Donor properties of thiohydantoin and pseudothiohydantoin towards cobalt(II) and nickel(II) salts

1976 ◽  
Vol 29 (1) ◽  
pp. 79 ◽  
Author(s):  
PP Singh ◽  
UP Shukla ◽  
AK Srivastava
Keyword(s):  
Physical Properties ◽  
Coordination Complexes ◽  
Carbonyl Oxygen ◽  
Magnetic Data ◽  
Spectral Studies ◽  
Cubic Symmetry ◽  
Elementary Analysis ◽  
Conductance Data ◽  
Halide Complexes

Coordination complexes of the type [CoL2] X2 (L = thiohydantoin (thn), pseudothiohydantoin (pthn); X = Cl, Br, I), [Ni(thn)4] Cl, and [Co(pthn)6] (ClO4), have been prepared and characterized by elementary analysis. The sites of bonding in ligands and configuration of the complexes have been determined with the help of physical properties, magnetic data, conductance data, i.r. and electronic spectral studies. The site of bonding in thn is thiocarbonyl sulphur and in pthn carbonyl oxygen. The cobalt halide complexes of thn and pthn are tetrahedral with C2v symmetry, [Ni(thn)4] Cl2 is octahedral with D4h symmetry and [Co(pthn)6] (ClO4), is octahedral with Oh cubic symmetry. All complexes except [Co(pthn)6] (ClO4)2, which is a 1 : 2 electrolyte, are non-conducting.

scholarly journals Synthesis and Structural Studies of Cr(III), Mn(II) and Fe(III) Complexes ofN(2-Benzimidazolyl)acetylacetohydrazone

2011 ◽  
Vol 8 (1) ◽  
pp. 421-426
Author(s):  
G. H. Anuradha ◽  
A. V. Chandra Pal
Keyword(s):  
Metal Complexes ◽  
Spectral Data ◽  
Microbial Activity ◽  
Coordination Complexes ◽  
Carbonyl Oxygen ◽  
Magnetic Data ◽  
Side Chain ◽  
Structural Studies ◽  
E Coli ◽  
Electronic Spectral Data

The ligandN(2-benzimidazolyl)acetylacetohydrazone (BAAH) have been synthesized and characterized. Coordination complexes of Cr(III), Mn(II) and Fe(III) have been synthesized with the ligand BAAH. These complexes were characterized on the basis of analytical, conductance, thermal, magnetic data and infrared and electronic spectral data. The ligand BAAH is behaving as a neutral tridentate NNO donar employing two azomethine nitrogens (ring and side chain) and carbonyl oxygen. The ligand and it's metal complexes were tested for anti microbial activity on the gram positiveS. Aureus, E. coliandProteus.

scholarly journals Synthesis and spectral studies of Cu(II), Ni(II), Co(II), Mn(II), Zn(II) and Cd(II) complexes of a new macroacyclic ligand n,n’-bis(2-benzothiazolyl)-2,6-pyridinedicarboxamide

2006 ◽  
Vol 71 (5) ◽  
pp. 529-542 ◽  
Author(s):  
Kalagouda Gudasi ◽  
Siddappa Patil ◽  
Ramesh Vadavi ◽  
Rashmi Shenoy ◽  
Manjula Patil
Keyword(s):  
Liquid Nitrogen ◽  
Magnetic Moments ◽  
Thermal Studies ◽  
Liquid Nitrogen Temperature ◽  
Octahedral Geometry ◽  
Spectral Studies ◽  
Conductance Data ◽  
X Band ◽  
Elemental Analyses ◽  
Uv Visible

A new macroacyclic amide ligand N,N?-bis(2-benzothiazolyl)-2,6-pyridinedicarboxamide (BPD), formed by the condensation of 2,6-pyridinedicarbonyldichloride with 2-aminobenzothiazole and its Cu(II), Ni(II), Co(II), Mn(II), Zn(II) and Cd(II) complexes were synthesized. Their structures were elucidated on the basis of elemental analyses, conductance measurements, magnetic moments, spectral (IR, NMR UV-Visible, EPR and FAB) and thermal studies. The complexes exhibit an octahedral geometry around the metal center. Conductance data of the complexes suggested them to be 1:1 electrolytes. The pentadentate behavior of the ligand was proposed on the basis of spectral studies. The X-band EPR spectra of the Cu(II) and Mn(II) complexes in the polycrystalline state at room (300 K) and liquid nitrogen temperature (77 K) were recorded and their salient features are reported.

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.

Resolution measures for 3D magnetic inversions

Geophysics ◽  
2016 ◽  
Vol 81 (2) ◽  
pp. J1-J9 ◽  
Author(s):  
Mark Pilkington
Keyword(s):  
Physical Properties ◽  
Theoretical Basis ◽  
3D Models ◽  
Magnetic Data ◽  
Limited Attention ◽  
Resolution Measure ◽  
Calculated Model ◽  
Geologic Information

Inversion of magnetic data into 3D models is becoming commonplace. The theoretical basis of the method is well established and has been extended to include constraints based on physical properties and geologic information. Nevertheless, only limited attention is paid to assessing the reliability of computed models, which usually involves deriving some measure of how well features within the models can be resolved. Resolution lengths determined from resolution matrices can be unrealistically small, suggesting that the recovered models are more reliable than they really are. One cause of this effect is the calculated model itself, which directly influences the character of the resolving functions. We have developed an approximate resolution measure not affected by the calculated model, and we found it to give more realistic resolving lengths. This approximation is computationally less demanding and can be calculated prior to inversion. It suggests that the resolution length is equal to the depth of the parameter or model feature of interest.

