Iron(II) and Nickel(II) Complexes of 6-(Pyrazol-1-yl)-2,2' -bipyridine

1999 ◽  
Vol 52 (4) ◽  
pp. 339 ◽  
Author(s):  
Anthony T. Baker ◽  
Jeremy P. Matthews
Keyword(s):  
Magnetic Susceptibility ◽  
Field Strength ◽  
Electronic Spectra ◽  
Strong Field ◽  
Electronic Spectroscopy ◽  
Magnetic Behaviour

Iron(II) and nickel(II) complexes of 6-(pyrazol-1-yl)-2,2′-bipyridine (pzbpy) have been prepared and characterized by magnetic susceptibility measurements and electronic spectroscopy. The magnetic behaviour of the iron(II) complexes and the electronic spectra of the nickel(II) complex indicate that pzbpy is a relatively strong-field ligand though its field strength is not as high as that of 2,2′:6′,2″-terpyridine. Comparisons of the field strength of terimine and analogous ligands are presented.

Transition Metal Complexes of Ambidinourea and Related Ligands.

1969 ◽  
Vol 24 (12) ◽  
pp. 1514-1517 ◽  
Author(s):  
A. Syamal
Keyword(s):  
Magnetic Susceptibility ◽  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Electronic Spectra ◽  
Strong Field ◽  
Absorption Bands ◽  
Effect Of Solvents ◽  
Infra Red ◽  
Solid Complexes

Copper (II), nickel (II), and palladium (II) complexes of amidinourea are reinvestigated in order to verify their structure. Electronic spectra and magnetic susceptibility measurements have been obtained on the solid complexes. Electronic spectral results indicate the donor strength of amidinourea is comparable to strong field ligands like biuret, biguanide, and I-amidino-O-alkylurea. Infra-red spectral results suggest that the carbonyl group of amidinourea is not involved in coordination and the donor atoms in amidinourea are amide nitrogens. The effect of solvents on the absorption bands is also discussed. The solution absorption spectra of bis (amidinourea) copper (II) chloride in different solvents indicate the following order of decreasing tetragonality:DMSO > methanol > ethyleneglycol > water.

The electronic spectra and magnetic behaviour of some dithiocacodylate complexes

1971 ◽  
Vol 24 (8) ◽  
pp. 1587 ◽  
Author(s):  
AT Casey ◽  
DJ Mackey ◽  
RL Martin
Keyword(s):  
Field Strength ◽  
Electronic Spectrum ◽  
Electronic Spectra ◽  
Magnetic Behaviour ◽  
The Other ◽  
Ligand Field ◽  
Ionic Character ◽  
Nephelauxetic Effect ◽  
Other Hand ◽  
Square Planar

The large nephelauxetic effect and low ligand field strength produced by the dithiocacodylate group [(CH3)2AsS2-] in complexes with Ni2+, Co2+, and Cr3+ is explained in terms of significant covalency of the metal- sulphur bonds. The Mn2+ compound, however, has properties consistent with considerable ionic character. ��� The electronic spectrum and magnetic behaviour of bisdithiocacodylato-cobalt(II) can be better interpreted in terms of tetrahedral rather than octahedral CoSx microsymmetry. On the other hand, the Ni2+ compound is square-planar and both the Mn2+ and Cr3+ compounds appear to be octahedrally coordinated by sulphur atoms.

scholarly journals Two-dimensional electronic spectroscopy as a tool for tracking molecular conformations in DNA/RNA aggregates

2018 ◽  
Vol 207 ◽  
pp. 233-250 ◽  
Author(s):  
Javier Segarra-Martí ◽  
Vishal K. Jaiswal ◽  
Ana Julieta Pepino ◽  
Angelo Giussani ◽  
Artur Nenov ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Ground State ◽  
Electronic Spectra ◽  
Crucial Role ◽  
Electronic Spectroscopy ◽  
Two Dimensional ◽  
Molecular Conformations ◽  
Computational Strategy

A computational strategy to simulate two-dimensional electronic spectra (2DES) is introduced, which allows characterising ground state conformations of flexible nucleobase aggregates that play a crucial role in nucleic acid photochemistry.

