scholarly journals Schiff bases derived from hydroxyaryl aldehydes: molecular and crystal structure, tautomerism, quinoid effect, coordination compounds

2010 ◽  
Vol 29 (2) ◽  
pp. 117 ◽  
Author(s):  
Anita Blagus ◽  
Dominik Cinčić ◽  
Tomislav Friščić ◽  
Branko Kaitner ◽  
Vladimir Stilinović
Keyword(s):  
Schiff Base ◽  
Schiff Bases ◽  
Coordination Compounds ◽  
Crystal Packing ◽  
Structural Characteristics ◽  
Intramolecular Hydrogen Bonding ◽  
Vast Number ◽  
Structural Database ◽  
Intramolecular Hydrogen ◽  
Schiff Base Metal Complexes

During the last 50 years a vast number of structural studies on Schiff bases derived from hydroxyaryl aldehydes and their coordination compounds have been undertaken. In this review we present a systematic and brief overview of the most important discoveries and achievements accomplished in this field. The occurrence of Schiff bases (and their complexes) derived from nine most commonly used hydroxyaryl aldehydes in the Cambridge Structural Database (CSD) has been investigated. Keto-enol tautomerism and intramolecular hydrogen bonding in salicylaldimines and naphthaldimines is discussed, with a comment of the most common errors in determining the correct tautomeric form. Also, the interrelationship of crystal packing and the substituents on the Schiff base is studied. Finally, we give a short overview of conformational differences between free Schiff bases and Schiff bases bonded to metal ions as well as some structural characteristics of Schiff base metal complexes.

N-tert-Butyl-N′-[5-cyano-2-(4-methylphenoxy)phenylsulfonyl]urea, a new TXA2receptor antagonist

2013 ◽  
Vol 69 (8) ◽  
pp. 901-903
Author(s):  
Sylvie-Mireille Bambi-Nyanguile ◽  
Peter Mangwala Kimpende ◽  
Bernard Pirotte ◽  
Luc Van Meervelt
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Crystal Packing ◽  
Theoretical Calculations ◽  
Intramolecular Hydrogen Bonding ◽  
Asymmetric Unit ◽  
Dimer Formation ◽  
Compound C ◽  
Structural Database ◽  
Intramolecular Hydrogen

The title compound, C19H21N3O4S, crystallizes in the space groupP2/cwith two molecules in the asymmetric unit. The conformation of both molecules is very similar and is mainly determined by an intramolecular N—H...O hydrogen bond between a urea N atom and a sulfonyl O atom. The O and second N atom of the urea groups are involved in dimer formationviaN—H...O hydrogen bonds. The intramolecular hydrogen-bonding motif and conformation of the C—SO2—NH(C=O)—NH—C fragment are explored and compared using the Cambridge Structural Database and theoretical calculations. The crystal packing is characterized by π–π stacking between the 5-cyanobenzene rings.

Intramolecular Hydrogen Bonding in o-hydroxy Aryl Schiff Bases

2009 ◽  
Vol 13 (2) ◽  
pp. 172-193 ◽  
Author(s):  
Aleksander Filarowski ◽  
Aleksander Koll ◽  
Lucjan Sobczyk
Keyword(s):  
Hydrogen Bonding ◽  
Schiff Bases ◽  
Intramolecular Hydrogen Bonding ◽  
Intramolecular Hydrogen

scholarly journals Intra-molecular Interactions in Porous Covalent Organic Frameworks

2014 ◽  
Vol 70 (a1) ◽  
pp. C530-C530
Author(s):  
Rahul Banerjee
Keyword(s):  
Hydrogen Bonding ◽  
Schiff Base ◽  
Molecular Interactions ◽  
Chemical Stability ◽  
Intramolecular Hydrogen Bonding ◽  
Covalent Organic Frameworks ◽  
Covalent Organic Framework ◽  
New Strategy ◽  
The Stability ◽  
Intramolecular Hydrogen

