21869-53-4Relevant academic research and scientific papers
Kinetic Selectivity and Thermodynamic Features of Competitive Imine Formation in Dynamic Covalent Chemistry
Kulchat, Sirinan,Chaur, Manuel N.,Lehn, Jean-Marie
, p. 11108 - 11118 (2017)
The kinetic and thermodynamic selectivities of imine formation have been investigated for several dynamic covalent libraries of aldehydes and amines. Two systems were examined, involving the reaction of different types of primary amino groups (aliphatic amines, alkoxy-amines, hydrazides and hydrazines) with two types of aldehydes, sulfobenzaldehyde and pyridoxal phosphate in aqueous solution at different pD (5.0, 8.5, 11.4) on one hand, 2-pyridinecarboxaldehyde and salicylaldehyde in organic solvents on the other hand. The reactions were performed separately for given amine/aldehyde pairs as well as in competitive conditions between an aldehyde and a mixture of amines. In the latter case, the time evolution of the dynamic covalent libraries generated was followed, taking into consideration the operation of both kinetic and thermodynamic selectivities. The results showed that, in aqueous solution, the imine of the aliphatic amine was not stable, but oxime and hydrazone formed well in a pH dependent way. On the other hand, in organic solvents, the kinetic product was the imine derived from an aliphatic amine and the thermodynamic products were oxime and hydrazone. The insights gained from these experiments provide a basis for the implementation of imine formation in selective derivatization of mono-amines in mixtures as well as of polyfunctional compounds presenting different types of amino groups. They may in principle be extended to other dynamic covalent chemistry systems.
Fluorimetric detection of Sn2?+ ion in aqueous medium using Salicylaldehyde based nanoparticles and application to natural samples analysis
Patil, Kishor S.,Mahajan, Prasad G.,Patil, Shivajirao R.
, p. 131 - 137 (2017)
The fluorescent 2-[(E)-(2-phenylhydrazinylidene)methyl]phenol nanoparticles (PHPNPs) were prepared by a simple reprecipitation method. The prepared PHPNPs examined by Dynamic Light Scattering show narrower particle size distribution having an average particle size of 93.3?nm. The Scanning Electron Microphotograph shows distinct spherical shaped morphology of nanoparticles. The blue shift in UV-absorption and fluorescence spectra of PHPNPs with respect to corresponding spectra of PHP in acetone solution indicates H- aggregates and Aggregation Induced Enhanced Emission (AIEE) for nanoparticles. The nanoparticles show selective tendency towards the recognition of Sn2?+ ions by enhancing the fluorescence intensity preference to Cu2?+, Fe3?+, Fe2?+, Ni2?+, NH4+, Ca2?+, Pb2?+, Hg2?+ and Zn2?+ ions, which actually seem to quench the fluorescence of nanoparticles. The studies on Langmuir adsorption plot, fluorescence lifetime of PHPNPs, DLS-Zeta sizer, UV–visible and fluorescence titration with and without Sn2?+ helped to propose a suitable mechanism of fluorescence enhancement of nanoparticles by Sn2?+ and their binding ability during complexation. The fluorescence enhancement effect of PHPNPs induced by Sn2?+ is further used to develop an analytical method for detection of Sn2?+ from aqueous medium in environmental samples.
In situ room temperature synthesis and characterization of salicylaldehyde phenylhydrazone metal complexes, their cytotoxic activity on MCF-7 cell line, and their investigation as antibacterial and antifungal agents
El-Seidy, Ahmed M. A.
, (2015)
In situ synthesis is usually used in industrial plants. As an approach new series of metal complexes of the salicylaldehyde phenylhydrazone, H2L, have been synthesized and characterized by elemental analysis, IR, UV, 1H-NMR, 13
Zeolite enslaved transition metal complexes as novel heterogeneous catalysts for synthesis of polycyclic heterocycles using suzuki–miyaura cross coupling reaction under greener conditions
Dwivedi, Jaya,Jain, Sonika,Kishore, Dharam,Mishra, Shruti,Sain, Shalu,Sankararamakrishnan, Nalini,Sharma, Swapnil,Sharma, Vivek,Srivastava, Manish,Wabaidur, Saikh M
, (2020)
In the present work we report the construction of zeolite enslaved transition metal complexes (Pd2+, Ni2 + ) as novel heterogenous catalysts for synthesis of polycyclic heterocycles using suzuki–miyaura cross coupling reaction in ethanolic medium. The synthesized catalysts were characterized by employing UV–Vis, FT-IR, magnetic susceptibility, N2 sorption, XRD, XPS, FE-SEM analysis. Results of the study advocate that newly developed catalysts give rise to a rapid and easy synthesis of various polycyclic heterocycles by Suzuki coupling reactions in impressive yields. In conclusion, developed catalyst may be used as versatile tool in the synthesis of various industrially and pharmaceutically important polycyclic heterocycles under greener conditions.
