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Journal ArticleDOI

TGA, DTA and DSC studies of phosphiniminocyclotrithiazenes, R3P=NS3N3 [R=(i) C6H5-, (ii) C5H10N-, (iii) OC4H8N-, (iv) H3CNC4H8N-]

25 Aug 1997-Thermochimica Acta (Elsevier)-Vol. 297, pp 139-142

AbstractThermal decomposition behaviour of phosphiniminocyclotrithiazenes [R=(i) phenyl-, (ii) piperidino-, (iii) morpholino- and (iv) N-methylpiperazino-] have been studied for the first time by employing thermogravimetric (TG), differential thermal (DT) and differential scanning calorimetric (DSC) methods. These heterocycles which do not show any melting behaviour begin to decompose above 130°C by following different pathways. The study indicates the possibility of obtaining new products by controlled solid-state pyrolysis method. Thermo-chemical parameters for the decomposition process have also been evaluated. more

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Abstract: In recent years, research in organophosphorus chemistry has mainly focused in designing newer and better phosphorus ligands for synthesizing novel metal complexes with improved catalytic activities. Aminophosphines [tricoordinate phosphorus(III)–nitrogen systems] are considered as versatile compounds owing to the presence of nitrogen centres which, in principle, can influence additional reactivity features. They are quite sensitive to air and moisture due to the presence of polar PN bond(s). In spite of this, research in aminophosphine chemistry is gaining momentum day-by-day and this is due mainly to one reason: their rich behaviour as ligands in metal complex chemistry and subsequently in catalysis. Their role as synthons in inorganic heterocyclic chemistry has also helped produce new types of heterocycles. In this paper, the chemistry of simple acyclic aminophosphines (synthesis, characterization, reactivity and applications) is covered and particular focus is given to their ability to form chalcogenides along with their role played as ligands in coordination chemistry and as synthons in inorganic heterocyclic chemistry. Copyright © 2009 John Wiley & Sons, Ltd.

67 citations

Journal ArticleDOI
Abstract: Electrochemical (polarographic, cyclic voltammetric, and coulometric) and coordination behaviour of several symmetrically and unsymmetrically substituted phosphiniminocyclotrithiazenes have been studied. Polarograms of R3PN-S3N3 (R = C6H5, p-ClC6H4, p-H3CC6H4, and (OC4H8N)), Ph2(OC4H8N)PN-S3N3, and Ph(OC4H8N)2PN-S3N3 give two cathodic waves. Cyclic voltammograms of Ph3PN-S3N3 (1) and (OC4H8N)3PN-S3N3 (2) reveal nearly the same oxidation peak potential but different reduction potentials. Controlled potential electrolysis of 1 and 2 at +0.6 V indicates exocyclic cleavage and ring degradation. Cathodic reduction behaviour of Ph3PN-S3N3 suggests the possibility for the formation of 1,5-(Ph3PN)2S4N4 under electrochemical conditions. Reaction of nickel chloride hexahydrate with heterocycle 1 in 1:2 molar ratio in acetonitrile affords the complex, [Ni(S2N2H)2] (A) (90% yield) and [Ph3PNH2]Cl salt as products. Analogous reactions with other ligands of this type (two symmetrical (sym.) and three unsymmetrical (uns...

7 citations

Journal ArticleDOI
Abstract: Iodination reactions of various phosphiniminocyclotrithiazenes [R3PNS3N3; R = (i) phenyl-, (ii) morpholino-, and (iii) p-chlorophenyl-] have been studied under different experimental conditions. Iodination of Ph3PNS3N3 yields interesting products such as [(Ph3PN)2S3N3]I3, ((Ph3PN)3S)2I4, (Ph3PNH2)I3, ((Ph3PSI2)2I2, and [(Ph3PN)3SO]2I6 depending on the experimental conditions. All the products have been isolated and characterized by the spectroscopic and analytical techniques.

2 citations

Journal ArticleDOI
Abstract: Though the chemistry of tetrasulfur tetranitride is very well developed and studied, that of phosphiniminocyclotrithiazenes is not. Reactions of symmetrically substituted R3PN-S3N3 [R = Ph, OC4H8N,...
Journal ArticleDOI
Abstract: GRAPHICAL ABSTRACT Abstract This study has been directed toward understanding the stability aspects from the mass spectral fragmentation patterns of two phosphiniminocyclotrithiazenes of the type (C6H5)[(C6H11)2N](R2N)P˭N−S3N3 [R‒Me (1) and n-Bu (2)]. Most of the structural features of the two ring systems considered are comparable for both the heterocycles. Some of the fragments that are formed under the operated mass spectral conditions are SN, S2N2, S3N, S3N2, S3N3, and S3N4, among others. Most of these observed fragments are already known to exist either as stable entities or as oligomerized species, and they are found to possess various applications.

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01 Jan 1964-Nature
Abstract: THE use of thermogravimetric data to evaluate kinetic parameters of solid-state reactions involving weight loss (or gain) has been investigated by a number of workers1–4. Freeman and Carroll2 have stated some of the advantages of this method over conventional isothermal studies. To these reasons may be added the advantage of using one single sample for investigation. However, the importance of procedural details, such as crucible geometry, heating rate, pre-history of sample, and particle size, on the parameters has yet to be fully investigated. It is also necessary to ensure accurate temperature measurement, both for precision and also to detect any departure from a linear heating rate due to endo- or exo-thermic reactions. (The effect of these may be largely eliminated by the use of small samples.) In our present work (using a Stanton HT–D thermobalance) the sample temperature is measured directly by means of a thermocouple the bead of which is positioned in or near the sample, depending on crucible design, the wires of which run down a twin-bore rise rod. The connexion between the end of the thermocouple wires on the balance arm and the terminal block is made by 0.001 in. platinum and platinum/rhodium wires5. It has been shown that these wires do not affect the performance of the balance but act merely as a subsidiary damping. From the terminal block compensated cable leads to the cold junction and a potentiometric arrangement for direct measurement of the thermocouple output.

5,308 citations

01 Jan 1980
Abstract: No wonder you activities are, reading will be always needed. It is not only to fulfil the duties that you need to finish in deadline time. Reading will encourage your mind and thoughts. Of course, reading will greatly develop your experiences about everything. Reading the inorganic heterocyclic chemistry of sulphur nitrogen and phosphorus is also a way as one of the collective books that gives many advantages. The advantages are not only for you, but for the other peoples with those meaningful benefits.

38 citations