MAGNETIC BEHAVIOUR OF UPdAl, UCuGa AND UCuSn

1993 ◽  
Vol 07 (01n03) ◽  
pp. 850-854 ◽  
Author(s):  
V.H. TRAN ◽  
R. TROĆ
Keyword(s):  
Electrical Resistivity ◽  
Magnetic Susceptibility ◽  
Low Temperatures ◽  
Magnetic Behaviour ◽  
Type Structure ◽  
Complex Structures ◽  
Temperature Dependent ◽  
Antiferromagnetic Ordering

Magnetic susceptibility and electrical resistivity have been measured on UCuGa, UCu1+xSn1−x, (x=0 and 0.1), and UPdAl. The first two compounds, crystallizing in the hexagonal CaIn2-type structure, show at low temperatures an antiferromagnetic ordering probably with complex structures. UPdAl, which adopts the orthorhombic TiNiSi-type structure, was found to be a weakly temperature-dependent paramagnet down to 4.2 K.

Magnetic concentration and polymorphism in di-n-octyl-, di-n-decyl-, and di-n-dodecylphosphinates of copper(II)

1985 ◽  
Vol 63 (5) ◽  
pp. 1111-1117 ◽  
Author(s):  
John S. Haynes ◽  
Katherine W. Oliver ◽  
Robert C. Thompson
Keyword(s):  
Differential Scanning Calorimetry ◽  
Magnetic Susceptibility ◽  
Heisenberg Model ◽  
Variable Temperature ◽  
Electronic Spectroscopy ◽  
Chain Structure ◽  
Magnetic Data ◽  
Scanning Calorimetry ◽  
Extended Chain ◽  
Linear Chains

Phosphinates of copper(II) of the type Cu(R2PO2)2 where R is n-octyl, n-decyl, and n-dodecyl have been synthesized and characterized by differential scanning calorimetry, vibrational and electronic spectroscopy, and variable temperature (300 to 4.2 K) magnetic susceptibility studies. Each of these compounds was obtained in distinct α and β structural forms. All materials appear to have the double phosphinate bridged extended chain structure and the magnetic data have been successfully analyzed according to the isotropic Heisenberg model for linear chains. The α forms exhibit antiferromagnetic behaviour with J values of −25, −29, and −29 cm−1 for the octyl, decyl, and dodecyl derivatives respectively. The β forms are ferromagnetic and have corresponding J values of 1.8, 2.1, and 2.3 cm−1 respectively. Magneto-structural correlations in these extended chain coordination polymers are discussed.

Studies of metal halides. Magnetic properties of some molybdenum(III) binuclear complex halides

1969 ◽  
Vol 22 (1) ◽  
pp. 121 ◽  
Author(s):  
IE Grey ◽  
PW Smith
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Binuclear Complex ◽  
Magnetic Behaviour ◽  
Metal Halides ◽  
Metal Interaction ◽  
Metal Metal ◽  
Halide Complexes

The variation of magnetic susceptibility with temperature for a number of binuclear halide complexes of molybdenum of formula A3IMo2X9 (A = Cs, Et4N, Et3NH; X = Cl, Br) has been studied over the range 90-400�K. The magnetic behaviour is consistent with that expected for magnetically isolated exchange-coupled pairs of molybdenum atoms. The coupling is interpreted as occurring mainly by direct metal-metal interaction rather than superexchange.

scholarly journals Field-Induced Single-Ion Magnet Phenomenon in Hexabromo- and Hexaiodorhenate(IV) Complexes

2020 ◽  
Vol 6 (2) ◽  
pp. 20
Author(s):  
Carlos Rojas-Dotti ◽  
Adrián Sanchis-Perucho ◽  
Marta Orts-Arroyo ◽  
Nicolás Moliner ◽  
Ricardo González ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
General Formula ◽  
Crystal Packing ◽  
Variable Temperature ◽  
Magnetic Behaviour ◽  
Octahedral Geometry ◽  
Organic Cations ◽  
Ac Magnetic Susceptibility ◽  
Halide Ions ◽  
Triclinic System

Two mononuclear ReIV complexes of general formula (PPh4)2[ReX6] [PPh4+ = tetraphenylphosphonium cation, X = Br (1) and I (2)] have been prepared and structurally and magnetically characterised. Both compounds crystallise in the triclinic system with space group Pī. Their structures are made up of hexahalorhenate(IV), [ReX6]2−, anions, and bulky PPh4+ cations. Each ReIV ion in 1 and 2 is six-coordinate and bonded to six halide ions in a quasi regular octahedral geometry. In their crystal packing, the [ReX6]2− anions are well separated from each other through the organic cations, generating alternated anionic and cationic layers, and no intermolecular Re−X···X−Re interactions are present. Variable-temperature dc magnetic susceptibility measurements performed on microcrystalline samples of 1 and 2 show a very similar magnetic behaviour, which is typical of noninteracting mononuclear ReIV complexes with S = 3/2. Ac magnetic susceptibility measurements reveal the slow relaxation of the magnetisation in the presence of external dc fields for 1 and 2, hence indicating the occurrence of the field-induced single-ion magnet (SIM) phenomenon in these hexabromo- and hexaiodorhenate(IV) complexes.

