The title compound (NC4H8NCH3)(C6H5)[N(C6H11)2]P{—N–S3N3 crystallizes in the triclinic crystal system with unit cell dimensions: a = 9.7572(2), b = 10.6845(1), c = 16.9381(3) A, α = 71.75(1)∘, β = 80.65(2)∘, γ = 65.93(1)∘, and Z = 2. The tricoordinated sulfur atom (S1) in the cyclotrithiazene deviates from the mean plane of the other five atoms by 0.716(6) A, which is the highest among the known phosphiniminocyclotrithiazene structures. In the exocyclic P{—N4–S1 moiety, the two bond distances are short: 1.585(6) and 1.527(6) A; but the bond angle is large 135.3(4)∘. The S1 displacement is highly correlated with the endocyclic angle at the nitrogen atom (diagonally opposite to S1), but the nature of correlation is bimodal (R = 1.0 + or −1.0) for the cyclic and acyclic substituents (R) in the (R)(C6H5)[N(C6H11)2]P{—N–S3N3 series. On the other hand, the S1–N4 bond distances are negatively correlated (R = −0.94) with the P{—N4–S1 bond angle in the above series.

Crystal structure analysis of (N-methyl piperazino) (phenyl) (dicyclohexylamino) phosphiniminocyclotrithiazene

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.

Studies on Iodination Reactions of Phosphiniminocyclotrithiazenes

The title compound (C6H12N)Ph2P-N
 
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 S3N3 ⋅ C7H8 crystallizes in the monoclinic space group P21/n with unit cell dimensions: a = 9.9200(5), b = 16.3316(11), c = 15.7009(17) A, β = 91.99(1)°, and Z = 4. The cyclotrithiazene ring adopts a chair conformation with equal bond distances and the norbornadiene is fused in an exo, exo fashion to the heterocycle. Norbornadiene addition to the cyclotrithiazene influences the bonding pattern in the ring as well as the P
 
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 N
 
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 S moiety.

M. V. Rao

Papers

Crystal structure analysis of norbornadiene adduct of diphenyl hexamethylenimino phosphiniminocyclotrithiazene