Synthesis and characterisation of fifteen-electron dihalo(carbonyl)tungsten(iii) complexes, Tp*WX2(CO) (X = Br, I)

2020 ◽  
Vol 56 (71) ◽  
pp. 10349-10352
Author(s):  
Simon Thomas ◽  
Robert W. Gable ◽  
Charles G. Young
Keyword(s):  
Nmr Spectra ◽  
Magnetic Moments ◽  
Ground States ◽  
Open Shell ◽  
Distorted Octahedral ◽  
Ir Bands

Open-shell, 15-electron, d3 dihalo(carbonyl)–WIII complexes, Tp*WX2(CO), are reported. These mononuclear, distorted octahedral complexes exhibit single ν(CO) IR bands and magnetic moments and isotropically shifted NMR spectra consistent with low-spin, double ground states.

scholarly journals Template Synthesis, Characterization and Biological Activity of Cu(II), Ni(II), Co(II), Zn(II)Complexes with Isonicotinoylhydrazone--2-aldehydefluorene Ligand

2010 ◽  
Vol 7 (1) ◽  
pp. 227-233
Keyword(s):  
Experimental Data ◽  
Escherichia Coli ◽  
Thermal Analysis ◽  
Biological Activity ◽  
Nmr Spectra ◽  
Magnetic Moments ◽  
Analytical Data ◽  
Azomethine Nitrogen ◽  
Tetrahedral Geometry ◽  
Metal Ligand

This is about synthesizing new complex combinations of Cu(II), Ni(II),Co(II), Zn(II) with aroylhydrazone ligand isonicotinoylhydrazone-2-aldehydefluorene (INHAF) made by condensation of isonicotinoylhydrazine with 2-aldehydefluorene. The complexes have been characterized by analytical data, IR, UV-Vis, NMR spectra, magnetic susceptibility values, thermal analysis and for the Cu(II) complex the ESR spectrum has been registered. For all complexes the biological activity against theStaphylo-coccus aureus, Escherichia coli, Klebssiella pneumoniaebacteria has been investigated. The experimental data sustain stoichiometry of 1:2 (metal/ligand) for the Cu(II), Ni(II), Zn(II) complexes and of 1:1 for the complex with Co(II). The electronic spectra and the magnetic moments suggest octahedral stereochemistry at the complexes with Cu(II), Ni(II) and the tetrahedral geometry for the Co(II) complex. The INHAF ligand is coordinated bidentate by the O=C amide oxygen and the azomethine nitrogen in the complexes of Cu(II), Ni(II), Co(II) and monodentate by the azomethine nitrogen in the complex of Zn(II).

scholarly journals cAAC‐Stabilized 9,10‐diboraanthracenes—Acenes with Open‐Shell Singlet Biradical Ground States

2020 ◽  
Vol 59 (43) ◽  
pp. 19338-19343 ◽  
Author(s):  
Christian Saalfrank ◽  
Felipe Fantuzzi ◽  
Thomas Kupfer ◽  
Benedikt Ritschel ◽  
Kai Hammond ◽  
...  
Keyword(s):  
Ground States ◽  
Open Shell

MAGNETIC ORDERING IN QUASICRYSTALS

2005 ◽  
Vol 19 (27) ◽  
pp. 1367-1385 ◽  
Author(s):  
E. Y. VEDMEDENKO
Keyword(s):  
Magnetic Moments ◽  
Ground States ◽  
Magnetic Ordering ◽  
Single Sample ◽  
Magnetic Frustration ◽  
Two Dimensional ◽  
Theoretical Evidence ◽  
Quasiperiodic Tilings ◽  
Magnetically Ordered

An overview of the theoretical advances in description of the magnetic ordering and its stability in two-dimensional quasiperiodic tilings with strongly localized magnetic moments is presented. It is demonstrated that combination of the magnetic frustration and the quasiperiodic order of atoms leads to noncollinear ground states. An experimental and theoretical evidence for the possibility of coexistence of stable, magnetically ordered subtilings with highly frustrated, glass-like phases in a single sample is given.

