The Flexibility of Long Chain Substituents Influences Spin-Crossover in Isomorphous Lipid Bilayer Crystals

2021 ◽  
Author(s):  
Iurii Galadzhun ◽  
Rafal Kulmaczewski ◽  
Namrah Shahid ◽  
Oscar Cespedes ◽  
Mark J Howard ◽  
...  
Keyword(s):  
Lipid Bilayer ◽  
High Spin ◽  
Room Temperature ◽  
Spin Crossover ◽  
Pyridine Derivatives ◽  
Long Chain

[Fe(bpp)2][BF4]2 (bpp = 2,6-di{pyrazol-1-yl}pyridine) derivatives bearing a bent geometry of hexadec-1-ynyl or hexadecyl substituents pyrazole are isomorphous, and high-spin at room temperature. However, only the latter compound undergoes an abrupt,...

Substituted phenanthrolines and their metal chelates

1973 ◽  
Vol 26 (5) ◽  
pp. 951 ◽  
Author(s):  
EJ Halbert ◽  
CM Harris ◽  
E Sinn ◽  
GJ Sutton
Keyword(s):  
Magnetic Properties ◽  
High Spin ◽  
Copper Complex ◽  
Magnetic Moment ◽  
Room Temperature ◽  
Spin Crossover ◽  
Metal Chelates ◽  
One Step

Substituents at and adjacent to the nitrogen atoms in 2,2?-bipyridyl and 1,10-phenanthroline are most likely to cause drastic changes in the magnetic properties of complexes with these ligands. Complexes of the N-oxides (2,2?-bipyridine 1,1?-dioxide, and 1,10-phenanthroline 1- oxide) with copper, and of 2-substituted phen (substituent = Cl, CONH2) with iron(II) are investigated, and a new one-step reaction to convert phno into cphn is reported. The copper complex Cu(bpyo)Br2 shows antiferromagnetic interactions, but other complexes Cu(bpyo)X2 (X = Cl, NO3) with this ligand are magnetically normal, as are Cu(phno)Cl2 and Cu(phno)Br2. The complex [Fe(cphn)3] (ClO4)2 lies near the high spin-low spin crossover for iron(II), and its magnetic moment is normal at room temperature but falls with decreasing temperature. The dioxide of phen appears not to be formed by the literature method and no successful synthesis can be reported here.

Steric Trapping of the High Spin State in FeIII Quinolylsalicylaldimine Complexes

2014 ◽  
Vol 67 (11) ◽  
pp. 1574 ◽  
Author(s):  
Darunee Sertphon ◽  
David J. Harding ◽  
Phimphaka Harding ◽  
Keith S. Murray ◽  
Boujemaa Moubaraki ◽  
...  
Keyword(s):  
Schiff Base ◽  
Electronic Properties ◽  
High Spin ◽  
Spin State ◽  
Schiff Base Ligand ◽  
Room Temperature ◽  
Spin Crossover ◽  
High Spin State ◽  
Electrochemical Studies ◽  
Magnetic Studies

A new sterically bulky Schiff base ligand, N-(8-quinolyl)-5-tert-butylsalicylaldimine (Hqsal-5-tBu) has been prepared and a series of FeIII complexes, [Fe(qsal-5-tBu)2]Y (Y = Cl 1, ClO4 2, NO3 3, BF4 4) utilising this ligand are reported and fully characterised. UV-vis spectroscopic and electrochemical studies indicate that 1–4 are high spin (HS) in solution at room temperature and further suggest that the tBu group only slightly alters the electronic properties of 1–4 compared with related [Fe(qsal-5-X)2]+ systems. The structures of [Fe(qsal-5-tBu)2]Cl·4MeOH·H2O 1, [Fe(qsal-5-tBu)2]ClO4·MeOH 2, and [Fe(qsal-5-tBu)2]NO3 3 determined at 100 K reveal HS FeIII centres in all cases. Four-fold parallel aryl embraces and π–π interactions serve to link the cations forming 2D sheets mirroring the motifs found in other [Fe(qsal-5-X)2]+ complexes. Despite this the tBu group causes strong distortions at the Fe centre which as magnetic studies reveal prevent spin crossover trapping 1–4 in the HS state.

