EFFECTIVE SEPARATION OF HAFNIUM(IV) FROM ZIRCONIUM(IV) AS PYRIDINIUM TERNARY HETEROPOLY SALTS

Thermolysis of pyridinium perchlorate salts

Three perchlorate salts of pyridine have been prepared and characterized by gravimetric and elemental analyses. Thermogravimetry (TG) and differential thermal analysis (DTA) have been carried out in static air, to examine the thermal decomposition process of these salts. Isothermal TG of these salts have been done to evaluate the kinetics of thermal decomposition in the temperature range 290-41...

From Pyrylium to Pyridinium Salts: Understanding Physicochemical Features

It is known that physical properties of pyridinium salts can be modulated by their chemical characteristics. Owing to their broad range of applications in biology, biotechnology and chemical research, the design and synthesis of a series of 2,4,6-triarylpyridinium salts with modified structural backbone have been carried out. The main strands of work have included modifications on pyrylium cati...

Pyridinium Salts, Insertion Reaction, Oximes Pyridinium Salts with electron-withdrawing groups in the 3-position react with aliphatic ketoximes

Die Anlagerung von Nucleophilen an quartäre Pyridinium-Salze ist seit langem bekannt [2], ebenso die Beobachtung, daß Ringöffnungsund Umlagerungsreakt ionen sich anschließen können, gerade bei der Einwirkung von z.B. Hydroxidoder Alkoxid-Ionen und Aminen [3, 4]. Quartäre Salze von Pyridincarbaldoximen, die ausgeprägt hydrophile Eigenschaf ten haben, werden als Reaktivatoren bei In toxika t ion ...

Synthesis and characterizations of pyridinium salts including poly(pyridinium salt)s and their applications

Tandem dinucleophilic cyclization of cyclohexane-1,3-diones with pyridinium salts

The cyclization of cyclohexane-1,3-diones with various substituted pyridinium salts afforded functionalized 8-oxa-10-aza-tricyclo[7.3.1.0(2,7)]trideca-2(7),11-dienes. The reaction proceeds by regioselective attack of the central carbon atom of the 1,3-dicarbonyl unit to 4-position of the pyridinium salt and subsequent cyclization by base-assisted proton migration and nucleophilic addition of th...