scholarly journals New red-emitting Schiff base chelates: promising dyes for sensing and imaging of temperature and oxygen via phosphorescence decay time

2018 ◽  
Vol 6 (33) ◽  
pp. 8999-9009 ◽  
Author(s):  
Sergey M. Borisov ◽  
Reinhold Pommer ◽  
Jan Svec ◽  
Sven Peters ◽  
Veronika Novakova ◽  
...  
Keyword(s):  
Schiff Base ◽  
Schiff Bases ◽  
Optical Sensors ◽  
Decay Time ◽  
Photophysical Properties ◽  
Phosphorescence Decay ◽  
One Step

New complexes of Zn(ii), Pd(ii) and Pt(ii) with Schiff bases are prepared in a one step reaction and show photophysical properties particularly interesting for applications in optical sensors.

Facile luminescent tuning of ZnII/HgII complexes based on flexible, semi-rigid and rigid polydentate Schiff bases from blue to green to red: structural, photophysics, electrochemistry and theoretical calculations studies

2015 ◽  
Vol 44 (17) ◽  
pp. 8107-8125 ◽  
Author(s):  
Xin-Ming Wang ◽  
Shuo Chen ◽  
Rui-Qing Fan ◽  
Fu-Qiang Zhang ◽  
Yu-Lin Yang
Keyword(s):  
Schiff Base ◽  
Schiff Bases ◽  
Theoretical Calculations ◽  
Photophysical Properties ◽  
Schiff Base Complexes

The photophysical properties of ZnII/HgII Schiff base complexes could be tuned by changing the ligand structures.

scholarly journals Styryl-based new organic chromophores bearing free amino and azomethine groups: synthesis, photophysical, NLO, and thermal properties

2020 ◽  
Vol 16 ◽  
pp. 2282-2296
Author(s):  
Anka Utama Putra ◽  
Deniz Çakmaz ◽  
Nurgül Seferoğlu ◽  
Alberto Barsella ◽  
Zeynel Seferoğlu
Keyword(s):  
Schiff Base ◽  
Schiff Bases ◽  
Free Amino ◽  
Second Harmonic ◽  
Photophysical Properties ◽  
Bathochromic Shift ◽  
Visible Region ◽  
Amino Derivative ◽  
Quantum Yields ◽  
Thermal Stabilities

Herein we report the synthesis and characterization of a new series of styryl-based push-pull dyes containing a free amino group and their Schiff base derivatives. The dyes include the dicyanomethylene group as an acceptor and different para-substituted alkylamines as donors. Morever as a proton-sensitive group a pyridin-2-yl substituent was attached to the para-position of the phenyl moiety in both series of compounds. The photophysical properties of the dyes were examined in various solvents with different polarities and showed absorption in the visible region and green-red emission with low quantum yields. The absorption and the emission maxima were shifted bathocromically by increasing the solvent’s polarity. However, there was no correlation with the polarity parameters of the solvents. The pH-sensitive properties of all prepared Schiff bases were examined against TBAOH in DMSO, via deprotonation of the OH group in the salicylidene moiety and their reverse protonation was also investigated using TFA. The Schiff bases exhibited a bathochromic shift upon the addition of TBAOH to their solutions in DMSO. Therefore, they showed potential to be utilized as colorimetric and luminescence pH sensors. The second-order nonlinear optical (NLO) responses of the dyes were measured by the electric field-induced second harmonic (EFISH) generation method. The highest μβ values were obtained for the dyes bearing the julolidine donor as 1430 × 10−48 esu (for free amino derivative) and 1950 × 10−48 esu (for Schiff base derivative), respectively. The structural and electronic properties of the dyes as well as their NLO properties were further studied using DFT calculations. The thermal stabilities of all dyes were evaluated by thermogravimetric analysis (TGA). The TGA data showed that all dyes were thermally stable up to 250 °C.

scholarly journals Optical Sensing and Supramolecular Cyanide Recognition Sites of Salophenes as Molecular Tweezers: The First Example of Recognition via Intramolecular Aldimine Condensation Cyclization

2021 ◽  
Author(s):  
Hossein Reza Darabi ◽  
Ramo Nazarian ◽  
Sepideh Alizadeh ◽  
Kioumars Aghapoor ◽  
Leila Ebadinia
Keyword(s):  
Schiff Base ◽  
Schiff Bases ◽  
Optical Sensors ◽  
Optical Sensing ◽  
Point Of View ◽  
Ease Of Use ◽  
Molecular Tweezers ◽  
Color Changes ◽  
Recognition Sites ◽  
Nmr Data

Abstract The optical sensing and supramolecular cyanide recognition sites of two dipodal Schiff bases having conjugated to catecols (1) and phenols (2) (namely, salophenes 1 and 2) have been studied. In the case of optical sensing, both probes recognized only cyanide (CN¯) ions in 30% PBS buffer CH3CN (pH 7.4) as confirmed from the changes of absorption and emission bands, resulting in color changes. From the supramolecular recognition point of view, probes 1 and 2 show the different recognition bahaviour toward CN¯, as evidenced by the fluoroscence and NMR data, as well the OH¯ and reversibility experiments. While 1 recognizes CN¯ via deprotonation, that of 2 is the first example of Schiff base which senses CN¯ through an intramolecular aldimine condensation cyclization, leading to formation of dihydroxyquinoxaline 4. In general, probes 1, 2 and 4 are promising on-site optical sensors in terms of easy prepared, selectivity, sensitivity (1–10 nM), ease of use, rapid response (< 5 s) and test kits.