An iron(II) complex tripodally chelated with 1,1,1-tris(pyridin-2-yl)ethane showing room-temperature spin-crossover behaviour

2016 ◽  
Vol 72 (11) ◽  
pp. 797-801 ◽  
Author(s):  
Takayuki Ishida ◽  
Takuya Kanetomo ◽  
Masaru Yamasaki
Keyword(s):  
High Spin ◽  
Room Temperature ◽  
Spin Crossover ◽  
Spin Transition ◽  
Complex Salt ◽  
Magnetic Study ◽  
The Novel ◽  
Bond Lengths ◽  
External Stimuli ◽  
Spin Species

The spin-crossover phenomenon is a reversible low- and high-spin transition caused by external stimuli such as heat. In the novel iron(II) complex salt tetraphenylphosphonium tris(thiocyanato-κN)[1,1,1-tris(pyridin-2-yl)ethane-κ3N,N′,N′′]ferrate(II), (C24H20P)[Fe(NCS)3(C17H15N3)], the Fe—N bond lengths are in the range 2.027 (2)–2.089 (2) Å, indicating that the specimen consists of comparable molar fractions of the low- and high-spin species at 296 K. A magnetic study confirmed that spin-crossover takes place at around 290 K.

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...

scholarly journals A family of heterobimetallic cubes shows spin‐crossover behaviour near room temperature

2021 ◽  
Author(s):  
Matthias Hardy ◽  
Jacopo Tessarolo ◽  
Julian J. Holstein ◽  
Niklas Struch ◽  
Norbert Wagner ◽  
...  
Keyword(s):  
Room Temperature ◽  
Spin Crossover

scholarly journals Influence of the ultra-slow nucleation and growth dynamics on the room-temperature hysteresis of spin-crossover single crystals

2021 ◽  
pp. 138442
Author(s):  
Volodymyr M. Hiiuk ◽  
Karl Ridier ◽  
Il'ya A. Gural'skiy ◽  
Alexander A. Golub ◽  
Igor O. Fritsky ◽  
...  
Keyword(s):  
Single Crystals ◽  
Room Temperature ◽  
Spin Crossover ◽  
Growth Dynamics ◽  
Nucleation And Growth ◽  
Temperature Hysteresis

Iron(II) and Nickel(II) Complexes of 2,6-Di(thiazol-2-yl)pyridine and Related Ligands

1991 ◽  
Vol 44 (8) ◽  
pp. 1041 ◽  
Author(s):  
AT Baker ◽  
P Singh ◽  
V Vignevich
Keyword(s):  
High Spin ◽  
Room Temperature ◽  
Spin Transition ◽  
Magnetic Behaviour ◽  
Diethyl Acetal ◽  
Thermally Induced ◽  
Field Strengths

2,6-Di(thiazol-2-yl]pyridine (1a), 2,6-di(4-methylthiazol-2-yl)pyridine (1b) and 2,6-di(2-imid-azolin-2-yl)pyridine (3) have been prepared by the reaction of pyridine-2,6-dicarbothioamide with bromoacetaldehyde diethyl acetal, bromoacetone and ethylenediamine, severally. Bis ( ligand ) iron(II) and nickel(II) complexes of all ligands have been prepared. The bis ( ligand ) iron(II) complexes of (1a) and (3) are low-spin whereas that of (1b) is high-spin at room temperature and undergoes a thermally induced spin transition. The field strengths of the ligands , determined from the spectra of their nickel(II) complexes, correlate well with the observed magnetic behaviour of their iron(II) complexes. The field strengths of (1a) and (1b) are found to be marginally less than those of the isomeric ligands 2,6-di(thiazol-4-yl)pyridine (2a) and 2,6-di(2-methylthiazol-4-yl)pyridine (2b).

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