Metal complexes of 1,10-Phenanthroline derivatives. VIII. Complexs of 1,10-Phenanthroline-2-carbaldehyde imines

1974 ◽  
Vol 27 (10) ◽  
pp. 2121 ◽  
Author(s):  
HA Goodwin ◽  
DW Mather
Keyword(s):  
High Spin ◽  
Room Temperature ◽  
Spin Transition ◽  
Significant Rise ◽  
High Field Strength ◽  
Aryl Group ◽  
Metal Atoms ◽  
Spin Pairing ◽  
Aryl Amines ◽  
Derivatives Of

Iron(11), cobalt(11) and nickel(11) complexes [ML2] [BF4]2 of a series of related tridentate imine derivatives of 1,l0-phenanthroline-2-carbaldehyde [N-(l,l0-phenanthrolin-2-ylmethylene)alkyl-(or aryl)amines in which the alkyl or aryl group is methyl, ethyl, propyl, isopropyl, butyl, s-butyl, t-butyl, phenyl or benzyl] are described. From the electronic spectra of the nickel complexes an order of field strengths is established which correlates reasonably well with the bulkiness of the imine moiety. All the ligands except that where R = But effect spin-pairing in iron(11) at room temperature. When R = But the iron(11) complex is essentially high-spin at room temperature but is predominantly low-spin at 83 K. The magnetism of this substance is typical for that of iron(11) systems in which a gradual spin transition, 5T2 ←→ lAl occurs. In the complexes where R = Bu Bu8, Ph, a significant rise in the magnetic moment above room temperature is observed, indicating the presence of some metal atoms in the 5T2 state. Certain of the ligands of high field strength (R = Me, Et, Pr, Pr1) yield cobalt(11) complexes whose magnetism is indicative of a gradual quartet-doublet transition. The remaining cobalt(11) complexes are high spin.

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).

Structural Systematics of 2/4-Nitrophenoxide Complexes of Closed-Shell Metal Ions. I 2-Nitrophenoxides of Group 1

1998 ◽  
Vol 51 (8) ◽  
pp. 707 ◽  
Author(s):  
Jack M. Harrowfield ◽  
Raj Pal Sharma ◽  
Todd M. Shand ◽  
Brian W. Skelton ◽  
Allan H. White
Keyword(s):  
Room Temperature ◽  
Closed Shell ◽  
Aromatic Rings ◽  
X Ray ◽  
Metal Atoms ◽  
Metal Derivatives ◽  
Derivatives Of ◽  
Fourth Coordination ◽  
Group 1 ◽  
Oxygen Atoms

Room-temperature, single-crystal X-ray studies are recorded for the variously hydrated Group 1 metal derivatives of 2-nitrophenol (2-npH = C6H5NO3). A provisional determination is reported for Li(2-np).½H2O, set as monoclinic, P21/c, a 3·535(3), b 15·06(1), c 24·42(2) Å, β 91·7(1)°, Z = 8, conventional R on F currently 0·18 for No 875 ‘observed’ (I > 3σ(I)) reflections. Na(2-np).H2O is monoclinic, C2/c, a 34 ·23(2), b 3·624(4), c 35·48(2) Å, β 91·24(4)°, Z = 24, R 0·060 for No 1371. Rb(2-np).½ H2O is monoclinic, C2/c (isomorphous with the previously determined potassium analogue), a 25·269(9), b 5·381(5), c 12·010(3) Å, β 105·35(3)°, Z = 8, R 0·046 for No 1380. Cs(2-np).½H2O is monoclinic, P21/n, a 7·648(3), b 26·19(1), c 8·713(6) Å, β 111·75(2)°, Z = 8, R 0·061 for No 2347. All compounds except the lithium derivative are two-dimensional polymeric sheets in which the aromatic rings project to either side of a core of metal atoms coordinated by a web of 2-nitrophenoxide oxygen atoms in various bridging functionalities. The lithium compound is a novel ‘stair’ polymer with two crystallographically independent lithium atoms at successive independent Li–O crossbars, the oxygen atoms of which are phenoxide-Oof each of the two independent ligands. The lithium atoms are alternately four- and five-coordinate, the fourth coordination site of the first being occupied by the water molecule oxygen atom, while the fourth and fifth sites of the second are occupied by the cis-2-nitro oxygen atoms of the two ligands

Metal complexes of 1,10-Phenanthroline derivatives. VII. Complexes of 1,10-Phenanthroline-2-carbaldehyde hydrazones

1974 ◽  
Vol 27 (5) ◽  
pp. 965 ◽  
Author(s):  
HA Goodwin ◽  
DW Mather
Keyword(s):  
Field Strength ◽  
Metal Complexes ◽  
High Spin ◽  
Spin State ◽  
Spin Transition ◽  
Pronounced Change ◽  
Temperature Range ◽  
Spin Pairing ◽  
Bivalent Iron ◽  
Experimental Temperature Range

A series of substituted hydrazones derived from 1,l0-phenanthroline-2-carbaldehyde and their bis-ligand complexes with bivalent iron and nickel are described. The hydrazones show a gradation in field strength and this is reflected in the spin-state of the iron complexes. The methylhydrazone complex is essentially low-spin over the temperature range 83-363 K but the presence of some spin-free species at high temperatures is evident. Within the same range the dimethylhydrazone complex is essentially high-spin but undergoes significant spin-pairing and the phenylhydrazone complex displays a complete 5T2 → 1A1 spin transition. This transition is very sharp, resulting in a pronounced change in the magnetism, and colour, of the complex within a few degrees. Complexes of the 2-pyridylhydrazone, the methylphenylhydrazone and the diphenylhydrazone are high-spin over the entire experimental temperature range.