scholarly journals New Cryptands Synthesized by [2 + 3] Condensation and Reduction with or without Templates

1999 ◽  
Vol 23 (12) ◽  
pp. 712-713
Author(s):  
Zhen Ma ◽  
Rudong Yang ◽  
Lan Yan
Keyword(s):  
Schiff Base ◽  
One Step ◽  
Presence And Absence

A Schiff base cryptand is synthesized in 65–75 and 20% yield, respectively, via one-step [2 + 3] condensation of a flexible dialdehyde with tris(2-aminoethyl)amine in the presence and absence of template; a polyoxa-aza cryptand is synthesized in 75% yield upon reduction of the Schiff base.

scholarly journals Synthesis and Evaluation of Schiff Bases of 4-Amino-5-(chlorine substituted phenyl)-4H-1,2,4-triazole-3-thione as Antimicrobial Agents

2020 ◽  
Vol 41 (1) ◽  
pp. 26-35
Author(s):  
Kishor Devkota ◽  
Govinda Pathak ◽  
Bhushan Shakya
Keyword(s):  
Schiff Base ◽  
Schiff Bases ◽  
Antimicrobial Agents ◽  
Triazole Ring ◽  
Antimicrobial Activities ◽  
Biologically Active ◽  
Spectral Techniques ◽  
Schiff Base Derivatives ◽  
Bacteria And Fungi ◽  
Different Strains

Triazole ring system has attracted a continuously growing interest of synthetic organic chemists and those dealing with the medicinal compounds due to its versatile potential to interact with biological systems. Schiff bases are also considered as one of the most biologically active compounds.  The aim of the present study was to synthesize new Schiff bases bearing triazole nucleus and to assess their antimicrobial activities. Four new Schiff base derivatives of 1,2,4-triazole-3-thione were synthesized by combining two different pharmacophores viz. triazole nucleus and Schiff base moiety and were characterized by spectral techniques (UV, FT-IR, and NMR). The Schiff bases were evaluated for antibacterial (Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae) and antifungal (Candida albicans) activities. The synthesized compounds exhibited good to moderate activities against different strains of bacteria and fungi tested.

Syntheses, Spectroscopy And Crystal Structures Of (R)-N-(1-Aryl-Ethyl)Salicylaldimines And [Rh{(R)-N-(1-Aryl-Ethyl)Salicylaldiminato}(η4-Cod)] Complexes

2007 ◽  
Vol 62 (6) ◽  
pp. 807-817 ◽  
Author(s):  
Mohammed Enamullah ◽  
A.K.M. Royhan Uddin ◽  
Anne-Christine Chamayou ◽  
Christoph Janiak
Keyword(s):  
Mass Spectrometry ◽  
Schiff Base ◽  
Schiff Bases ◽  
Structure Determination ◽  
Chelate Ring ◽  
Optical Rotation ◽  
X Ray ◽  
Mononuclear Complexes ◽  
Chiral Schiff Base ◽  
C Nmr

Condensation of salicylaldehyde with enantiopure (R)-(1-aryl-ethyl)amines yields the enantiopure Schiff bases (R)-N-(1-aryl-ethyl)salicylaldimine (HSB*; aryl = phenyl, 2-methoxyphenyl, 3- methoxyphenyl, 4-methoxyphenyl (4), 4-bromophenyl (5), 2-naphthyl). These Schiff bases readily react with dinuclear (acetato)(η4-cycloocta-1,5-diene)rhodium(I), [Rh(μ-O2CMe)(η4-cod)]2, to afford the mononuclear complexes, cyclooctadiene-((R)-N-(1-aryl-ethyl)salicylaldiminato-κ2N,O)- rhodium(I), [Rh(SB∗)(η4-cod)] (SB* = deprotonated chiral Schiff base = salicylaldiminate; aryl = phenyl (7), 2-methoxyphenyl, 4-methoxyphenyl, 4-bromophenyl, 2-naphthyl). The complexes have been characterized by IR, UV/vis, 1H/13C NMR and mass spectrometry, optical rotation as well as by single-crystal X-ray structure determination for 4, 5 and 7. The structure of 5 shows C-Br· · ·π contacts. Compound 7 is only the second example of a Rh(η4-cod) complex with a six-membered Rh-N,O-chelate ring

Notizen: Magnetic Studies on Schiff Base Complexes of Al(III) and Si(IV)

1974 ◽  
Vol 29 (7-8) ◽  
pp. 565-566 ◽  
Author(s):  
R. N. Prasad ◽  
J. P. Tandon
Keyword(s):  
Schiff Base ◽  
Schiff Bases ◽  
Schiff Base Complexes ◽  
Magnetic Studies ◽  
Magnetic Susceptibilities

The magnetic susceptibilities of some newly syntesized Al(III) and Si(IV) complexes of Schiff bases derived from the condensation of o-hydroxyacetophenone or 2-dydroxy-1-naphthaldehyde with hydroxyalkylamines or diamines have been measured and the data indicate their diamagnetic character.

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