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
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.