Sami Ullah Bhat

Polypyrrole and its composites with various cation exchanged forms of zeolite X and their role in sensitive detection of carbon monoxide

Composites of polypyrrole and various cation exchanged forms of zeolite X were successfully synthesized and characterized by Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and thermo-gravimetric analysis (TGA). The effects of cation type, zeolite content, cyclic interval, and CO concentration on CO interactions with PPy were investigated. The sensitivity of the synthesized composites was found to obey the following order: Na+-X/PPy > H+-X/PPy > Fe+-X/PPy > Cu+-X/PPy > PPy depending upon the ionic radius of the cation present in the zeolite–polymer composites and the electronegativity. The sensitivity of the Na-X/PPy composite increased from 25.49% to 50.06% as the zeolite content was increased from 10% to 60% (w/w%). This increase in the sensitivity on increasing the zeolite content is due to the increase in the surface area of the composite. The sensitivity of Na-X/PPy at 500 ppm for CO was found to be 56.02, 50.28, 44.79 and 38.66% during the 1st, 2nd, 3rd and 4th cyclic intervals, respectively.

Synthesis of 14-Aryl-14H-dibenzo[a,j]xanthene Derivatives Using H-Zeolite A as an Efficient and Reusable Catalyst under Solvent-Free Condition

H-Zeolite A is an efficient, excellent, and reusable catalyst for the synthesis of 14-aryl-14H-dibenzo[a,j]xanthene derivatives by one-pot synthesis of β-naphthol with various aromatic aldehyde derivatives under solvent-free condition. The synthesized zeolite H-Zeolite A was characterized by XRD, SEM, and FT-IR. The synthesized products were characterized by FT-IR and 1H-NMR spectra. Simple workup procedure, short reaction time, high yield, and reusability of the catalyst are the characteristic features of these reactions.

Synthesis of N-Formylation of Amines using Various Ion Exchanged Forms of Zeolite-A as Catalysts

Formamides represent an important class of intermediates in various organic syntheses. They have been used in the synthesis of some pharmaceutically important compounds such as Fluoroquinolones [1], 1, 2 dihydro quinolones [2] and Nitrogen based heterocyclic compounds [3]. In Lewis bases, its main importance is to catalyze some important reactions such as allylation [4] and hydrosilyation of carbonyl compounds [5] Formamides Act as useful reagent in Vilsmeier Formylation reaction [6]. The main application of Formamides is to use in the synthesis of Formamidines [7] and in peptide synthesis acts as useful amino protecting group [8]. Various methods have been previously reported in literature for the synthesis of N-Formylation of amines and various catalysts were used for this reaction, such as acetic formic anhydride [9], activated formic acid using Dicyclohexylcarbodiimide [10] or,1Ethyl3-(3-dimethylaminopropyl) carbodiimide [11], chloral [12], activated formic esters [13], ammonium formate [14], 2,2,2-trifluoroethyl formate [15], ZnO [16], PEG-400 [17], Formic acid-ZnCl2 [18], polyvinyl alcohol[19], Na+-montmorillonite[20], Nano Cerium Oxide [21], Natrolite zeolite [22], HCOOH Sodium formate [17], Silica-bonded N-Propyl Sulfamic acid [23], TiCl3(OTF) [24], CDMT [25], KF-AL2O3 [26], Formic acid in Toluene [18], Formic acid in polyethylene glycol [17], Natural HEU Zeolite [27]. However above listed methods have some limitations such as long reaction time, formation of undesirable byproducts, hygroscopicity expensive reagents, and thermal instability of the reagents, and high temperature for reaction completion. Keeping in view the above disadvantages, we report a less time consuming method for the synthesis of N-Formylation of amines using various ion exchanged forms of Zeolite A as reusable catalysts.