A new strategy of intramolecular hydrogen bonding in 2D covalent organic framework as an extra stabilizing factor has been introduced, which helps to improve the crystallinity, porosity and chemical stability of the COF. Using this concept, highly stable porphyrin containing covalent organic frameworks have been synthesized using the Schiff base reaction. The stability of the COFs mainly arises due to the strong intramolecular O-H...N=C hydrogen bonding. Validation of this postulate was cross-checked by synthesizing methoxy (OCH3) substituted COF in which no hyrogen bonding exists. It was found that methoxy substituted COF have a low crystallinity, porosity and chemical stability as compared to hydrogen bonded COF.

scholarly journals A review on versatile applications of novel Schiff bases and their metal complexes

2019 ◽  
Vol 8 (4) ◽  
pp. 675-681
Keyword(s):  
Schiff Base ◽  
Metal Complexes ◽  
Schiff Bases ◽  
Carbonyl Compounds ◽  
Biological Activities ◽  
Schiff Base Complexes ◽  
Amino Compound ◽  
Azomethine Group ◽  
Catalytic Activities ◽  
Schiff Base Metal Complexes

Metal complexes synthesized from Schiff bases and furthermore Schiff bases are versatile in nature. Such types of compounds were prepared from the condensation of an amino compound with carbonyl compounds (aldehyde or ketone) during which the carbonyl group is replaced by an imine or azomethine group. Schiff bases and their derivatives are widely employed in industries, polymers, dyes and medicative and pharmaceutical fields and additionally exhibit biological activities like antibacterial, antifungal, anti-inflammatory, antimalarial, antiviral, and antipyretic properties. Many Schiff base metal complexes exhibit glorious catalytic activities in numerous mechanisms. Their several applications in homogenous and heterogeneous catalysis were according troughout last decade. Several Schiff base complexes were helpful for their application as catalysts in reactions involving at high temperatures because of the high thermal and moisture stabilities. This text totally based on literature review with examples of the most promising applied Schiff bases and their complexes in several areas, summarizing the applications of Schiff bases and their numerous derivatives and complexes.

scholarly journals Performance of Schiff Bases Metal Complexes and their Ligand in Biological Activity: A Review

2021 ◽  
Vol 24 (1) ◽  
pp. 1-10
Author(s):  
Farah M. Ibrahim ◽  
◽  
Saifaldeen M. Abdalhadi ◽  
Keyword(s):  
Biological Activity ◽  
Schiff Base ◽  
Metal Complexes ◽  
Schiff Bases ◽  
Base Metal ◽  
Broad Class ◽  
Condensation Process ◽  
Human System ◽  
Wide Range ◽  
Schiff Base Metal Complexes

Schiff bases are a broad class synthesized compound, which is prepared for the condensation process between the primary amine group and an aldehyde or ketone group. Schiff base metal complexes play an important role in many applications such as biological activity, catalytic activity, and optical property. The wide range application of Schiff base metal complexes came from the versatility of Schiff base reactions with many different transition metals. This flexibility of the reactions was given these complexes, many different properties and uses in a biological human system such as antibacterial, antifungal, anticancer, antimalarial, and others. This review gives many examples of Schiff bases, metal complexes, and there ligands with biological applications in the human system.

scholarly journals On the Aggregation and Sensing Properties of Zinc(II) Schiff-Base Complexes of Salen-Type Ligands

Molecules ◽  
2019 ◽  
Vol 24 (13) ◽  
pp. 2514 ◽  
Author(s):  
Consiglio ◽  
Oliveri ◽  
Failla ◽  
Di Bella
Keyword(s):  
Schiff Base ◽  
Schiff Bases ◽  
Coordination Compounds ◽  
Cell Imaging ◽  
Spectroscopic Properties ◽  
Lewis Base ◽  
Schiff Base Complexes ◽  
Sensing Properties ◽  
Lewis Bases