Realizing bias-induced spin transition with high-spin MnII complexes at room temperature

2017 ◽  
Vol 5 (44) ◽  
pp. 11598-11604
Author(s):  
Hua Hao ◽  
Ting Jia ◽  
Xiaohong Zheng ◽  
Lingling Song ◽  
Zhi Zeng
Keyword(s):  
High Spin ◽  
Spin State ◽  
Ground State ◽  
Room Temperature ◽  
State Transition ◽  
Spin Transition ◽  
Memory Devices ◽  
Spin State Transition ◽  
Molecular Transistors ◽  
Magnetic Ions

Complexes in the ground state with high-spin magnetic ions (3d5/3d4) can be used to realize the electrically-induced spin-state transition and build room-temperature molecular transistors or memory devices.

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.

Evidence for high-spin-to-low-spin transition under pressure in Fe 72 Pt 28 Invar alloy

2000 ◽  
Vol 80 (2) ◽  
pp. 155-163 ◽  
Author(s):  
S. Odin, F. Baudelet, E. Dartyge, J. P
Keyword(s):  
High Spin ◽  
Spin Transition ◽  
Invar Alloy

Development of the room temperature protocol based on room temperature ionic liquids and surfactant ionic liquids for the synthesis of derivatives of 2-amino-thiazoles and thermo-physical analysis of the synthesized derivatives using TGA-DSC.

2020 ◽  
Vol 10 ◽  
Author(s):  
Chandrakant Sarode ◽  
Sachin Yeole ◽  
Ganesh Chaudhari ◽  
Govinda Waghulde ◽  
Gaurav Gupta
Keyword(s):  
Thermal Analysis ◽  
Heat Capacity ◽  
Ionic Liquids ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Room Temperature ◽  
Heat Capacity Data ◽  
General Strategy ◽  
Capacity Data ◽  
Derivatives Of

Aims: To develop an efficient protocol, which involves an elegant exploration of the catalytic potential of both the room temperature and surfactant ionic liquids towards the synthesis of biologically important derivatives of 2-aminothiazole. Objective: Specific heat capacity data as a function of temperature for the synthesized 2- aminothiazole derivatives has been advanced by exploring their thermal profiles. Method: The thermal gravimetry analysis and differential scanning calorimetry techniques are used systematically. Results: The present strategy could prove to be a useful general strategy for researchers working in the field of surfactants and surfactant based ionic liquids towards their exploration in organic synthesis. In addition to that, effect of electronic parameters on the melting temperature of the corresponding 2-aminothiazole has been demonstrated with the help of thermal analysis. Specific heat capacity data as a function of temperature for the synthesized 2-aminothiazole derivatives has also been reported. Conclusion: Melting behavior of the synthesized 2-aminothiazole derivatives is to be described on the basis of electronic effects with the help of thermal analysis. Additionally, the specific heat capacity data can be helpful to the chemists, those are engaged in chemical modelling as well as docking studies. Furthermore, the data also helps to determine valuable thermodynamic parameters such as entropy and enthalpy.

Structural, magnetic and Mössbauer spectroscopic studies of the [Fe(3-bpp)2](CF3COO)2 complex: role of crystal packing leading to an incomplete Fe(ii) high spin ⇋ low spin transition

CrystEngComm ◽  
2021 ◽  
Vol 23 (15) ◽  
pp. 2854-2861
Author(s):  
Kristian Handoyo Sugiyarto ◽  
Djulia Onggo ◽  
Hiroki Akutsu ◽  
Varimalla Raghavendra Reddy ◽  
Hari Sutrisno ◽  
...  
Keyword(s):  
High Spin ◽  
Crystal Packing ◽  
Spin Transition ◽  
Spectroscopic Studies ◽  
Mononuclear Complex

Mononuclear complex [Fe(3-bpp)2](CF3COO)2 exhibits a thermal (HS + HS) ⇋ (HS + LS) transition at ∼226 K which is not associated with any crystallographic transition.

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,...

High Spin-Low Spin Transition in MnAs1-xPx(x=0.075)

1977 ◽  
Vol 42 (1) ◽  
pp. 31-35 ◽  
Author(s):  
Satoshi Haneda ◽  
Noriaki Kazama ◽  
Yasuo Yamaguchi ◽  
Hiroshi Watanabe
Keyword(s):  
High Spin ◽  
Spin Transition
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