New Schiff bases derived from trans-pyrazolylcyclohexanol: synthesis, co-ordination chemistry and structural features

1997 ◽  
pp. 2155-2162 ◽  
Author(s):  
Michael Barz ◽  
Monika U. Rauch ◽  
Werner R. Thiel
Keyword(s):  
Schiff Bases ◽  
Structural Features

scholarly journals Synthesis and Study the Chelating Activity of some Polymers Containing Heterocyclic Rings, The Derivatives from 1,2,4- trizol Levofloxacin acid

2018 ◽  
Vol 34 (4) ◽  
pp. 2031-2042 ◽  
Author(s):  
Tahseen Saddam Fandi Al-Mathkuri ◽  
Hamid Mohammed Saleh Al-Jubori ◽  
Ali Taha Saleh
Keyword(s):  
Schiff Bases ◽  
Treatment Time ◽  
Phenol Formaldehyde ◽  
Thermal Studies ◽  
Structural Features ◽  
Batch Method ◽  
Synthetic Compounds ◽  
Chelating Activity ◽  
Effect Of Treatment ◽  
Chelating Polymers

The compound 6-amino-5-mercapto-4H-1,2,4-triazol-3-yl)-9-fluoro-3-methyl-10-(4-methylpiperazin-1-yl)-2,3-dihydro-7H-[1,4] oxazino[2,3,4-ij] quinolin-7-one (M1) synthesize from the reaction of thiocarbohydrazide with levofloxacin acid by using ethanol as a solvent, phenolic Schiff bases (Z)-9-fluoro-6-(4-((4-hydroxybenzylidene) amino)-5-mercapto4H1,2,4-triazol-3-yl)-3-methyl-10-(4-methylpiperazin-1-yl)-2,3-dihydro-7H-[1,4]oxazino[2,3,4-ij] quinolin-7-one (M2), (Z)-6-(4-((2,4-dihydroxybenzylidene) amino)-5-mercapto-4H-1,2,4-triazol-3-yl)-9-fluoro-3-methyl-10-(4-methylpiperazin-1-yl)-2,3-dihydro-7H-[1,4] oxazino[2,3,4-ij]quinolin-7-one (M3) and (Z)-6-(4-((5-chloro-2-hydroxybenzylidene) amino)-5-mercapto-4H-1,2,4-triazol-3-yl)-9-fluoro-3-methyl-10-(4-methylpiperazin-1-yl)-2,3-dihydro-7H- [1,4] oxazino[2,3,4-ij] quinolin-7-one (M4) were prepared from the reaction of trizol derivative of [M1] compound with the appropriate phenolic aldehydes by using ethanol as a solvent. The synthetic Schiff bases used to prepare numbers of phenolic polymers [M5-M7] from the reaction of Schiff bases [M2-M4] with phenol formaldehyde. The analytical efficiency of the synthetic chelating polymers studied by the batch method with different transition metals ions (Cd2+, Fe3+, Cu2+), in terms of the effect of treatment time and the pH on the loading capacity of the polymers, controlling the other factors such as temperature, ions concentration and quantity of polymers. The result shows that the capacity of the polymer increased with increasing of the pH and treating time. The synthetic compounds were characterized by various instrumental techniques like FTIR, 1H-NMR, DTG and TGA studies.These spectral and thermal studies provide very valuable information about the structural features.

The ligand mediated pseudohypersensitivity of the 3H4 → 3P2, 3H4 → 3P1, 3H4 → 3P0, and 3H4 → 1D2 transitions of praseodymium(III) complexes in solution media

1992 ◽  
Vol 70 (1) ◽  
pp. 46-54 ◽  
Author(s):  
Sudhindra N. Misra ◽  
Shaun O. Sommerer
Keyword(s):  
Amino Acids ◽  
Quantitative Analysis ◽  
Present Article ◽  
Oscillator Strength ◽  
Schiff Bases ◽  
High Sensitivity ◽  
Structural Features ◽  
Absorption Spectrophotometry ◽  
Nucleic Bases ◽  
Hypersensitive Transitions

The absorption difference, comparative absorption spectrophotometry, and quantitative analysis of 4f–4f spectra of praseodymium(III) complexes with ligands possessing varying structural features and binding capabilities have clearly indicated that the 3H4 → 3P2, 3H4 → 3P1, 3H4 → 3P0, and 3H4 → 1D2 transitions exhibit substantial intensification as well as a wide variation of oscillator strength. Since these transitions do not follow the selection rules they cannot be considered hypersensitive. Ligands such as β-diketones, Schiff bases, amino acids, diols, nucleic bases, nucleosides, nucleotides, alkoxides, and haloacetates with widely differing binding features in terms of coordinating ability, denticity, and normalized bite appear to induce, to varying degrees, high sensitivity in these non-hypersensitive transitions. The present article reports the high sensitivity of the 3H4 → 3P2, 3P1, 3P0, and 1D2, transitions of Pr(III) by considering the solution spectra of 173 species. This unique sensitivity is termed Ligand Mediated Pseudohypersensitivity. Keywords: praseodymium(III), 4f–4f transitions, hypersensitive transitions.

scholarly journals Structural features of some organotin (IV) complexes of ONO donor Schiff bases

2007 ◽  
Vol 63 (a1) ◽  
pp. s169-s169
Author(s):  
S. Ide ◽  
N. Ancın ◽  
H. Malkaş ◽  
S. G. Öztaş
Keyword(s):  
Schiff Bases ◽  
Structural Features

scholarly journals Hypercoordinated Organosilicon(IV) and Organotin(IV) Complexes: Syntheses, Spectral Studies, and Antimicrobial Activity In Vitro

