scholarly journals Solvent Effects on the Spin Crossover Properties of Iron(II) Imidazolylimine Complexes

Crystals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 116 ◽  
Author(s):  
Darunee Sertphon ◽  
Phimphaka Harding ◽  
Keith Murray ◽  
Boujemaa Moubaraki ◽  
Suzanne Neville ◽  
...  
Keyword(s):  
Low Temperature ◽  
Hydrogen Bonds ◽  
Solvent Effects ◽  
Spin Crossover ◽  
Magnetic Measurements ◽  
X Ray ◽  
Π Interactions ◽  
X Ray Crystallography ◽  
Solvent Loss

A series of Fe(II) complexes, fac-[Fe(4-ima-Bp)3](Y)2⋅sol (Y = ClO4; sol = 3EtOH 1, 3MeOH 2; Y= BF4; sol = EtOH⋅4H2O 3, 4H2O 4 and 3.5MeCN 5) have been prepared and structurally and magnetically characterized. The low temperature structures of 1, 2 and 5 have been determined by X-ray crystallography with LS Fe(II) centres found in all cases. Extensive C–H···π interactions between the cations form 2D layers, which are linked to one another through N-H···O and O-H···O hydrogen bonds, resulting in high cooperativity. Despite 5 containing MeCN, N-H···O/F hydrogen bonds, and C–H···π and π-π interactions combine to give similar 2D layers. Magnetic measurements reveal moderately abrupt spin crossover for 1-4; becoming more gradual and only 50% complete in 1 due to solvent loss. The MeCN solvate shows more gradual SCO and reinforces how subtle changes in packing can significantly influence SCO behaviour.

Systhesis, Characterization and Spectroscopic Properties of (2E,6E)-2,6-Bis(2,3,4-tri-methoxy-benzylidene)cyclohexanone

2011 ◽  
Vol 396-398 ◽  
pp. 2338-2341
Author(s):  
Xing Chuan Wei ◽  
Zhi Li Liu ◽  
Kun Zhang ◽  
Zhi Yun Du ◽  
Xi Zheng
Keyword(s):  
Crystal Structure ◽  
Acetic Acid ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
Spectroscopic Properties ◽  
Spectral Studies ◽  
Double Bonds ◽  
X Ray ◽  
Π Interactions ◽  
X Ray Crystallography

In this paper, (2E,6E)-2,6-Bis(2,3,4-tri-methoxy -benzylidene)cyclohexanone (omitted as tmbcho) (1) was obtained by the reaction of acetic acid, tetrahydrofuran, cyclohexanone and 2,3,4-tri-methoxy-benzaldehyde. Three non-classic hydrogen bonds were observed in the compound. X-ray crystallography shows that the crystal structure is stabilized by intermolecular C-H•••π interactions and it contains plenty of conjugated double bonds. The title compound was characterized by UV-vis and fluorescent spectral studies.

A Zinc(II)-Silver(I) Bimetallic Coordination Polymer Assembled Through Argentophilic and π-π Interactions, f[Zn(phen)2(H2O) {Ag(CN)2g][Ag(CN)2]·MeOH}n (phen=1,10-Phenanthroline)

2013 ◽  
Vol 68 (2) ◽  
pp. 161-167 ◽  
Author(s):  
Muhammad Monim-ul-Mehbooba ◽  
Muhammad Ramzan ◽  
Tobias Rüffe ◽  
Heinrich Lang ◽  
Shafqat Naddem ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermal Analysis ◽  
Ir Spectroscopy ◽  
Coordination Polymer ◽  
Hydrogen Bonds ◽  
X Ray ◽  
Π Interactions ◽  
X Ray Crystallography ◽  
3D Network ◽  
Argentophilic Interactions

A cyanido-bridged Zn(II)-Ag(I) bimetallic coordination polymer, {[Zn(phen)2(H2O){Ag(CN)2}] [Ag(CN)2]·MeOH}n (1), was prepared using ZnCl2, 1,10-phenanthroline (phen) and K[Ag(CN)2] and characterized by IR spectroscopy, thermal analysis and X-ray crystallography. The crystal structure of 1 consists of dinuclear [Zn(phen)2(H2O){Ag(CN)2}]+ cations, [Ag(CN)2]- anions and a methanol molecule. The non-coordinated [Ag(CN)2]- anions are linked to the [Zn(phen)2(H2O){Ag(CN)2}]+ complex cations through argentophilic interactions leading to the formation of chains. The chains are connected by hydrogen bonds and π-π interactions to give a 3D network.

scholarly journals Crystal Packing and Supramolecular Motifs in Four Phenoxyalkanoic Acid Herbicides—Low-Temperature Redeterminations