Basic halides and related species of molybdenum(III). II. Spectroscopic and magnetic properties of MoOF(H2O)3 and MoOCl(H2O)3

1976 ◽  
Vol 29 (4) ◽  
pp. 717 ◽  
Author(s):  
DJ Stabb
Keyword(s):  
Magnetic Properties ◽  
Magnetic Susceptibility ◽  
Absorption Spectroscopy ◽  
Infrared Spectra ◽  
Electronic Spectra ◽  
Related Species ◽  
Bound Water ◽  
Temperature Range ◽  
Field Dependent

Two basic halides of molybdenum(111), namely MoOF(H2O)3 and MoOCl(H2O)3 (some samples containing additional loosely bound water), were investigated by absorption spectroscopy in the range 200-50000 cm-1, and by magnetic susceptibility measurements over a temperature range of 100-300 K. Infrared spectra showed bands at about 670 and 1600 cm-l, but not in the range 800-1100 cm-1. Electronic spectra showed poorly defined bands superimposed on strong general absorption. Very weak paramagnetism was observed: this was field dependent. The results are interpreted to show the compounds to be oxygen-bridged polymers [MOX(H2O)3O]n, rather than species containing Mo=O or Mo-0-H groups.

Infrared and Electronic Spectral Studies of Cobalt(II) and Nickel(II) Complexes of N-Allyl Urea and N-Allyl Thiourea

1972 ◽  
Vol 50 (16) ◽  
pp. 2603-2609 ◽  
Author(s):  
P. P. Singh ◽  
I. M. Pande
Keyword(s):  
Magnetic Susceptibility ◽  
Electronic Spectra ◽  
Electrical Conductance ◽  
Spectral Studies ◽  
Ligand Field ◽  
Magnetic Susceptibility Data ◽  
Susceptibility Data ◽  
Halide Complexes ◽  
Ligand Field Parameters ◽  
Allyl Thiourea

Complexes of N-allyl urea (NAU) and N-allyl thiourea (NATU) with cobalt (II) and nickel (II) halides and perchlorates have been prepared and characterized by electrical conductance, magnetic susceptibility, infrared and electronic spectra. Infrared spectra suggest coordination in NAU through oxygen and in NATU through nitrogen. The electronic spectra and magnetic susceptibility data indicate tetrahedral and octahedral stereochemistry for cobalt (II) and nickel (II) halide complexes, respectively. The various ligand field parameters Dq, B′, and β calculated for these complexes show about 25 and 11% covalency for Co (II) and Ni (II), respectively, and suggest a weak ligand field.

scholarly journals SOD-Mimic Cu(II) Dimeric Complexes Involving Kinetin and Its Derivative: Preparation and Characterization

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Radka Novotná ◽  
Zdeněk Trávníček ◽  
Radovan Herchel
Keyword(s):  
Mass Spectrometry ◽  
Magnetic Susceptibility ◽  
Temperature Dependence ◽  
Elemental Analysis ◽  
Antiradical Activity ◽  
Electronic Spectroscopy ◽  
Antiferromagnetic Exchange ◽  
Dimeric Complexes ◽  
Esi Mass Spectrometry

Two SOD-mimic active dimeric Cu(II) chlorido complexes of the compositions [Cu2(μ-HL1)4Cl2]Cl2(1) and [Cu2(μ-HL2)2(μ-Cl)2(HL2)2Cl2] · 4H2O (2) involving the cosmetologically relevant cytokinin kinetin (N6-furfuryladenine, HL1) and its derivative N6-(5-methylfurfuryl)adenine (HL2) have been synthesized and characterized by elemental analysis, infrared, and electronic spectroscopy, ESI+ mass spectrometry, conductivity and temperature dependence of magnetic susceptibility measurements, and thermogravimetric (TG) and differential thermal (DTA) analyses. The results of these methods, particularly the temperature dependence of magnetic susceptibility, showed the complexes to be dimeric with a strong antiferromagnetic exchange (J= −290 cm−1for complex1andJ= −160 cm−1for2). The complexes have been identified as auspicious SOD-mimics, as their antiradical activity evaluated by thein vitroSOD-mimic assay resulted in the IC50values equal to 8.13 μM (1) and 0.71 μM (2).

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