Magnetic moments of the ground states ofTe127,Te129, andTe131

1979 ◽  
Vol 20 (3) ◽  
pp. 1171-1174 ◽  
Author(s):  
R. Geerts ◽  
C. Nuytten ◽  
E. Schoeters ◽  
R. Silverans ◽  
L. Vanneste
Keyword(s):  
Magnetic Moments ◽  
Ground States

scholarly journals Sol-Gel Synthesis, Magnetic and Optical Properties of Co2+:Nd3+::2:1 molar ratio doped in SiO2

2015 ◽  
Vol 11 (3) ◽  
pp. 3367-3374
Author(s):  
Bidhu Bhusan Das ◽  
Ruppa Govinda Rao
Keyword(s):  
Magnetic Moments ◽  
Sol Gel ◽  
Broad Band ◽  
Molar Ratio ◽  
Amorphous Sio2 ◽  
Asymmetric Mode ◽  
Distorted Octahedral ◽  
Bending Mode ◽  
Sio2 Phase ◽  
Sol Gel Synthesis

Synthesis of Co2+:Nd3+::2:1 molar ratio doped SiO2 with Co2+ ions concentrations viz. 0.0004, 0.001,  0.002, 0.003, 0.004 moles in S1-S5, respectively are performed by sol-gel method. Observed values of the densities and the concentrations of the Co2+ ions in S1-S5 are found to be 2.26, 2.29, 2.37, 3.44, 2.49 g/cm3, and ~ 1020 ions/g, respectively. Powder XRD results show the formation of amorphous SiO2 phase in the samples. DTA-TGA/DTG traces in the range 27-700 ˚C show no characteristic event in the samples. The IR peak in the range 412-418 cm-1 is ascribed to the asymmetric mode of the octahedral [NdO6/2]3- units. The peak around 440 cm-1 in S1-S5 is due to the ν2-symmetric bending mode of the tetrahedral [SiO4/2]4- units. The weak IR peak ~ 670 cm-1 is due to the ν1-mode of the tetrahedral [CoO4/2]4- units. The calculated values of the magnetic susceptibility from the observed magnetic moments data at 300 K are found to be ~10-6  emu/gG in S1-S5 which show the weak paramagnetic nature of the materials.  The EMR lineshapes recorded at 6, 50, 77, and 300 K are very broad, isotropic and smeared out with only two detectable characteristic peaks. The giso-value ~ 2.3 is due to the doped Co2+(3d7) ions in tetrahedral coordinations, while the giso-value ~ 2.01 is due to the doped Nd3+(4f3) ions in distorted octahedral coordinations. The lineshapes only at 6 K are distinct, while at higher temperatures  these peaks are severely smeared out. The optical absorption broad band at ~750 nm (13262 cm-1) is assigned to 4I9/2 ® 4F7/2 + 4S3/2 transitions in optically active Nd3+(4f3) ions, and the  peak ~ 520 nm (19230 cm-1) is attributed to 4A2g ® 4T1g(P) transitions in Co2+ (S=3/2, 3d7) ions in tetrahedral coordinations.

Copper(II) complexes with 1-phenyl-4,6-dimethylpyrimidine-2-thione. Chemical, spectroscopic, magnetic, conductivity and polarographic studies

1990 ◽  
Vol 55 (9) ◽  
pp. 2199-2215 ◽  
Author(s):  
Raffaele Battistuzzi ◽  
Marco Borsari
Keyword(s):  
Room Temperature ◽  
Copper Ions ◽  
Magnetic Moments ◽  
Thermal Analyses ◽  
Ligand Field ◽  
L System ◽  
Counter Ions ◽  
Ligand Field Spectra ◽  
Ir Bands ◽  
Magnetic Conductivity

New copper(II) complexes of general composition: CuLX2.nH2O (X = Cl-, n = 0.25; X = NO3-, n = 0.5), Cu2L3Cl4.2H2O, CuL2X2.H2O (X = ClO4-, BF4- and NO3-) and Cu2L7X4 (X = ClO4-, BF4- and NO3-), where L = 1-phenyl-4,6-dimethylpyrimidine-2-thione, have been isolated. Chemical and thermal analyses, conductivity, magnetic susceptibility, infrared and ligand field spectroscopic data and, for the perchlorate complexes also polarographic studies, are reported. Diagnostic IR bands frequencies of counter-ions, χ(Cu-X) modes and ligand field spectra for the mono-and bis-ligand compounds, having an equatorial [CuNSCl2], [CuNSO2] and [CuN2S2] microsymmetry, indicate a coordinating character of some anions, suggesting an elongated octahedral geometry for these complexes. For the [Cu2L7]X4 (X = ClO4-, BF4- and NO3-) complexes, which exhibit at room temperature subnormal magnetic moments, a polynuclear structure with the copper(II) in a roughly square-pyramidal environment, is proposed. Polarographic data for the perchlorate complexes and for the Cu(ClO4)2-L system at various ligand concentrations, have shown that in DMF solution the prevailing species are [CuL2]2+, [CuL3]2+ and [Cu2L7]4+ confirming the oxidation state II for the copper ions in the [Cu2L7]X4 complexes.

