scholarly journals Syntheses, Structures, and Catalytic Hydrocarbon Oxidation Properties of N-Heterocycle-Sulfonated Schiff Base Copper(II) Complexes

Inorganics ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 17 ◽  
Author(s):  
Susanta Hazra ◽  
Bruno G. M. Rocha ◽  
M. Fátima C. Guedes da Silva ◽  
Anirban Karmakar ◽  
Armando J. L. Pombeiro

Reaction of the o-[(o-hydroxyphenyl)methylideneamino]benzenesulfonic acid (H2L) (1) with CuCl2·2H2O in the presence of pyridine (py) leads to [Cu(L)(py)(EtOH)] (2) which, upon further reaction with 2,2’-bipyridine (bipy), pyrazine (pyr), or piperazine (pip), forms [Cu(L)(bipy)]·MeOH (3), [Cu2(L)2(μ-pyr)(MeOH)2] (4), or [Cu2(L)2(μ-pip)(MeOH)2] (5), respectively. The Schiff base (1) and the metal complexes (2–5) are stabilized by a number of non-covalent interactions to form interesting H-bonded multidimensional polymeric networks (except 3), such as zigzag 1D chain (in 1), linear 1D chain (in 2), hacksaw double chain 1D (in 4) and 2D motifs (in 5). These copper(II) complexes (2–5) catalyze the peroxidative oxidation of cyclic hydrocarbons (cyclooctane, cyclohexane, and cyclohexene) to the corresponding products (alcohol and ketone from alkane; alcohols, ketone, and epoxide from alkene), under mild conditions. For the oxidation of cyclooctane with hydrogen peroxide as oxidant, used as a model reaction, the best yields were generally achieved for complex 3 in the absence of any promoter (20%) or in the presence of py or HNO3 (26% or 30%, respectively), whereas 2 displayed the highest catalytic activity in the presence of HNO3 (35%). While the catalytic reactions were significantly faster with py, the best product yields were achieved with the acidic additive.

2021 ◽  
pp. 138537
Author(s):  
Oleg A. Levitskiy ◽  
Olga I. Aglamazova ◽  
Alena V. Dmitrieva ◽  
Tatiana V. Magdesieva

2021 ◽  
Author(s):  
Raúl Díaz-Torres ◽  
Jorge Echeverría ◽  
Oliver Loveday ◽  
Phimphaka Harding ◽  
David Harding

<div>The influence of the halogen substituent on crystal packing and redox properties is investigated in a series of heteroleptic complexes [Fe(qsal-X)(dipic)]MeOH (qsal-X = 4-halogen-2-[(8-quinolylimino)methyl]phenolate; dipic = 2,6-pyridinedicarboxylate; X = F 1, Cl 2, Br 3 and I 4).</div><div>Compounds 1 and 2 exhibit triclinic symmetry (P1̅), whereas 3 and 4 crystallise in monoclinic P21/n. The crystal packing shows self-sorting of the ligands with - interactions between the qsal-X ligands and overlap of the dipic ligands to form a 1D chain, that is supported by C-H···O interactions. In 1 and 2, the cross-section of the 1D chain is square, while for 3 and 4, it is rectangular. In the former, the dipic ligands interact through C=O··· interactions, while - interactions are found in 3 and 4. Neighbouring chains are connected via - interactions involving the quinoline rings, but their relative position is driven by the preference of 1 and 2, for C-H···X interactions, whereas 3 and 4 form O···X halogen bonds. The nature and topology of the electron density of these interactions have been investigated using molecular electrostatic potential (MEP) mapping, quantum theory of atoms in molecules (QTAIM) and ‘non-covalent interactions’ (NCI) analysis. UV-Visible experiments show MLCT bands associated with the qsal-X ligands, confirming the structure is stable in solution. Electrochemical studies reveal slight tuning of the Fe3+/Fe2+ redox couple showing a linear relationship between E° and the Hammett parameter σp.</div><div><br></div>


RSC Advances ◽  
2014 ◽  
Vol 4 (102) ◽  
pp. 58643-58651 ◽  
Author(s):  
Anik Bhattacharyya ◽  
Prasanta Kumar Bhaumik ◽  
Antonio Bauzá ◽  
Partha Pratim Jana ◽  
Antonio Frontera ◽  
...  

Three new copper(ii) Schiff base complexes have been prepared and characterized. DFT calculations were employed to estimate the contribution of different non-covalent interactions in the extended supra-molecular networks.


Polyhedron ◽  
2016 ◽  
Vol 117 ◽  
pp. 834-846 ◽  
Author(s):  
Barnali Naskar ◽  
Ritwik Modak ◽  
Dilip K. Maiti ◽  
Sushil Kumar Mandal ◽  
Jayanta Kumar Biswas ◽  
...  

2017 ◽  
Vol 2 (22) ◽  
pp. 6286-6295 ◽  
Author(s):  
Tanmoy Basak ◽  
Anik Bhattacharyya ◽  
Mithun Das ◽  
Klaus Harms ◽  
Antonio Bauzá ◽  
...  

2019 ◽  
Vol 29 (2) ◽  
pp. 121-127 ◽  
Author(s):  
Elena S. Osipova ◽  
Oleg A. Filippov ◽  
Elena S. Shubina ◽  
Natalia V. Belkova

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