The zinc(II) ion forms stable complexes with a wide variety of ligands, but those related to Schiff-bases are among the most largely investigated. This review deals with the peculiar aggregation characteristics of Zn(II) Schiff-base complexes from tetradentate N2O2 salen-type ligands, L, derivatives from salicylaldehydes and 1,2-diamines, and is mostly focused on their spectroscopic properties in solution. Thanks to their Lewis acidic character, ZnL complexes show interesting structural, nanostructural, and aggregation/deaggregation properties in relation to the absence/presence of a Lewis base. Deaggregation of these complexes is accompanied by relevant changes of their spectroscopic properties that can appropriately be exploited for sensing Lewis bases. Thus, ZnL complexes have been investigated as chromogenic and fluorogenic chemosensors of charged and neutral Lewis bases, including cell imaging, and have shown to be selective and sensitive to the Lewis basicity of the involved species. From these studies emerges that these popular, Lewis acidic bis(salicylaldiminato)Zn(II) Schiff-base complexes represent classical coordination compounds for modern applications.

Syntheses and structural studies of η5-pentamethylcyclopentadienyl rhodium(III) and iridium(III) complexes of a Schiff-base expanded porphyrin

2010 ◽  
Vol 14 (01) ◽  
pp. 41-46 ◽  
Author(s):  
Luciano Cuesta ◽  
Vincent M. Lynch ◽  
Jonathan L. Sessler
Keyword(s):  
Schiff Base ◽  
Intramolecular Hydrogen Bonding ◽  
X Ray Diffraction ◽  
Nmr Studies ◽  
Coordination Environment ◽  
Metal Centers ◽  
X Ray ◽  
Hydrogen Bonding Interactions ◽  
Intramolecular Hydrogen ◽  
Expanded Porphyrin

Reported here is the synthesis of new binuclear rhodium(III) and iridium(III) semi-sandwich complexes of a Schiff-base expanded porphyrin. Single crystals of these new complexes were subject to X-ray diffraction analysis. The resulting structures revealed that the Schiff-base macrocycle adopts a V-shape in which two {(η5- C 5 Me 5) MCl } ( M = Rh and Ir ) fragments are accommodated within the macrocyclic pocket. The coordination environment of the metal centers is typical to that of "piano stool"-type complexes. The X-ray analyses and complementary NMR studies (carried out in CD 2 Cl 2) provide evidence for the existence of strong intramolecular hydrogen-bonding interactions between the pyrrolic NH protons and the chloride counteranion both in solution and in the solid state.

catena-Poly[[(2,9-dimethyl-1,10-phenanthroline-κ2 N,N′)lead(II)]-di-μ-2-hydroxybenzoato-κ3 O 1,O 1′:O 2;κ3 O 2:O 1,O 1′]

2007 ◽  
Vol 63 (11) ◽  
pp. m2678-m2678 ◽  
Author(s):  
Xiao-Peng Xuan ◽  
Pei-Zheng Zhao
Keyword(s):  
Hydrogen Bonding ◽  
Crystal Packing ◽  
Rotation Axis ◽  
Intramolecular Hydrogen Bonding ◽  
Polymeric Chain ◽  
Π Interactions ◽  
Intramolecular Hydrogen ◽  
Hydroxy Groups

In the title polymeric comound, [Pb(C7H5O3)2(C14H12N2)] n , the PbII atom is located on a twofold rotation axis and is coordinated by two N atoms from one 2,9-dimethyl-1,10-phenanthroline (dmphen) ligand and six O atoms from four 2-hydroxybenzoate anions. The compound forms a zigzag polymeric chain along the c axis through bridging hydroxy groups of two 2-hydroxybenzoate ligands. The crystal packing is stabilized by the intramolecular hydrogen bonding and π–π interactions between dmphen rings of neighboring molecules, with a distance between the ring planes of 3.385 (3) Å.

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