Non-traditional thermal behavior of Co(II) coordination networks showing slow magnetic relaxation

2021 ◽  
Author(s):  
Anna Switlicka ◽  
Barbara Machura ◽  
Alina Bieńko ◽  
Dariusz Bieńko ◽  
Cyril Rajnák ◽  
...  
Keyword(s):  
Thermal Behavior ◽  
Coordination Polymers ◽  
Spin System ◽  
Magnetic Relaxation ◽  
Magnetic Data ◽  
Zero Field ◽  
Two Dimensional ◽  
Coordination Networks ◽  
One Dimensional ◽  
Slow Magnetic Relaxation

Three new coordination polymers, one-dimensional ones [Co(5,6-(Me)2–bzim)2(dca)2] (1), [Co(5-Mebzim)2(dca)2]n (2) and two-dimensional polymer [Co(2-Mebzim)(dca)2]n (3), show DC magnetic data consistent with the S = 3/2 spin system with large zero-field...

scholarly journals Reciprocating Thermal Behavior in Multichannel Relaxation of Cobalt(II) Based Single Ion Magnets

2021 ◽  
Vol 7 (6) ◽  
pp. 76
Author(s):  
Cyril Rajnák ◽  
Ján Titiš ◽  
Roman Boča
Keyword(s):  
Thermal Behavior ◽  
Magnetic Relaxation ◽  
Additional Term ◽  
Negative Temperature ◽  
Point Of View ◽  
Magnetic Data ◽  
Phonon Bottleneck ◽  
Slow Magnetic Relaxation ◽  
Relaxation Channel ◽  
Frequency Relaxation

A series of mononuclear Co(II) complexes showing slow magnetic relaxation is assessed from the point of view of relaxation mechanisms. In certain cases, the reciprocating thermal behavior is detected: On cooling, the slow relaxation time is prolonged until a certain limit and then, unexpectedly, is accelerated. The low-temperature magnetic data can be successfully fitted by assuming Raman and/or phonon bottleneck mechanisms of the slow magnetic relaxation for the high-frequency relaxation channel. An additional term with the negative temperature exponent is capable of reproducing the whole experimental dataset.

scholarly journals Nitronyl Nitroxide Biradical-Based Binuclear Lanthanide Complexes: Structure and Magnetic Properties

2020 ◽  
Vol 6 (4) ◽  
pp. 48
Author(s):  
Lu Xi ◽  
Jing Han ◽  
Xiaohui Huang ◽  
Licun Li
Keyword(s):  
Magnetic Properties ◽  
Magnetic Relaxation ◽  
Lanthanide Complexes ◽  
Magnetic Data ◽  
Antiferromagnetic Coupling ◽  
Zero Field ◽  
Nitronyl Nitroxide ◽  
Ferromagnetic Exchange ◽  
Binuclear Structure ◽  
Slow Magnetic Relaxation

Employing a new nitronyl nitroxide biradical NITPhPzbis(NITPhPzbis = 5-(1-pyrazolyl)-1,3-bis(1’-oxyl-3’-oxido-4’,4’,5’,5’-tetramethyl-4,5-hydro-1H-imidazol-2-yl)benzene), a series of 2p-4f complexes [Ln2(hfac)6(H2O)(NITPhPzbis)] (LnIII = Gd1, Tb2, Dy3; hfac = hexafluoroacetylacetonate) were successfully synthesized. In complexes 1–3, the designed biradical NITPhPzbis coordinates with two LnIII ions in chelating and bridging modes to form a four-spin binuclear structure. Direct-current magnetic study of Gd analogue indicates that ferromagnetic exchange exists between the Gd ion and the radical while antiferromagnetic coupling dominates between two mono-radicals. Dynamic magnetic data show that the χ” signals of complex 3 exhibit frequency dependence under zero field, demonstrating slow magnetic relaxation behavior in complex 3. And the estimated values of Ueff and τ0 are about 8.4 K and 9.1 × 10−8 s, respectively.

Field-induced slow magnetic relaxation in two-dimensional and three-dimensional Co(ii) coordination polymers

2019 ◽  
Vol 48 (41) ◽  
pp. 15529-15536 ◽  
Author(s):  
Deyun Ma ◽  
Guo Peng ◽  
Ying-Ying Zhang ◽  
Bo Li
Keyword(s):  
Coordination Polymers ◽  
Magnetic Relaxation ◽  
Three Dimensional ◽  
High Dimensional ◽  
Two Dimensional ◽  
The Family ◽  
Slow Magnetic Relaxation

Two two-dimensional and three-dimensional Co(ii) coordination polymers with slow magnetic relaxation are reported, which enlarge the family of high-dimensional coordination polymers exhibiting single ion magnet behavior.

