Isomerism in Coordination Complexes and Polymers Derived from Bispyridylurea Ligands:  Effect of Solvents, Conformational Flexibility, and Positional Isomerism of the Ligands

2007 ◽  
Vol 7 (10) ◽  
pp. 2096-2105 ◽  
Author(s):  
D. Krishna Kumar ◽  
Amitava Das ◽  
Parthasarathi Dastidar
Keyword(s):  
Coordination Complexes ◽  
Conformational Flexibility ◽  
Effect Of Solvents ◽  
Positional Isomerism

Positional Isomerism and Conformational Flexibility Directed Structural Variations in the Molecular Complexes of Dihydroxybenzoic Acids

2015 ◽  
Vol 15 (8) ◽  
pp. 3832-3841 ◽  
Author(s):  
Sunil Varughese ◽  
Anna A. Hoser ◽  
Katarzyna N. Jarzembska ◽  
V. R. Pedireddi ◽  
Krzysztof Woźniak
Keyword(s):  
Molecular Complexes ◽  
Conformational Flexibility ◽  
Structural Variations ◽  
Positional Isomerism

Coordination chemistry of the tetrakis(2-hydroxyphenyl)ethene support mimic — Polymetallic magnesium, aluminum, and titanium derivatives

2005 ◽  
Vol 83 (6-7) ◽  
pp. 922-928 ◽  
Author(s):  
Udo H Verkerk ◽  
Robert McDonald ◽  
Jeffrey M Stryker
Keyword(s):  
Coordination Chemistry ◽  
Crystal Structures ◽  
Coordination Complexes ◽  
Conformational Flexibility ◽  
Titanium Complexes ◽  
Dimeric Complexes ◽  
Aluminum Complexes ◽  
Magnesium Complexes

The crystal structures of magnesium, aluminum, and titanium coordination complexes of the structurally preorganized tetrakis(2-hydroxyphenyl)ethene are reported. As a result of the absence of steric shielding and the conformational flexibility of the ligand, pseudo-dimeric complexes are formed instead of crown- or raft-like compounds. The unsubstituted tetrakis(2-hydroxyphenyl)ethene ligand thus emulates the complexation characteristics of the sterically open calix[4]arene system.Key words: coordination chemistry, polymetallic, titanium complexes, magnesium complexes, aluminum complexes, tetrakis(2-hydroxyphenyl)ethene ligands, crystal structures.

Conductivity Studies of Schiff Base Ligands Derived from O-Phenylenediamine and Their Co(II) and Zn(II) Complexes

2015 ◽  
Vol 12 (2) ◽  
pp. 13
Author(s):  
Muhamad Faridz Osman ◽  
Karimah Kassim
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Fourier Transform ◽  
Schiff Base ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Impedance Spectroscopy ◽  
Ftir Spectroscopy ◽  
Coordination Complexes ◽  
Frequency Range ◽  
Schiff Base Ligands

The coordination complexes of Co(II) and Zn(II) with Schiff bases derived from o-phenylenediamine and substituted 2-hydroxybenzaldehyde were prepared All compounds were characterized by Fourier transform infrared (FTIR) spectroscopy and Nuclear magnetic resonance (NMR) spectroscopy elemental analyzers. They were analyzed using impedance spectroscopy in the frequency range of 100Hz-1 MHz. LI and L2 showed higher conductivity compared to their metal complexes, which had values of 1.3 7 x 10-7 and 6.13 x 10-8 S/cm respectively. 

The model rotator phase

1988 ◽  
Vol 53 (5) ◽  
pp. 889-902
Author(s):  
Josef Šebek
Keyword(s):  
High Temperature ◽  
Partition Function ◽  
Conformational Flexibility ◽  
Small Probability ◽  
Crystalline Phases ◽  
Rotator Phase

It is shown that the formation of the so-called rotator phase of alkanes (one of the high temperature crystalline phases) might be connected with a partial increase of the conformational flexibility of chains. The conformations with higher number of kinks per chain, which have been neglected till now, are shown to contribute effectively to the conformational partition function. Small probability of these states given by the Boltzmann exponent is compensated by a large number of ways in which they can be distributed along the chain. The deduced features of the rotator phase seem to be in agreement with the experimentally observed properties.

Computational prediction of Au(i)–Pb(ii) bonding in coordination complexes and study of the factors affecting the formation of Au(i)–E(ii) (E = Ge, Sn, Pb) covalent bonds

2021 ◽  
Author(s):  
José M. López-de-Luzuriaga ◽  
Miguel Monge ◽  
M. Elena Olmos ◽  
María Rodríguez-Castillo ◽  
Alba Sorroche
Keyword(s):  
Computational Prediction ◽  
Coordination Complexes ◽  
Model Systems ◽  
Computational Studies ◽  
Covalent Bonds ◽  
Factors Affecting

Computational studies on Au(i)–E(ii) in [R3PAu–(ECl3)] (E = Ge, Sn, Pb) model systems indicate the covalent dative nature from the [ECl3]− metalloligands to Au(i) fragments and predict the existence of Au(i)–Pb(ii) bonds using electron widthdrawing PR3 ligands.

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