Polyamine ligands. I. The stereochemistry of transition metal complexes with the ligand 1,8-Bis(2'-pyridyl)-3,6-diazaoctane

1970 ◽  
Vol 23 (3) ◽  
pp. 491 ◽  
Author(s):  
AT Phillip ◽  
AT Casey ◽  
CR Thompson
Keyword(s):  
Transition Metal Complexes ◽  
Metal Ion ◽  
Electronic Absorption Spectra ◽  
Magnetic Moments ◽  
Temperature Dependent ◽  
Physical Measurements ◽  
Square Planar ◽  
First Time ◽  
Perchlorate Complex ◽  
Complex Ion

The new polyamine ligand 1,8-bis(2'-pyridyl)-3,6-diazaoctane has been synthesized for the first time by the reaction between 2-vinylpyridine and ethyl-enediamine. The ligand could not be distilled without decomposition and hence it was purified by converting it into the crystalline copper(11) perchlorate complex, from which the ligand was liberated by the reaction with sodium sulphide solution. The pure ligand was obtained in an overall yield of 28%, based on starting materials. The complexes formed by the ligand with the metal ions copper(11), nicke1(11), palladium(11), zinc(11), and cobalt(111) were isolated and characterized by physical measurements of their conductance in solution, magnetic moments, infrared and electronic absorption spectra. The ligand adopts the planar-N4 configuration around the metal ion in the complexes with copper(11), nicke1(11), and palladiurn(11), whereas it probably adopt's a tetrahedral-N4 configuration around the zinc(11) complex ion. The nickel(11) perchlorate complex is diamagnetic in the solid state and it most likely contains the metal ion in square-planar cordination. When dissolved in coordinating solvents, this complex undergoes a reversible, temperature-dependent equilibrium between diamagnetic and solvated, paramagnetic forms.

scholarly journals Transition metal complexes of 5-bromosalicylidene-4-amino-3-mercapto-1,2,4-triazine-5-one: Synthesis, characterization, catalytic and antibacterial studies

2011 ◽  
Vol 76 (1) ◽  
pp. 75-83 ◽  
Author(s):  
A.S. Ramasubramanian ◽  
Ramachandra Bhat ◽  
Ramakrishna Dileep ◽  
Sandya Rani
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Pathogenic Bacteria ◽  
Magnetic Moments ◽  
Spectroscopic Techniques ◽  
Antibacterial Studies ◽  
Metal Precursors ◽  
Square Planar ◽  
Bactericidal Properties

Transition metal complexes of 5-bromosalicylidene-4-amino-3- mercapto-1,2,4-triazine-5-one with metal precursors, such as Cu(II), Ni(II), Co(II) and Pd(II), were synthesized and characterized by physicochemical and spectroscopic techniques. All the complexes are of the ML type. Based on analytical, spectral data and magnetic moments, the Co(II) and Ni(II) complexes were assigned octahedral geometries, while the Cu (II) and Pd(II) complexes square planar. A study on the catalytic oxidation of benzyl alcohol, cyclohexanol, cinnamyl alcohol, 2-propanol and 2- methyl-1-propanol was performed with N-methylmorpholine-N-oxide (NMO) and molecular oxygen as co-oxidants. All the complexes and their parent organic moiety were screened for their biological activity on several pathogenic bacteria and were found to possess appreciable bactericidal properties.

Cobalt(II), nickel(II) and copper(II) complexes of some 2'-hydroxychalcones

1980 ◽  
Vol 33 (4) ◽  
pp. 737 ◽  
Author(s):  
M Palaniandavar ◽  
C Natarajan
Keyword(s):  
Infrared Spectra ◽  
Metal Ion ◽  
Magnetic Moments ◽  
Phenyl Group ◽  
Ligand Field ◽  
Square Planar ◽  
Spin Pairing ◽  
Square Configuration ◽  
Electron Sink ◽  
Octahedral Configuration

Metal(II) bis-chelates of the type ML2 [M = CoII, NiII, CuII; L = 2'- hydroxy-5'-X-chalcone where X = H, CH3, Cl] have been prepared and studied. Structures have been assessed by the measurement of magnetic moments, ligand field and infrared spectra and thermal properties. These chelates possess low-spin trans-square-planar configuration and show resistance to adduct formation in contrast to metal(II) chelates of β-diketones, salicylaldehyde, o-hydroxyaryl ketones and esters and o-hydroxy-crotonophenones, which have high-spin octahedral configuration. Extensive conjugation lowers the energy of the π3* orbital which enters into a very strong dπ-π3* interaction leading to spin-pairing. ��� Infrared spectra indicate that the carbonyl group is perturbed only slightly by coordination to metal. A change in metal ion affects v(C=O), v(M-O) and other vibrations and the order of stability, namely, Co ≈ Ni < Cu, inferred from these vibrations is as expected for the low-spin square configuration of the chelates. Introduction of substituents (5'-X) alters only v(M-O) significantly and the order of stability, namely, Cl > CH3 > H, derived from v(M-O) is consistent with Taft's resonance polar parameters of the substituents. All these observations are explained by the electron sink property of the phenyl group.

