73476-26-3Relevant articles and documents
Organic solvents as catalysts of formation of phosphorus-containing thiosemicarbazides
Yanchuk
, p. 1236 - 1239 (2006)
The kinetics of the reaction of O,O-diphenyl phosphorohydrazidothioate with phenyl isothiocyanate at 25°C in benzene in the presence of organic bases is studied. The dependences of the catalytic activity on the nature and structure of organic bases and on various parameters characterizing their basicity are analyzed. The catalytic activity exhibited in the formation of phosphorus-containing thiosemicarbazides by donor solvents added to benzene correlates well with both spectroscopic and thermodynamic parameters of basicity: Taft (pK HB), Koppel-Palm (B), and Gutmann (DN) parameters. A common mechanism of the base catalysis of the thiosemicarbazide formation by organic bases of different classes is suggested and discussed. Nauka/Interperiodica 2006.
Effect of the nucleophile structure and basicity on pyridine-catalyzed formation of thiosemicarbazides
Yanchuk
, p. 1059 - 1062 (2006)
The kinetics of pyridine-catalyzed reaction of O,O-diaryl hydrazidothiophosphates with phenyl isothiocyanate in benzene at 25°C were studies. Pyridine was found to exhibit a considerable catalytic effect in the formation of phosphorus-containing thiosemicarbazides. A correlation between the reactivity of phosphorus hydrazides in the catalytic reaction and their structure was revealed. The catalytic activity of pyridine increases as the basicity of hydrazide decreases. The effects of the substituents in the aromatic rings and the basicity of hydrazides weaken in going from the noncatalytic to catalytic process. The catalysis by pyridine conforms to the general base catalysis pattern. Pleiades Publishing, Inc., 2006.
Kinetic regularities of reactions of O,O-diaryl phosphorohydrazidothioates with phenyl isothiocyanate in benzene
Yanchuk,Ivanets
, p. 841 - 844 (2005)
The effect of the temperature on the rate of reactions of O,O-diaryl phosphorohydrazidothioates with phenyl isothiocyanate in benzene is studied, and the activation parameters of the reactions are calculated. It is established that the reaction series under study obeys the isokinetic relationship with an enthalpy control and an isokinetic temperature of 690±24 K. The effect of electronically diverse substituents on phosphorus on the reactivity of O,O-diaryl phosphorohydrazidothioates is additive. It is described by the Hammett equation with σP constants.
Quantitative estimation of the α-effect in the reactions yielding phosphorus-containing thiosemicarbazides
Yanchuk
, p. 1240 - 1242 (2008/02/03)
The α-effect in the reactions of O,O-diaryl phosphorohydrazidothioates with phenyl isothiocyanate in benzene at 25°C was quantitatively evaluated from the kinetic data. The probable reaction mechanism was suggested, and the causes of the α-effect in these reactions are discussed. An approximate linear correlation is observed between the α-effect in the reactions of O,O-diaryl phosphorohydrazidothioates with phenyl isothiocyanate, basicity constants of the hydrazides, and σp constants of the substituents at the P atom. The value of the α-effect is largely determined by the structure of the transition state. Nauka/Interperiodica 2006.
