scholarly journals Iron(II) Spin Crossover Complex with the 1,2,3-Triazole-Containing Linear Pentadentate Schiff-Base Ligand and the MeCN Monodentate Ligand

Crystals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 276 ◽  
Author(s):  
Tomoe Matsuyama ◽  
Keishi Nakata ◽  
Hiroaki Hagiwara ◽  
Taro Udagawa
Keyword(s):  
Schiff Base ◽  
Schiff Base Ligand ◽  
Spin Crossover ◽  
Variable Temperature ◽  
Spin Transition ◽  
Ligand Field ◽  
X Ray Diffraction ◽  
Monodentate Ligand ◽  
X Ray ◽  
Mononuclear Iron

A mononuclear iron(II) complex bearing the linear pentadentate N5 Schiff-base ligand containing two 1,2,3-triazole moieties and the MeCN monodentate ligand, [FeIIMeCN(L3-Me-3Ph)](BPh4)2·MeCN·H2O (1), have been prepared (L3-Me-3Ph = bis(N,N′-1-Phenyl-1H-1,2,3-triazol-4-yl-methylideneaminopropyl)methylamine). Variable-temperature magnetic susceptibility measurements revealed an incomplete one-step spin crossover (SCO) from the room-temperature low-spin (LS, S = 0) state to a mixture of the LS and high-spin (HS, S = 2) species at the higher temperature of around 400 K upon first heating, which is irreversible on the consecutive cooling mode. The magnetic modulation at around 400 K was induced by the crystal-to-amorphous transformation accompanied by the loss of lattice MeCN solvent, which was evident from powder X-ray diffraction (PXRD) studies and themogravimetry. The single-crystal X-ray diffraction studies showed that the complex is in the LS state (S = 0) between 296 and 387 K. In the crystal lattice, the complex-cations and B(1)Ph4− ions are alternately connected by intermolecular CH···π interactions between the methyl group of the MeCN ligand and phenyl groups of B(1)Ph4− ions, forming a 1D chain structure. The 1D chains are further connected by P4AE (parallel fourfold aryl embrace) interactions between two neighboring complex-cations, constructing a 2D extended structure. B(2)Ph4− ions and MeCN lattice solvents exist in the spaces of the 2D layer. DFT calculations verified that the 1,2,3-triazole-containing ligand L3-Me-3Ph gives a stronger ligand field around the octahedral coordination environment of the iron(II) ion than the analogous imidazole-containing ligand H2L2Me (= bis(N,N′-2-methylimidazol-4-yl-methylideneaminopropyl)methylamine) of the known compound [FeIIMeCN(H2L2Me)](BPh4)1.5·Cl0.5·0.5MeCN (2) reported by Matsumoto et al. (Nishi, K.; Fujinami, T.; Kitabayashi, A.; Matsumoto, N. Tetrameric spin crossover iron(II) complex constructed by imidazole⋯chloride hydrogen bonds. Inorg. Chem. Commun. 2011, 14, 1073–1076), resulting in the much higher spin transition temperature of 1 than that of 2.

Synthesis of an Unprecedented H-stitched Binuclear Crystal Structure Based on Selective Fluorescence Recognition of Zn2+ in Newly Synthesized Schiff Base Ligand with DFT and Imaging Application in Living Cells

2021 ◽  
Author(s):  
SOUMYA SUNDAR MATI ◽  
Dr. SAUGATA KONAR ◽  
BOBY SAMAI
Keyword(s):  
Crystal Structure ◽  
Schiff Base ◽  
Elemental Analysis ◽  
Schiff Base Ligand ◽  
Binuclear Complex ◽  
Living Cells ◽  
X Ray Diffraction ◽  
Schiff Base Ligands ◽  
X Ray ◽  
Imaging Application

A zinc coordinated rare binuclear complex was synthesised and characterized by elemental analysis and single-crystal X-ray diffraction. Two mononuclear units formed by two Schiff base ligands 2-((2-(pyrimidin-2-yl)hydrazono)methyl)phenol (PHP) coordinated with...

Cyclometalated Pt(ii) complexes with a bidentate Schiff-base ligand displaying unexpected cis/trans isomerism: synthesis, structures and electronic properties

2017 ◽  
Vol 46 (37) ◽  
pp. 12500-12506 ◽  
Author(s):  
A. Poma ◽  
A. Forni ◽  
C. Baldoli ◽  
P. R. Mussini ◽  
A. Bossi
Keyword(s):  
Schiff Base ◽  
Electronic Properties ◽  
Computational Methods ◽  
Schiff Base Ligand ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bidentate Schiff Base Ligand

Unexpected cis/trans isomerism in a bis-cyclometalated Pt(ii) complex is investigated by NMR, X-ray diffraction, optical, electrochemical and computational methods and rationalized.

scholarly journals Spin State Behavior of A Spin-Crossover Iron(II) Complex with N,N′-Disubstituted 2,6-bis(pyrazol-3-yl)pyridine: A Combined Study by X-ray Diffraction and NMR Spectroscopy