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Lesław Sieroń ◽  
Joanna Kobyłecka ◽  
Anna Turek
Keyword(s):  
Low Temperature ◽  
Propionic Acid ◽  
Crystal Packing ◽  
Dichlorophenoxyacetic Acid ◽  
X Ray ◽  
Π Interactions ◽  
X Ray Crystallography ◽  
Supramolecular Motifs ◽  
2,4 Dichlorophenoxyacetic Acid ◽  
Acid Herbicides

A low-temperature redetermination by X-ray crystallography of four phenoxyalkanoic acid herbicides, 4-chloro-2-methylphenoxyacetic acid (MCPA), rac-2-(4-chloro-2-methylphenoxy)propionic acid (MCPP), 2,4-dichlorophenoxyacetic acid (2,4-D), and 2,4-dichlorophenoxybutyric acid (2,4-DB), allowed the supramolecular structures of these compounds to be precisely described in terms of C⋯O/C–H⋯π interactions. The geometric parameters of the redetermined structures agree with those previously reported, but with improved precision.

A Promising New Schiff Base-like Ligand for the Synthesis of Octahedral Iron(II) Spin Crossover Complexes

2010 ◽  
Vol 65 (3) ◽  
pp. 323-328 ◽  
Author(s):  
Wolfgang Bauer ◽  
Tanja Ossiander ◽  
Birgit Weber
Keyword(s):  
Schiff Base ◽  
High Spin ◽  
Spin Crossover ◽  
Magnetic Measurements ◽  
X Ray ◽  
X Ray Crystallography ◽  
Tetradentate Schiff Base ◽  
Spin Crossover Complexes

A new tetradentate Schiff base-like ligand H2L (1) ((E,E)-dimethyl-2,2´-[1,2-phenylenebis(aminomethylidyne)] bis[3-oxobutanoate]) was synthesised and structurally characterised. Its reaction with iron(II) acetate leads to the formation of the octahedral N2O4-coordinated complex [FeL(MeOH)2] (2). The complex is a pure high-spin (HS) compound as is evident from magnetic measurements and X-ray crystallography.

Synthesis and Crystal Structure of the Hydrogen Bonded Complex of Tri-metatoluidylphosphazenyl Oxide with Bis-metatoluidine Hydrochloride

1977 ◽  
Vol 32 (9) ◽  
pp. 1001-1002 ◽  
Author(s):  
T. Stanley Cameron
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Oxygen Atom ◽  
Title Complex ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
Bond Lengths ◽  
Π Interactions ◽  
X Ray Crystallography ◽  
Phosphoryl Oxygen

The title complex was synthesised and its structure determined by x-ray crystallography. The structure contains two hydrogen bonds between the phosphoryl oxygen atom and the two meta-toluidinium ions. The P–N bond lengths are significantly different and the differences, attributed to varying p π-d π interactions along the bonds, confirm earlier observations on tri-para-toluidylphosphazenyl oxide.

scholarly journals Synthesis and Coordination Chemistry of 2-(Di-2-pyridylamino)pyrimidine; Structural Aspects of Spin Crossover in an FeII Complex

2012 ◽  
Vol 65 (7) ◽  
pp. 842 ◽  
Author(s):  
Rachel S. Crees ◽  
Boujemma Moubaraki ◽  
Keith S. Murray ◽  
Christopher J. Sumby
Keyword(s):  
Spin Crossover ◽  
Palladium Complex ◽  
Magnetic Measurements ◽  
Structural Basis ◽  
Temperature Dependent ◽  
X Ray ◽  
X Ray Crystallography ◽  
Bridging Ligand ◽  
Metal Atoms ◽  
Structural Aspects

2-(Di-2-pyridylamino)pyrimidine (L), a potentially ditopic tetradentate ligand, was synthesized from commercially available di-2-pyridylamine and 2-chloropyrimidine. Despite being capable of bridging two metal atoms with bidentate chelation of both metal centres, L prefers to chelate or bridge through the more basic pyridyl donors of the di-2-pyridylamine moiety. Mononuclear trans-[Fe(NCS)2(L)2] and [Cu(L)2(H2O)](BF4)2·H2O complexes, and a discrete [Ag2(L)4](PF6)2 metallo-macrocycle, were isolated and structurally characterized by X-ray crystallography. A mononuclear palladium complex [PdCl2(L)]·(solvate), where solvate = 1/2H2O or CH2Cl2, was also readily obtained in 71 % yield. One example of the ligand acting as a bis(bidentate) bridging ligand was observed in a dinuclear [(PdCl2)2(L)]·3/4H2O complex that was obtained only in very low yield (~3 %) from the reaction that produced [PdCl2(L)]·1/2H2O. trans-[Fe(NCS)2(L)2] undergoes a temperature-dependent high-spin–low-spin crossover at ~205 K that was observed by X-ray crystallography and magnetic measurements, and attempts were made to understand the structural basis of this process. Despite efforts to isolate examples of L bridging two iron(ii) centres, only the mononuclear trans-[Fe(NCS)2(L)2] species could be obtained.