Darstellung und Kristallstrukturen einiger Übergangsmetall-Komplexverbindungen mit Liganden mit dem 4,5-Benzo-3-methyl-1,3,2-oxazaphosphorinan-6-on-Gerüst / Synthesis and X-Ray Crystal Structures of Some Transition-Metal Complexes Involving Ligands with the 4,5-Benzo-3-methyl-1,3,2-oxazaphosphorinan-6-one Framework

1994 ◽  
Vol 49 (11) ◽  
pp. 1481-1493 ◽  
Author(s):  
Axel Fischer ◽  
Ion Neda ◽  
Peter G. Jones ◽  
Reinhard Schmutzler
Keyword(s):  
Transition Metal ◽  
Single Crystal ◽  
Transition Metal Complexes ◽  
Nmr Spectra ◽  
Coordination Geometry ◽  
X Ray ◽  
Distorted Octahedral Coordination ◽  
Envelope Conformation ◽  
Square Planar ◽  
Distorted Octahedral

4,5-Benzo-2-diethylamino-3-methyl-1,3,2-oxazaphosphorinan-6-one 1 and 4,5-benzo-2-[bis- (2-chlorethyl)amino]-3-methyl-1,3,2-oxazaphosphorinan-6-one 3 reacted with dichloro- (cycloocta-1,5-diene)platinum(II) [(COD)PtCl2] to give the ds-dichloro-platinum(II) com­plexes 2 and 4, respectively. The reaction of 1 with tricarbonyl(cycloheptatriene)molybdenum(0) led to a mixture of isomers including fac-tris-(4,5-benzo-2-diethylamino-3-methyl- 1,3,2-oxazaphosphorinan-6-one)tricarbonylmolybdenum(0) 5. The reaction of 4,5-benzo- 2-acetylamino-3-methyl-1,3,2-oxazaphosphorinan-6-one 6 with dichloro(cycloocta-1,5-diene)- platinum(II) furnished the cis-complex 7. 4,5-Benzo-2-fluoro-3-methyl-1,3,2-oxazaphosphorinan-6-one 8 reacted with both tetracarbonyl(norbornadiene)molybdenum(0) and dichloro- (cycloocta-1,5-diene)platinum(II) to form the cis-complexes 9 and 10. 31P-31P coupling con­stants from the 31P NMR spectra for the complexes 2, 4 and 9 are reported. The structures of 5, 7, 9 and 10 were established by single crystal X-ray analysis. All ligands coordinate via phosphorus only. The structure of 5 shows strongly distorted octahedral coordination geome­try associated with the presence of three bulky ligands. The Mo-P bond lengths in 5 are, for the same reason, significantly longer than in 9. The heterocycles of the ligands in 5 do not show the expected envelope conformation but are almost planar. The platinum(II) complex 7 shows crystallographic C2-symmetry, the coordination geometry at platinum being almost ideally square-planar. The same coordination geometry is observed for 10, the ligands of which possess the expected envelope conformation with phosphorus out of the plane.

ELECTRONIC AND MAGNETIC PROPERTIES OF SILICENE AND SILICANE NANORIBBONS

2013 ◽  
Vol 02 (02) ◽  
pp. 1350011 ◽  
Author(s):  
KAI LI ◽  
ANNA SHIN HWA LEE ◽  
YONG-WEI ZHANG ◽  
HUI PAN
Keyword(s):  
Magnetic Properties ◽  
First Principles ◽  
Magnetic Moments ◽  
Ground States ◽  
Band Gaps ◽  
Metastable States ◽  
First Principles Calculations ◽  
Ribbon Width ◽  
Electronic And Magnetic Properties ◽  
Silicene Nanoribbons

In this paper, first-principles calculations are carried out to study the electronic and magnetic properties of silicene and silicane nanoribbons, with and without H -passivation at the edges. We predict that the armchair nanoribbons are nonmagnetic and semiconducting. Interestingly, the band gaps of armchair silicene nanoribbons show oscillating behavior as the ribbon width increases. When their edges are passivated with H atoms, However, the oscillating phase is reversed. The zigzag nanoribbons are anti-ferromagnetic and semiconducting in their ground states, except that the zigzag silicane nanoribbons with edges passivated by H atoms are nonmagnetic. The zigzag silicane nanoribbons with bare edges show the highest magnetic moments in their ground states. The band gaps of zigzag nanoribbons in their ground states decrease with the increment of width. The metastable states of zigzag silicene nanoribbons are ferromagnetic and metallic. The zigzag silicane nanoribbons with bare edges are ferromagnetic and semiconducting in their metastable states. The silicene/silicane nanoribbons with attractive functions, which are achievable by edge engineering or external fields, may be applied to spintronic technologies and nanodevices.

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