scholarly journals Physical properties of iodate solutions and the deliquescence of crystalline I<sub>2</sub>O<sub>5</sub> and HIO<sub>3</sub>

2010 ◽  
Vol 10 (24) ◽  
pp. 12251-12260 ◽  
Author(s):  
R. Kumar ◽  
R. W. Saunders ◽  
A. S. Mahajan ◽  
J. M.C. Plane ◽  
B. J. Murray
Keyword(s):  
Water Activity ◽  
Temperature Dependent ◽  
Activity Data ◽  
Gas Phase Chemistry ◽  
Activity Density ◽  
Phase Chemistry ◽  
First Time ◽  
Measured Water ◽  
Complex Ion

Abstract. Secondary aerosol produced from marine biogenic sources in algal-rich coastal locations will initially be composed of iodine oxide species, most likely I2O5, or its hydrated form HIO3, formed as a result of iodine gas-phase chemistry. At present, there is no quantitative hygroscopic data for these compounds and very little data available for iodate solutions (HIO3 and I2O5 share a common aqueous phase). With increased interest in the role of such aerosol in the marine atmosphere, we have conducted studies of (i) the deliquescence behaviour of crystalline HIO3 and I2O5 at 273–303 K, (ii) the efflorescence behaviour of aqueous iodate solution droplets, and (iii) properties (water activity, density, and viscosity) of subsaturated and saturated iodate solutions. The deliquescence of I2O5 crystals at 293 K was observed to occur at a relative humidity (DRH) of 80.8±1.0%, whereas for HIO3, a DRH of 85.0±1.0% was measured. These values are consistent with measured water activity values for saturated I2O5 and HIO3 solutions at 293 K of 0.80±0.01 and 0.84±0.01 respectively. At all temperatures, DRH values for HIO3 crystals were observed to be higher than for those of I2O5. The temperature-dependent DRH data, along with solubility and water activity data were used to evaluate the enthalpy of solution (ΔHsol) for HIO3 and I2O5. A ΔHsol value of 8.3±0.7 kJ mol−1 was determined for HIO3 which is consistent with a literature value of 8.8 kJ mol−1. For I2O5, we report for the first time its solubility at various temperatures and ΔHsol = 12.4±0.6 kJ mol−1. The measured water activity values confirm that aqueous iodate solutions are strongly non-ideal, consistent with previous reports of complex ion formation and molecular aggregation.

Discotic liquid crystals of transition metal complexes 34: spectroscopic properties of bis[octakis(3,4-dialkoxy-phenoxy)phthalocyaninato]lutetium(III) complexes

2003 ◽  
Vol 07 (02) ◽  
pp. 105-111 ◽  
Author(s):  
Kazuaki Hatsusaka ◽  
Kazuchika Ohta
Keyword(s):  
Thin Film ◽  
Absorption Spectra ◽  
Electronic Absorption ◽  
Liquid Crystalline ◽  
Electronic Absorption Spectra ◽  
Solvent Polarity ◽  
Spectroscopic Properties ◽  
Temperature Dependent ◽  
First Time ◽  
Hexane Solution

Spectroscopic properties of discotic liquid crystalline bis[octakis(3,4-dialkoxyphenoxy)-phthalocyaninato]lutetium(III) complexes, {[( C n O )2 PhO ]8 Pc }2 Lu (n = 12: 2a and n = 13: 2b), were investigated by recording electronic absorption spectra in the region of 250-2600 nm under three different conditions; solution, mixed solvent solutions, and a thin film at various temperatures. An intermolecular charge transfer (CT) band was found at about 2000-2100 nm both for the n-hexane solution and the thin film. It was established for the first time from the solvent-polarity-dependent and temperature-dependent electronic absorption spectra that the intermolecular CT band is attributable to molecular aggregation.