Gravity and magnetic inversion with minimization of a specific functional

Geophysics ◽  
1984 ◽  
Vol 49 (8) ◽  
pp. 1354-1360 ◽  
Author(s):  
A. Guillen ◽  
V. Menichetti
Keyword(s):  
Physical Properties ◽  
Magnetic Data ◽  
Constant Density ◽  
Minimum Volume ◽  
Data Inversion ◽  
Gravity And Magnetic ◽  
Magnetic Inversion ◽  
Line Passing ◽  
Susceptibility Contrast ◽  
The Moment

The nonuniqueness of gravity or magnetic data inversion is well known. In order to remove ambiguity, some authors have sought solutions minimizing a functional describing geometrical or physical properties. Last and Kubik (1983), in particular, developed a method explaining the observed anomaly by structures of minimum volume. In this method the domain where anomalous sources are searched is divided into elementary prisms of a constant density or susceptibility contrast. Each elementary contrast is allowed to vary individually. Thus a contrast distribution is computed. The search for this kind of solution leads in general to geologically more appropriate bodies, but exceptions do occur. In this paper, the technique is broadened to include the search for solutions minimizing the moment of inertia with respect to the center of gravity or with respect to a given dip line passing through it. The resulting structures are both deeper and more compact, precisely as is required in specific cases. Theoretical and actual examples illustrate this flexible inversion technique.

ASSOCIATION OF URACIL WITH Zn2+ AND THE HYDRATED Zn2+: A DFT INVESTIGATION

2007 ◽  
Vol 06 (02) ◽  
pp. 197-212 ◽  
Author(s):  
NANA WANG ◽  
PING LI ◽  
YI HU ◽  
YUXIANG BU ◽  
WEIHUA WANG ◽  
...  
Keyword(s):  
Density Functional ◽  
Coordination Mode ◽  
Coordination Complexes ◽  
Carbonyl Oxygen ◽  
Water Molecules ◽  
Bidentate Coordination ◽  
Hydration Effect ◽  
The Density Functional Theory ◽  
Before And After ◽  
Monodentate Coordination

The association behaviors between Uracil and Zn 2+ in vacuum and in the presence of extra water molecules have been investigated systematically using the density functional theory (DFT). In these systems, the interaction of Zn 2+ with the carbonyl oxygen O 4 is systematically favored relative to O 2. For Uracil- Zn 2+ complexes, the more stable coordination mode among the possible complexes corresponds to the bidentate one, where the monodentate coordination mode is about 37 kcal/mol higher in energy relative to the bidentate case. Correspondingly, the stabilities of these structures are enhanced due to the formations of the four-membered chelate ring in the bidentate coordination processes. In the monodentate coordination complexes, the hydration effects are larger than those in the bidentate coordination complexes. The most basic center in the Uracil remains the same regardless of whether introducing the water molecules to Zn 2+ or not. The calculated Zn 2+ bonding energies in Uracil- Zn 2+( H 2 O ) complexes are reduced in comparison to those of the unhydrated Uracil- Zn 2+ complexes. Moreover, investigations of stepwise hydration of Zn 2+ in the most stable Uracil- Zn 2+ complex suggest that the successive hydration effect on the Zn 2+ site can enhance the strength of C = O bond in the Uracil- Zn 2+ complexes and reduce the association interaction of Uracil with Zn 2+. Additionally, the most acidic site of Uracil has been changed from N 1- to N 3– H group before and after introducing the Zn 2+ and there is a significant increase in the overall acidity of the system.

scholarly journals Template synthesis of macrocyclic complexes of Co(II), Ni(II), Cu(II), Zn(II) and Cd(II): Spectroscopic, antibacterial and antifungal studies

2010 ◽  
Vol 75 (6) ◽  
pp. 763-772 ◽  
Author(s):  
Dharam Singh ◽  
Vandna Malik ◽  
Ramesh Kumar ◽  
Krishan Kumar
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Metal Ion ◽  
Inhibitory Concentration ◽  
Condensation Reaction ◽  
Carbonyl Oxygen ◽  
Macrocyclic Complexes ◽  
Spectral Studies ◽  
Distorted Octahedral Geometry ◽  
Divalent Metal Ions

A new series of macrocyclic complexes of the type [M(C17H14N4O2)X2], where M = Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and X = Cl-, NO3-, CH3COO-was synthesized by the condensation reaction of malonyldihydrazide with benzil in the presence of divalent metal ions. The complexes were characterized with the aid of elemental analyses, conductance measurements, magnetic susceptibilities, electronic, NMR and infrared spectral studies. On the basis of these studies, a six coordinate distorted octahedral geometry, in which two nitrogen and two carbonyl oxygen atoms are suitably placed for coordination towards metal ion, is proposed for all the complexes. The complexes were tested for their in vitro antibacterial activity and antifungal activities. The minimum inhibitory concentration shown by these complexes were compared with the minimum inhibitory concentration shown by standard drugs.

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