy-plane magnetic anisotropy and slow magnetic relaxation.

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Magnetic anisotropy and slow magnetic relaxation processes of cobalt(ii)-pseudohalide complexes

Dalton Transactions ◽

10.1039/c9dt00644c ◽

2019 ◽

Vol 48 (28) ◽

pp. 10743-10752 ◽

Cited By ~ 8

Author(s):

Hui-Hui Cui ◽

Yi-Quan Zhang ◽

Xue-Tai Chen ◽

Zhenxing Wang ◽

Zi-Ling Xue

Keyword(s):

Magnetic Anisotropy ◽

Ab Initio ◽

Magnetic Relaxation ◽

Magnetic Measurements ◽

Relaxation Processes ◽

Slow Magnetic Relaxation

Magnetic measurements, HFEPR and ab initio calculations were used to study the magnetic anisotropies and magnetic relaxation of four cobalt(ii)-pseudohalide complexes.

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Investigation of easy-plane magnetic anisotropy in P-ligand square-pyramidal CoII single ion magnets

Chemical Communications ◽

10.1039/c7cc02584j ◽

2017 ◽

Vol 53 (38) ◽

pp. 5338-5341 ◽

Cited By ~ 30

Author(s):

Amit Kumar Mondal ◽

Jesús Jover ◽

Eliseo Ruiz ◽

Sanjit Konar

Keyword(s):

Magnetic Anisotropy ◽

Magnetic Relaxation ◽

Easy Plane ◽

Relaxation Behavior ◽

Donor Ligand ◽

Slow Magnetic Relaxation ◽

First Time

Field induced slow magnetic relaxation behavior has been studied for the first time for two P-donor ligand-based square-pyramidal CoII complexes with an easy-plane magnetic anisotropy.

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Cu(ii)–Dy(iii) and Co(iii)–Dy(iii) based single molecule magnets with multiple slow magnetic relaxation processes in the Cu(ii)–Dy(iii) complex

Dalton Transactions ◽

10.1039/c5dt00960j ◽

2015 ◽

Vol 44 (29) ◽

pp. 13242-13249 ◽

Cited By ~ 28

Author(s):

Malay Dolai ◽

Mahammad Ali ◽

Ján Titiš ◽

Roman Boča

Keyword(s):

Schiff Base ◽

Single Molecule ◽

Schiff Base Ligand ◽

Magnetic Relaxation ◽

Magnetic Behaviour ◽

Dinuclear Complexes ◽

Relaxation Processes ◽

Single Molecule Magnets ◽

Slow Magnetic Relaxation

Two CuII–DyIII and CoIII–DyIII dinuclear complexes of a Schiff base ligand (H3L) exhibit single-molecule magnetic behaviour with multiple slow magnetic relaxation processes for the former.

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Slow Magnetic Relaxation in a One-Dimensional Coordination Polymer Constructed from Hepta-Coordinate Cobalt(II) Nodes

Magnetochemistry ◽

10.3390/magnetochemistry6040045 ◽

2020 ◽

Vol 6 (4) ◽

pp. 45

Author(s):

Amit Kumar Mondal ◽

Arpan Mondal ◽

Sanjit Konar

Keyword(s):

Magnetic Susceptibility ◽

Coordination Polymer ◽

Magnetic Anisotropy ◽

Ab Initio Calculations ◽

Direct Current ◽

Magnetic Relaxation ◽

Relaxation Processes ◽

Ac Magnetic Susceptibility ◽

One Dimensional ◽

Slow Magnetic Relaxation

A one-dimensional coordination polymer was synthesized employing hepta-coordinate CoII as nodes and dicyanamide as linkers. Detailed direct current (DC) and alternating current (AC) magnetic susceptibility measurements reveal the presence of field-induced slow magnetic relaxation behavior of the magnetically isolated seven-coordinate CoII center with an easy-plane magnetic anisotropy. Detailed ab initio calculations were performed to understand the magnetic relaxation processes. To our knowledge, the reported complex represents the first example of slow magnetic relaxation in a one-dimensional coordination polymer constructed from hepta-coordinate CoII nodes and dicyanamide linkers.

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Low-dimensional compounds containing cyanido groups. Part XXXII. Field-induced multiple slow magnetic relaxation in [Co II (dcnm)(H 2 O)(phen) 2 ](dcnm) complex with dominant easy-plane anisotropy (dcnm = dicyanonitrosomethanide)

Polyhedron ◽

10.1016/j.poly.2017.08.009 ◽

2017 ◽

Vol 137 ◽

pp. 112-121 ◽

Cited By ~ 5

Author(s):

Ivan Potočňák ◽

Katarína Ráczová ◽

Erik Čižmár ◽

Lucia Váhovská ◽

Oleksandr Bukrynov ◽

...