Metallkomplexe mit paramagnetischen Salicylaldimin- und Thiosemicarbazon-Liganden / Metal Complexes of Paramagnetic Salicylaldimine and Thiosemicarbazone Ligands

1971 ◽  
Vol 26 (12) ◽  
pp. 1210-1215 ◽  
Author(s):  
Dieter Jahr ◽  
Karl E. Schwarzhans ◽  
Dietrich Nöthe ◽  
Paul K. Burkert
Keyword(s):  
Free Radicals ◽  
Metal Complexes ◽  
Metal Ion ◽  
Magnetic Moments ◽  
Epr Spectra ◽  
Temperature Dependent ◽  
Unpaired Electrons ◽  
Stable Free Radicals ◽  
Dependent Interaction

A series of complexes formed between metals and the stable free radicals 2,2,6,6-tetramethylpiperidine-1-oxyl-4- (N-salicylaldimine) and 2,2,6,6-tetramethylpiperidone (4) -1-oxyl-thiosemicarba-zone has been prepared. The magnetic moments and the epr spectra of the complexes have been investigated. Some of the complexes show a temperature dependent interaction between the radicalic nitroxyl groups of the ligands. No interaction was found, however, between the metal ion and the unpaired electrons of the ligands.

Transition metal complexes of thiabendazole

1971 ◽  
Vol 24 (7) ◽  
pp. 1369 ◽  
Author(s):  
C Kowala ◽  
KS Murray ◽  
JM Swan ◽  
BO West
Keyword(s):  
Electrical Conductivity ◽  
Transition Metal ◽  
Transition Metals ◽  
Metal Complexes ◽  
Organic Solvents ◽  
Transition Metal Complexes ◽  
Metal Ion ◽  
Magnetic Moments ◽  
Anthelmintic Activity ◽  
Metal Chlorides

Complexes of thiabendazole with transition metals (Co2+, Cu2+, Fe2+, Fe3+, Mn2+, Ni2+, and Zn2+) containing one, two, or three molecules of ligand per metal ion are described. Their spectra and magnetic moments are reported. In general, the complexes are insoluble or only slightly soluble in water or most organic solvents. Only complexes of metal chlorides are sufficiently soluble in methanol to show electrical conductivity. It is suggested that most of the insoluble complexes are of polymeric character. � The anthelmintic activity of all complexes is only slightly higher than that of thiabendazole.

scholarly journals Synthesis, Spectroscopic, and Electrochemical Studies on Some New Copper(II) Complexes Containing 2-{[(Z)-Phenyl (Pyridine-2-yl) Methylidene] Amino}Benzenethiol and Monodentate Ligands

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
S. P. Rawat ◽  
M. Choudhary
Keyword(s):  
Cyclic Voltammetry ◽  
Metal Ion ◽  
Copper Complexes ◽  
Magnetic Moments ◽  
Planar Geometry ◽  
Spectroscopic Techniques ◽  
Electrochemical Studies ◽  
Square Planar ◽  
Monodentate Ligands ◽  
Tridentate Schiff Base

Five new mononuclear copper(II) complexes, namely, [Cu(L)(ImH)]·ClO41; [Cu(L)(Me-ImH)]·ClO42; [Cu(L)(Et-ImH)]·ClO43; [Cu(L)(2-benz-ImH)]·ClO44; [Cu(L)(benz-ImH)]·ClO45, where HL = 2-{[(Z)-phenyl (pyridine-2-yl) methylidene] amino} benzenethiol; ImH = Imidazole; Me-ImH = Methy-limidazole; Et-ImH = Ethyl-imidazole; 2-benz-ImH = 2-methyl-benzimidazole; benz-ImH = benz-imidazole, have been synthesized and characterized by various physicochemical and spectroscopic techniques. Magnetic moments, electronic spectra, and EPR spectra of the complexes suggested a square planar geometry around Cu(II) ion. The synthesized HL ligand behaves as monobasic tridentate Schiff base bound with the metal ion in a tridentate manner, with N2S donor sites of the pyridine-N, azomethine-N, and benzenethiol-S atoms. The redox behaviour of the copper complexes has been studied by cyclic voltammetry. Superoxide dismutase activity of these complexes has been revealed to catalyse the dismutation of superoxide (O2-) and IC50 values were evaluated and discussed.

scholarly journals New complexes of Co(II), Ni(II), Cu(II) with Schiff base N,N’-bis-(3-methoxy-saliciliden)-3,3’-dimethylbenzidine

2013 ◽  
Vol 78 (7) ◽  
pp. 947-957 ◽  
Author(s):  
Ionela Alan ◽  
Angela Kriza ◽  
Olguta Dracea ◽  
Nicolae Stanica
Keyword(s):  
Schiff Base ◽  
Thermogravimetric Analysis ◽  
Spectral Data ◽  
Elemental Analysis ◽  
Room Temperature ◽  
Magnetic Moments ◽  
Magnetic Behaviour ◽  
Molar Ratio ◽  
Square Planar ◽  
Perchlorate Complex

