Systematic Design of Crystal Structure for Hofmann-Like Spin Crossover Fe(L)2[Ag(CN)2]2 Complexes

Crystals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 370 ◽  
Author(s):  
Takashi Kosone ◽  
Yoshinori Makido ◽  
Syogo Okuda ◽  
Ayaka Haigo ◽  
Takeshi Kawasaki ◽  
...  
Keyword(s):  
Self Assembly ◽  
Spin Crossover ◽  
Interlayer Space ◽  
Layer Structure ◽  
Spin Transition ◽  
Axial Position ◽  
Systematic Design ◽  
Crystal Design ◽  
Critical Temperature Tc ◽  
Benzyl Nicotinate

The synthesis, crystal structures, and magnetic properties of a new two-dimensional (2D) Hofmann-like series, FeII(L)2[AgI(CN)2]2 (L = 3-cyano-4-methylpyridine (1), allyl isonicotinate (2), phenyl-isonicotinate (3), and benzyl nicotinate (4)) were studied. These compounds have a 2D sheet structure because of their strongly determinate self-assembly process. An octahedral FeII ion is coordinated with the nitrogen atoms of[AgI(CN)2 linear units at equatorial positions and monodentate pyridine derivatives at the axial position. The layers construct a parallel stacking array. Compounds 1–3 show pairs of layers constructed by intermetallic Ag···Ag interactions. Compound 4 shows a mono-layer structure. The substituent bulk of the ligands affects the interlayer space. Compounds 1–4 undergo a 100% spin transition. However, compound 1, incorporating a smaller group, has a relatively lower critical temperature (Tc = 182 K (1), Tc = 221 K (2), Tc = 227 (3) and Tc1 = 236 K, Tc2 = 215 K (4)). We investigated the correlations between our systematic crystal design, substituent size, and the spin crossover profiles.

scholarly journals Iron(III) Azadiphenolate Compounds in a New Family of Spin Crossover Iron(II)–Iron(III) Mixed-Valent Complexes

2019 ◽  
Vol 5 (2) ◽  
pp. 37 ◽  
Author(s):  
Wasinee Phonsri ◽  
David S. Macedo ◽  
Barnaby A. I. Lewis ◽  
Declan F. Wain ◽  
Keith S. Murray
Keyword(s):  
Crystal Structures ◽  
Spin Crossover ◽  
Crystal Packing ◽  
Spin Transition ◽  
Double Salt ◽  
Magnetic Studies ◽  
Cationic Precursor ◽  
New Family ◽  
Double Spin ◽  
Crystal Design

A new family of mixed valent, double salt spin crossover compounds containing anionic FeIII and cationic FeII compounds i.e., [FeII{(pz)3CH}2][FeIII(azp)2]2·2H2O (4), [FeII(TPPZ)2][FeIII(azp)2]2]·H2O (5) and [FeII(TPPZ)2][FeIII(azp)2]2]·H2O·3MeCN (6) (where (pz)3CH = tris-pyrazolylmethane, TPPZ = 2,3,5,6, tetrapyridylpyrazine and azp2− = azadiphenolato) has been synthesized and characterised. This is the first time that the rare anionic spin crossover species, [FeIII(azp)2]−, has been used as an anionic component in double salts complexes. Single crystal structures and magnetic studies showed that compound 6 exhibits a spin transition relating to one of the FeIII centres of the constituent FeII and FeIII sites. Crystal structures of the anionic and cationic precursor complexes were also analysed and compared to the double salt products thus providing a clearer picture for future crystal design in double spin crossover materials. We discuss the effects that the solvent and counterion had on the crystal packing and spin crossover properties.

scholarly journals Structural studies of a flexible 2D layer spin crossover coordination polymer

2014 ◽  
Vol 70 (a1) ◽  
pp. C1238-C1238
Author(s):  
Yu-Chun Chuang ◽  
Chung-Kai Chang ◽  
Ching-Che Kao ◽  
Jey-Jau Lee ◽  
Chih-Chieh Wang
Keyword(s):  
Magnetic Property ◽  
Spin State ◽  
Spin Crossover ◽  
Layer Structure ◽  
Dominant Role ◽  
Spin Transition ◽  
High Spin State ◽  
Structural Studies ◽  
Synchrotron Powder Diffraction ◽  
Solvent Molecules

The first coordination sphere of spin crossover material has been comprehended to play a dominant role to its magnetic property. However, the intermolecular interactions, such as π···π interaction and hydrogen bonding, also play a crucial factor. The contents of the solvent in a 2D layer structure, Fe (μ-atrz)(μ-pyz)(NCS)2·nH2O where n=4, 2 and 0, has been reported to be able to affect the spin transition behavior dramatically.[1] As loss of solvent molecules, the inter-layer distance becomes shorter and the transition temperature shifts to lower temperature and accompanies a larger hysteresis loop. To further understand the correlation between the inter-layer distance and magnetic property, the guest ab/desorption and pressure-induced synchrotron powder diffraction experiments were performed at BL01C2 in NSRRC. Based on the cyclic TGA measurements, the guest molecules, H2O, MeOH and EtOH, all can be removed and retaken repeatedly. The pressure-induced PXRD experiment was performed using a Boehler-Almax design diamond anvil cell (DAC). The detail structural studies attempt to understand not only the spin state changes from HS (high spin state) to LS (low spin state) but also the cooperative effect through the inter-layer distance.