Single molecule magnet behavior observed in a 1-D dysprosium chain with quasi-D5h symmetry

2015 ◽  
Vol 44 (48) ◽  
pp. 20834-20838 ◽  
Author(s):  
Xing-Cai Huang ◽  
Ming Zhang ◽  
Dayu Wu ◽  
Dong Shao ◽  
Xin-Hua Zhao ◽  
...  
Keyword(s):  
Coordination Polymers ◽  
Single Molecule ◽  
Magnetic Relaxation ◽  
Single Molecule Magnet ◽  
One Dimensional ◽  
Slow Magnetic Relaxation

Two one-dimensional coordination polymers with pentagonal bipyramidal DyIII centres show slow magnetic relaxation featuring single molecule magnet behavior.

Two-dimensional heterometallic CuIILnIII (Ln = Tb and Dy) coordination polymers bridged by dicyanamides showing slow magnetic relaxation behavior

CrystEngComm ◽  
2019 ◽  
Vol 21 (34) ◽  
pp. 5145-5151 ◽  
Author(s):  
Jiao-Jiao Kong ◽  
Jia-Chen Zhang ◽  
Yu-Xuan Jiang ◽  
Jin-Xia Tao ◽  
Wen-Yan Wang ◽  
...  
Keyword(s):  
Hysteresis Loop ◽  
Coordination Polymers ◽  
Magnetic Relaxation ◽  
Magnetic Hysteresis ◽  
Magnetic Hysteresis Loop ◽  
Relaxation Behavior ◽  
Relaxation Behaviour ◽  
Two Dimensional ◽  
Slow Magnetic Relaxation

Two-dimensional heterometallic CuIILnIII (Ln = Gd, Tb and Dy) coordination polymers bridged by dicyanamides showed slow magnetic relaxation behaviour and a magnetic hysteresis loop at 1.8 K was observed for the CuTb compound.

scholarly journals Magnetostructural Studies on Zigzag One-Dimensional Coordination Polymers Formed by Tetraamidatodiruthenium(II,III) Paddlewheel Units Bridged by SCN Ligands

2019 ◽  
Vol 5 (3) ◽  
pp. 40 ◽  
Author(s):  
Sara Moreno-Da Silva ◽  
Patricia Delgado-Martínez ◽  
Miguel Cortijo ◽  
Rodrigo González-Prieto ◽  
José Luis Priego ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Coordination Polymers ◽  
Ground State ◽  
Magnetic Data ◽  
Zero Field ◽  
Donor Atom ◽  
Zero Field Splitting ◽  
One Dimensional ◽  
Linkage Isomerism ◽  
New Compounds

We report herein on three zigzag one-dimensional coordination polymers of {[Ru2(μ-NHOCR)4](μ-SCN)}n (R = o-Me-C6H4 (2), m-Me-C6H4 (3), p-Me-C6H4 (4)) formula. These new compounds have been obtained by reaction of the corresponding [Ru2(μ-NHOR)4(THF)2](BF4) complex with (NBu4)(SCN) under different synthetic conditions. The crystal structure of [Ru2(μ-NHOCC6H4-o-Me)4(THF)2](BF4) (1), 2 and 3 are presented. A cis-(2,2) arrangement of the amidate ligands of the [Ru2(μ-NHOCR)4]+ units is observed in all cases. Interestingly, the structures of 2 and 3 show linkage isomerism in alternated tetraamidatodiruthenium units whose axial positions are occupied by the same type of donor atom of the SCN ligands. This results in zigzag chains with a Ru-S-C angle of 98.97° and Ru-N-C angle of 169.36° in the case of 2 and 97.99° and 159.26°, respectively, in the case of 3. The magnetic data obtained for 2–4 are indicative of a σ2π4δ2(π*δ*)3 ground state (S = 3/2) and a large zero-field splitting (ZFS) in all cases (D = 54.57, 62.72 and 43.00 cm−1 for 2–4, respectively). Similar small antiferromagnetic interactions between diruthenium units (zJ = −0.93, −0.79 and −1.11 cm−1 for 2–4, respectively) are estimated for all the polymers, suggesting an analogous zigzag arrangement of the chains for 4.

scholarly journals Chalcogen S∙∙∙S Bonding in Supramolecular Assemblies of Cadmium(II) Coordination Polymers with Pyridine-Based Ligands

