Thermal 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. © 1997 Elsevier Science B.V.

M. Ramakrishna Udupa

DECOMPOSITION PROCESS

DIFFERENTIAL THERMALS

DSC STUDIES

Heterocycles

New product

PHOSPHINIMINOCYCLOTRITHIAZENES

Substituent effect

Thermal decompositions

THERMO-CHEMICAL

Pyrolysis

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

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

Thermochimica Acta

Iodination reactions of various phosphiniminocyclotrithiazenes [R 3PNS3N3; 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)2S3N 3]I3, ((Ph3PN)3S)2I 4, (Ph3PNH2)I3, ((Ph 3PSI2)2I2, and [(Ph 3PN)3SO]2I6 depending on the experimental conditions. All the products have been isolated and characterized by the spectroscopic and analytical techniques. Copyright © Taylor &amp; Francis Group, LLC.

Synthesis and Reactivity in Inorganic, Metal-Organic and Nano-Metal Chemistry

Studies on iodination reactions of phosphiniminocyclotrithiazenes

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)), Ph2OC4H8N)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-(Ph)3(PN)2S4N4 under electrochemical conditions. Reaction of nickel chloride hexahydrate with heterocycle 1 in 1:2 molar ratio in acetonitrile affords the complex, ([NiS2N2H2] (A) (90% yield) and [Ph3PNH2]Cl salt as products. Analogous reactions with other ligands of this type (two symmetrical (sym.) and three unsymmetrical (unsym.)) except 2 also give A, while ligand 2 reacts with anhyd NiCl2 in an equimolar ratio to afford a dark green, square-planar complex ((OC4H8N)3(PN-S3(N·NiCl 2 (B)) whose ESCA results assist in providing its coordination details. The study reveals a high tendency of these heterocycles to different types of ring cleavage.

Canadian Journal of Chemistry

Studies on electrochemical and coordination behaviour of phosphiniminocyclotrithiazenes

The reactions of the tertiary (amino)phosphines (R2N)3P [R2N = C4H8N-, C5H10N-, C6H12N-, OC4H8N-, and CH3NC4H8N-·] with S4N4 are described. The phosphiniminocyclotrithiazenes (R2N)3PN-S3N3 (1-5) are the only heterocyclic products isolated (60-80% yield). Excess (amino)phosphines cleave the heterocycles readily while norbornadiene reacts with them to give rise to the addition products, (R2N)3PN-S3N3·C7H8 (6-9) in small yields. The single crystal X-ray structure of (C5H10N)3PN-S3N3 (triclinic system, space group P1̄) gave the unit cell dimensions: a = 9.573(5), b = 10.372(6), c = 10.916(6) Å, α = 85.46(3), β = 81.13(4), γ = 79.73(4)°, V = 1052.25 Å3 and Z = 2. The structure has been compared with that of Ph3PN-S3N3 which is the only other compound of this type (R3PN-S3N3) whose X-ray structure is known. © 1990.

Polyhedron

Cyclic SN compounds and phosphorus reagents-VII. Reactions of S4N4 with tertiary (amino)phosphines: Synthesis and characterization of (R2N)3PN-S3N3 derivatives and their addition products with norbornadiene. X-ray crystal structure of (C5H10N)3PN-S3N3

Inorganic Chemistry

Thermal decomposition of (triphenylphosphoranediyl)aminocyclotrithiazene and (Triphenylarsoranediyl)aminocyclotrithiazene, Ph3E = NS3N3(E = phosphorus, arsenic). Preparation and structure of (triphenylphosphoranediyl)amine(thiosulfinyl)amine sulfide, Ph3P = NSN = S = S, and a novel synthesis of disulfur dinitride

Reaction of triphenylphosphine with tetrasulfur tetranitride: synthesis and structure of 1,5-bis(triphenylphosphinimino)cyclotetrathiazene, (Ph3P:N)2S4N4

Journal of the American Chemical Society

Synthesis and structure of metallic polymeric sulfur nitride, (SN)x, and its precursor, disulfur dinitride, S2N2

Nature

Kinetic Parameters from Thermogravimetric Data

TGA, DTA and DSC studies of phosphiniminocyclotrithiazenes, R 3P=NS3N3 [R=(i) C6H5-, (ii) C5H10N-, (iii) OC4H8N-, (iv) H3CNC4H8N-]

Journal	Thermochimica Acta
ISSN	00406031
Open Access	No