New P–S–N containing ring systems. Reaction of 2,4-(naphthalene-1,8-diyl)-1,3,2,4-dithiadiphosphetane 2,4-disulfide with methylbis(trimethylsilyl)amine

Abstract

From the reaction of 2,4-(naphthalene-1,8-diyl)-1,3,2,4-dithiadiphosphetane 2,4-disulfide 1 with methylbis(trimethylsilyl)amine 2 in dichloromethane a product of the P₂S₂ ring cleavage, (C₁₀H₆)P(S)(SSiMe₃)(µ-S)P(S)(NMeSiMe₃) 3, was isolated, existing in an equilibrium between two diastereomeric forms in solution. Compound 3 was also obtained when toluene was used as a solvent. Its subsequent reaction with pyridine (py) led to the desilylated ionic product [Hpy⁺][(C₁₀H₆)P(S)(NHMe)(µ-S)PS₂^–] 4, which reacts with tetraphenylphosphonium chloride to give [PPh₄⁺][(C₁₀H₆)P(S)(NHMe)(µ-S)PS₂^–] 5. When acetonitrile was used as a solvent a cage compound 2,6-(naphthalene-1,8-diyl)-3,4-dimethyl-1,3,5,2λ⁵,6λ⁵-thiadiazadiphosphinine 2,6-disulfide 6 containing a six-membered CN₂P₂S heterocycle was obtained. The new compounds were studied spectroscopically (1- and 2-D high resolution NMR, IR, MS) and in the cases of 3, 5 and 6 by X-ray crystallography.