Substituted phenanthrolines and their metal chelates

1973 ◽  
Vol 26 (5) ◽  
pp. 951 ◽  
Author(s):  
EJ Halbert ◽  
CM Harris ◽  
E Sinn ◽  
GJ Sutton

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.

2021 ◽  
Author(s):  
Iurii Galadzhun ◽  
Rafal Kulmaczewski ◽  
Namrah Shahid ◽  
Oscar Cespedes ◽  
Mark J Howard ◽  
...  

[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,...


Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2301
Author(s):  
Akihiro Tsuruta ◽  
Shuji Kawasaki ◽  
Masashi Mikami ◽  
Yoshiaki Kinemuchi ◽  
Yoshitake Masuda ◽  
...  

We investigated the Co substitution effect for the magnetic properties in room-temperature ferromagnetic oxide Sr3.1Y0.9Co4O10.5. The substituted element (Al and Ga) and low-spin state Co3+, which was changed from a high-spin or intermediate-spin state by Al or Ga substitution, reduced the Curie temperature to even 1.5 times lower than the temperature estimated from a simple dilution effect. Al3+ preferentially substituted for intermediate-spin-state Co3+ in the ferrimagnetic CoO6 layer and deteriorated the saturation magnetization of Sr3.1Y0.9Co4O10.5. By contrast, Ga3+ substituted for high-spin-state Co3+ in the CoO6 layer and/or the antiferromagnetic CoO4.25 layer and enhanced the saturation magnetization per Co ion. These results indicate that the magnetic properties of Sr3.1Y0.9Co4O10.5 can be controlled by selectively substituting for Co3+ with different spin states.


2013 ◽  
Vol 52 (19) ◽  
pp. 11585-11592 ◽  
Author(s):  
Magdalena Milek ◽  
Frank W. Heinemann ◽  
Marat M. Khusniyarov

2015 ◽  
Vol 29 (19) ◽  
pp. 1550099 ◽  
Author(s):  
Hai-Bin Wang ◽  
Zhong-Xiang Xie ◽  
Xia Yu ◽  
Yong Zhang ◽  
Dan Wang

First-principles calculations are performed to study the effect of isotropic stress on the electronic and magnetic properties of cubic bixbyite Indium oxide [Formula: see text] doped with substitution C impurities. In comparison with undoped [Formula: see text] materials, the defects can induce a spin moment with 2 [Formula: see text]B when two C atoms substitutes for two O atoms in the system. In addition, the spin moment remains the same under the condition of strain less than 2%. When the strain is more than 2%, there is a sharp transition to a high-spin magnetic moment with 4 [Formula: see text]B and it stays in this position with the increase of strain. This high magnetoelastic effect could be utilized to design pressure-tunable spin devices based on C-doped [Formula: see text].


2014 ◽  
Vol 67 (11) ◽  
pp. 1574 ◽  
Author(s):  
Darunee Sertphon ◽  
David J. Harding ◽  
Phimphaka Harding ◽  
Keith S. Murray ◽  
Boujemaa Moubaraki ◽  
...  

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.


2001 ◽  
Vol 40 (16) ◽  
pp. 3986-3991 ◽  
Author(s):  
Nicolás Moliner ◽  
Ana B. Gaspar ◽  
M. Carmen Muñoz ◽  
Virginie Niel ◽  
Joan Cano ◽  
...  

Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 855 ◽  
Author(s):  
Fabian Fürmeyer ◽  
Danny Münzberg ◽  
Luca M. Carrella ◽  
Eva Rentschler

Herein we report the synthesis and characterization of a novel bis-tridentate 1,3,4-thiadiazole ligand (L = 2,5-bis[(2-pyridylmethyl)thio]methyl-1,3,4-thiadiazole). Two new mononuclear complexes of the type [MII(L)2](ClO4)2 (with M = FeII (C1) and CoII (C2)) have been synthesized, containing the new ligand (L). In both complexes the metal centers are coordinated by an N4S2-donorset and each of the two ligands is donating to the metal ion with just one of the tridentate pockets. The iron(II) complex (C1) is in the low spin [LS] state below room temperature and shows an increase in the magnetic moment only above 300 K. In contrast, the cobalt(II) complex (C2) shows a gradual spin crossover (SCO) with T1/2 = 175 K. To our knowledge, this is the first cobalt(II) SCO complex with an N4S2-coordination.


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