scholarly journals Crystal structures of two dis-symmetric di-Schiff base compounds: 2-({(E)-2-[(E)-2,6-dichlorobenzylidene]hydrazin-1-ylidene}methyl)-6-methoxyphenol and 4-bromo-2-({(E)-2-[(E)-2,6-dichlorobenzylidene]hydrazin-1-ylidene}methyl)phenol

2020 ◽  
Vol 76 (6) ◽  
pp. 862-869
Author(s):  
Rohit B. Manawar ◽  
Chandankumar T. Pashavan ◽  
Manish K. Shah ◽  
Mukesh M. Jotani ◽  
Edward R. T. Tiekink
Keyword(s):  
Schiff Base ◽  
Benzene Ring ◽  
Torsion Angles ◽  
Linear Chains ◽  
Non Covalent Interactions ◽  
The Common ◽  
Imine Bond ◽  
Covalent Interactions ◽  
Supramolecular Chains ◽  
Secondary Bonding

Each of the title dis-symmetric di-Schiff base compounds, C15H12Cl2N2O2 (I) and C14H9BrCl2N2O (II), features a central azo-N—N bond connecting two imine groups, each with an E-configuration. One imine bond in each molecule connects to a 2,6-dichlorobenzene substituent while the other links a 2-hydroxyl-3-methoxy-substituted benzene ring in (I) or a 2-hydroxyl-4-bromo benzene ring in (II). Each molecule features an intramolecular hydroxyl-O—H...N(imine) hydrogen bond. The C—N—N—C torsion angles of −151.0 (3)° for (I) and 177.8 (6)° (II) indicates a significant twist in the former. The common feature of the molecular packing is the formation of supramolecular chains. In (I), the linear chains are aligned along the a-axis direction and the molecules are linked by methoxy-C—H...O(methoxy) and chlorobenzene-C—Cl...π(chlorobenzene) interactions. The chain in (II) is also aligned along the a axis but, has a zigzag topology and is sustained by Br...O [3.132 (4) Å] secondary bonding interactions. In each crystal, the chains pack without directional interactions between them. The non-covalent interactions are delineated in the study of the calculated Hirshfeld surfaces. Dispersion forces make the most significant contributions to the identified intermolecular interactions in each of (I) and (II).

scholarly journals Chain stopper engineering for hydrogen bonded supramolecular polymers

2010 ◽  
Vol 6 ◽  
pp. 869-875 ◽  
Author(s):  
Thomas Pinault ◽  
Bruno Andrioletti ◽  
Laurent Bouteiller
Keyword(s):  
Hydrogen Bond ◽  
Molar Mass ◽  
Strong Hydrogen Bond ◽  
Supramolecular Polymers ◽  
Supramolecular Polymer ◽  
Hydrogen Bond Donor ◽  
Linear Chains ◽  
Non Covalent Interactions ◽  
Viscous Solutions ◽  
Covalent Interactions

Supramolecular polymers are linear chains of low molar mass monomers held together by reversible and directional non-covalent interactions, which can form gels or highly viscous solutions if the self-assembled chains are sufficiently long and rigid. The viscosity of these solutions can be controlled by adding monofunctional compounds, which interact with the chain extremities: chain stoppers. We have synthesized new substituted ureas and thioureas and tested them as chain stoppers for a bis-urea based supramolecular polymer. In particular, the bis-thiourea analogue of the bis-urea monomer is shown not to form a supramolecular polymer, but a good chain stopper, because it is a strong hydrogen bond donor and a weak acceptor. Moreover, all substituted ureas tested reduce the viscosity of the supramolecular polymer solutions, but the best chain stopper is obtained when two hydrogen bond acceptors are placed in the same relative position as for the monomer and when no hydrogen bond donor is present.

Computational evidence that hyperconjugative orbital interactions are responsible for the stability of intramolecular Te⋯O/Te⋯S non-covalent interactions and comparable to hydrogen bonds in quasi-cyclic systems

2016 ◽  
Vol 40 (11) ◽  
pp. 9132-9138 ◽  
Author(s):  
Mrinal Kanti Si ◽  
Bishwajit Ganguly
Keyword(s):  
Hydrogen Bonds ◽  
Bond Strength ◽  
Orbital Interactions ◽  
Non Covalent Interactions ◽  
Cyclic Systems ◽  
The Stability ◽  
Covalent Interactions ◽  
Secondary Bonding

The intramolecular secondary bonding interactions involving quasi-cyclic tellurium are comparable to H-bond strength and partially governed by orbital interactions.

Diastereomeric Ni(II) Schiff-base cysteine derivatives: non-covalent interactions and redox activity

2021 ◽  
pp. 138537
Author(s):  
Oleg A. Levitskiy ◽  
Olga I. Aglamazova ◽  
Alena V. Dmitrieva ◽  
Tatiana V. Magdesieva
Keyword(s):  
Schiff Base ◽  
Redox Activity ◽  
Non Covalent Interactions ◽  
Covalent Interactions

scholarly journals 1,3-Bis{(+)-(S)-[1-(1-naphthyl)ethyl]iminomethyl}benzene dichloromethane solvate

2009 ◽  
Vol 65 (6) ◽  
pp. o1316-o1316 ◽  
Author(s):  
Armando Espinosa Leija ◽  
Guadalupe Hernández ◽  
Sandra Cruz ◽  
Sylvain Bernès ◽  
René Gutiérrez
Keyword(s):  
Schiff Base ◽  
Benzene Ring ◽  
Dihedral Angle ◽  
Title Compound ◽  
Rotation Axis ◽  
Naphthalene Ring ◽  
Compound C ◽  
The Common ◽  
Solvent Molecules

In the title compound, C32H28N2·CH2Cl2, the complete Schiff base and solvent molecules are both generated by crystallographic twofold axes, with the two C atoms of the former and the C atom of the latter lying on the rotation axis. The central benzene ring is substituted with two chiral groups including imine functionalities, with the commonEconfiguration. The dihedral angle between the central benzene ring and the terminal naphthalene ring is 45.42 (9)° and that between the two naphthalene rings is 89.16 (8)°. The conformation of the Schiff base allows solvent molecules to fill the voids in the crystal, affording a stable 1:1 solvate, but the solvent interacts poorly with the Schiff base, as reflected by its rather high displacement parameters.

A combined experimental and computational study of supramolecular assemblies in ternary copper(ii) complexes with a tetradentate N4donor Schiff base and halides

RSC Advances ◽  
2014 ◽  
Vol 4 (102) ◽  
pp. 58643-58651 ◽  
Author(s):  
Anik Bhattacharyya ◽  
Prasanta Kumar Bhaumik ◽  
Antonio Bauzá ◽  
Partha Pratim Jana ◽  
Antonio Frontera ◽  
...  
Keyword(s):  
Schiff Base ◽  
Dft Calculations ◽  
Computational Study ◽  
Supramolecular Assemblies ◽  
Schiff Base Complexes ◽  
Molecular Networks ◽  
Non Covalent Interactions ◽  
Covalent Interactions

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.

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
Keyword(s):  
Schiff Base ◽  
Catalytic Reactions ◽  
Benzenesulfonic Acid ◽  
Double Chain ◽  
Mild Conditions ◽  
Polymeric Networks ◽  
1D Chain ◽  
Non Covalent Interactions ◽  
Oxidation Properties ◽  
Covalent Interactions

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.

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