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Kiran Singh ◽  
Parvesh Puri ◽  
Yogender Kumar ◽  
Chetan Sharma
Keyword(s):  
Antimicrobial Activity ◽  
Schiff Bases ◽  
Structural Features ◽  
Antimicrobial Activities ◽  
Molar Conductance ◽  
Spectral Studies ◽  
Nmr Studies ◽  
Trigonal Bipyramidal ◽  
Elemental Analyses

This paper deals with the syntheses and structural features of some new diorganosilicon(IV) and diorganotin(IV) complexes having general formulae (CH3)2MCl(L1), (CH3)2MCl(L2), (CH3)2M(L1)2, and (CH3)2M(L2)2 with new Schiff bases (M = Si and Sn). The Schiff bases HL1 and HL2 have been derived from the condensation of 3-bromobenzaldehyde with 4-amino-3-ethyl-5-mercapto-1,2,4-triazole and 4-amino-5-mercapto-3-propyl-1,2,4-triazole, respectively. The compounds have been characterized by the elemental analyses, molar conductance, and spectral (UV, IR, 1H, 13C, 29Si, and 119Sn NMR) studies. The resulting complexes have been proposed to have trigonal bipyramidal and octahedral geometries. In vitro antimicrobial activities of the compounds have been carried out.

Experimental and theoretical studies of the products of addition–elimination reactions between benzil dihydrazone and three isomeric chlorobenzaldehydes

2015 ◽  
Vol 71 (7) ◽  
pp. 554-563 ◽  
Author(s):  
Yun-Na Liu ◽  
Shuang-Shuang Cheng ◽  
Chao Wang ◽  
Dian-Xiang Xing ◽  
Yun Liu ◽  
...  
Keyword(s):  
Schiff Bases ◽  
Density Functional ◽  
Double Helix ◽  
Structural Features ◽  
Supramolecular Interactions ◽  
Monoclinic Space Group ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Double Helix Structure ◽  
Homo Lumo

A series of mono- and di-Schiff bases formed between benzil dihydrazone {BDH; systematic name: (1Z)-[(2E)-2-hydrazinylidene-1,2-diphenylethylidene]hydrazine} and three isomeric chlorobenzaldehydes were designed and synthesized to be used as model compounds to help to explain the reaction mechanisms for the formation of Schiff bases. These compounds are 1-(2-chlorobenzylidene)-2-{2-[2-(2-chlorobenzylidene)hydrazin-1-ylidene]-1,2-diphenylethylidene}hydrazine (BDHOCB), and the 3-chloro (BDHMCB) and 4-chloro (BDHPCB) analogues, all having the formula C28H20Cl2N4. Surprisingly, only di-Schiff bases were obtained; our attempts to push the reaction in favour of the mono-Schiff bases all failed. Density functional theory (DFT) calculations were performed to explain the trend in the experimental results. In the case of the systems studied, the type of Schiff base produced exhibits a clear dependence on the HOMO–LUMO energy gaps (ΔEHOMO–LUMO),i.e.the product is mainly governed by its stability. The compounds were characterized by single-crystal X-ray diffractometry, elemental analysis, melting point,1H NMR and13C NMR spectroscopy. The structural features of the three new Schiff bases are similar. For instance, they have the same chemical formula, all the molecules have a symmetrical double helix structure, with each Ph—C=N—N=C—Ph arm exhibiting ananticonformation, and their supramolecular interactions include intermolecular π–π and weak C—H...π stacking interactions. The crystal systems are different, however,viz.triclinic (space groupP\overline{1}) for BDHPCB, monoclinic (space groupP21/n) for BDHOCB and orthorhombic (space groupPnna) for BDHMCB.

scholarly journals A Novel ZnII Complex Bearing Two Monodentate (4-Methoxyphenyl)[(1E, 2E)-3-phenylprop-2-en-1-ilidene] Schiff Bases: Crystal Structure and DFT Study

2019 ◽  
Vol 2019 ◽  
pp. 1-6
Author(s):  
Giuliano M. Cordeiro ◽  
Emanoel Hottes ◽  
Andressa Esteves-Souza ◽  
Guilherme P. Guedes ◽  
Carlos Maurício R. de Sant’Anna ◽  
...  
Keyword(s):  
Schiff Bases ◽  
Structural Features ◽  
Chloride Ions ◽  
Basis Set ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Hybrid Functional ◽  
Schiff Base Ligands ◽  
Tetrahedral Geometry ◽  
H Nmr

A novel ZnII complex bearing two monodentate (4-methoxyphenyl)[(1E, 2E)-3-phenylprop-2-en-1-ilidene] Schiff bases was synthesized and investigated both in the solid state by single-crystal X-ray diffraction, elemental analysis, and FTIR and in solution by 1H NMR spectroscopy. The complex crystallizes in the P21/c monoclinic space group. The asymmetric unit contains one ZnII ion coordinated to two Schiff base ligands and two chloride ions, in a distorted tetrahedral geometry. The title complex was also investigated by DFT, using the hybrid functional B3LYP with basis set 6-31G++, which reproduced the geometry and structural features of the complex in the crystal, and was used to assign the main bands in the FTIR spectrum. In solution, the complex maintains its integrity against decomposition to the parent reagents.

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