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 697
Author(s):  
Nives Matijaković Mlinarić ◽  
Nikolina Penić ◽  
Boris-Marko Kukovec ◽  
Marijana Đaković
Keyword(s):  
Hydrogen Bonds ◽  
Nicotinic Acid ◽  
Coordination Polymers ◽  
Acid Hydrazide ◽  
Polymer Chains ◽  
Supramolecular Interactions ◽  
Two Dimensional ◽  
Coordination Networks ◽  
One Dimensional ◽  
Polymeric Chains

Two cadmium(II) coordination polymers, with thiocyanate and pyridine-based ligands e.g., 3-acetamidopyridine (3-Acpy) and niazid (nicotinic acid hydrazide, nia), namely one-dimensional {[Cd(SCN)2(3-Acpy)]}n (1) and two-dimensional {[Cd(SCN)2(nia)]}n (2), are prepared in the mixture of water and ethanol. The adjacent cadmium(II) ions in 1 are bridged by two N,S-thiocyanate ions and an N,O-bridging 3-Acpy molecule, forming infinite one-dimensional polymeric chains, which are assembled by the intermolecular N–H∙∙∙S hydrogen bonds in one direction and by the intermolecular S∙∙∙S chalcogen bonds in another direction. Within the coordination network of 2, the adjacent cadmium(II) ions are bridged by N,S-thiocyanate ions in one direction and by N,O,N’-chelating and bridging nia molecules in another direction. The coordination networks of 2 are assembled by the intermolecular N–H∙∙∙S and N–H∙∙∙N hydrogen bonds and S∙∙∙S chalcogen bonds. Being the only supramolecular interactions responsible for assembling the polymer chains of 1 in the particular direction, the chalcogen S∙∙∙S bonds are more significant in the structure of 1, whilst the chalcogen S∙∙∙S bonds which act in cooperation with the N–H∙∙∙S and N–H∙∙∙N hydrogen bonds are of less significance in the structure of 2.

scholarly journals Counterintuitive Single-Molecule Magnet Behaviour in Two Polymorphs of One-Dimensional Compounds Involving Chiral BINOL-Derived Bisphosphate Ligands

2021 ◽  
Vol 7 (11) ◽  
pp. 150
Author(s):  
Carlo Andrea Mattei ◽  
Bertrand Lefeuvre ◽  
Vincent Dorcet ◽  
Gilles Argouarch ◽  
Olivier Cador ◽  
...  
Keyword(s):  
Single Molecule ◽  
Magnetic Relaxation ◽  
Magnetic Measurements ◽  
Solvent Mixture ◽  
Zero Field ◽  
Coordination Environment ◽  
Single Molecule Magnet ◽  
One Dimensional ◽  
Slow Magnetic Relaxation ◽  
Coordination Reaction

The coordination reaction of the [Dy(hfac)3(H2O)2] units (hfac− = 1,1,1,5,5,5-hexafluoroacetylacetonate) with the [8′-(Diphenoxylphosphinyl)[1,1′-binaphthalen]-8-yl]diphenoxylphosphine oxide ligand (L) followed by a crystallisation in a 1:3 CH2Cl2:n-hexane solvent mixture led to the isolation of a new polymorph of formula [(Dy(hfac)3((S)-L))3]n (1). The X-ray structure on single crystal of 1 revealed the formation of a mono-dimensional coordination polymer with three crystallographically independent DyIII centres, which crystallised in the polar chiral P21 space group. Ac magnetic measurements highlighted single-molecule magnet behaviour under both zero and 1000 Oe applied magnetic field with magnetic relaxation through quantum tunneling of the magnetisation (QTM, zero field only) and Raman processes. Despite the three crystallographically independent DyIII centres adopting a distorted D4d coordination environment, a single slow magnetic relaxation contribution was observed at a slower rate than its previously studied [(Dy(hfac)3((S)-L))]n (2) polymorph.

Correlating the axial Zero Field Splitting with the slow magnetic relaxation in GdIII SIMs

2021 ◽  
Author(s):  
Júlia Mayans ◽  
Albert Escuer
Keyword(s):  
Magnetic Relaxation ◽  
Zero Field ◽  
Zero Field Splitting ◽  
Field Splitting ◽  
Slow Magnetic Relaxation

A possible relation between the value of the axial Zero Field Splitting and the occurrence of field-induced slow magnetic relaxation has been established for a new gadolinium(iii) compound.

Sign in / Sign up

Export Citation Format

Share Document