Keyword(s):

Magnetic Relaxation ◽

Easy Plane ◽

Plane Anisotropy ◽

Slow Magnetic Relaxation ◽

Low Dimensional

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Coligand Effects on the Field-Induced Double Slow Magnetic Relaxation in Six-Coordinate Cobalt(II) Single-Ion Magnets (SIMs) with Positive Magnetic Anisotropy

Inorganic Chemistry ◽

10.1021/acs.inorgchem.9b01719 ◽

2019 ◽

Vol 58 (23) ◽

pp. 15726-15740 ◽

Cited By ~ 9

Author(s):

Julia Vallejo ◽

Marta Viciano-Chumillas ◽

Francisco Lloret ◽

Miguel Julve ◽

Isabel Castro ◽

...

Keyword(s):

Magnetic Anisotropy ◽

Magnetic Relaxation ◽

Slow Magnetic Relaxation

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Slow Magnetic Relaxation in Distorted Tetrahedral Dy(III) Aryloxide Complexes

Chemical Communications ◽

10.1039/d1cc02707g ◽

2021 ◽

Author(s):

Vijay Parmar ◽

Gemma Kate Gransbury ◽

George F. S. Whitehead ◽

David P Mills ◽

Richard E. P. Winpenny

Keyword(s):

Magnetic Anisotropy ◽

Magnetic Relaxation ◽

Easy Axis ◽

Slow Magnetic Relaxation

Three distorted tetrahedral Dy(III) aryloxide complexes, [Na(THF)6][Dy(OArAd2tBu)2Cl2] (1) (OArAd2tBu = OC6H2Adamantyl2-2,6-tBu-4) and [Na(THF)6][Dy(OMes*)3X] (X = Cl, 2; BH4, 3), (OMes* = OC6H2tBu3-2,4,6) exhibit easy axis magnetic anisotropy and slow magnetic...

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Incorporation of expanded organic cations in dysprosium(III) borohydrides for achieving luminescent molecular nanomagnets

Scientific Reports ◽

10.1038/s41598-021-88446-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Wojciech Wegner ◽

Jakub J. Zakrzewski ◽

Mikolaj Zychowicz ◽

Szymon Chorazy

Keyword(s):

Magnetic Anisotropy ◽

Single Molecule ◽

Unit Cell ◽

Organic Cations ◽

Single Molecule Magnets ◽

Higher Symmetry ◽

Magnetic Switching ◽

Unit Cells ◽

Slow Magnetic Relaxation ◽

Insight Into

AbstractLuminescent single-molecule magnets (SMMs) constitute a class of molecular materials offering optical insight into magnetic anisotropy, magnetic switching of emission, and magnetic luminescent thermometry. They are accessible using lanthanide(III) complexes with advanced organic ligands or metalloligands. We present a simple route to luminescent SMMs realized by the insertion of well-known organic cations, tetrabutylammonium and tetraphenylphosphonium, into dysprosium(III) borohydrides, the representatives of metal borohydrides investigated due to their hydrogen storage properties. We report two novel compounds, [n-Bu4N][DyIII(BH4)4] (1) and [Ph4P][DyIII(BH4)4] (2), involving DyIII centers surrounded by four pseudo-tetrahedrally arranged BH4– ions. While 2 has higher symmetry and adopts a tetragonal unit cell (I41/a), 1 crystallizes in a less symmetric monoclinic unit cell (P21/c). They exhibit yellow room-temperature photoluminescence related to the f–f electronic transitions. Moreover, they reveal DyIII-centered magnetic anisotropy generated by the distorted arrangement of four borohydride anions. It leads to field-induced slow magnetic relaxation, well-observed for the magnetically diluted samples, [n-Bu4N][YIII0.9DyIII0.1(BH4)4] (1@Y) and [Ph4P][YIII0.9DyIII0.1(BH4)4] (2@Y). 1@Y exhibits an Orbach-type relaxation with an energy barrier of 26.4(5) K while only the onset of SMM features was found in 2@Y. The more pronounced single-ion anisotropy of DyIII complexes of 1 was confirmed by the results of the ab initio calculations performed for both 1–2 and the highly symmetrical inorganic DyIII borohydrides, α/β-Dy(BH4)3, 3 and 4. The magneto-luminescent character was achieved by the implementation of large organic cations that lower the symmetry of DyIII centers inducing single-ion anisotropy and separate them in the crystal lattice enabling the emission property. These findings are supported by the comparison with 3 and 4, crystalizing in cubic unit cells, which are not emissive and do not exhibit SMM behavior.

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