The new N,N?-bis-(3-methoxy-saliciliden)-3,3?-dimetilbenzidine (H2L) Schiff base and complexes with Co(II), Ni(II) and Cu(II) of type [M(HL)Cl(H2O)] (M=Co(II), Cu(II)) [M2L(H2O)4]X2 (M=Co(II), X=ClO4 and M=Cu(II), X=NO3) and [M2L(CH3COO)2] (M=Co(II), Ni(II), Cu(II)) were synthesised. The ligand and complexes were characterized by elemental analysis, conductibility measurements, magnetic moments at room temperature, IR, NMR, UV-VIS-NIR, EPR spectra and thermogravimetric analysis. A molar ratio of 1:1 or 1:2 between ligand and metal was determined from the elemental analysis. Except for perchlorate complex that behave as electrolyte, the rest of complexes are non-electrolytes. The spectral data suggest a tetrahedral, pseudo-tetrahedral or square-planar stereochemistry respectively, data confirmed by magnetic behaviour of complexes. The antimicrobial tests indicate a fungicide effect both for ligand and complexes.

scholarly journals Physical properties of iodate solutions and the deliquescence of crystalline I<sub>2</sub>O<sub>5</sub> and HIO<sub>3</sub>

2010 ◽  
Vol 10 (9) ◽  
pp. 20823-20856 ◽  
Author(s):  
R. Kumar ◽  
R. W. Saunders ◽  
A. S. Mahajan ◽  
J. M. C. Plane ◽  
B. J. Murray
Keyword(s):  
Water Activity ◽  
Temperature Dependent ◽  
Activity Data ◽  
Gas Phase Chemistry ◽  
Activity Density ◽  
Phase Chemistry ◽  
First Time ◽  
Measured Water ◽  
Complex Ion

Abstract. Secondary aerosol produced from marine biogenic sources in algal-rich coastal locations will initially be composed of iodine oxide species, most likely I2O5, or its hydrated form HIO3, formed as a result of iodine gas-phase chemistry. At present, there is no quantitative hygroscopic data for these compounds and very little data available for iodate solutions (HIO3 and I2O5 share a common aqueous phase). With increased interest in the role of such aerosol in the marine atmosphere, we have conducted studies of (i) the deliquescence behaviour of crystalline HIO3 and I2O5 at 273–303 K, (ii) the efflorescence behaviour of aqueous iodate solution droplets, and (iii) properties (water activity, density, and viscosity) of subsaturated and saturated iodate solutions. The deliquescence of I2O5 crystals at 293 K was observed to occur at a relative humidity (DRH) of 80.8±1.0%, whereas for HIO3, a DRH of 85.0±1.0% was measured. These values are consistent with measured water activity values for saturated I2O5 and HIO3 solutions at 293 K of 0.80±0.01 and 0.84±0.01 respectively. At all temperatures, DRH values for HIO3 crystals were observed to be higher than for those of I2O5. The temperature-dependent DRH data, along with solubility and water activity data were used to evaluate the enthalpy of solution (ΔHsol) for HIO3 and I2O5. A (ΔHsol value of 8.3±0.7 kJ mol−1 was determined for HIO3 which is consistent with a literature value of 8.8 kJ mol−1. For I2O5, we report for the first time its solubility at various temperatures and (ΔHsol=12.4±.6 kJ mol−1. The measured water activity values confirm that aqueous iodate solutions are strongly non-ideal, consistent with previous reports of complex ion formation and molecular aggregation.

Metallkomplexe mit paramagnetischen Derivaten des Piperidin-1-oxyls / Metal Complexes of Paramagnetic Derivatives of Piperidine-1-oxyl

1973 ◽  
Vol 28 (1-2) ◽  
pp. 55-62 ◽  
Author(s):  
Dieter Jahr ◽  
Karl Heinz Rebhan ◽  
Karl E. Schwarzhans ◽  
Josef Wiedemann
Keyword(s):  
Free Radicals ◽  
Solid State ◽  
Metal Ion ◽  
Magnetic Moments ◽  
Transition Metal Ions ◽  
Epr Spectra ◽  
Temperature Dependent ◽  
Derivatives Of ◽  
Stable Free Radicals ◽  
Dependent Interaction

A series of complexes formed between transition metal ions and the stable free radicals 2,2,6,6- tetramethyl-4-amino-4-caboxypiperidine-1-oxyl, 2,2,6,6-tetramethyl-4-aminopiperidine-l -oxyl, 2,2,6,6-tetram ethyl-piperidine-l-oxyl and glyoxal-bis(2,2,2,6,6-tetramethyl-4-iminopiperidine-1- oxyl) has been prepared. The magnetic moments and the epr-spectra of the complexes have been investigated. Some of the complexes show a temperature dependent interaction between the radicalic nitroxyl groups of the ligands. By analysis of the epr-spectra in the solid state there was found in some cases an interaction between the metal ion and the unpaired electrons of the ligands.

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