Synthesis and Structural Study of the Thermochromic Compounds Bis(2-amino-4-oxo-6-methylpyrimidinium) Tetrachlorocuprate(II) and Bis(2-amino-4-chloro-6-methylpyrimidinium) Hexachlorodicuprate(II)

1999 ◽  
Vol 54 (6) ◽  
pp. 718-724 ◽  
Author(s):  
Isabel Díaz ◽  
Vicente Fernández ◽  
Vitaly K. Belsky ◽  
Jose Luis Martínez
Keyword(s):  
Charge Transfer ◽  
Low Temperature ◽  
Magnetic Measurements ◽  
Variable Temperature ◽  
Major Change ◽  
Crystal Data ◽  
X Ray ◽  
X Ray Crystallography ◽  
Square Planar ◽  
Intermediate States

The compound bis(2-amino-4-oxo-6-methylpyrimidinium) tetrachlorocuprate(II) 1 contains CuCU42- square-planar anions, and bis(2-amino-4-chloro-6-methylpyrimidinium) hexachlorodicuprate( II) 2 quasi-planar CU2CI62- anions. Both compounds show thermochromic behaviour. This phenomenon has been studied by X-ray crystallography at variable temperature, with the result that no major change is observed in the geometry of the copper atom. Thus it is possible to assume some influence of the hydrogen bonds and o f the different geometries of intermediate states on the color of the compounds due to the modifications provoked in the L→M charge transfer and in the energy o f the metal d-d transitions. Magnetic measurements of the compounds give information on magneto-structural correlations. Compound 1 is ferromagnetic (Tc ≅ 20 K) due to the perpendicular arrangement of the square anions that allows exchange pathways only via Cu-Cl -Cu , H-bonding or cationic n electron interactions. Compound 2 shows a very complicated behavior at low temperature with local antiferromagnetic fluctuations. Crystal data: 1 C10H10N6O2Cl4Cu, triclinic, P1; 393(2) K: α = 11.053(2), b = 11.334(2), c =14.038(3) (Å), α = 95.76(3), β = 101.35(3), γ=90.15(3)(°) ; 293(2) K: a = 11.022(2), b = 11.289(2), c = 14.001(3) (Å), α = 95.86(2), β = 101.34(2), γ=90.09(3)(°) ; 155(2) K: a = 11.008(2), b = 11.231 (2), c = 13.967(3) (A), a = 95.86(2), β = 101.37(2), γ=89.99(2)(°) ; Z = 4. 2 (C5H7N3Cl3Cu)2 , monoclinic, P21/c; 293(2) K: a = 5.998(1), b =18.669(4), c = 9.466(2) (Å), β =100.93(3)(°) ; 150(2) K: a = 5.971(1), b = 18.655(4), c = 9.383(2) (Å), ß =101.64(1)(°);Z=4

Spin-crossover iron(II) long-chain complex with slow spin equilibrium at low temperature

2021 ◽  
Author(s):  
Qi Zhao ◽  
Jin-Peng Xue ◽  
Zhi-Kun Liu ◽  
Zi-Shuo Yao ◽  
Jun Tao
Keyword(s):  
Low Temperature ◽  
Single Crystal ◽  
Spin Crossover ◽  
Chain Complex ◽  
Mononuclear Complex ◽  
X Ray ◽  
Alkyl Chains ◽  
Long Chain

A mononuclear complex with long alkyl chains, [FeII(H2Bpz2)2(C9bpy)] (1; H2Bpz2 = dihydrobis(1-pyrazolyl)borate, C9bpy = 4,4'-dinonyl-2,2'-bipyridine), was synthesized. Single-crystal X-ray crystallographic studies revealed that - and - forms of the complex...

C−H- - -O Hydrogen Bonds in β-Sheetlike Networks:  Combined X-ray Crystallography and High-Pressure Infrared Study

2003 ◽  
Vol 125 (40) ◽  
pp. 12358-12364 ◽  
Author(s):  
Kwang Ming Lee ◽  
Hai-Chou Chang ◽  
Jyh-Chiang Jiang ◽  
Jack C. C. Chen ◽  
Hsiang-En Kao ◽  
...  
Keyword(s):  
High Pressure ◽  
Hydrogen Bonds ◽  
Infrared Study ◽  
X Ray ◽  
X Ray Crystallography
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