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 793
Author(s):  
Elizaveta K. Melnikova ◽  
Dmitry Yu. Aleshin ◽  
Igor A. Nikovskiy ◽  
Gleb L. Denisov ◽  
Yulia V. Nelyubina
Keyword(s):  
Nmr Spectroscopy ◽  
Spin State ◽  
Metal Ion ◽  
Spin Crossover ◽  
Molecular Design ◽  
Chemical Shifts ◽  
Variable Temperature ◽  
High Spin State ◽  
X Ray Diffraction ◽  
X Ray

A series of three different solvatomorphs of a new iron(II) complex with N,N′-disubstituted 2,6-bis(pyrazol-3-yl)pyridine, including those with the same lattice solvent, has been identified by X-ray diffraction under the same crystallization conditions with the metal ion trapped in the different spin states. A thermally induced switching between them, however, occurs in a solution, as unambiguously confirmed by the Evans technique and an analysis of paramagnetic chemical shifts, both based on variable-temperature NMR spectroscopy. The observed stabilization of the high-spin state by an electron-donating substituent contributes to the controversial results for the iron(II) complexes of 2,6-bis(pyrazol-3-yl)pyridines, preventing ‘molecular’ design of their spin-crossover activity; the synthesized complex being only the fourth of the spin-crossover (SCO)-active kind with an N,N′-disubstituted ligand.

Syntheses, Structures, Thermal and Photoluminescence Properties of Two Zn(II) and Cd(II) Coordination Polymers Constructed from Taurine-derived Schiff Base and 4,4’-Bipyridine Ligands

2012 ◽  
Vol 67 (8) ◽  
pp. 774-782 ◽  
Author(s):  
Wei-Ting Guo ◽  
Zhi-Min Miao ◽  
Yun-Long Wang
Keyword(s):  
Schiff Base ◽  
Coordination Polymers ◽  
Tridentate Ligand ◽  
Supramolecular Architecture ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Monodentate Ligand ◽  
Metal Centers ◽  
X Ray ◽  
Ethanesulfonic Acid

Two chain-like coordination polymers, namely, {[Zn(saes)(4,4'-bipy)(H2O)]·H2O}n (1) and {[Cd (Hsaes)2(4,4'-bipy)(H2O)2]·2H2O}n (2), where H2saes=2-(2-hydroxybenzylideneamino)ethanesulfonic acid and 4,4'-bipy=4,4'-bipyridine, have been synthesized and characterized by singlecrystal X-ray diffraction, IR spectroscopy, elemental, thermogravimetric and photoluminescence analysis. X-Ray diffraction analyses indicate that 1and 2display octahedral metal centers with N3O3 and N2O4 donor sets, respectively. The Schiff base serves as a common N,O'-tridentate ligand in 1, and as a unique O-monodentate ligand in 2. In the crystal, both 1and 2form a 3D supramolecular architecture by O-H···O, C-H···O interactions or π···π stacking. The thermal and solid-state photoluminescence properties of both complexes have been investigated

Platinum(II) complex with 4-nitro-N-(pyridin-2-ylmethylidene)aniline: synthesis, characterization, crystal structure and antioxidant activity

2020 ◽  
Vol 76 (11) ◽  
pp. 1005-1009
Author(s):  
Mehdi Khalaj ◽  
Abolfazl Olyaei ◽  
Mahdieh Sadeghpour ◽  
Arash Lalegani ◽  
Janusz Lipkowski ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Antioxidant Activity ◽  
Schiff Base ◽  
Schiff Base Ligand ◽  
Chain Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Square Planar ◽  
Dpph Method ◽  
Bidentate Schiff Base Ligand

A novel complex has been prepared using the (E)-4-nitro-N-(pyridin-2-ylmethylidene)aniline bidentate Schiff base ligand and PtCl2, namely, dichlorido[(E)-4-nitro-N-(pyridin-2-ylmethylidene)aniline-κ2 N,N′]platinum(II) acetonitrile hemisolvate, [PtCl2(C12H9N3O2)]·0.5CH3CN, 1. According to the X-ray measurements of the crystal structure, the PtII ion adopts a PtCl2N2 square-planar coordination. The coordination of the Schiff base ligand to the PtII ion occurs in a cyclic bidentate fashion, as a result of which a five-membered metallacycle is formed. Furthermore, in the structure of 1, the neutral molecules form a one-dimensional chain structure through C—H...Cl and C—H...O hydrogen bonds. The characterization of the complex was performed via single-crystal X-ray diffraction, IR spectroscopy and elemental analysis, and the antioxidant activity of the complex was evaluated using spectrophotometry by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method.

scholarly journals Spin-Crossover in Iron(II) Complexes of N,N′-Disubstituted 2,6-Bis(Pyrazol-3-yl)Pyridines: An Effect of a Distal Substituent in the 2,6-Dibromophenyl Group

