Tetrasulfurtetranitride, S4N4 reacts with (2‐pyridylamino)‐diphenylphosphine in MeCN at room temperature to form the cyclotrithiazene (NC5H4NH)‐Ph2PNS3N3 (1) in good yield. By contrast, the cyclophosphathiazenes Ph2PS2N3 (2) and 1,5(Ph2P)2S2N4 (3) are isolated from the same reaction mixture under reflux conditions. In solution, compound 1 is found to be transformed into 2. The reaction of S4N4 with (2‐pyridylamino)phenyl(dicyclohexylamino)phosphine in MeCN at room temperature affords Ph(DCA)PS2N3 (4) (DCA = dicylohexylamino) as the only reaction product. This on treatment with norbornadiene produces the addition product Ph(DCA)PS2N3·C7H8 ( 5 ). The structure of 4 has been established by X‐ray diffraction. Its PSN ring adopts a skew boat conformation with SN bond lengths varying from 1.574(4) to 1.606(4) Å. The mean value of the endocyclic PN bonds amounts to 1.618(3) Å. Copyright © 1994 VCH Publishers, Inc.

Talla Venkata Rama Mohan

Colacot J. Thomas

Gopalaswamiengar Aravamudan

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

Heteroatom Chemistry

The phosphetidine 2,4-Di-tert-buty1-3-chloro-1λ6-thia-2, 4-diaza-3-phosphetidine-1,1-dioxide, O2S (tBuN) 2PCl, reacts with tetrasulfur tetranitride, S4N 4, in benzene under reflux to afford the novel 4,6-spirocycle in moderate yield. The deep-blue crystals of the spirocycle are airstable and high melting in nature. The spiro phosphorus atom subtends a four-membered P VSVIN2 ring which is saturated, and a six-membered PVS2IVN3 ring which is unsaturated. The single-crystal X-ray structure of this first example of the spirocycle reveals a planar PSN2 ring and a puckered PS 2N3 ring and the molecule is symmetric in nature. Copyright © 2006 John Wiley &amp; Sons, Ltd.

Applied Organometallic Chemistry

A new synthetic route to cyclophosphadithiatriazenes: Synthesis and X-ray structural characterization of the first spirocycle containing thiadiazaphosphetidine and phosphadithiatriazene heterocycles

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 S4N4 with phosphines of the type PhPR2 (1-5) and PhR′PR [6-11 (R′ = dicyclohexylamino), R: 1,6 = pyrrolidino; 2,7 = piperidino; 3,8 = morpholino; 4,9 = N-methylpiperazino; 5,10 = hexamethylenimino; and 11 = anilino] afford the phosphiniminocyclotrithiazene derivatives, 12-22 at room temperature. Only in the case of the phosphine 10 was the disubstituted derivative 23 isolated (in 65% yield). The trithiazene derivatives of the chiral phosphines in refluxing CH3CN produce the acyclic compounds → PN-S3N, 24-27 in ca. 60% yield. Norbornadiene reacts at room temperature with the cyclotrithiazene derivatives to give the addition products 28-35. → P=N-S3N3 derivatives are found to be stable in 2M NaOH. © 1997 John Wiley &amp; Sons, Inc.

Reactions of S4N4 with tertiary phosphines - Synthesis of phosphiniminocyclothiazenes and their reactions

Cyclic sulfur nitrogen compounds and phosphorus reagents: Part XII. Reactions of S4N4 with (2‐pyridylamino) phosphines [1]

Title full: Cyclic SN compounds and phosphorus reagents part 6. Reactions of S4N4 with symmetrical tertiary phosphines, R3P (R = t-C4H9, c-C6H11, C6H5CH2, p-MeOC6H4 and p-ClC6H4): Isolation and characterization of phosphinimino substituted cyclic sulphur nitrides. Unlike Ph3P, reactions of S4N4 with symmetrical tertiary phosphines, R3P (R = t-butyl, cyclohexyl, benzyl, p-methoxyphenyl and p-chlorophenyl) afford only the corresponding phosphiniminocyclotrisul-phurtrinitrides, R3PNS3N3 (I-V) in moderate to good yields. (p-ClC6H4)3P alone yields the disubstituted S4N4 derivative, 1,5-[(p-ClC6H4)3PN]2S4N4 (VI) in low yield which undergoes a ring contraction in solution. Among the red crystalline compounds I-V, those containing aliphatic substituents on phosphorus (I-III) are less stable both in solid and solution phases than those containing aromatic substituents (IV and V). Various spectroscopic data have been discussed. © 1989.

Inorganica Chimica Acta

Cyclic SN compounds and phosphorus reagents part 6. Reactions of S4N4 with ...

Reaction of PhPCl2 with dicyclohexylamine followed by a secondary amine affords stable tertiary phosphine (Ph)(DCA)(NR2)P in good yield which reacts readily with sulphur to give the phosphine sulphide (Ph)(DCA)(NR2)P(S). © 1989.

Tetrahedron Letters

Stable chiral but racemic phosphines (R)(R′)(R″)P containing two different (amino) substituents : high yield synthesis and conversion to the respective phosphine sulphides

(Morpholino)diphenylphosphine, unlike PPh3, gives only two new compounds, (OC4H8N)Ph2PNS3N3, (1), and 1,5-[(OC4H8N)Ph2PN]2S 4N4, (2), on reacting with S4N4. The reaction temperature, solvent, and mole ratio of the reactants are critically important in their synthesis. For the first a ring contraction of compound (2) to compound (1) in solution at room temperature has been observed and evidence for the elimination of the 'NSR' group (R = phosphinimino group) obtained.

Journal of the Chemical Society, Dalton Transactions

Cyclic sulphur-nitrogen compounds and phosphorus reagents. Part 2. Reactions of tetrasulphur tetranitride with (morpholino)diphenylphosphine. First observation of the ring contraction of 1,5-[(OC4H8N)Ph2PN]2S 4N4 to (OC4H8N)Ph2PNS3N3 in solution

Journal	Heteroatom Chemistry
ISSN	10427163
Open Access	No