1,3,2,4-Dithiadiphosphetane 2,4-disulfides
Other examples of this class of compound have been made; many inorganic chemists are now using Fc2P2S4 (Fc = ferrocene) as a starting material in reactions investigating the general chemistry of the 1,3,2,4-dithiadiphosphetane 2,4-disulfides, one reaction for this is that the Fc2P2S4 compound and all its derivatives are red which make column chromatography of the products more easy.
[citation needed] These highly soluble versions of Lawesson's reagent are created by the reaction of P4S10 with aryl ethers which are different from anisole.
An important subclass of these compounds are the naphthalen-1,8-diyl 1,3,2,4-dithiadiphosphetane 2,4-disulfides; these are intellectually interesting because the two dithiophosphine ylides are fixed together in space by the rigid naphthalene unit.
Such a compound could act as an acetylcholinesterase inhibitor in insects, but in order to make a better insecticide it would be best to convert the halide to another leaving group which would form a less water sensitive product.
It was claimed in a German patent[citation needed] that the reaction of 1,3,2,4-dithiadiphosphetane 2,4-disulfides with dialkyl cyanamides formed plant protection agents which contained six-membered (P−N=C−N=C−S−) rings.
It has been proven in recent times by the reaction of diferrocenyl 1,3,2,4-dithiadiphosphetane 2,4-disulfide (and Lawesson's reagent) with dimethyl cyanamide that in fact a mixture of several different phosphorus containing compounds is formed.
For instance the reaction of Woollins' reagent with a dialkyl cyanamide has been found to form a bicyclic PC2N2Se3 system.