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 922
Author(s):  
Igor A. Nikovskiy ◽  
Alexander V. Polezhaev ◽  
Valentin V. Novikov ◽  
Dmitry Yu. Aleshin ◽  
Rinat R. Aysin ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Spin Crossover ◽  
Molecular Design ◽  
Variable Temperature ◽  
Bromine Atom ◽  
X Ray Diffraction ◽  
Methyl Group ◽  
X Ray ◽  
Active Iron ◽  
Switchable Materials

A series of new bis(pyrazol-3-yl)pyridines (LR) N,N′-disubstituted by 4-functionalized 2,6-dibromophenyl groups have been synthesized to study the effect of a distal substituent on the spin-crossover (SCO) behaviour of the iron(II) complexes [Fe(LR)2](ClO4)2 by variable-temperature magnetometry, NMR spectroscopy, and X-ray diffraction. The SCO-assisting tendency of the substituents with different electronic and steric properties (i.e., the bromine atom and the methyl group) in the para-position of the 2,6-dibromophenyl group is discussed. Together with earlier reported SCO-active iron(II) complexes with N,N′-disubstituted bis(pyrazol-3-yl)pyridines, these new complexes open the way for this family of SCO compounds to emerge as an effective ‘tool’ in revealing structure–function relations, a prerequisite for successful molecular design of switchable materials for future breakthrough applications in sensing, switching, and memory devices.

Synthesis, crystal structures and characterizations of two homochiral coordination polymers based on a chiral reduced Schiff base ligand

2014 ◽  
Vol 70 (4) ◽  
pp. 375-378 ◽  
Author(s):  
Shao-Ming Ying ◽  
Xiao-Hui Huang ◽  
Wu-Kui Luo ◽  
Yan-Chun Xiao
Keyword(s):  
Schiff Base ◽  
Coordination Polymers ◽  
Schiff Base Ligand ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
Strong Emission ◽  
X Ray ◽  
Dimensional Network ◽  
Elemental Analyses ◽  
Reduced Schiff Base

Two homochiral coordination polymers based on a chiral reduced Schiff base ligand, namely poly[(μ5-4-{[(NR,1S)-(1-carboxylato-2-phenylethyl)amino]methyl}benzoato)zinc(II)], [Zn(C17H15NO4)]n, (1), and poly[(μ5-4-{[(NR,1S)-(1-carboxylato-2-phenylethyl)amino]methyl}benzoato)cobalt(II)], [Co(C17H15NO4)]n, (2), have been obtained by hydrothermal methods and studied by single-crystal X-ray diffraction, elemental analyses, powder X-ray diffraction, thermogravimetric analysis, IR spectroscopy and fluorescence spectroscopy. Compounds (1) and (2) are isostructural and crystallize in theP212121space group. Both display a three-dimensional network structure with a one-dimensional channel, with the benzyl group of the ligand directed towards the channel. An investigation of photoluminescence properties shows that compound (1) displays a strong emission in the purple region.

Large interaction energy for the homodimer and the heterodimer extracted from the supramolecular chain of a bent trinuclear zinc(II) complex with a reduced Schiff base ligand

2022 ◽  
Author(s):  
Mainak Karmakar ◽  
Rosa M. Gomila ◽  
Antonio Frontera ◽  
Shouvik Chattopadhyay
Keyword(s):  
Schiff Base ◽  
Diffraction Analysis ◽  
Schiff Base Ligand ◽  
Zinc Complex ◽  
Spectroscopic Methods ◽  
X Ray Diffraction ◽  
Amino Groups ◽  
X Ray ◽  
Reduced Schiff Base ◽  
Large Interaction

A bent trinuclear zinc complex, [Zn{ZnIL}2]•DMF {H2L = 2,2'-[(2,2-Dimethyl-1,3-propanediyl)bis(iminomethylene)]bis[6-methoxyphenol]} was synthesized and characterized by standard spectroscopic methods and X-ray diffraction analysis. The existence of coordinated amino groups and iodide counter...

An X-ray powder diffraction study of the spin-crossover transition and structure of bis(2,6-dipyrazol-1-ylpyrazine)iron(II) perchlorate

2004 ◽  
Vol 60 (1) ◽  
pp. 41-45 ◽  
Author(s):  
Victoria A. Money ◽  
Ivana Radosavljevic Evans ◽  
Jerome Elhaïk ◽  
Malcolm A. Halcrow ◽  
Judith A. K. Howard
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Spin Crossover ◽  
Spin Transition ◽  
High Spin State ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Crossover Transition

The crystal structure of the iron(II) spin-crossover compound [Fe(C10H8N6)2](ClO4)2 in the high-spin state has been solved from powder X-ray diffraction data using the DASH program and refined using Rietveld refinement. The thermal spin transition has been monitored by following the change in unit-cell parameters with temperature. The title compound has been found to undergo a crystallographic phase change, involving a doubling of the crystallographic a axis, on undergoing the spin transition.

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