Abrupt spin crossover in iron(iii) complexes with aromatic anions

2019 ◽  
Vol 48 (41) ◽  
pp. 15515-15520 ◽  
Author(s):  
Sharon E. Lazaro ◽  
Adil Alkaş ◽  
Seok J. Lee ◽  
Shane G. Telfer ◽  
Keith S. Murray ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Spin Crossover ◽  
Spin Transition ◽  
Halogen Bonds ◽  
Aromatic Anions

Two iron(iii) complexes, [Fe(qsal-X)2]OTs·nH2O, are found to exhibit abrupt spin crossover with the spin transition temperature substituent dependent, and X⋯O halogen bonds linking the spin centres.

scholarly journals Electrical read-out of light-induced spin transition in thin film spin crossover/graphene heterostructures

2021 ◽  
Author(s):  
Nikita Konstantinov ◽  
Arthur Tauzin ◽  
Ulrich Nguetchuissi Noumbé ◽  
Diana Dragoe ◽  
Bohdan Kundys ◽  
...  
Keyword(s):  
Thin Film ◽  
Spin Crossover ◽  
Spin Transition ◽  
Switching Device ◽  
Electronic Switching ◽  
Spin Transitions

An opto-electronic switching device made from an evaporated spin crossover thin film over a graphene sensor is presented. The electrical transduction of both temperature and light-induced reversible spin transitions are demonstrated.

Restricted Rotational Motion of InterlayerWaterMolecules in Vanadium Pentoxide Hydrate, V2O5·n D2O, as Studied by Deuterium NMR

2002 ◽  
Vol 57 (6-7) ◽  
pp. 419-424 ◽  
Author(s):  
Sadamu Takeda ◽  
Yuko Gotoh ◽  
Goro Maruta ◽  
Shuichi Takahara ◽  
Shigeharu Kittaka
Keyword(s):  
Double Layer ◽  
Vanadium Pentoxide ◽  
Rotational Motion ◽  
Interlayer Space ◽  
Layer Structure ◽  
Bond Distance ◽  
Adsorbed Water ◽  
Deuterium Nmr ◽  
Water Molecules ◽  
Layer Structures

The rotational behavior of the interlayer water molecules of deuterated vanadium pentoxide hydrate, V2O5.nD2O, was studied by solid-state deuterium NMR for the mono- and double-layer structures of the adsorbed water molecules. The rotational motion was anisotropic even at 355 K for both the mono- and double-layer structures. The 180° flipping motion about the C2-symmetry axis of the water molecule and the rotation around the figure axis, which makes an angle Ɵ with the C2-axis, occurred with the activation energy of (34±4) and (49±6) kJmol-1, respectively. The activation energies were almost independent of the mono- and double-layer structures of the water molecules, but the angle Ɵ made by the two axes varied from 33° for the monolayer to 25° for the double-layer at 230 K. The angle started to decrease above 250 K (e. g. the angle was 17 at 355 K for the double-layer structure). The results indicate that the average orientation of the water molecules in the two dimensional interlayer space depends on the layer structure and on the temperature. From the deuterium NMR spectrum at 130 K, the quadrupole coupling constant e2Qq/h = 240 kHz and the asymmetry parameter η= 0.12 were deduced. These values indicate the average hydrogen bond distance R(O H) = 2.0 Å for the D2O molecules in the 2D-interlayer space

Spin-crossover in a trans-[FeL2(NCS)2] family (L = triaryltriazole): remote substituent effects on spin transition modes and temperature

2013 ◽  
Vol 42 (28) ◽  
pp. 10144 ◽  
Author(s):  
Guo-Ping Shen ◽  
Li Qi ◽  
Lei Wang ◽  
Yan Xu ◽  
Jing-Jing Jiang ◽  
...  
Keyword(s):  
Spin Crossover ◽  
Spin Transition ◽  
Substituent Effects ◽  
Transition Modes ◽  
Remote Substituent

Self-assembly with colloidal clusters: facile crystal design using connectivity landscape analysis

Soft Matter ◽  
2017 ◽  
Vol 13 (39) ◽  
pp. 7098-7105 ◽  
Author(s):  
Mehdi B. Zanjani ◽  
John C. Crocker ◽  
Talid Sinno
Keyword(s):  
Self Assembly ◽  
Landscape Analysis ◽  
Efficient Design ◽  
Geometrical Analysis ◽  
Design And Optimization ◽  
Colloidal Clusters ◽  
Crystal Design

Geometrical analysis of connectivity enables efficient design and optimization of colloidal cluster assemblies.

scholarly journals Thermal and near-infrared light induced spin crossover in a mononuclear iron(ii) complex with a tetrathiafulvalene-fused dipyridophenazine ligand

2016 ◽  
Vol 45 (28) ◽  
pp. 11267-11271 ◽  
Author(s):  
F. Pointillart ◽  
X. Liu ◽  
M. Kepenekian ◽  
B. Le Guennic ◽  
S. Golhen ◽  
...  
Keyword(s):  
Spin Crossover ◽  
Near Infrared ◽  
Spin Transition ◽  
Infrared Light ◽  
Near Infrared Light ◽  
Mononuclear Iron

A thermal and photo-induced spin transition in a tetrathiafulvalene-based Fe(ii) complex.

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